GRADUATE THESIS PROPOSAL - Dalhousie Universityearthsciences.dal.ca/.../thesis_proposals/Walsh... · core samples from the Mackenzie Delta, Beaufort Shelf, Beaufort Sea and Amundsen

2010 GRADUATE THESIS PROPOSAL

EARTH SCIENCES 6300

NAME (Last, First)

Walsh, Fred Dalhousie Student ID:

B00100887

DEGREE PROGRAMME: MSc FIELD(S) OF SPECIALIZATION: Micropaleontology

SUPERVISOR and COMMITTEE:

Supervisor:

Dr. David B. Scott, Dalhousie University, Centre for Environmental and Marine Geology, and the

Department of Earth Sciences

Committee:

Dr. Martin Gibling, Dalhousie University, Department of Earth Sciences

Dr. Lawrence Plug, Dalhousie University, Department of Earth Sciences

TITLE OF PROPOSAL:

Foraminifera as proxies for recent and paleo methane release in ocean floor sediments

Key words: (up to 10)

Beaufort Sea, proxies for methane, foraminifera, Ammotium cassis and Elphidiella hannai, radiocarbon

dating, Mackenzie delta, CASES

LIST INNOVATIONS or EXPECTED SIGNIFICANT OUTCOMES (100 words total max):

(1) Foraminiferal as a proxy to detect methane which allow scientists and hydrocarbon exploration

teams to identify methane (biogenic or thermogenic) areas, regardless of whether there is

methane gas detected in the water column

(2) Identification of these foraminiferal proxies in the seafloor sediment record can be used to

recognize paleo-methane events. Once these events have been dated using the radiocarbon

method, they can be then added to information supporting time frames of climate studies

completed by other scientists.

STUDENT’S SIGNATURE: SUPERVISOR’S SIGNATURE:

DATE: DATE:

2

SUMMARY OF PROPOSED RESEARCH (IN LAY TERMS):

In 2004, scientists and crew aboard the Canadian Coast Guard Ship Amundsen collected box and piston

core samples from the Mackenzie Delta, Beaufort Shelf, Beaufort Sea and Amundsen Gulf, in the

Canadian Arctic. This was initiated as a joint venture of the Canadian Arctic Shelf Exchange Study

(CASES) and Canadian Arctic Net, both designed to gather information on the Canadian Arctic. A.

Rochon, S. Blasco and P. Travaglini (2006) and C. Paull, W. Ussler III, S. Dallimore, S. Blasco, T.

Lorenson, H. Melling, B. Medioli, F. Nixon and F. McLaughlin (2007) completed papers revealing

certain areas on the Mackenzie Delta, Beaufort Slope and Beaufort Sea that regularly release methane.

Research by F. Walsh ( 2006), that analyzed foraminifera (very small, primitive, single cell animals),

from core samples on the Mackenzie delta, suggested that two foraminifera (Elphidiella hannai and

Ammotium cassis) may be proxies for methane. Further investigations in papers by D. Scott, T. Schell,

A. Rochon and S. Blasco (2008a) and D. Scott, T. Schell, A. Rochon and S. Blasco (2008b) show the

Elphidiella hannai and Ammotium cassis have been found in these methane (biogenic or thermogenic)

areas; however, thus far, they have not been found outside these areas. Three core samples from inside

and outside the known methane areas on the Mackenzie Delta, Beaufort Shelf, and Beaufort Sea, will be

studied for Elphidiella hannai and Ammotium cassis, along with any other foraminifera that follow the

same tendency. This information along with data from other cores already analyzed, (inside and outside

known methane areas on the Mackenzie Delta, Beaufort Shelf, and Beaufort Sea), should determine if

the Elphidiella hannai and Ammotium cassis are proxies to methane. If this study concludes that there

are foraminifera proxies for methane, then a dependable way of detecting methane (a hazard for

hydrocarbon exploration) can be established and by dating the sections in the core that show these

foraminifera, ages of paleo(ancient)-methane occurrences (a contributor to past global climate changes)

will also be established.

TIMETABLE: (include work completed to date):

Activity Start Date End Date

Methane Research July 2008 Oct. 2011

Micropaleontological Analysis Nov. 2008 Sept. 2011

Radiocarbon Dating Sept. 2010 Oct. 2010

Environmental Scanning Electron Microscope Imagery Nov. 2010 Dec. 2010

Interpretation of data Oct. 2011 March 2012

Write thesis April 2012 July 2012

Thesis completed July 2012

Have all permissions for access to data or samples been acquired (briefly explain if NO):

Yes

Are there any risks to data acquisition? (if YES, explain risk and mitigation):

No

3

BUDGET: (salaries not included; do not index for inflation)

Item Year 1 Year 2 Year 3 Year 4

Field work N/A N/A N/A N/A

Laboratory expenses N/A N/A N/A N/A

Materials and supplies (other than lab) Photocopying

and printing

Travel N/A N/A N/A N/A

Other costs 14

C Accelerator Mass Spectrometry

Analyses 12 @ $700

Total

In-kind support:

NSERC research grant was awarded to Dr. D. B. Scott of the Centre for Environmental and Marine

Geology and the Department of Earth Sciences, Dalhousie University. The Geological Survey of Canada

in Dartmouth, NS, Canada, has provided the core storage facility, as well as the splitting, photography

and Environmental Scanning Electron Microscope (ESEM) equipment. Dr. D. B. Scott at Dalhousie

University acquired x-ray imagery (to denote internal structures), also the lab space and equipment

necessary for washing and sieving the sediment, as well as the tools for foraminiferal study. The

microscope was provided by John Batt (manager) at the Aquatron research facility in the Department of

Oceanography of Dalhousie University. Dr. D. B. Scott has also provided reference material and a

foraminiferal archive for species identification.

Budget justification:

In order for Elphidium hannai and Ammotium cassis to be used as paleo-indicators of methane seeps,

calcareous material from different layers of the sediment must be radiocarbon (14

C) dated. Six cores will

have 2 mg of CaCO3 foraminifera (from layers bearing the species of interest Elphidium hannai and

Ammotium cassis, or unusual changes in sedimentation) removed and dried for 14

C dating. Since each

core needs radiocarbon dating in at least two different places (to date areas of interest and to constrain

sedimentation rates), at least 12 analyses will be required at a cost of $8400. Radiocarbon ages will

allow the intervals bearing Elphidium hannai and Ammotium cassis to be linked to paleo climate records

and should identify the age of past methane seepages. The prepared samples will be sent to Woods Hole

Oceanographic Institution for analysis.

Materials and supplies (Printer cartridges, paper and photocopying) are needed for completion of the

thesis.

4

Statement of Problem

Within the Beaufort Sea and Mackenzie Delta, Canadian Arctic, there are known sites of natural gas

emission at which methane concentrations are 3-5 times higher than in average seawater (Rochon et al.

2003; Paull et al. 2007). Methane stores significantly more organic carbon than conventional

hydrocarbons (e.g., oil, natural gas, Kvenvolden 1993) and is thus of potentially great economic value,

resulting in a recent expansion in methane exploration. However, due to its flammability, methane

exploration is also more hazardous than conventional hydrocarbon exploration. If methane gas is

detected or suspected during hydrocarbon exploration, procedures can be adapted accordingly to deal

with the additional hazard. If methane is present in seafloor sediments but not detected in the sea water,

exploration personnel may be at risk. Therefore, it is important to identify quick and inexpensive proxies

to methane in seafloor sediments, such as certain fauna of foraminifera, which could be used to identify

methane-rich areas and mitigate the corresponding risk to hydrocarbon exploration programs. Species of

foraminifera have been observed in several methane seep areas throughout the world, but none have

been specifically linked to the presence of methane thus far. Preliminary research on foraminifera in the

Beaufort Sea and Mackenzie Delta has suggested that the foraminifera Elphidiella hannai and

Ammotium cassis are potential proxies for methane (Walsh 2006), leading to the following hypothesis,

“Foraminifera in core and box samples may be used to identify the presence of methane, both present

and past, in seafloor sediments”.

Region of study

Box and piston cores 803 and 650, both on the Beaufort shelf, will be studied for all foraminifera

with an emphasis on Elphidiella hannai and Ammotium cassis. The results of former research; (cores

805A, 805C, 609A, 850BX and PC, 750BX and PC and124PC), from inside known methane regions,

like mud volcanoes and pingo-like feature areas and outside known methane regions, will be referenced

5

for all foraminifera and presented as additional verification for this master’s thesis (locations shown on

Fig. 1).

←

Known pingo-like feature area

NStudy Area

Kopanoar mud volcano

Mackenzie Delta Beaufort sea

Amundsen Gulf

Figure 1. Diagram shows locations of box and piston cores utilized in this study. Insert upper left corner

with arrow showing area of the Beaufort Sea in the Canadian Arctic. Shaded area denotes the pingo-like

feature area (PLF). Box and piston core 803, 250 meters of water (an area of no known methane), along

with box and piston core 650, 245 meters of water (methane seeps present) on the Beaufort shelf have to

be researched for this thesis. The data collected from former research, box cores 805A, 36 meters of

water, 805C, 66 meters of water (Kopanoar mud volcano), 609, 44 meters of water (PLF area on the

Beaufort shelf). Box and piston core 850, 1071 meters of water, box and piston core 750, 1087 meters of

water, (Beaufort Slope) and core 124, 442 meters of water (Amundsen Gulf), all in an area of no known

methane, will be incorporated into this thesis (modified from Google Earth Feb. 2010).

Background

The amount of methane in the Canadian arctic has been estimated at 16 x 1012

m3 (Smith and

Judge 1995). As conventional hydrocarbon resources grow scarce, this methane reservoir has attracted

the attention of the hydrocarbon industry and has been discussed as a future energy resource in the

magazine Geotimes as the future energy resource. An understanding of the spatial and temporal

6

distribution of both past and present methane seeps is pertinent to this exploration. Mud volcanoes in the

Beaufort Sea (e.g., Fig.1) are sites of active methane release, as demonstrated by above average methane

concentrations in their vicinities (Rochon et al., 2003). Water above pingo-like-features (PLFs) on the

Beaufort Sea Shelf as well as cores from eight PLFs showed elevated methane concentrations (Fig. 1)

(Paull et al., 2007). A Remotely Operated Vehicle (ROV) has observed streams of gas bubbles coming

from the crests of the PLFs: the gas samples collected by the ROV were predominantly methane (Paull

et al., 2007). Exploration in such methane-rich areas poses a serious risk which could be mitigated if a

suitable proxy were identified.

Proxies for Methane

Methane is currently identified in seafloor sediments in a number of ways. Geophysical surveys

using Bottom Simulating Reflection (BSR), a distinctive seismic reflection, can indicate the presence of

methane gas hydrates trapped in seafloor sediments (Tréhu et al. 2006). If methane is being actively

released into the water column, it can be directly measured from water samples (e.g., Paull et al. 2007).

Preliminary research on foraminifera in the Mackenzie Delta has shown that the foraminifera Elphidiella

hannai and Ammotium cassis are potential proxies to methane (Walsh 2006). The advantage of a

foraminiferal proxy to methane over BSR is a higher spatial resolution. Furthermore, it can be also used

as a paleomethane indicator in seafloor sediments (making exploration more efficient). Paleomethane

information can be used to understand the role of methane in climate change. The proposed research will

analysis foraminifera from box and piston cores 803 and 650 from the Beaufort Shelf (Fig. 1) and

compare these results with existing data from the other locations, retrieved from both methane-present

and methane-absent seafloor sediments in the Mackenzie Delta, Beaufort Shelf and slope and the

Amundsen Gulf in the Canadian Arctic (Fig.1).

7

Potential Foraminifera Proxies

Previous studies (Panieri 2005, Heinz et al. 2005) have demonstrated associations between

various species of foraminifera and hydrocarbons; however, none have confirmed that foraminifera are

proxies to methane. Benthic foraminifera have been found associated with a hydrocarbon seep in the

Rockall Trough in the north east Atlantic. Although there were no species specifically restricted to the

seepage area, several species appeared to be more resilient to seepage areas (Panieri 2005). Research on

living benthic foraminifera in close proximity to gas hydrates at the Cascadia convergent margin in the

north east Pacific yielded one foraminifera species (Spiroplectammina biformis), that tolerated the seep

environment. However, because Spiroplectammina biformis was also found in non-seep environments, it

could not be used as an indicator for seep environments (Heinz et al. 2005). More recently

Spiroplectammina biformis was identified as a dominant species in methane-present areas of the

Beaufort Sea and Mackenzie Delta; 805A and 805C on the Kopanoar mud volcano and 609, a known

PLFs area (Fig. 1) (Walsh 2006). Two other species, Elphidiella hannai and Ammotium cassis, were also

found in these areas (Walsh 2006). However, unlike Spiroplectammina biformis, they have yet to be

identified in methane-free areas. These data suggest that foraminiferal proxies for methane may be

limited to only a few species. Thus far, Elphidiella hannai and Ammotium cassis are the most

prospective candidates: they are present in known methane areas (e.g. mud volcanoes and PLF’s) and

not observed outside methane areas. These two foraminiferal species are found in other areas of the

world, particularly in polluted areas that contain methane (Scott 1974, Wefer 1976, Scott et al. 1977,

Jones and Ross 1979, Scott et al. 1980; 2008a; 2008b). However, in these areas there are many other

contaminants (e.g., heavy metals and chemicals) that could affect the foraminifera, whereas the

Canadian Arctic is considered to be largely free of such contaminants. By extension, it is hypothesized

that methane exerts a primary control on their spatial distribution in the Beaufort Sea.

8

Objectives

Safe hydrocarbon exploration in Canada’s Arctic requires knowledge about the presence and

distribution of potentially hazardous methane seeps. The foraminifera Elphidiella hannai and Ammotium

cassis have been suggested as proxies for the presence of methane (present and past) in seafloor

sediments (Walsh 2006, Scott et al. 2008a; 2008b and Walsh and Scott 2010). I propose three objectives

for this thesis: (1) compile a detailed map on known methane areas on the Beaufort shelf, Canadian

Arctic using all present available data; (2) document foraminifera populations in core and box samples

inside and outside the known methane areas (e.g. mud volcanoes and PLFs) to analyze for all species of

foraminifera (particularly Elphidiella hannai and Ammotium cassis) in the ocean sediments, thereby

investigating the spatial link between Elphidiella hannai and Ammotium cassis and methane; and (3)

date material from particular layers of the sediment that contain Elphidiella hannai and Ammotium

cassis, by the radiocarbon (14

C) method, to determine when methane was present in the past.

My long term objective is to evaluate whether Elphidiella hannai and Ammotium cassis can be linked

spatially and temporally with known methane seeps on the Beaufort Shelf in the Canadian Arctic,

thereby providing a proxy for both present methane seeps (a hazard for hydrocarbon exploration) and

past methane (a contributor to past global climate changes).

Methods

Collection of material The box and piston cores used in this study were collected during the 2004 Canadian Arctic

Shelf Exchange Study (CASES) (Leg 8) onboard the NGCC Amundsen. Box cores retrieve large,

undisturbed samples from the seafloor, and are subsampled with push cores. Piston cores were sampled

in an adjacent area to the box cores. The push and piston cores were refrigerated at 4˚ C to prevent

sample deterioration and later stored at the Bedford Institute of Oceanography (BIO). Photos, of the

seafloor, were also taken in the area at the time of sampling. Before sampling, the push cores and piston

cores were split and half was photographed. The working half was described by staff of BIO for texture,

9

color and grain size and later wrapped and sent to Dalhousie University. The other half was sealed up

and again refrigerated for archival purposes. The cores were then x-rayed (to illustrate internal

structures) at the dental x-ray unit at Dalhousie University, using high resolution mammography film.

Then, along their length at the Centre for Environmental and Marine Geology, Dalhousie University

Earth Sciences, the core were sampled at 1 cm intervals (push core), or 10 cm intervals (piston core).

Laboratory processing

10cc aliquots will be sampled from each push core and piston core sample and washed through

two sieves (>63µm and >45<63µm sieves). Samples will then be examined in liquid suspension under a

binocular microscope for foraminifera at magnifications of 20-40x. Samples with large numbers of

foraminifera (n = >500) will be split using a 6-way-wet-splitter (Scott and Hermelin 1993). The samples

will be poured into a column of turbulent water and left for at least 1 hour to settle into 6 equal chambers

at the bottom of the column. This method provides a uniform distribution with a 10% margin of error

and reduces the foraminifera abundance to a manageable count size. For sufficient quantitative

examination a minimum of 300 foraminifera should be counted from each sample (Phleger 1960 and

Patterson and Fishbien 1989). For example if the estimated abundance of the foraminifera is N =1000

and after the split, N =166 per chamber, then two chambers must be counted (n=332) to obtain the

desired abundance. The examined material will then be stored in containers with formaldehyde (a long

term preservative) and borax (to prevent dissolution of calcareous foraminifera) for later study.

Data sorting

The foraminiferal species are identified and abundances are noted. The number of species in a

sample has no bearing on the counts required to measure accurately the fractional abundance of a

species (Patterson and Fishbien 1989). However, details on species diversity are required to better

understand the environment in which these foraminifera grew. Abundances of individual foraminiferal

species will be converted into percentages.

10

Assuming that the foraminifera are normally distributed in the samples, the standard error (SE)

will be calculated using Eq.1 (Patterson and Fishbien 1989),

Eq. 1

where Xi is the percentage (as a decimal) of the total abundance of a foraminifera species, and N is the

total population of foraminifera counted.

The resultant standard error (SXi) provides a 95% confidence limit (2σ) for the abundance of each

foraminiferal species in a particular sample.

Environmental Scanning Electron Microscope (ESEM)

Selected foraminifera will be imaged using the ESEM at the Bedford Institute of Oceanography.

Unlike the Scanning Electron Microscope (SEM) which requires a conductive coating on samples, and

has a vacuum in the specimen chamber, the ESEM allows a gaseous environment to occupy the

specimen chamber, and a carbon coating or other treatments are not required. This allows for a more

cost effective means of obtaining high-resolution images (capturing the fine features on foraminifera),

which will contribute to a visual archive of foraminiferal species in the Canadian Arctic.

Radiocarbon dating

For Elphidiella hannai and Ammotium cassis to be linked to the climate change record as paleo-

indicators of methane seeps, calcareous material from different layers of the sediment must be

radiocarbon (14

C) dated. Six cores will have 2 mg of CaCo3 foraminifera (from layers bearing the species

of interest Elphidiella hannai and Ammotium cassis, or unusual changes in sedimentation) removed and

dried for 14

C dating. Since each core requires radiocarbon dating in at least two different places (to date

areas of interest and to constrain sedimentation rates), at least 12 analyses will be required. Radiocarbon

ages will allow the intervals bearing Elphidiella hannai and Ammotium cassis to be linked to paleo

climate records and should assist in identifying the age of periods of past methane seepage. The

11

prepared samples will be sent to Woods Hole Oceanographic Institution for 14

C analysis. Core 850 (Fig.

1) from 1071 m water on the Beaufort Shelf has been dated, showing that the upper 16 cm yielded a

210Pb age of ~100 years, with a confidence limit (2sigma). This same core has been radiocarbon dated

and yielded 14

C ages that I calibrated (utilizing the computer program CALIB 6), for magnetic field

variations and marine reservoir effect (circulation), (Gosse 2010). The 100 cm level reveled a

calibrated age of 8089 + 70 yr BP, the 151 cm level was 12142 + 133 yr BP, and the 202 cm level was

7286 + 68 yr BP, all with a confidence limit (1 sigma) (Schell et al. 2008).

Interpretation

If the cores inside the known methane areas (mud volcanoes and PLF areas in Fig.1) have

foraminifera (at present only the Elphidiella hannai and Ammotium cassis) that are not found in the

other cores outside the known methane areas then it should establish the Elphidiella hannai and

Ammotium cassis as proxies for methane. This being the case and foraminifera are found in deeper

sections of other cores, then those sections can be dated to obtain paleo-methane occurrences.

Anticipated Results and Significance

If Elphidiella hannai and Ammotium cassis are found to be reliable proxies for the presence of

methane, then two benefits will be developed from this thesis; (1) a dependable way of detecting

methane (a hazard for hydrocarbon exploration) can be established; thus mitigating the hazard,

especially if no methane was detected in the water column; and (2) the 14

C ages can be used to constrain

paleo-methane occurrences (a contributor to past global climate changes) and used to substantiate

previous research referring to past climate alterations.

References Gosse, J. 2010. Explanation of radiocarbon dating method for calibration of

14C dates, for magnetic field

variation and marine reservoir effect (circulation). By personal communication.

Heinz, P., Sommer, S., Pfannkuche, O., and Hemleben, C. 2005. Living benthic

foraminifera in sediments influenced by gas hydrates at the Cascadia convergent

margin, NE Pacific. Marine Ecology Progress Series, Vol. 304: pp. 77-89.

Jones, G. D., and Ross,C. A. 1979. Seasonal distribution of foraminifera in Samish Bay,

Washington. Journal of Paleontology 53, pp. 245-257.

12

Kvenvolden, K. A. 1993, Gas hydrates- geological perspective and global change. Reviews of

Geophysics, 31, pp. 173-187.

Panieri, G. 2005. Benthic foraminifera associated with a hydrocarbon seep in the

Rockall Trough (NE Atlantic). Geobios, 38, pp. 247-255.

Patterson, R. T., and Fishbien, E. 1989. Re-Examination of the Statistical Methods Used

to determine the Number of Point Counts Needed for Micropaleontological

Quantitative Research. Journal of Paleontology, Vol. 63, No. 2, pp. 245-248.

Paull, C. K., Ussler III, W., Dallimore, S. R., Blasco, S. M., Lorenson, T. D., Milling, H.,

Medioli, B. E., Nixon, F. M., and McLaughlin, F.A. 2007. Origin of pingo-like- features on the

Beaufort Sea Shelf and their possible relationship to decomposing methane gas hydrates.

Geophysical Research Letters, Vol. 34, LO1603, 5 pages.

Phleger, F. B. 1960. Ecology and Distribution of Recent Foraminifera. John Hopkins

Press, Baltimore, pp. 297.

Rochon, A., Blasco, S. and Travaglini P. 2003, Cruise MR02-K05 on board the RV Mirai: Joint western

Artic Climate Study (JWACS) 2002 Geoscience Program- LEG2 – Tuktoyaktuk (Northwest

Territories) to Dutch Harbor (Alaska) September 20 – October 10, 2003. Geological Survey of

Canada, Open File 1781. pp 15-16.

Schell, T. M. Scott, D. B., Rochon, A. and Blasco, S. M. 2008, Late Quaternary paleoceanography and

paleo-sea ice conditions in the Mackenzie Trough and Canyon, Beaufort Sea: Can. Journal of

Earth Sciences, v. 45, no. 11, pp. 1399-1415.

Scott, D. B. 1974. Recent benthonic foraminifera from Samish and Padilla Bays,

Washington. Northwest Science 48, pp. 1566-1587.

Scott, D. B., Medioli, F. S., and Schafer, C. T. 1977. Temporal changes in foraminiferal

distributions in Miramichi River Estuary, New Brunswick. Canadian Journal of

Earth Sciences 14, pp. 1560-1587.

Scott, D. B., Schafer, C. T., and Medioli, F. S. 1980. Eastern Canadian estuarine

foraminifera: a framework for comparison: Journal of Foraminiferal Research, V. 10, pp. 205-

234.

Scott, D. B., and Hermelin, J. O. R. 1993. A device for precision splitting of

micropaleontological samples in liquid suspension. Journal of paleontology, v. 67,

pp. 151-154.

Scott, D. B., Schell, T., Rochon, A., and Blasco, S. 2008a. Benthic foraminifera in the

surface sediments of the Beaufort Shelf and Slope, Beaufort Sea, Canada:

Applications and Implications for past sea-ice conditions. Journal of Marine

Systems, 74, pp. 840-863.

Scott, D. B., Schell, T., Rochon, A., and Blasco, S. 2008b. Modern benthic foraminifera

in the surface sediments of the Beaufort Shelf, Slope and Mackenzie Trough, Beaufort Sea,

Canada: Taxonomy and summary of surficial distributions. Journal of Foraminiferal Research,

V. 38, pp. 36-57.

Smith, S. L., and Judge, A. S. 1995. Estimates of methane hydrate volumes in the

Beaufort-Mackenzie region, Northwest Territories, in Current Research, 1995-B,

Geological Survey of Canada, 81-88 (also Geoligical Survey of Canada Open File

2746, 1993).

Tréhu, A. M., Ruppel, C., Holland, M., Dickens, G. R., Torres, M. E., Collett, T. S.,

Goldberg, D., Riedel, M., and Schultheiss, P. 2006. Gas Hydrates in Marine

Sediments; lessons From Scientific Ocean Drilling. Oceanography, Vol. 19, No.4,

pp. 124-142.

13

Walsh, F. B. 2006. The Kopanoar mud volcano on the Mackenzie shelf, Beaufort Sea;

Implications for Methane release on Arctic shelves. Honours Thesis, Department of Earth Sciences,

Dalhousie University, Halifax, Nova Scotia, February 2006, 63 pages.

Walsh, F. B., and Scott, D. B. 2010. Foraminifera associated with the Kopanoar mud

Volcano and other “pingo-like” features on the Beaufort Shelf, Arctic Ocean:

Possible paleo-indicators of methane seeps. Paper in progress.

Wefer, G. 1976. Environmental effects on growth rates of benthic foraminifera (shallow

water, Baltic sea). 1st International Symposium on Benthonic Foraminifera of 0Continental

Margins, Part A. Ecology and Biology. Maritime Sediments, Special Publication, 1, pp. 39-50.