geotechnical framework study of shelikof strait, alaska

GEOTECHNICAL FRAMEWORK STUDY OF SHELIKOF STRAIT, ALASKA

by

Monty A. Hampton

U.S. Geological Survey

Final ReportOuter Continental Shelf Environmental Assessment Program

Research Unit 589

1983

637

TABLE OF CONTENTS

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643

GEOLOGIC SETTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643

METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651

RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655

Sediment Description, Index Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 655

Consolidation Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574

Static Strength Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 680

Dynamic Strength Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 682

DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 686

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 692

APPENDIX : Index Property Charts for Sediment Cores fromShelikof Strait . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,. 697

LIST OF FIGURES

Figure 1. Location map of the study area in Shelikof Strait.

Figure 2. A. Tracklines of continuous seismic-reflection profiles.Solid lines represent a regional survey contracted by theConservation Division, and dashed lines represent site surveyson cruises of the R/V S.P. LEE (1980) and NOAA ship DISCOVERER(1981).

Figure 3. Bathymetry of Shelikof Strait, 20-m contour interval. Depthscorrected to mean lower low water.

Figure 4. Thickness of sedimentary units of probably Pleistocene andyounger age. Contour interval: 50 meters except for thicknessgreater than 500 m where contour interval is 100 m.

Figure 5. Representative seismic-reflection profiles showing seismic-stratigraphic units.

Figure 6. Thickness of highest seismic-stratigr-aphic unit that coversmost of the seafloor of Shelikof Strait. Contour interval: 20m.

Figure 7. Pie-diagrams showing relative abundances of textural classes inseafloor sediment samples.

Figure 8. Mean grain size of seafloor sediment, in phi-units.

Figure 9. Sediment accumulation rates, in cm/100 yr.

Figure 10. Water content (percent dry weight) at l-m depth in sedimentcores.

Figure 11. Bulk sediment density (gm/cm3) at l-m depth in sediment cores.

Figure 12. Average grain-specific gravity in sediment cores.

Figure 13. Average liquid limit (percent dry weight) in sediment cores.

Figure 14. Average plastic limit (percent dry weight) in sediment cores.

Figure 15. Average plasticity index in sediment cores.

Iigure 16. Liquid limit versus grain size.

Figure 17. Plastic limit versus grain size.

Figure 18. Plasticity index versus grain size.

641

Figure 19. Plasticity chart.

Figure 20. Vane shear strength (kPa) at lm depth in sediment cores.

Figure 21. Vane shear strength versus water content.

Figure 22. Average organic carbon content in sediment cores.

Figure 23. Average calcium carbonate content in sediment cores.

Figure 24. Graph of compression index versus liquid limit.

Figure 25. Graph of effective angle of internal friction versus plasticityindex. Solid line shows empirical relation derived by Lambeand Whitman (1969); dashed line indicates limits of their data.

Figure 26. Graph of normalized undrained shear strength versusoverconsolidation ratio.

Figure 27. Graph of cyclic stress level versus number of cycles tofailure.

LIST OF TABLES

Table 1. Consolidation test results.

Table 2. Static triaxial strength test results.

Table 3. Dynamic triaxial strength test results.

642

INTRODUCTION

Studies have been conducted by the U.S. Geological Survey to ‘identify

geologic conditions that might impose constraints on offshore industrial

activities in Shelikof Strait, Alaska, an area designated for petroleum

leasing (Fig. 1; Hampton and others, 1981; Hampton and Winters, 1981). w

part of these studies sediment cores were collected throughout the strait

(Fig. 2), and physical properties of sediment samples were measured by

laboratory geotechnical testing methods. The geotechnical data are presented

in this report and are evaluated from a regional perspective to infer the

reformational reponse of the sedimentary deposits to static and dynamic loads.

Application of the test data to a regional analysis is restricted by the

degree to which core samples are representative of the sedimentary deposits.

Interpretive geologic studies indicate that the cores used for geologic

testing cover the range of surficial sediment types in the Shelikof Strait

lease area, but analysis of seismic-reflection profiles reveals the existence

of buried stratigraphic units that were not sampled because they lie beneath

the maximum core length of 3 m (Hampton and others, 1981; Hampton and Winters,

1981) . Therefore, the conclusions reached in this report apply directly to

the uppermost deposits in the stratigraphic section, only. Extrapolation

beyond the depths of sampling is limited by the vertical uniformity of

sediment type.

GEOLOGIC SETTING

Shelikof Strait is a nearly parallel-sided marine channel situated

between the Kodiak Island group and the Alaska Peninsula (Fig. 1). The strait

marks the location of a northeast-trending inner forearc basin that is located

643

‘war% W@?

... . ,-.644

7X2”” (5 Y“

1I

\ 1

\ II ●

II

III

~.--:----

$ 0- - - - - D

L-- 8,08I8a

+●

9

II10

1 I Y 1

Figure 2-A. Tracklines of continuous seismic-reflection profiles. Solidlines represent a regional survey contracted by theConservation Division, and dashed lines represent site surveyson cruises of the R/V S.P. LEE (1980) and NOAA ship DISCOVERER(1981).

645

.-

.

1 -L

●

.I

Figure 2-B. Locations of sediment-sampling stations.

near the convergent margin of the North America plate where it is being

underthrust by the Pacific plate (von Huene, 1979). Large earthquakes are

common to the region; at least 95 potentially destructive events (magnitude

>6) have occurred since recording began in 1902. Twelve volcanoes have

erupted within the last 10,000 years along the Alaska Peninsula adjacent to

the strait.

The seafloor of Shelikof Strait consists of a gently southwest-sloping

central platform bordered by narrow marginal channels parallel to the Kodiak

islands and the Alaska Peninsula (Fig. 3). Shallow shelves trend along the

adjacent landmasses, and they are connected to the marginal channels by

steeply sloping seafloor. Water depth in the northeast part of the strait is

generally less than 200 m, whereas in the southwest it generally exceeds 200 m

and is as much as 300 m. Superimposed on the platform are some local highs.

and lows that have as much as 100 m relief. Along the axes of the marginal

channels are several closed depressions on the order of 30 m relief.

Sedimentary deposits of presumed Pleistocene and Holocene age overlie an

irregular unconformity above Tertiary and older bedrock. Thickness of the

sediment above bedrock, measured from seismic-reflection profiles, is about 80

to 100 m in the northeast half of the strait and increases abruptly to more

tnan 800 m in the southwest (Fig. 4). The thickening reflects a deepening of

the unconformity.

Four seismic-stratigraphic units can be distinguished above bedrock (Fig.

5). The lowest unit (unit 1 in Fig. 5) fills the bedrock depression and

reaches a thickness of 800 m. This unit is interpreted as being of glacial

and glaciomarine origin (Whitney and others, 1980 a, b). The next highest

unit (unit 2 in Fig. 5) is relatively thin (<60 m) and occurs mainly in the

647

+

+

h\ ‘\\\,

+

●

Figure 3. Bathymetry of Shelikof Strait, 20-m contour interval. Depthscorrected to mean lower low water.

648

-oma-or

Figure 4. Thickness of sedimentary units of probably Pleistocene andyounger age. Contour interval: 50 meters except for thicknessgreater than 500 m where contour interval is 100 m.

649

——

—-

—

0-

-,---

——

—

:. ,.i.’

650

+. ..., -.$, ...!,-.

:::

;

:,. .“ “-’-.. . . .

,. .

;.?F

,..., -

;

,.. ,

. .

. . . .

,.

-——

.,..

,.,-

-—

“1

.. .

. .

, . .

, .. . . . ~,.: -,

mal

,

central part of the strait. Sediment of this unit was deposited within low

areas on the upper surface of bedrock and the glacial unit, and it apparently

was emplaced by marine processes during the Holocene sea-level rise. The

third unit (unit 3 in Fig. 5), which covers essentially all of the seafloor in

the central part of the strait (platform and marginal channels), is up to 180

m thick (Fig. 6) and was deposited by the modern-day oceanic current regime of

southwesterly baroclinic flow from Cook Inlet and the eastern Gulf of Alaska

(Muench and Schumacher, 1980). Unit 4 in Figure 5 underlies the shallow

shelves and interfingers seaward with unit 3. It is composed of sediment

eroded from the adjacent landmasses. The cores subjected to geotechnical

testing and discussed in this paper were taken from unit 3.

METHODS

Sediment cores were collected at 65 stations on two cruises in Shelikof

Strait, in June 1980 aboard the USGS R/V S.P. LEE and in July and August 1981

aboard the NOAA ship DISCOVERER (Fig. 2). A gravity coring system with 8.5-cm

diameter plastic liners in steel core barrels was used on the 1980 cruise,

whereas a vibracoring system with a 10-cm square cross-section plastic liner

in thin-wall stainless steel barrel was employed on the 1981 cruise. Some

grab samples were taken at locations of coarse sediment where the coring

devices were ineffective.

TWO cores were taken at most stations. One was designated mainly for

geological analysis. It was cut into l-m or 1.5-m-long sections, then split

lengthwise for geological description and vane-shear strength testing.

Subsamples were taken for index property determinations.

651

+

.

.

Figure 6. Thickness of highest seismic-strati9raPhic ‘nit ‘hat cove~~most of the seafloor of Shelikof Strait. contour interval:

m.

652

The second core was taken expressly for geotechnical testing. It was cut

into l-m-long sections, wrapped in cheesecloth, covered with microcrystalline

wax, and stored upright in a refrigerator. These cores were later subjected

to a suite of geotechnical tests in laboratories at the USGS and at a

commercial testing company. .

Several index properties were determined for subsamples of the sediment

cores. Grain size was measured by sieving and pipetting into four size

classes: gravel (>2 mm), sand (2-0.062 mm), silt (0.062-0.004 mm), and clay

(<0.004 mm). Water content, as a percentage of dry sediment weight, was

determined from the weight of sediment samples before and after even drying at

105”C. A correction for salt content of sea water (3.5%) was made to the

weighings. Atterberg limits were determined according to standard procedures

(American Society for Testing and Materials, 1976), except that samples were

not sieved prior to testing. Carbon content was measured with a LECO carbon

determinator with induction furnace and acid digestion. Vane shear

determinations of undrained shear strength were made on split core halves with

a motorized device at a vane rotation rate of 90°/min. The vane is l/2 inch

diameter by l/2 inch high and was inserted into the sediment to a depth twice

the height of the vane.

Consolidation tests were run on subsamples from geotechnical cores to

determine sub-failure reformational properties. Most tests were run on an

oedometer in a stress-controlled mode (Lambe, 1951). Others were run in a

triaxial loading cell under constant rate of strain conditions (Wissa and

others, 1971). The consolidation tests measure change in volume with change

in applied load. The results are normally plotted as void ratio (e = volume

of voids/volume of solids ) versus the logarithm of effective (buoyant)

653

.

vertical stress (p’). Two useful parameters are derived from these curves:

the compression index and the maximum past pressure. The compression index

(Cc) is the slope of the straight-line portion of the e-log p’ curve and

indicates the amount of compression produced by a particular load increment.

The maximum past pressure (u’ ) is the greatest effective overburden stress to

which the sediment has ever been exposed and is determined from the e-log p’

curve by a simple graphical construction (Casagrande, 1936). The ratio

of 0; to the effective overburden stress at the time of sampling (ov~) is the

overconsolidation ratio (OCR), which is a measure of unloading that the

sediment may have experienced, by erosion for example. A third parameter, the

coefficient of consolidation (Cv)I is determined for each load increment of

the one-dimensional consolidation test and is related to the rate of

consolidation.

Static traxial tests were run on cylindrical samples 3.6-cm diameter and

7.6-cm long in order to determine strength properties of the sediment. Tests

were run under undrained conditions with pore pressure measurements (Bishop

and Henkel, 1964) . Most samples were consolidated isotropically prior to

testing, but some were consolidated anisotropically.

Dynamically loaded triaxial tests were also run, with the axial stress on

samples varied sinusoidally at 0.1 Hz. Both compression and tension were

applied at a predetermined percentage of the static strength. These tests can

be used to evaluate the failure conditions of sediment under repeated loading,

such as by earthquakes.

A first set of triaxial tests was run on sediment samples that were

consolidated to somewhat arbitrary stress levels. However, the later testing

program followed the normalized stress parameter (NSP) approach (Ladd and

654

Foott, 1974), whereby consolidation

maxi mum past pressure (u;) , as

stresses are chosen on the basis of

determined from consolidation tests.

Typically, the triaxial test specimen was consolidated to four times o; ,

which eliminates some of the disturbance effects associated with coring.

Overconsolidation was artificially induced in some tests by rebounding the

specimen to lower stress levels before applying the triaxial load. Measured

values of undrained shear strength (Su) are normalized with respect to

effective overburden stress (aj) . A premise

ratio S /a’ is constant for a particular valueU v

of the NSP method is that the

of CCR. Moreover, a relation

exists between s/u’ and CXR that allowsU v

depths below the level of sampling (Mayne,

prediction of sediment strength at

1980) .

RESULTS

Sediment description, index properties: Sediment samples could only be

collected to shallow depths (<3 m) beneath the seafloor. Therefore, most are

from the highest stratigraphic unit (unit 3, Fig. 5). However, judging from

seismic-reflection profiles over sampling stations, a few outcrops of other

units were also sampled. Seismic-reflection profiles also show that unit 3

has a typical thickness of about 80 to 100 m

acoustic reflectors within this unit indicates

with depth, but there is no reason to suspect

type, except for possible thin beds of volcanic

for the

of the

this.

(Fig. 6). The appearance of

some lithologic variability

radical changes in sediment

ash. The physical properties

cores should therefore be representative of the terrigenous component

unit as a whole, but drill-hole samples would be necessary to confirm

655

The texture of surficial

adjacent marginal channels grades

northeast part of the strait

,

sediment on the central platform and in the

from gravelly and sandy material in the

to mud in the southwest (Figs. 7 and 8;

Appendix). A general fining trend from northwest to southeast across the

platform also exists.

The two grab samples of coarse sediment recovered from Stevenson Entrance

appear to have been taken from outcrops of unit 1. Most of the coarse clasts,

which range to boulder size, are angular to subangular, and some are faceted.

This supports the hypothesis that unit 1 was deposited by glacial processes.

A few grab samples of coarse material were also recovered from the

shallow shelves and from the adjacent slopes. They probably are from unit

4. Coarse clasts have similar morphology to those from unit 1, perhaps

reflecting glacial transport at some point in their history.

Sediment cores from the platform and marginal channels in the central

portion of the strait have a fairly uniform stratigraphy with depth. Sandy

sediment in the northeast end of the strait is predominantly greenish-gray,

with variations from black to yellowish brown. Sand-filled burrows, pebble

clasts, and whole or broken shells are common. In progressively finer-grained

cores to the southwest, color remains greenish-gray but is less varied, and

shells and clasts are rare.

A layer of

layer is nearly

few millimeters

The refractive

volcanic ash occurs in many cores. Maximum thickness of the

20 cm. It is size-graded, with the coarsest basal fragments a

diameter. The color is from tan to white with a pink cast.

index of the ash is 1.485 + 0.002, which in this region is

unique to the outfall from the 1912 Katmai eruption (Nayudu, 1964; Pratt and

others, 1973). Depth of the ash beneath the seafloor was used to calculate

656

@‘&

e

I?igure 7. Pie-diagrams showing relative abundances of textural classes inseafloor sediment samples.

+ . “ Y1 ,?

.

Figure 8. Mean grain size of seafloor sediment, in phi-units.

values of post-1912 sediment accumulation rate (Fig. 9). Accumulation rate

varies significantly throughout the strait. It is greatest near the Alaska

Peninsula at the southwest end of the strait, whereas it is near zero at

places in the marginal channel along the Kodiak island group.

Water content of sediment is shown in Figure 10 as interpolated values at

l-m depth in cores. It is calculated as a percentage of dry sediment weight,

and therefore, values in excess of 100% are possible if the weight of water

exceeds the weight of sediment grains. Water content generally decreases to

the northeast, inversely correlating with grain size. Moreover, water content

increases across the strait, from the Alaska peninsula to Kodiak Island. Bulk

sediment density at l-m depth, which is calculated from water content and

grain specific gravity, correspondingly decreases down and across the strait

(Fig. 11). Average grain specific gravity itself shows no discernible trend

(Fig. 12).

Atterberg limits describe the plasticity of sediment, in terms of the

liquid limit (water content that separates plastic and liquid behavior) and

the plastic limit (water content that separates semi-solid and plastic

behavior). Useful derivatives are the plasticity index (difference between

the liquid and plastic limits), and the liquidity index (position of the

natural water content relative to the liquid and plastic limits). Certain

trends in plasticity are evident in Shelikof Strait. Average liquid limit,

plastic limit, and plasticity index increase down the strait toward the

southwest, and also generally across the strait, toward the southeast (Figs.

13, 14, and 15; Appendix). These properties also generally increase with

decrease in mean grain size (Figs. 16, 17, and 18), although the data for

plastic limit are quite scattered. Plastic limit is less variable than liquid

limit, which is typically the case (Mitchell, 1976; Richards, 1962).

659

Figure 9. Sediment accumulation rates, in cm/100 yr.

660

.

● .‘+’

j ,,,

0

la●

00

0

m● .

●

Figure 10. Water content (percent dry weight) at l-m depth in sedimentcores.

661

al m Iv

P 1- .

1550

00’

1540

00’

1530

00’

T+

..#9

mW

mn

U-1

?*

su M

W,UL ●

ILU

WU

n M

4um

-m

‘-;

(U

T:

;(2

. . .

+?+

. Ual

/-\

)-I/

.*7

.1“

I

-A.22-

--”

-,●

l”%

!xz’!

!-

● 1

.94

● 79

\

9000

’

58”3

0’

58°0

0’

5703

0”

●●

N

“’o‘t“v+

w

‘l\

+ .

-?

)’, .,

.

0a.

co.

Figure 12. Average grain-specific gravity in sediment cores.

l“ E

i’:

‘+ “-!-

+

+,,

‘J) ..’.

●

● r.0

Figure 1 3 . Average liquid limit (percent dry weight) in sediment cores.

664

-g*

N&‘o-l

+.UY N3 c-l m

&, ● ● . - }. .

~,. .-J-% 0

+

+/

}

A ‘.l--

+ ‘+j ,’(

o

am

.

CT●

.

\.

t 1

Figure 14. Average plastic limit (percent dry weight) in sediment cores.

-o -o

> -CJ p 0:

. ,

Ib

IG

●0m

/ l <r-L).-*

1-.

1

II

Figure Is. Average plasticity index in sediment cores.

666

100

●

90

80

70

u

30

20

10

● “

● - 0& ● O-+

●

:000●

● ° 00

-$‘#@: 4’

● ● ☛

● ☛☛ ●

✎ ● 0 ● 0 ●

● o “:-. ●

● ●● O

● ● * m

●●

● ●☛

mean grain size (())

Figure 16. Liquid limit versus grain size.

667

50

40

10

T

m

m

m

m

m

m

D

1 9 1 1 1 I I \

10987654 3mean grain size (W

●

●

Figure 17. Plastic limit versus grain size.

668

●

9

Figure 18. Plasticity index versus grain size.

669

Correlations have been made between liquid limit and compressibility

(Herrmann and others, 1972; Skempton, 1944). The majority of Shelikof Strait

samples fall within the medium (30 < liquid limit < 50) and high (liquid limit

> 5 0 ) c o m p r e s s i b i l i t y r a n g e s .

Nearly all measured liquidity indices in Shelikof Strait are greater

1 (Appendix), which is usual for near-seafloor marine sediment. Sediment

than

with

a liquidity index greater

A plot of liquidity

chart (Casagrande, 1948)

than one behaves as a liquid when remolded.

index versus plasticity index - termed a plasticity

shows a trend parallel to the A-line that divides

basic soil types (Fig. 19). Most sediment samples from Shelikof Strait plot

below the A-1ine, which is typical of inorganic silt and silty clay of high

compressibility. The

taken throughout the

1962) .

linear trend of data points is expected for samples

same sedimentary deposit (Terzaghi, 1955; Richards,

Undrained shear strength of sediment samples (Su), as measured with a

laboratory miniature vane shear device, generally decreases toward the

southwest end of the strait, and thus correlates with the water content trend,

although there is much scatter (Figs. 20 and 21; Appendix). The consistency

of most of the near-seafloor sediment can be classified as very soft (Su < 12

kilopascals), but some is soft (12 kpa < Su < 24 kpa) to medium (24 kpa < SU <

48 kPa) (Terzaghi and Peck, 1948). Hampton and others (1981) showed that

shear strength is anisotropic in Shelikof Strait sediment cores. Values of

shear strength measured with the axis of vane rotation perpendicular to the

axis of core samples exceed the values of strength measured with the axis of

vane rotation parallel to the core axis. The magnitude of sediment strength

thereby depends on the orientation of the applied stress.

670

6C

5C

40x~.-

+m0

E20

10

10

.

s88

●

8

●

1 I I I 1 I J20 3 0 4 0 50

Liquid limit6 0 70 8 0 90 100

Figure 19. Plasticity chart.

-.

I .

●

Figure 20. Vane shear strength (kPa) at lm depth in sediment cores.

672

●:●

●●

O

●

●

●

●

●

●

Lg

II

II

1t

I1

I1

11

1I

II

1#

I9

1I

&

1-

Sediment samples from Shelikof Strait are characterized by low to

intermediate content of organic carbon, compared to other marine areas

(Bordovskiy, 1965, 1969; Gardner and others, 1980; Lisitzin, 1972; Rashid and

Brown, 1975). Most values are between 0.40% and 1.50%. Organic carbon

generally increases down the strait toward the southwest, as well as across

the strait toward the southeast (Fig. 22; Appendix A). Correlations with

other physical properties were shown by Hampton and others (lW1). Organic

carbon content correlates positively with water content and plasticity index,

whereas an inverse correlation is found with grain size and vane shear

strength. Correlations similar to those described above have been reported by

others for low organic-carbon content sediment (Bordovskiy, 1965, 1969; Bush

and Keller, 1981; Keller and others, 1979; Lisitzin, 1972; Mitchell, 1976;

Odell and others, 1960).

Percent calcium carbonate is typically low in Shelikof Strait sediment

(Fig. 23; Appendix). Most values are less than 3.50%. Two locations with

anomalously high values, off Shuyak Island and in Stevenson Entrance, are near

the boundary of the strait.

Consolidation properties: Consolidation properties as determined from

laboratory tests are listed in Table 1. All tests indicate a maximum past

pressure (a~) greater than the present overburden pressure (cv~) . The

for all tests.

the overconsolidation ratio (OCR) and is greater than 1.0

The usual implication is that the sediment has experienced

unloading as a consequence of erosion.

evidence for erosion; in fact, sediment

throughout most of the strait (Fig. 9).

However, there is no geological

is accumulating at high rates

The high values of OCR probably

k-“-o ‘al

,

)

. ) /’[

\

CT● 0

0

Figure 22. Average organic carbon content in sediment cores.

675

-o -~o0m %In

I \ u {

IJ--J Om~.‘1 –“

I ‘2.

+

hj ,’. (+

t

Figure 23. Average calcium carbonate content in sediment cores.

676

I Table 1. Consolidation test results.

Depth * tin a u

Station core Vo Vxlocc

rmmbe r (cm) (kPa ) (kPa ) frGo OCR

1 507 39 1.1 6.o 0.94 0.17 1*1O 5

171 5.0 32.0 0.76 0.22 1.13 6

509

511

6 4 9

5 2 5

528

540

8 9 3 . 7 20.0 0.86 0.27 2.67 5

94 3.7 23.0 0.88 0.12 0.81 6

6 4

111

1 9 1

41

116

167

4 5

96.

165

64

144

4 7

1 3 1

2 0 1

2 . 8

4 . 6

9 . 8

2.0

6.1

8.9

3*3

6.9

13.8

4.7

10.4

2 . 8

6 . 1

1 1 . 6

15.0

9.0

12.0

56.0

30.0

29.0

26.0

28.0

64.0

43.0

45.0

20.0

48.0

65.0

0.52

0.66

0.45

0.33

0.54

0.60

0.30

0.26

0.26

0.28

0.29

0.50

0.54

0.37

677

0.05

0.09

0.18-

0.04

0.12

0.08

0.30

0.35

0.54

0.18

0.31

0.11

0.20

0.16

2 . 1 7

1.10

1.38

1.30

0.97

1.49

1.52

1.68

2.23

.1.57

3.59

0.50

0.67

0.98

5

2

1

2 8

5

3

8

4

5

9

4

7

8

6

represent initial cementation of sediment

are not indicative of overconsolidation in

particles or grain interlocking and

the strict sense of the term.

Compression index (Cc) is a measure of the amount of consolidation that

occurs for a given increment in load. The coarse sediment at the northeast

end of the strait is less compressible than the progressively finer sediment

to the southwest, as indicated by a southwest trend of increasing Cc ((rable

1). Richards (1962) reported a range of 0.20 to 0.87 for Cc measured on

samples of marine sediment from many areas, and most values fror.~ Shelikof

Strait fall within this range.

Compression index commonly shows a linear relation

(LL). The data from Shelikof Strait, when

general trend, but with much scatter (Fig.

plotted in this

24). Skempton

t o l i q u i d limit

manner, exhibit a

(1$344) found that

the relation can be expressed as

cc = 0.009

and the regression equation for Shelikof

cc = 0.006

( LL - lo),

is similar:Strait sediment

(LL + 5.7).

The rate at which consolidation occurs in response to loading determines

the coefficient of consolidation (cv). It is directly related to permeability

of a sediment and inversely related to the compressibility. The coefficient

is calculated for each load increment during a laboratory consolidation test

from plots of deformation versus tine. & shown in Table 1, Cv commonly

varies through one to two orders of magnitude for a single test. No general

trend in the data is evident, although the high expected permeability and low

compressibility of coarse-grained sediment would suggest a decrease of Cv to

the southwest. Measurements of Cv for clay sediment from various marine

locations by Richards and Hamilton (1967) are in the range 3.2 - 6.0 x

10-4 cm2/see, which are lower than typical values in Shelikof Strait.

●

e

t-.N0

0m

*.-E9-

679

Static strength properties: Sediment properties derived from static triaxial

strength tests are listed in l’able 2. The primary measured property is the

undrained shear strength (Su). It is the maximum sustainable shear stresst

within a sample subjected to a particular consolidation stress (oc) . Su acts

along a plane inclined at 45° to the axial load. The arisen of Su divided by

the effective normal stress across this plane is the effective angle of

internal friction

behavior of the

(+’), whose magnitude is an indication of the strength

sediment uncle r slow (drained) loading conditions. In

comparison, the ratio S [a’ gives an indication of the strength behaviorUc

during rapid (undrained) loading conditions. The difference in drained and

undrained strength behavior depends on the pore water pressure generated in

response to the tendency for volume change when the sediment is axially

loaded. If a sediment has a high tendency for volume change, the difference

in strength between rapid

The effective angle

sediment samples (OCR =

Compare with values given

and slow loading can be substantial.

of internal friction for the normally consolidated

1) in this study is relatively high (35° - 460).

by Lambe and Whitman (1969, p. 149 and 306). The

higher values (> 40°) are in the finer sediment cores from the southwest half

of the strait (Table 2). Therefore, sediment from Shelikof Strait appears to

be atypically strong under conditions of drained loading, with the finer

~ediment exhibiting higher strength. Samples tested at OCR > 1 tend to have

$’ comparable to that of normallY consolidated samples, except for station 649

where some overconsolidated samples have significantly higher values. The

data indicate similar drained behavior of normally consolidated and

overconsolidated sediment in the strait.

.,

680

Table 2. Stat ic triaxial strength test r e s u l t s .

Depth 1in a Su

Station ccore Induced su/ 0: $number (cm) (kPa) OCR (kPa) (degrees)

509 120

170

511 17

28

44

180

121 8.3

649 86

86

109

109

127

132

525 8

73

85

152

528 37

80

94

122

139

540 29

69

120

140

159

507 30 53.9

130 140.0

172.4

47.0

20.7

2.8

1.4

48.2

5.8

24.0

46.7

0.3

142.3/70.7

4.4

160.5

1.4

19.3

6.9

282.5

1.4

179.2

6.9

30.3

178.8/89.6

15.2

1.4

10.3

199.8

114.0

1

1

1

4.1

3

118.6

5.93

181

6

1

1

3.61

6

11.8681

18.8

73*5

73.4

68.9

25.4

8.8

9.6

27.0

3.2

57.6

52.3

13.0

58.3

12.3

76.5

18.5

47.5

25.2

121.6

18.6

79.8

19.0

77.4

66.7

24.2

15.4

16.7

79.9

82.8

0.3

0.5

0.4

1.5

1.2

3.1

6.3

0.6

41

2.4.

1.1

43.3

0.4

2.8

0.5

13.2

2.5

3.6

0.4

12.8

0.4

2.8

2.5

0.3

106

11.0

1.6

0.4

0.7

39

46

40

<42

39

64

64

43

<40

<54

<57

39

<69

41

48 .

34

45

37

50

35

43

38

41

40

60

47

35

40

Lambe and Whitman (1969, p. 307, Figs. 21-24) detected

+’ anti plasticity index for normally consolidated soil.

wnich there are plasticity index values in Shelikof Strai

a relation between

Triaxial data for

t plot within the

range of Lambe and Whitman’s data, except for the core at station 511, which

is abnormally strong for sediment with such high plasticity (Fig. 25).

Evaluation of undrained strength,

judgment in order to detect trends. In

consolidation stress (act) seem to give

1in terms of su/o , requires some

c

particular, the tests run at low

erratic values of Su/U ‘. This wasc

also shown to be the case for triaxial data from nearby Kodiak Shelf (Hampton,

in press). Tests run at high values of consolidation stress (which corrects

some of the effects of disturbance) and OCR = 1 have values of Su/acqbetween

0.3 and 0.6, with no areal trend (Table 2). The value of Su/ac increases with

OCR for each core tested.

The static triaxial test data are plotted according to the NSP approach

in Figure

change in

and 0.97.

26. The slope (A) of the line for each core is a measure of the

undrained strength with OCR. Most cores have A values between 0.79

Mayne (1980) compiled the results of many triaxial tests and found

a mean value of A = 0.64 with a standard deviation of 0.18. The sediment in

Shelikof Strait, with its relatively high values of h would tend to retain

more of its strength after unloading compared to most sediment examined by

Mayne (1980). The A = 1.43 calculated for the sediment of station 52~ is

greater than the theoretical limit of A = 1.0, and further testing is required

to resolve this conflict.

Dynamic strength properties: The data from triaxial strength tests are given

in Table 3. The quantity =Cyc /su is the cyclic stress level, the average

.

●

ot-0@0100:

.-CM

.-

m

.u)

N

109

8

7

6

5

4

3

2

1

.

.

.

.

.

2 3 4 5 6 7 8 9 1 0

OCR

Figure 26. Graph of normalized undrained shear strength versusoverconsolidation ratio.

684

Table 3. Dynamic triaxial strength test results.

Depth vin u

c cycisuT Cycles

Station core Induced tonumber (cm) (kPa) OCR (%) failure

509 137 173.6 1 49 145

137 175.0 1 66 64

511

649

525

528

540

152 46.9 1 70 10

167 46.9 1 47 48

96 153.1 1 70 22

96 146.0 1 .56 450

140 30.2 4.4 79 17

140 139.8 1 72 39

135 282.4 1 47 30

117 282.4 1 70 7

23 27.5

178 179.1

193 179.1

152 199.8

227 199.8

238 299.8

4

1

1

1

1

1

32

70

46

71

43

56

51

13

110

12

900+

28

685

~yc) applied sinusoidally with full stress reversal atvalue of shear stress (T

0.1 Hz, expressed as a percentage of the static undrained shear strength

(Su).

Tcyc “

strain

chosen

Pore water pressure and strain accumulate with repeated application of

At some point, the pore water pressure approaches the confining stress,

increases abruptly, and the sediment fails. In our tests, failure was

when 20% strain was reached.

Samples typically fail

levels. Figure 27 shows the

for Shelikof Strait samples.

within the range of test results

and others, 1981; Anderson and

cyclic strength degradation is i

in fewer cycles at

number of cycles to

Although there is

progressively higher stress

failure versus stress level

some scatter, the data fall

on terrigenous

others, 1980;

ndicated;

(as might be imparted by an earthquake,

stress levels between 60% and 80% of their

DISCUSSION

The primary geotechnical concerns in

that

for

sediment from other areas (Lee

Hampton, in press). Moderate

is, after 10 cycles of loading

example), the samples fail at

static strength.

Shelikof Strait include settlement

of structures, bearing capacity under static and cyclic loading lateral load

capacity, and anchor breakout resistance. Natural slope failures are not a

serious problem because only one small sediment slide has been documented

(Hampton and others, 1981). There is some evidence for gas-charged sediment,

but the problem of low strength that might exist in sediment of this type was

not addressed in the present study.

Quarternary sediment in Shelikof Strait covers bedrock to a thickness of

from 20 m to more than 800 m (Fig. 4). The sequence consists of Pleistocene

glacial and glaciomarine sediment at the base, overlain by Holocene marine

686

1.(

()$

O.c

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0 5 0 9● 511● 6490 5 2 5

1 1 I t I 1 1 I I 1 1 I 1 1 1 1 I I I t 1 n 1 t I I10

Cycles

Figure 27. Graph of cyclic stress levelfailure.

100 1 0 0 0to failure

versus number of cycles to

deposits. The highest stratigraphic unit, deposited by oceanic currents as

exist today, has accumulated to a thickness of 80-100 m over most of the

strait; the total range is about 20 m to 180 m. Geotechnical testing was

performed only on samples from this uppermost unit. A geotechnical analysis

based on these data probably addresses most situations of engineering

concern. Deeper stratigraphic units appear from interpretive geologic studies

to be relatively coarse-grained (Hampton and Winters, 1981; Whitney, Holden,

and Lybeck, 1980; Whitney, Hoose, Smith, and Lybeck, 1980), and they probably

are stable, but deep drill-core samples would have

confirm this by geotechnical testing.

The pattern of grain-size variation (Figs. 7

to be obtained in order to

and 8) evidently reflects

progressive sorting by the southwesterly flowing barotropic current tnat

dominates circulation in the strait. The present study and the previous

report by Hampton and others (1981) show that some index properties vary in

relation to grain

therefore increase

across the strait

size. Properties that show a direct correlation and

to the southwest down the strait and to the southeast

include water content, liquid limit, plastic limijz,

plasticity index, and organic carbon content (Figs. 10, 13, 14, 15, and 22).

Properties that correlate inversely with grain size include bulk sediment

density and undrained (vane) shear strength (Figs. 11 and 20).

Consolidation

but this probably

than a result of

tests indicate that sediment samples are overconsolidated,

is a near-seafloor diagenetic or fabric phenomenon rather

erosion, because net sediment accumulation is presently

occurring throughout the strait (Table 1, Fig. 9). The fine-grained sediment

to the southwest has high values of compression index (Cc), which indicates

that it is more compressible than the coarser material to the northeast. The

rate of consolidation, as shown by the coefficient of consolidation (cv)* is

688

highly variable for each consolidation test and does not show an areal trend

(Table 1). Intuitively, a higher value of Cv would be expected for the

coarser-grained sediment because of its normally higher permeability and lower

compressibility, but apparently this is not the case.

Another unexpected result is that the static drained strength, in terms

of the effective angle of internal friction ($), is higher for the fine-

grained sediment than it is for to the coarser-grained samp--es (Table 2).

Drained strength does not vary appreciably with OCR. Undrained static

strength behavior does not exhibit significant areal variation. Values

of S#Jc’ for tests run at OCR = 1 are between 0.3 and 0.6. This parameter

increases with OCR for each core that was tested. The NSF pore-pressure.

parameter (A) varies from 0.79 to 0.97, which indicates significant static

strength increase with OCR (Fig. 26). Again, no areal trend is apparent.

But, because few data points were used to plot the lines in Figure 26 and

because large scatter of data exists for some individual cores, additional

strength testing at more levels of OCR would add precision to the plots and

perhaps reveal some systematic variation.

Test data for most cores define similar response to cyclic loading over a

broad range of number of cycles required to cause failure (e.g., cores 511,

525, 528, and 540 in Fig. 27). Dynamic strength degradation varies over a

limited range at low number of cycles; for instance, it is between about 60%

and 80% for 10 cycles.

Geotechnical properties of Shelikof Strait sediment can be compared with

data from other studies to determine if the sediment has normal reformational

behavior. However, few data exist for some properties, which makes the

evaluations tentative.

689

Most values of compression index fall within the range of 0.20 to 0.87

reported by Richards and Hamilton (1967) for silty clay to highly colloidal

clay; one test on the core from station 507 has a high value of 0.94 (Table

1). Skempton’s (1944) classification of compressibility based on liquid limit

indicates that Shelikof Strait samples are moderately to highly compressible

(Appendix). Substitution of the class-boundary values of liquid limit

(moderate compressibility: 30 < LL < 50; high compressibility: LL > 50) into

the regression equation for Shelikof Strait data (Fig. 24),

cc = 0.006 (LL + 5.7),

indicates that the range of moderate compressibility is 0.21 < Cc < 0.33 and

the high range is Cc < 0.33, which is consistent with classifying the sediment

as moderately to highly compressible (Table 1).

Effective friction

(35” - 46°) compared to

(1969, p. 149 and 306)

angle ($’) for sediment in Shelikof Strait is high

the range (20° - 40°) reported by Lambe and Whitman

for normally consolidated sediment. Apparently, no

compilations of $’

made. Hampton (in

terrigenous samples

exclusively for terrigenous marine sediment have been

press) reports $’ mostly in the 30° - 40° range for

from the Kodiak Shelf. Shelikof Strait terrigenous

sediment is relatively strong under drained loading conditions.

Lambe and Whitman (1969, p. 452, Fig. 29.19) present

undrained strength of normally consolidated marine clay,

1

data on the

and values

of su/a “are between about 0.2 and 0.4. The range for normally consolidatedc

Shelikof Strait samples is 0.3 to 0.6, so they are relatively strong under

conditions of undrained loading. S /a ‘for normally consolidated terrigenousUc

690

sediment from the Kodiak Shelf are also high, from 0.4 to 1.0 (Hampton, in

press ) .

Values of the NSP factor A are high (0.79 - 0.97) compared to the average

value of 0.64 (standard deviation = 0.18) in the extensive compilation by

Mayne (1980). The implication is that the increase of strength with

overconsolidation is higher than normal.

The low to moderate cyclic strength degradation of Shelikof Strait

samples is similar to the behavior of clay sediment reported in other studies

(Lee and others, 1981; Anderson and others, 1980; Hampton, in press).

Sediment failure in response to large earthquakes certainly is a possibility,

but the potential is not as great as has been predicted for some deposits of

silt in the northeast Gulf of Alaska (cyclic strength at 10 cycles as low as

40% of the static strength; Lee and Schwab, in press) and volcanic ash on the

Kodiak Shelf (cyclic strength at 10 cycles is 12% of the static strength;

Hampton, in press). The deposit of Katmai ash in Shelikof Strait was not

subjected to geotechnical testing. However, its in situ density is so great

that normal gravity coring devices could not penetrate the layer. The

relative density appears to be high and therefore the liquefaction potential

is low. The possibility that more deeply buried ash layers are present and

might be highly susceptible to liquefaction cannot be evaluated with the

information presently available.

691

REFERENCES

American Society for Testing and Materials, 1976, Annual Book of ASTM

Standards. Philadelphia, ASTM, 485 p.

Anderson, K.H., Pool, J.H., Brown, S.F., and Rosenbrandr W.F., 1980, Cyclic

and static laboratory tests on Drammen clay. Journal of the Geotechnical

Engineering Division, ASCE, v. 106, p. 499-529.

Bishop, A.W., and Henkel, D.J., 1964, The Measurement of Soil Properties in

the Triaxial Test. London, Edward Arnold Ltd., 228 p.

Bordovskiy, O.K., 1965, Accumulation of organic matter in bottom sediments.

Marine Geology,. v. 3, p. 33-82.

Bordovskiy, O.K., 1969, Organic matter of recent

Sea. Oceanology, v. 9, p. 799-807.

Busch, W.H., and Keller, G.H., 1981, The physical

continental margin sediments - the influence

sediment physical properties. Jour. Sedimentary

719.

sediments of the Caspian

properties of Peru-Chile

of coastal upwelling on

Petrology, v. 51, p. 705-

Cassagrande, A., 1948, Classification and identification of soils.

Transactions, American Sot. Civil Engineerst v. 113, p. 901-991.

692

Gardner, J.V.,

geochemistry

Bering Sea.

Dean, W.E., and Vallier, T.L., 1980, Sedimentology and

of surface sediments, outer continental shelf, southern

Marine Geology, v. 35, p. 299-329.

Hampton, M.A., in press, Geotechnical framework study of the Kodiak Shelf,

Alaska. U.S. Geological Survey Open-File Report.

Hampton, M.A., and Winters, w.J., 1981, Environmental geology of Shelikof

Strait, OCS sale area 60, Alaska. Proceedings 13th Offshore Technology

Conference, p. 19-34.

Hampton, M.A., Johnson, K.H., Torresan, M.E., and Winters, W.J., 1981,

Description of seafloor sediment and preliminary geo-environmental

report, Shelikof Strait, Alaska. U.S. Geological Survey Open-File Report

81-1133, 86 p.

Herrmann, H. G., Rocker, K,, and Babineau, P.H., 1972, LOBSTER and FMS:

Devices for monitoring long-term seafloor foundation behavior. NaVal

Civil Engineering Laboratory,

Keller, G.I-I., Lambert, D.N., and

Technical Report R-775, 63 p.

Bennett, R.H., 1979, Geotechnical properties

of continental slope deposits - Cape Hatteras to Hydrographer Canyon.

Sot. Economic Paleontologists and Mineralogists Special Publication 27, p.

131-151.

693

Ladd, C. C., and Foott, R., 1974, New design procedure for stability of soft

clays. Journal of the Geotechnical Engineering Division, ASCE, v. 100, p.

763-786.

Lambe, T.W., 1951, Soil Testing for Engineers. New York, John Wiley and sons,

165 p.

Lambe, T.W., and Whitman, R.V., 1969, Soil Mechanics. New York, John Wiley

and sons, 553 p.

Lee, H.J., Edwards, B.D., and Field, M.E., 1981, Geotechnical analysis of a

submarine slump, Eureka, California. Proceedings 13th Offshore Technology

Conference, p. 53-65.

Lee, H.J., and Schwab, W.C., in press, Geotechnical framework, northeast Gulf

of Alaska. U.S. Geological Survey Open-File Report.

Lisitzin, A.P., 1972, Sedimentation in the World Ocean. SOc . Economic

Paleontologists and Mineralogists Special Publication 17, 218 p.

Mayne, P.W., 1980, Cam-clay predictions of undrained strength. Journal of the

Geotechnical Engineering Division, ASCE, v. 106, p. 1219-1242.

Mitchell, J.K., 1976, Fundamentals of Soil Behavior. New York, John Wiley and

Sons, Inc., 422 p.

694

Muench, R. D., and Schumacher, J.D., 1980, Physical oceanographic and

meteorological conditions in the northwest Gulf of Alaska. NOAA Technical

Memorandum ERL PMEL-22, 147 p.

.

Nayudu, Y.R., 1964, Volcanic ash deposits in the Gulf of Alaska and problems

of correlation of deep-sea ash deposits. Marine Geology, v.1, p. 194-212.

Odell, R.T., Thornburn, T.H., and McKenzie, L.T., 1960, Relationships of

Atterberg limits to some other properties of Illinois soils. Proceedings

of the Soils Society of America, v. 24, p. 297-300.

Pratt, R.M., Scheidegger, K.F.,

site 178, Gulf of Alaska.

V. XVIII, p. 833-834.

and Kulm, L.D., 1973, Volcanic ash from DSDP

Initial Reports of Deep Sea Drilling Project,

Rashid, M.A., and Brown, J.P., 1975, Influence of

engineering properties of remolded sediment.

p. 141-154.

marine organic compounds on

Engineering Geology, v. 9 ,

Richards, A.F’., 1962, Investigation of deep-sea sediment cores, II. Mass

physical properties. U.S. Navy Hydrographic Office Tech. Rept. 106,

146 p.

Richards, A.F., and Hamilton, E.L., 1967, Investigations of deep-sea sediment

cores, III. Consolidation. In: Richards, A.F. (cd.), Marine—

Geotechnique, Urbana, University of Illinois Presst p. 93-117.

695

Skempton, A.W., 1944, Notes on the compressibility of clays. Geological

Society of London, Quarterly Journal, v. 100, p. 119- 35.

Terzaghi, K., 1955, Influence of geological factors on the engineering

properties of sediments. Economic Geology, 50th Anniversary Volume 1905-

1955, p. 557-618.

Terzaghi, K., and Peck, R.B., 1948, Soil Mechanics in Engineering Practice.

New York, John Wiley and Sons.

von Huene, R., 1 9 7 9 , Structure of the outer convergent margin off Kodiak

Island, Alaska, from multichannel seismic records. In: Watkins, J.S.,—

Montadert, L., and Dickerson, P.W., (eds.), Geological and Geophysical

Investigations of Continental Margins, AAPG Memoir 29, Tulsa, American

Association of Petroleum Geologists, p. 261-272.

Whitney, J., Holden, K.D., and Lybeck, L., 1980,

glacial-marine sediments, outer continental

Alaska. U.S. Geological Survey Open-File Report

Whitney, J., Hoose, P.J., Smith, L.M.,

sections of the outer continental

Geological Survey Open-File Report

Isopach map of Quaternary

shelf, Shelikof Strait,

80-2036, 1 p.

and Lybeck, L., 1980, Geologic cross

shelf, Shelikof Strait, Alaska. Us.

80-2036, 1 p.

Wissar A.E., Christian, J.T., Davis, E.H., and Heiberg, s . , 1971,

Consolidation at constant rate of strain. Journal of the Soil Mechanics

and Foundation Division, ASCE, v. 97, p. 1393-1410.

696

APPENDIX:

INDEX PROPERTY CHARTS FOR SEDIMENT CORES

FROM SHELIKOF STRAIT

●

697

p);h

5 0 -

100 -

150 -

2 0 0 -

m

2 5 0 -

3 0 0 –

Station S08 Location 57”ZI.011N 155”36.41’IY Water depth zTOrn

Grain size(weight %)

Bulk den Ity8(gmtcm ) Atterberg limitSH i n d e x -

(% dry weight)

Bulk densityat 1 m.: JJIL

Water content ● Plasticity Llauldity

50- 100- 1?

H

50

index

) 1 .02.0 2

Grainspecificgravity2.5 3.

I I l“”

/

Organiccarbon

‘?w:’!lh:

IT

Water content kverage Liquidity Average Average

at Ire.: 87.2 plasticity index grain specific organicAverage3~lastic index: at 1 m.: gravity: carbon

limit: _ 30 1 . 5 8 2.84 0.931

Carbonate Vane shear(%drywehht) strenath

r

!verage. . Vane shearcar~onat e:

1.291strength

at ??8

Average l iquidlimit 65

Depth(cm) :

5 0 “

100 -

1 5 0 -

2 0 0 -

7d

250-

3oo—

Station 509 Location 57°21 .29’N 155 °08.66’W Water depth zzsrn


20406080

T

Isilt clay

Bulk den ItyJ(gin/cm )

Water content. Plasticity LiquidityAtterberg limitsH Index(% ;;Y :$ght~* 1 , I

Bulk densityat Ire.: 1.46

Water contentat lm.: 104.5

Index

01.02.0

Average Liquidityplasticity index

Average plastic index: at 1 m.:limit: ~ 34 3.56

F

Qralnspecificgravity,

) 2.5d

/

LAverage

carbon (%drywelght)I,

Organic Carbonate Vane shearutrength

, (kPa) ~

I I I I

weragegrain 9peclflc organicgravity: carbon

2.81 1.009Average liquid, -.

1 2 3

r

verage Vane shearcarbonate:0.990

strengthat lm.:

6 .34

limit. “/5.—

510 Location s7”w”z2’N M5”17”1B’w Water depth 30SCIStation

Llauiditv Grain Organiccarbon

Carbonate Vane shearBulk den ity8(gin/cm )

W a t e r c o n t e n t . PiaaticityGrain sizeindex - specific (%dryweight) strength

1 2 3 4 o(kpa)50

(weight %) Atterberg llIIIitSH i n d e x$IDepth,(cm) :

80 < -

100 -

150 “

200 -?7

250 -

300-

‘/’w;i!lh:r% dry weight)

50 100 1 5 0 0 5 0I

gravity2.5 3

, 1 r2I 1.5 2.0

i

r

\verage

-100

Vane shear.iquidit y ~verageindex grain specific organic carbonate:. .n/

AverageBulk densityat 1 m.: W

limit: ‘U

Water contentat Ire.: ‘9.7

Averageplasticity strength

at Ire.: gravity: carbon u . BYO at 1 m.:1.87 2.80 0.839 6.62::~g%’iastic index:

31Averag~~quid

Depth(cm)

I

50

100

150

2 0 0

2 s 0

300[

Station 511 Location 57 °39.08’N 154”50.14’w Water depth Zldm


2 0 4 0 6 0 3 0

T

silt

1

clay

Bulk densityatlm.: 1.49

Water contentat lm.: 100.6Average3~lasticlimitAverage7~quidlimit

o 1.02J

Qraln Organicspecific carbon

Bulk den MyJ

Water content ● Plasticity Llquldlty(gmicm ) Atterberg limitsH index Index

(% ;iy ;vght;1gr~;ty3.J%~r~w;i#~

1 l “ 1 (~ 7 ’ - -

—,verage

Carbonate Vane shear(%dryweight)

verage

!Wrongth(kPa)

50I I I

$erage lquidit y verageplasticity index grain specific organicindex: at 1 m.: gravity: carbon. 0.874

36 1.74 2.84 1.075 at Y’i

Vane shearstrength

Depth(cm)

1

/

50

100

150

2 0 0

2 5 0

3 0 01

Station 512 Location ST”SZ.S’N 154”14.9’W Water depth lgsrn


m

Bulk den ityt(gin/cm )

I 1.5 2.0

●

Buik density

Water content ● Plasticity Liquidity Grain Organic C a r b o n a t e < J* s h e a r

% dry ;eight)50 100 1!

~

Water content

--i%●

g-ravity (q01 .02 .0 2 .0 2 .5 3 .0

Atterbera iimitsH i n d e x index specific carbon (%dryweightj “s!rength

‘?w;i~hi) 0 1 2 3 4 ‘k P a ) 5 0~11—f—11

●

piastitity index

1 i , 1 “1’●

k I 1

hverage iverage. . Vane shearAverage Liquidity Averagea t 1 m . : . _ at 1 m; grain specific organic

Average plastic index: at lm.: gravity: carbon.ilmit: 4 1 30 2.81 0.879

carbonate:0.960

strengthat 1 m.:

Average liquidiimit: 7 1

Depth(cm) y

n5 0 -

100 -

150 -

200 -

250-

3oo—

Station 513 Location 57”54.8’N lS4°19.8’W Water depth zosrn


204060m

W

Mkd-1’’;ty Water content . Plasticity LlquldityAtterberg llt?dtSH(% dry weight)

50 I@l 150I1 1.5 2.0

●

Buik densityat 1 m;

Water contentat lm.:

index

!501 I If

●

index -

0 1.02.a●

iquidity

d

Grainspecificgravity

) 2.5 {I 1“1~

●

Organiccarbon

Average

Carbonate Vane shear(%dryweight) aj~~a~th

1 2 3 4 0 50- ,

verage

I I 1 I

)

verage Average Vane shealplasticity index grain specific organic carbonate

Average3~iasticstrength

index: at 1 m.: gravity: carbon: 1.10

iimi~ 30 2.77 0.863at 1 m.:

Average6~idiimit:

*o.P

Depth(cm)

1

50 I

100

150

2 0 0

2 5 0

3 0 0I

I

Station 514 Location 57”55.3’N 154 °25.0’W


2 0 4 0 6 0 6 0

v

) 1.5 2.0

●

Water content. Plasticity LiauldltyBulk den Ity#(gin/cm ) Atterberg lhIIitSH i n d e x -

(% dry weight).50: 100- 1!

H.

Bulk density Water content

50m

●

index -

) 1.02.0

— at 1 m; plasticity index

:

Water depth ppprn


I 2.5 3I I 1 “1’

●

Organiccarbon

‘/’w;i!h!

iverageAverage Liquidity Averageat Ire.: - grain specific organic

Average pkiStiC ind;;: at Ire.: gravity: carbon:

limit: 3 62.85 0.856

Carbonate Vane shear

9 , 1

~verage Vane shearcarbonate:

1.04strengthat Ire.:

Average liquidlimit 6 3

-doU-I

Depth(cm)

5 0

100

150

[

2 0 0

2 5 0

3 0 0I

Station 515 Location 57 °59.0’N 154 °27.3’W Water depth 238m


2 0 4 0 6 0 5 0

Bulk den Ity#

Water content ● Plasticity Liquidity(gin/cm ) Atterberg hIHSH i n d e x index

D 1.5

●

(% dry weight),,,5p, ,,!w, ,,1150

●


0 5 0 0 1 . 0 2 . 0 :

a t 1 m . : at 1 m: plasticity indexAverage plastic index: at 1 m,:

Qralnspecificgravity

1 2.5 <1 1 1 I’lwf

●

‘i,’

Organiccarbon

Average Liquidity Averagegrain specific organicgravity: carbon

limit: - 2.65 0.721

Carbonate Vane shear(%tiryweight)

cal—

strength(kPa) ,I I I I

●

Vane shearstrengthat Ire.:

Average liquidlimit:

Depth(cm)

50

100

150

I

2 0 0

2 5 0

3 0 0[

Station S16 Location SS”OO.S’N lSdOIO.G’~~ Water depth Z05


2 0 4 0 5 0 5 0~

clay

Bulk den ity#

Water content ● Plasticity Liquidity(gmtcm ) Atterberg iimitsH i n d e x

[% dry weight)) 1.5 2.0

●

Buik density

5C- 100- 1!

●

Water contentat 1 m.: - at 1 m;

I 50,

index

31.0 2.(

plasticity indexAverage piastic index: at Ire.:

2


2.5 3J, 1 l’rl~

Average

Organiccarbon

Carbonate Vane shear(%dryweight) s t rength

( k P a ) ~

I 1 I I

Average Liquidity Vane sheargrain specific organic carbo;ate:

1.05strength

gravity: carbon: at Ire.:limit 2 .65 0.898

iveraga

Average liquidiimik

Station 517 Location 57 °55.31N 154 °00.91hI Water depth lsorn


Bulk den ityJ(gin/cm )

Water content ● Plasticity LiquidityAtterberg iimitsH i n d e x(% $ ~sJght)

~

Grain Organic Carbonate Vane shearspecificindex

D 1.0 2.(

a

carbon (%dryweight) strength(kPa)

+

dg r a v i t y !) 2.5 3.

, I I“lf;~$h

m50 -

1 (JO -

150 -

2 0 0 -

2 5 0 -

3oo—

m 1.0 1.5 2.0

●

t 1 2 3 4

+-IO ●

-+0-1

AverageL

,verageBuik density Vane shearat 1 m.: at 1 m.: - - - - grain specific organic carbonate:

0.846strengthat Ire.:

Water content Average LiquidityDiasticitv index

Average piastic index: at lm.:iimik 3 9 33

gravity: carbon:2 .78 0.967

Average iiquidiimit: 7 2

Depth(cm)

5 0

100

150

1

200

250

300I

Station 518 Location 58 °00.3’N 153”51.6’W Water depth lsorn

20406x ) 1.5 2.0

t

tterberg llmitsH i n d e x -Grain size Bulk den Ity

8Water content . Plasticity Liquidity

(weight %) (gmicm ) index;% dry weight)

1 t 50 100 150 I o 1 . 0 2 . 0 i


50?1

limit:


w

Organiccarbon

Average

Carbonate !larie shear

1 2 3 4

7

\verageverage Liquidity Averagea t 1 m . : _ at 1 m; plasticity index grain specific organic carbonate:

Average plaStiC index: at lm.: gravity: carbon 0.9402.62 1.104

Vane shearstrengthat 1 m.:


Depth(cm) :

r

5 0 -

100 -

150 -

200 -

250 -

300 —

Station 519 Location 58”05.5’N 154°01 .3’Iv Water depth zoom

C3raln size(weight %)

204060B0

Wxz) 1.5 2.0

●

Bulk densitya t l m . :

Water content Averageat lm.:Average plasticlimit 3 9Average liquidlimi~ 65. .—

lquidityplasticity indexindex: at lm.:-

Average ,veragegrain specific organicgravity: carbom

2.70 0.829

Carbonate Vane shearBulk den ItyJ

Water content ● Plasticity Liquidity Qrain Organic(gin/cm ) Atterberg iimitsH i n d e x index llpecific carbon

(% dry weight)(%dryweight) af~~a~th

grav i ty (qD 1.02.0 2.0 2.5 3.0 1 2 3 4 (

-

verage Vane shearcarbonate strength

0.920 at lm.:

)

Depth(cm)

5 0

100

1

150

200

250

300“ I

Station SZO Location 58”13.2’N 153 °56.2tlV Water depth Zlsm

Grain size(Welgtlt %)

Bulk den Ity#(gin/cm )

) 1.5 2.0

Bulk densityat lm.:_

Water content ● Plasticity LlauldltVtterberg liI’dtSH i n d e x - index ‘“t% dry weight)

50 100 1{r

50

I

Water content Average

1

iquidityat Im: plasticity indexAverage PiaStiC index: at Ire.:

24iimit ~ —


1 2.5 3, 1 I’ll’

)

,verage

Organiccarbon

‘?w;i!lh!r

Average

gravity: carbon2.72 0.704


‘,verage

(kPaj5

I I I I

Vane sheargrain specific organic carbonate:

1.458strengthat lm.:

Average iiquidiimit 58

Depth(cm) ~

77

50 -

100 -

150 -

200 -

2 5 0-

300 —

Station 521 Location 58”07.931N 1s3”45.4’w Water depth lssrn


m

Bulk den ItyJ

Water content ● Plasticity Liquidity(gin/cm ) Atterberg liITtit8H i n d e x

(% ~;y ~~ght)1 5 0 0 5 01 1’ I

o 1.5 2.0

Bulk densityat lm.:

--m

Index

01.02 .0 :

Iquidit y

Average plastic index: - at lm.:


I 2.5 fr I , l’J1f

verage

Oraanlc Carbonate Vane shear

Average

(%cfryweidtt)

1 2 3

verage

strength(kPaj ~

1 I I I

Water content Average Vane shearplasticity index grain ;pecific organic carbonate

1.07strength

gravity: carbon:limit: 0.984

at 1 m.:—


;:;;h

** 60 -w

100 -

150 -

200 -

250 -

300 —

Station 522 Location S8”OS.S’N 153”41.1’W Water depth M5~

Qraln size(weight %)

204060B0

~

4

Bulk den Ity#

Water content . P last ic i ty Llquldlty(gin/cm ) Atterberg limitsH i n d e x Index

(% dry welaht)) 1.5 2.0

Bulk density

50 - 100- 1!

“ d ”

Water contenta t 1 m . : _ at 1 m.:

Average plasticlimit ~Average liquidlimit 8 6

3 1.02.C

verage Liquidlt yplasticity indexi n d e x : at 1 m.:

41

Grainspecific

2

Average

Organiccarbon

Averagegrain specific organicgravity: carbon

2.60 1.046

Carbonate Vane shear(%dryweight) strength

1234w , I

‘tverage

( k P a ) ~

-1 1 I 1

carbonate:0.950 at lm.:

Vane shearstrength

Depth(cm)

I

5 0

100

150

200

250

300[

Stahn 523 Location 58 °01.7’N 153”34.2’W Water depth lsom

(3raln size(weight %)

,~,y,y,y( I

13:l;l:nl;t y W a t e r contento Plaatlclty L iquid i ty GrainAtterberg iimit8H i n d e x index specific(% $ry wvvght)

o 1.02.a 2.0 ‘rYJt ‘s~ ~~

T

,

.—

Organiccarbon

Carbonate Vane shear(%dwweight) strenath

I I 1 I

Buik density Water content Average Liquidity- A~rage Average Vane shearat lm.: 1.84 at lm.: 43,0 grain specific organio carbonato

gravity: carbon 0.560iimit 7 0.472 at 1~:i8

plasticity index strengthAverage piastic index: at Ire.:

Average iiquidiimit

Depth(cm)

5 0

100

150

I

200

260

3001

Station 524 Location SS”lS.94’N 153°41 .87’~V Water depth lTsrn

Grain 8ize(weight %)

2 0 4 0 3 0 3 0

~

1 1.6 2.0

Bulk densitya t I r e . :

Atterbera limitSH i n d e x13#l(&T4J;t y Water content ● Plasticity Liquidity Grain Organic Carbonate Vane shear

Index specific (%dryweight) s t rengtho (kPa) ~

11% dry weight)

50 100 150I

so, I Ifdg-ravlty I

0 1 . 0 2 . 0 2 . 0 2 . 5 3 .

Water contentat lm;

Average Liquidityplasti~ty i n d e x

Average plastic index: at 1 m.:

t 1 1 “1’

Average

carbon

“7W;’8:

4verage

1234, , r

$verage

I I I I

Vane sheargrain specific organic carbonate: strengthgravity: c a r b o n

limit _at Ire.:

Average liquidlimit . _ .

‘r

Depth(cm)

5 0 -

100 -

150 -

m2oo -

250-

3oo-

Station —!2S Location 58°Z3.7’N 153”37.2’W Water depth lssrn


2040e030

Bulk den ItyJ

Water content ● Plasticity Liquidity Grain(gmlcm ) Atterberg iimitsH i n d e x

(% :Jy ;#ght) g-ravityD 1.02.0 2.0 2.5 <

~ I , 1 1D 1.5 2.0

I

Water content

)

index St)ecific

,verage

Organiccarbon


1 2 3

r

(%dryweight) s t rength~ ( k P a ) ~

r t 1 I

)

Average Liquidity Average Vane sheara t Ifn.: 4 5 . 2 plasticity index grain specific organic carbonate:Average plastic index:

strengthat lm.: gravity: carborc 1.034

limit: 27 ~-Uli.l_ 2.79 0.882at Ire.:

22.59Average liquidiimiti 3 9.—

Depth(cm) -

so -

100 -

150 -

m

200 -

250 -

3oo–

Station 526 Location SS”Z9.O’N lSsOzT.l’w Water depth lssrn

(3raln size Water content . Plasticity LiauidityBuik don ity

(weight %) #(gin/cm ) Atterberg lhIltSH i n d e x -

(% dry weight)2Q4060W

a

50 - 100- 1!-!

Water contentat lm: ~

501

Index -

Average Liquidityplasti~ty index

GrainSpecificgravity

I 2.5 3

I

Average

Organiccarbon

verage

carbon‘ra3i!;9 0.561


123A, I

~verage

(kPa)5

T I I I

!

Buik density Vane shearat Ire.: 1.79 grain specific organic carbonate

1.104strength

::t:agt’?iasticindex: at 1 m.:

13at 1 m.:

11.13

Avera~3;quidlimit:

~~;;h

so -

100 -

m

150 -

200 -

250 -

3oo—


204050Wmil

sand

Bulk den ItyJ

Water content ● Plasticity Liquidity(gmtcm ) Atterberg limitSH

(% :Jy vvvght)1{

1 1“1’1”””1) 1.5 2.0

Bulk densityat lm. : 1 .94

1Water contentat lm.: 31.2

index

50I IT

)

index

o 1.02.0 i-

\

plasticity index

Grainapeclficgravity

) 2.5 4

/

~vera9e

Oraanlc Carbonat@ ~ ane shear(%dryweight} ‘ strengthca;bon

‘rYwY8h’

r

verage

1 2 3 4(kPa)

50

Average Liquidity Vane sheargrain ;peoiflc 0r9anic carbonate:

1.353strength

Averag~ ;Iastic ind;x: at lm.: carbon:limit: 2.07 ‘r3:iP4: 0 .528

at lm;24.72

Average liquidlimit: !32

~&h

50 -

100 -

150 -

2 0 0 -

2 5 0 m

3 0 0 -

Station 528 Location S8”S9.4’N 153”0.7’w Water depth lsgrn


204060W

silt

sand tb

1a)

Bulk den ity#

Water content ● Plasticity Llquldlty Grain 0r9anlc(gin/cm ) Atterberg limitSH i n d e x specific

1% dry weight)50 100 1500 50~v

) 1.5 2.0

Bulk densityat 1 m.: J.J$L

H

H{ )

tater content

index

0 1 . 0 2 . 0 z

\

Average Liquidityplasticity index

\

Average

‘ra;!l’4

Ierage

carbon0.643


\verage Vane shearat lm: 46 .9 grain specific organic carbonate:

Average plastic 2.197strength

index: at 1 m.:11

at lm.:limit: ~ — 2.23 16.91

I

Avera@3;quldlimit

Depth(cm) ~

5 0 -

100 -

150 -

200 -m

250 -

300 —

Station 529


2040e030

\\

silt

;and

Bulk densityat Im: JJIZ_

Bulk den Ity#(gin/cm )

1.0 1.5 2.0

\

Location 58 °44.4’N 152 °57.4’W water depth 136m

Water content ● Plasticity Llquldity (iraln OrganicAtterberg limitsH index apecfflc carbon(% $y vvvght)

1! grav i ty (q=0 2.0 2.5 3.0 (1 II , I I

!ater content

I

index

50#

Iquidit y

, 1 1 “1’

—verage

“1’W:’3’

F

Average

Carbonate Vane 8hear

1 2 3 4

strength( k P a ) ~

verage Vane shearat 1 m; 29.9 plasticity index grain specifk organk ca;b~i~

index: at lm.: gravity: carbom . at lm.:2.69 0.551 18.50

Average plasticlimitAverage liquidlimit

strength

-1wo

;:;;h

60

100 “

150 -

200 “

250 -

3oo—

Station 530 Location 58”49.7’N 152”47.6’W water depth 165m

Grain size(Weight %1

2040eow

Tsand

Bulk don Ity#(gin/cm ) Atterberg limltsH

[% dry weight),,y, ,,ly, ,,l;) 1.s 2.0

Bulk densityat 1 m.:

Water content ● Plasticity Llauldltv

later contentat 1 m;

I

Index -

50

index -

D 1.02*O :

Qralnspecific,gravity

2.5 31

{

Averageplasticity index

,iquidlt y Average

Average plastic index: at 1 m.:limit:

Orgardc Carbonate Vane shearcarbon (%dryweight) strength

~ ‘r?w:igh;) 0 1 2 3 4 0 ‘k P a ) 5 0

I

iveragegrain specific organicgravity: carbon

2.79 0.462

,

,verage. . Vane shearcarbonate:3.049

strengthat Ire.:


Depth

1

(cm) ,

50

100

150

2 0 0

2 5 0

3 0 0[

“

Station 531 Location 58 °54.91N 152 °37.3’W Water depth lGlrn


2 0 4 0 6 0 8 0sand

~glkd:g;ty Water content. Plasticity LlauldityAtterberg limitsH I n d e x(% dry weight), ,=$ , ,!W, ,,1,!) 1.5 2.0

Bulk density Water contenta t 1 m . : _ at 1 m.:

index -

0 1.02.C

P

plasticity index


) 2.5 3, 1 ,

Organiccarbon

‘rYw#i3:

Average

Carbonate Vane shear(%drywoight) strength

~ (kPa) ~

191 I I

Average Liquidity Average Vane shealgrain specific organic carbonate

3.25strength

gravity: carbon: at Ire.:Average piastic index: at lm.:limit

.

0.388A v e r a g e iiquidlimit

Depth(cm) :

m

50 -

100 -

150 -

200 -

250 -

3oo–


204050W

coarse sand

I 1.5 2.0

Bulk density

Atterberg limitsH i n d e xBulk den ity

JWater content . Plasticity Liquidity Grain

(gmlcm )Organic

index specific carbon;% ~y &&ght)

150 (1“’’1’’”1

Water contentat 1 m.:

50,

g r a v i t y (901 .02 .0 2 .0 2 .5 3 .0

plasticity index\verage

Carbonato Vane shear(%dryweight) s t rength

01234, r I

(kPa)5

1 I I I

Average Liquidity Average Average Vane sheara t lm.: _ grain specific organic carbonate

2 8 . 1 5strength

Average plastic index: at Ire.: gravity: carbon0.335

at 1 m;limitAverage liquid11—9..

Depth(cm) ~

!50 “

100 -

150 -

2 0 0 -

250-

3oo—


2 0 4 0 3 0 3 0coarse’

Location S8”S0.A’N Isz”zs.g’w Water depth lzorn

(% dry ~eight)50 100 1r,

Water content

01.02.0 /!g“ravity !) 2.5 3.

Bulk den ityJ

Water content ● Plasticity Llquldity(gin/cm )

Qraln OrganicAtterbera limit9H I n d e x index specific

1.0 1.5 2.0

r

Bulk density Average Liquidityat 1 m.: at 1 m.: grain specific organk

Average plasticlimitAverage liquidlimit”.—

plasticity indexindex: at Ire.: gravity: carbom

Carbonate V~ne s h e a r(%dryweight) ‘strength

1 2 3

verage. . me shearcarbonate: strength

at Im;

Station 534 Location S8”S9.G’N 152”47.1’W water depth 185m

Depth(cm)

so -

m1 0 0 -

1 5 0 -

2 0 0 -

2 5 0 -

3 0 0 —

Grain alze(weight %)

2040W50

T

ygl:,:n$ty Water content ● Plasticity LiquidityAtterbera iimit8H

Buik densityat 1 m;

Water contentat 1 m:

index

dasticitv indexAverage piastic index: at lm.:limit: 30 11

GrainsDecificgravity

2.5 3J, v , 1“11

Organiccarbon

‘r?w:i3h\ 0 1 . 0 2 . 0 2 { I

~

Average Liquidity Average Average Vane shear. . . carbonate: strength

gravity: carbon: 3. 172.66 0.424

at Ire.:9rain specific organic


(kPa)5

I I I

\

Average iiquidlimit. 4 1

Depth(cm)

[

5 0

100

150

2 0 0

2 5 0

3 0 0[

Station 535 Location SS”ST.O’N Isz”dz.o’w Water depth gsrn


2 0 4 0 6 0 3 0

=

Bulk don i ty8

Water content ● Plasticity Liquidity(gmlcm ) Atterberg iimitsb-1 i n d e x

D 1.5 2.0

●

(% dry weight)50 100 1t

●

index

01.0 2.(

Grain Organicspecific carbon

dg r a v i t y qI 2.5 3.

1 , I“lf●

Buik densityat 1 m.: at 1 m.: .–. —._– _._z

Water content Average Liquidity AverageDiasti&tv index

Average plastic index: at lm.:

yw:i3h

veragegrain specifk organicgravity: carbom


1 2 31

verage

H

(kPa)t

I 1 I●

Vane eheafcarbonate:

21.67strengthat 1 m.:

Average liquidiimit-.—

Depth(cm) -

so “

100 -

150 -

200 -

T2!50 - ’

3oo-

Statlon 536 Location 58”31.41N 152”52.6’W Water depth lgorn


2040 BOW

an

Water content ● Plasticity LiquidityBuik den ityJ(gin/cm ) Atterberg iimitsH i n d e x

;% dry wt,,y, ,l:

H

H

i n d e x

) 1.02.0 2


I 2.5 3, 1 , 1 “1’

/

Organiccarbon


-

iverage Average Average

‘1 I I I

Buik densit Water content Average Jquidity Vane shearat lm.: J& at lm; 61.4 plasticity index grain specific organic carbonate:

Average piastic2.01

strengthindex: at 1 m.: gravity: carbon at 1 m.:

iimit: 3 2 19 1.73 2.78 0.785 10.47Avera

Yiiquid

Ilml+. 1

Depth(cm) ~

5 0 -

100 -

150-

m2 0 0 - ‘

2 5 0 -

3oo—

Station SST Location 58”29. O’N 153”07.6’W Water depth lGOrn


2 0 4 0 6 0 3 0

Ksilt cla,

and

Bulk den ity8

Water content ● Plastlclty Llquldlty(9m/cm )

Grain Organic Carbonate Vane shearAtterberg limitsH i n d e x index(% dry weight)

specific carbon (%drywelght)

~,y,,,!~,,,y 01.02.0 2.0 ‘rydt ‘:D 1.5 2.0

Bulk densitya t lm.: 1 . 6 9

Water content

Average plastlclimit: 32

) 50

I●

plasticity indexindex: at 1 m.:

24

‘r?w?’3h

7LAverageAverage Liquidity-

at lm.: 61.5Vane shear

grain ipeclfic organic carbonate:gravity: carbom 2.775

2.78 1.973 at2drn~8

123

1

veraga

strength(kPa)

50

strength -

Average liquidiimit~ 5 6.—

-JNm

2 0 0

I

/

2 5 0

3 0 0

Station 538 Location ss”zs.2 ‘N 153°00 .2’w Water depth lgorn


2040tmm

and

) 1.5 2.0

\

Bulk density

Atterberg limitSH I n d e x - IndexB#kdrl$t y Water content ● Plasticity Liquidity Qraln Organic

specific carbon(% dry weight)

(%dryweight) at~p~~th

{50 - 100- 1!

H

H

H

H

Water content

50,

i

4g“ravity 9D 1.02.0 2.0 2.5 3.

dasticity index~verage

Carbonat. Vane shear

1 2 3 4-

werageAverage Liquidityat lm.: W at lm~~ grain specific organic carbo~ate:

Average plastic index: - at Ire.: gravity: carbon 1.42

limit: 33 —29 1.46 2.78 0.871

I I I I

Vane shearstrengthat Ire.:

16.09Average liquidtimit 6 2

wNJu)

Depth(cm) :

5 0 -

100 -

w1 5 0 - ‘

2 0 0 -

250-

3oo—

Station 539 Location SS”Z1.S’N 153”12.4’w Water depth lTSrn

Grain SIZO(weight %)

2 0 4 0 6 0 6 0

silt‘1

claj

o 1.5 2.0

Bulk densitat lm.: 1.4~

l\I /’

50nwl

index -

01.0 2.(

Mkdn$ty W a t e r content . P last ic i ty Llauldity Qraln Organic Carbonate ~ane shearAtterberg limit8H I n d e x(% dry weight)

specific carbon (%dryweight) ‘ sj;~a~th

o 50 100 150

r

1 2 3 4 1 {

T

plasticity indexindex: at lm.:

gravity2.0 2.5 :

verage

‘r?wm’r

verage

L

i I 1 I

Water content Average Liquidity109 7 Vane shear

at lm.: . grain specific organic carbonateAverage plastic

strengthgravity: carbom 1.70

2.82 1.102at91~:

limitAverage liquidl i m i t :

Depth(cm)

so

100

150

1

Station S40 Location S8”21”5’N 15s”07.6’w Water depth Z1O”

(weight %)

2 0 4 0 6 0 8 0

-

Grain size Bulk den Ity#

Water content . Plastlclty Liquidity Grain(grn/cm )

Organictterberg llmltSH i n d e x~% dry weight)

1 50 100 150 () 1.5 2.0

2 0 0

250

3 0 0[Water contentat lm.: 74.0

50,

index specific carbong r a v i t y (q

O 1.02.0 2.0 2.5 3.0

plasticity indexAverage plastic index: at lm.:limit

1 I 8 l’lv~‘r/’w#i3h!


0 1 2 3 4 O(kpa)50. 1 1

iverage

I I 1 I

\

Average Liquidity Average Vane sheargrain specific organic carbonate:

1.10 strengthgravity: carbon

2.76 0.799at 1 m.:

15.86


Depth(cm)

.1

5 0

100

150

2 0 0

2 5 0

3 0 0[

Station 541 Location 58 °15.8’N 153 °22.0’UI water depth 167m


2 0 4 0 3 0 3 0

m

3 1.5 2.0

Buik densityat lm.:

50) 1

●

at lm.: plasticity indexAverage piasticiimit 39Average iiquidiimiti 63

specificBulk den i t y

#Water content ● Pia8ticlty Liquidity

(gin/cm )Grain Organic

Atterberg lltWSH index index(% dry weight),,, y,, ,!~, ,,l;

g r a v i t y (1O 1.02.Q ‘ 1 2.5 3.0~ 1~

index: at 1 m.:24

carbon

‘r7w;i3:

Average


( k P a ) ~

I I 1 IB

Average Liquidity Average Vane sheargrain specifk organk carbonate

1.270strength

gravity: carbom1.082

at 1 m.:.

1+

‘I

● m

I

1

732

Depth(cm) :

m

5 0 -

100 -

150 -

200 “

250-

3oo—

Station 543 Location 58 °10.77’N 153 °31.97’lv Water depth 180”


2 0 4 0 , 6 0 6 0~shlf- ‘e l’a~

Mlmdn ;ty8

Water content ● Plasticity LlquldltyAtterberg limitSH index(% dry weight)

) 1.5 2.0

,:


50- 100- 1500 50b

Water contentat 1 m.:Average plasticIlmit:

1 , 1 1 If

i n d e x

0 1 . 0 2 . 0 :gravity

1 2.5 {v l’vl~

verage

1

,verage

Carbonate Vane shear(%dvmlght)

1231, 1

verageAverage Liquidityplasticity index grain speclfk organk cati-ate:index: - at Ire.: gravity: carbon

strength( k P a ) ~

I I I I

.

strengthat Ire.:—.

Average liquidlimit

l));;h

8 0 -

100 -

1 so -

2 0 0 -

2 5 0 -

m

3oo-

%

Station 545 Location 58 °22.5’N 153”53.5’W


Bulk den Ity8(gin/cm )

1.5, 2.0-1,111,1,1,~

I


Water content ● Plasticity LlquldityAtterbera limitsH i n d e x

% dry ~elght)50 100 1!>

Water content

50-t I

Index

0 1 . 0 2

(

Water depth 175”

2


2.5 3.t, , I’ll’

Cwl:; Carbonato Vane shear(%dryweight) s t rength

1 2 3 4 O(kpa) 50

Average Liquidity Averagea t Imi 69.1 plasticity index grain specific organic

index:&~fJe?P’ic 2,

at 1 m.: gravity: carbon:2 .02 2.79 0.663

.—

iverage Vane shearcarbonate

0.710strengthat 1 m.:

Average Ii.guidIimi* 49

uwm

Depth(cm)

m

5 0 -

100 -

150 -

200 -

250-

3oo—

Station 546 Location s~OzB.B’N 153 °37.011v Water depth 9Trn


2040eo Bos i l t

lmdl ;tyJ

Water content ● Piaaticity LiquidityAtterberg limit~H i n d e x(% dry weight)

Buik densityat Ire.:

50- 100- 1

Hb

)0 50

index

01.024T’yr


1 2.5 $,

‘oI I

‘4,,I

Organiccarbon

‘r?w;igh

Carbonate ‘?? ?me shear(%dryweight) ‘strength

( k P a ) ~1234 0w I

Average plasticiimit 2 8Average iiquidIimik 4 5

wrage

D’ I I I

Vane shearstrength

Water content verage Liquidity Averageplasticity index grain specifk organicindex: at 1 m.: carbom 1.02

20 ‘YY8at 1 m.:

0.565

-Jham

Depth(cm)

5 0

100

1

150

2 0 0

2 5 0

13 0 0

Station 547 Location 58”33. O’N 153”34.4’W Water depth ggrn


20406030

T

)

silt 1 ay


i

\

Water content ● Plasticitterberg limitsH i n d e x% dry weight)

50 100 It? , I

H

H/


r

Llquldity Grainindex specific

gravity~ 1.02.0 2.0 2.5 3

l’Jlr

~verage

Organiccarbon

‘rw?’!ih:r

Average


)1 2 3 4(kpa)

9I I I I

1

Average Lif Vane shear

a t I r e . : _ . at 1 m; plasticity index grain specific organic carbonate:1.05

strength

Average plastic index: at lm.: gravity: carbon at 1 m:

limit: ~ 14 2.79 0.591


Depth(cm) -

50 -

100 ~

1 5 0 -

2 0 0 -

2 5 0 -

3oo-

Station 5 4 8 Location 58 °37.9’N 153 °25.1 ‘If Water depth Garn


20406030

T

silt claj

r

D 1.5 2.0

Bulk densityat lm.:

5011 ,1,1

rindex

o 1.02J

7

,

Bulk den i t y8

Water content ● Plasticity Llquldity(gmlcm )

Grain Organic Carbonato Vane shearAtterberg iimit8H i n d e x(% dry weight) (%dryweight) $;~a~th

50 100 1I 1 2 3 4 !

Average Liquidityat 1 m; plasticity indexAverage plasticiimit: ~Average liquidIimir 35.—

index: at Ire.:~ —,

specificgravity

2.0 2.5 i

LAverage

carbon

werage

I I I !

Vane sheargrain specific organk carbonate: strengthgravity: carbon 1.0s

2.72 0.671at lm.:

2 0 0

2 5 0

3 0 0I

Station sag Location s8043.3’N 1s3015. oIw Water depth ~.

Qraln 8120(weight %)

w

Bulk den Ity#

Water content ● Plasticity Liquidity Grain(gmlcm ) Atterberg limitsH i n d e x

(% dry weight)o 50 100 150(

g“ravity31.02.0 2.0 2.5 3) 1.5 2.0

{


IIH

Water contentat lm;

index specific

Average Liquidityplastidty index

I I , l“”

L

Average

Organiccarbon

Averagegrain specifk organic

Carbonate Vane shear(%drywelght) strength

1 2 3 4 O(kpa) 50

Vana shearcarbonate:

Average plastic index: 1.01 strengthat lm.: gravity: carbon: at lm.:

limit: 25 4 2 .76 0.517

w t #

iverage

Average Uquidlimit ~,

Depth(cm) :

so -

100 -

150-

?Z

2 0 0 -

250-

3oo—

Station SSO Location SS”SO.S’N 153”1o.3Iw Water depth 165 m


2 0 4 0 6 0 [

Jsand sillfr

Bulk don ItyJ

Water content. Plasticity Llquldlty(gin/cm )

Qraln 0r9anlcAtterberg limit8H i n d e x(% &y w&ght)

~o 1.5 2.0

\


)0 !50

index

01.02.

specific caibon

‘r?w:i3h

Iverage

Carbonate Vane shear(%dryweight) $trength

( k P a ) ~

Water content Average Liquidity Averageat Ire.: 37.5

Vans shearplasticity index grain specific organk carbm-ate: strength

;~ge YPs’k 7index: at 1 m.: gravity: carbon 1.07

2.72 0.631 a!ll%io

2 0 0

2 5 0

3 0 01

Station 551 Location SS”SS.G’N lszOsA.A’~$’ Water depth lssrn


204060Wvsilt

and


I 1.s 2.0

\

W a t e r contento Plastlclty L iquid i tyAtterberg limit8H i n d e x

% dry weight),,p, , ,1 OOJ,SO

l-l

(H

Water content

index

o 1.02.a

at 1 m.: plasticity index


2.5 3,I 1 I I I

/

Organiccarbon

‘l’w;i!ilh:

Average Average


::34

;*

Werags Vane shearBulk density Average Liquldlt ya t I r e . : _ grain specific organic carbonate

2 . 1 4strength

;:rag~glastic index: at 1 m.: gravity: carbon at 1 m;10 2 .76 0.801. ——

Average liquidlimit: 36

Station 552 Location S8”4Y.Z’N Iss”oz.s’w Water depth lssrn


2 0 4 0 6 0 3 0

E

silt

cla

sand

Bulk den Ity8

Water content ● Plastlclty Llquldlty(gin/cm )

Qraln Organic Carbonate ~~ne shearAtterberg limit8H I n d e x(% dry weight)

index (%dryvvelght) ‘ a~;~a~th

50 100 150r, 1234 1

speclflc carbon

“?W;’3’g-ravity

2.0 2.5 {Depth(cm)

6 0 -

100 “

150-

7/

2 0 0 -

250-

3 o o -

0 1.s 2.0

\

D

.

H

{

H

Average Liquidity ferageat Ire.: 47.5 grain specific organk

Bulk densitya t l m . : 1.78

verage Vane *hearplasticity index strengthindf;: at lm.: carbon: 1.46

1.90 ‘a;i!% 0.655 at lrn.:15.60

u.SN

Depth(cm) ~

5 0 -

100 -

150 -

200 -

v2 50 -

3 00-

Station GQO Location 58 °1S.3’N 153 °59.26’w Water depth z7dm


204060W

silt clay

()

\\

Buik densitya t lm.: 1.60

1.5 2.0>Ie

Water content ● Plasticity LiquidityAtterberg iimit~H i n d e x(% dry weight)

5(- Im- 1!-1

H

H

H

H

Water content

index

) 1.02.0

1

iverage Liquidity


2.5 3<-1 I , 1 “1’

Organic Carbonate Vane shearcarbon (%dryweight) s t rength

Average

a t lm~ ~ ~e$itY ~~~ grain specific organicAverage ~tic

?. gravity: carbon

28.iimit — — 1.55 2.69 0.771——

1234, 1

Average

(kPa~ ~

1 I I I

Vane shearcarbonate:0 . 8 4 0

strengthat 1 m.:

8.90

AverageJ~luidiimit

Station 643 Location 58 °05.7 ‘N 154 “09.1’W Water depth zggrn


Bulk den ItyJ

Water content . Plasticity Llquldlty(gin/cm ) Atterberg lirnitSH i n d e x

(% ~y vvvght)1

I 1

Qralnepeciflc

Organic Carbonato V a n e shear(%dryweight)index

D 1.0 2.(

1

strength(kPa)

50gravity

I 2.5 3., I 11111

Depth(cm) -

50 “

ml

1 0 0 -

1 5 0 -

200 -

250 -

300“

20406060 301 #11

[

1 2 3 4

Average Liquidity Vane shear. grain specific organk

0.966 at lm.:

Average AverageWater contentat 1 m.:

Bulk densitya t 1 m . : rdasticitv index strength .

Average plastic index: at lmo:limit ~ 32

carbon‘raY84 0.796

Average liquidIimir 6 9.—

Depth(cm) -

so -

m

100 -

150 -

200 “

2 5 0 -

300 –

Station 644 Location 57”54.6’N lS4033.9’W


2040eo Bo

T

silt clay

) 1.s 2.01

Bulk densityat Ire.:

Water content. Plasticity LiquidityAtterber!a limitsH i n d e x

Bulk den ity#(gin/cm )

[% dry weight)50 100 150

H

H )

Water content

5 0v

I

index

3 1.02.C

\

Average Liquidityat 1 m; plasticity indexAverage plastic index: at 1 m.:Ilmik 3 4 2 6

.Water depth ~

Qralnj specific

gravity2.5 3,

I 1 , 1 “1’

{

Average

Organiccarbon

)

Vane sheargrain specific organic carbonate:

0 . 8 3 7strengthat 1 m:

Average



\verage

(kPa) ~

I I I I

)

t


L1

745

I

R.+v

)I

0●

a

746

Depth(cm)

so -

100 -

150 -

U77

2 0 0 -

250-

3oo—

Shthn 647 Location 57”59.8’N 154”1o.7’w Water depth zzom


Bulk den Ity#

W a t e r c o n t e n t ● Plastlclty Llquldity(gin/cm )

Qrain Organic Carbonate $ ma shearAtterberg iimitSH index index

[% dry weight)(%dryweight~ ‘s~;~a~th

50 100 1500 50 t3 1.5 2.0

~ silt

)

cla

Buik densitya t l m . : 1.57

01.0 2.(

ater content Liquidity

specific

4g r a v i t y ~

3 2.5 aI I

(

carbon

‘m!

Average Averageat lmi 76,4 Diasticity index

f#yw-ticAve~age i id

(!Piimit

incjelx: - at 1 m.:1.11

,veragegrain specifk organlogravity: carbom

2.S8

0 1 2 3 4I

Averagecarbonate

I

Vane shearstrength .

at8’.”&i

Depth(cm) ~

6 0 “

100 -

150 -m

200 -

250 -

300 —

StatiOn 649 Location SS”04.7’N 1s4”01.91w Water depth zogrn

C3raln 8129(weight %)

2040mw

silt

1

clay

1

4

Bl#dty;t y W a t e r c o n t e n t . Plastlcitv Llquldity Qraln Organic Carbonate Vane shearindex specific (%dryweight) 8trength

(% ~y ~~ght~a ,( 1 2 3 4 O(kpa) 5 0

l“1”l’’ *’I) 1.s 2.0

Atterberg IimitsH I n d e x -

50

1●

grav i ty (q) 1.02.0 2.0 2.5 3.0

1 1 I I’fl’

%

1

LAverage

:arbon

‘?w;i3h:

I

iverage iverage

I I I I

I

strengthBulk density Water content Average Llquidit y Vane shearat lm.: L&Z_ at Im: 77.6 plasticity index grain specific organic carbonate:

;;~ge?~tic ,, at ‘m”’ ‘?:;;index: carbon: at lm.:

7.97Ave;age..lluidlimit:

Depth(cm) :

5 0 -

100 -

150 -

v

200 “

250-

3oo—

Station GSO Location 57 °5s.0 ‘N 154 °01.1 ‘iv Water depth 199~


silt)

clay

i3uJkdlJJ;ty Water contente Plaatlclty LiquidityAtterberg iimitsH index index(% ~;y tvvht)

150I l“s”l’gr~l0 1.5 2.0

THl - i

Water contentBuik densitya t I r e . : 1.51 a t lm.:.&6.8

Average4~iasticIimlkAverage7~quidlimit:

5011, ,,1

!Average Liquidityplasticity indexindex: at 1 m.:

37 1.73


J 2.5 3

)

<

Organiccarbon

Average

Carbonato Vane shear(%drywelght)

0 1 2 3 4, i

strength( k P a ) ,

-

1

Vane sheargrain specific organk carbonate: strengthgravity: carbon

2.61 at %o

750

Depth(cm) -

n

5 0 -

100 -

150 -

2 0 0 -

2 5 0 -

3 0 0 —

Station 654 L o c a t i o n 57*07.4’N 154 °09.0’~f Water depth zszrn

Grain 9120(weight %)

2040 .5050

silt clajD 1.5 2.0

●

Bulk densitya t l m . :

50- 100- 1I

● 0

Water contentat lm;

index

50I If

verage Imidit y

Average plastic i n d e x : at lm.:limit

11-r, [lllr

●

verage ,verage

Carbonate Vane sheari3uul:,kd:$t y Water content ● Plasticity Liquidity Qraln OrganicAtterberg lkIltSH index specific carbon (%dryweight) s t rength(% dry weiaht) dg r a v i t y q

21.02.0 2.0 2.5 3. I

gravity: carbon:2.61 1.006

1 2 3 4 O(kpa) 5 0

Vane slmarplasticity index grain specific organk carbw-ate:

0.870 at 1 m.:strength

Average liquidlimit

Station 655 Location 57”51.8’N 154 °09.0’w Water depth Z04

Depth(cm) -

m

so -

100 -

150 -

200 -

250 -

3oo—

Grain 0120(weight %)

204060B0

-

Bulk don ItyJ(gin/cm )

) 1.5 2.0

●

Bulk densityat 1 m.: -

Water content . Plaatlcity Llauldltvtterberg limitsH i n d e x -

[% dry weight),,y, ,,i~j, ,l)

Ho

Water content

501●

,verage

index -

D 1.02.0

●

.iquidityat 1 m; plasticity indexAverage plastic index: at lm.:


I 2.5 31 “1’

●

Average

Organiccarbon

‘rl’wr!lh:

tverage

Carbonate Vane shear(%dryweight) 8trength

12341

werags Vane sheargrain specific organic carbonate:

0.750strength

gravity:limit ’38

carbon~ 2.67 1.101

at Ire.:

Average Ilquidlimit 7 9

Depth(cm)

I

so )

100

150

station 1556 Location 58 °0S.7’N 153”43.8’W Water depth lgxm


204030W

silt. clay

Bulk den Ity8

Water content . Plastlclty L iquid i ty(gmlcm ) Atterberg Iir + index index

(% dry weico 1.5 2.0

2 0 0

2 5 0

3 0 0IBulk densityat 1 m.:

50- loo-) I

‘r

) 01.0 2.(i-r-r

●

Water content Average Liquidityat 1 m; plasticity indexAverage plastic in~~: at lm.:limit 4 6


) 2.5 t, , I’lfl

f

Average

Organiccarbon

:IW?Y3:

iveragegrain specific organk

carbon‘r?:!~ :

Carbonate tiane shear(%dryweight) : strength

1 2 3,

uerage

(kPa) ,

-

;

Vane shearcarbonate strength

at Ire.:

)

Averag~~quldlimit

-Ja.P

Depth(cm) ;

so -

100 -

150 -

200 -

250 -

300 -

Station 657 Location 58”12.9’N 153”57-4’W Water depth zszrn


02040 Boal

Bulk don ity8(gin/cm )

I 1.5 2.0

Bulk densityat lm.: ._U&.

Water content ● Plasticity LiquidityAtterbera iimit8H i n d e x

~% dry ~eight)50 100 1!

index

11.02.0 2-

I.iquldit y

Grain Organic Carbonato Vane shearspecific carbon (%dryweight) strength

dg-ravity q2.5 3. I ‘rw$i3h! 0 1 2 3 4

Water content iverage Average Average

at lm.: 70.0Vane shear

plasticity index grain specifk organic carbonate: strengthAverage f$astic index: at 1 m.:

30 1.28carbon

limit ‘ra??6——a%?l-b

Avera@jlccidiimi~

2 0 0

2 5 0

3 0 0[

station 658 L o c a t i o n 58”1O.6’N 153 °32.6’lV Water depth 190M

(3raln size(weight %)

sil~ clay

Bulk den Ity#

Water content ● Plastlclty Llquldlty(gin/cm ) Atterberg limit8H I n d e x

(% ~y ~sJght)150t l’”1’lqlt?r

D 1.5 2.0

1


Index

01.0 2.(

●

Average Liquidityat 1 m.:;&rs~o plastk

.


40

t,


) 2.5 3I I

1

Average

IOrganiccarbon

‘rlw$i$

.

,veragegrain specifk orgsnkgravity: carborc

2.55

Carbonate Vane shear(%dry weight)

1 2 3, #

verage

strength( k P a ) ~

t I I I

I

[

Vane shearcarbm-atw strength -

at 1 m.:

AveraE

IlquidIlmiv.—

Depth(cm) -

u5 0 “

zYJ

100 -

150 -

200 -

250 -

3oo-

Station 1559 Location 58”01.8’N 153 °28.S’W Water depth llzm

Grain 81ze(weight %)

2040wm

7

sandclay

) 1*5 2.0

T


(!01.02.0 2.0 ‘rYJt ‘3.91

ygl:,:r$t y Water content ● Plasticity Llquidlty Grain Organic Carbonate Vane sheartterberg limitsH I n d e x index specific carbon (%dryweight) s t rength~% dry weight)

1 2 3 4 O(kpa) 50

‘+”’, I , I , I 1 I

‘“t

Average

, I

Lverage Vane shesrAverage Llquidit yat Im”. . — at 1 m: plasticity index grain specific 0r9anic carbonate:

Average plastic 0.340strength

index: at 1 m.: gravity: carbon. at lm.:limit 2 1 - 16 2 .47 0.228

Avera@3#kluidlimit _ .

Depth(cm) ;

n5 0 -

100 -

150 -

2 0 0 -

250-

3oo–

Station GGO Location SS”OS.9’N 153 °32.91W Water depth 146”


2 0 4 0 5 0 5 0

Z.

Bulk don Ity8

Water content ● Plaetlcity Llquldlty(gin/cm ) Atterberg Iimltsw i n d e x

(% dry weight)50 100 150I

Q 1.6 2.0

Bulk densitya t 1 m . :

J’

Water content

50rl. , I

I

index

D 1.024

●


8

C3ralnspecificgravity

) 2.5 4,

\

, I I

verage

I

Or9anlc Carbonate Vane shear(%dryweight) atrenath

1 2 3, 1 I f I I

●

Average plasticIimik 27Avera e liquidIlmit” ?35.—

Average Vane shearAverage Llquidit yat 1 m: grain specifk organic


at lm.:caoti~7aJe

. strength

Depth(cm)

60

100

150

I

2 0 0

2 5 0

3 0 01

Station 661 Location 58”06.50’N 153 °34.20’W water depth 238m

Qraln alze(weight %)

204060B0

isilt clay

Bulk den Ity#(gmlcm )

) 1.5 2.0

\’

Bulk densitya t 1 m . : , _

Water content ● Plasticity Liquldlty Graintterberg limitsH i n d e x[% dry weight)

50 100 1!501 71.02.0 2.0 ‘rYlt ‘3

~

H

H \

-%

I’

index specific

I

Water contentat 1 m.:

Average Liquidityplasti&y index

Average

Organiccarbon

‘sr?w:i8h!

Averagegrain spedfk organic


1 2 3 4

Vane shearcarbonate:

0.590strength

index: at Ire.:;Fg:t’astic

gravity: carbon3 9 2.62

at lm.:0.397

-

kverage

(kPa)!5

I I I I

●

AverageJiquidlimit _ ,

Depth(cm)

5 0 ~

100 -

150 -

200 -

250 -

300 —

Station 662 Location 58 °15.80’N 153 °23.00’W Water depth lTbrn


2040 G050‘slit’-’ ‘Cl!l$

Bulk den ity#

Water content. Plasticity Liquidity(gmlcm ) Atterbera llftIitSH i n d e x

t) 1.5 2.0

Buik densityat 1 m.:

(% dry ~eight)50 100 1t

“J

Water contentat 1 m:

50,●

index

D 1.02.(

●

piastic-ity index


1 2.5 3, I v l’llr

/

verage Averaae

Carbonate ye ne shear(%dryweight) ‘ strength

01234 O(kf’a) ~, , r

verageAverage Liquidity Vane sheargrain speoifk organk carbonate

index:::t:age4?iastic 39 at ‘m.:

gravity: carbom at lm.:2.51

strength .

Averaw8]quidiimifi.—

Depth(cm) -

so -

100 ~

150 -

200 -

250 -

300-

Station 664 Location 58 “55.00N 153”36.90W Water depth lTdrn


sand

!

Bulk den Ity8(gin/cm )

) 1.5 2.0I , 1 “ ’ ’ 1 ”

{

Bulk densityat lm.:

Water contento Plast ic i ty L iquid i tytterberg limitsH i n d e x -

% dry weight)50 100 1!

-I

}

Water content

soI I I l!

index

) 1.02.0 2

Qrainspecificgravity

2.5 34, 1 “1’

I

:::;:: Carbonate Vane shear(%dryweight) s~~p;~th

w

4veragsiverage Liquidity Average

at 1 m: plasticity index grain specific organicAverage plastic index: at Ire.: carbon

limit _ —

gra~~~g

1 2 3 4, , I

\verage

c I I I I

Vane shearcarbonate strength

at 1 m;

Average liquidlimit

geotechnical framework study of shelikof strait, alaska

Documents