Wyatt Ancient Transpacific Voyaging Americas

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Ancient Transpacific Voyaging to the

New World via Pleistocene SouthPacific Islands

Steve Wyatt

15 Whitsetts Fork Ridge Road, Wildwood, Missouri 63038

How humans first arrived in America remains a mystery. Although the Beringian and coastal

options have been discussed in detail, a transpacific route from the Old World to the New

World via the islands of Oceania has been essentially ignored. Of the many factors involved incompleting such a voyage, besides an adequate watercraft, landfall frequency and prevailing

winds and currents were most important. A chain of islands in the landless eastern South

Pacific, with its consequent and possibly favorable modifications of regional sea surface cur-

rents, would have been particularly beneficial to eastbound mariners. Comparing present-day

bathymetry with estimated late Pleistocene glacially induced sea level fluctuations suggests

that latent islands may actually exist, especially when the effects of other geological phe-

nomena are also considered. If exposed during the last glacial maximum (LGM), such a chain

of islands could have provided facilitating layover points for ancient eastbound seafaring

explorers, thus making a transpacific journey more plausible. 2004 Wiley Periodicals, Inc.

INTRODUCTIONThe tripartite issue embracing how and when the first humans reached the New

World and who they were persists as one of the most troublesome archaeological

mysteries of all time. Legitimate proposals for how the first colonists arrived fall

into only three broad categories: (1) trekking overland across the Bering Land Bridge

as per the long-governing Beringian/Clovis-first paradigm; (2) skirting the coastline

on foot, by boat, or a combination of the two along the North Pacific rim from Asia

(Meltzer, 1995; Dixon, 1999), the North Atlantic ice pack from Europe (Hall, 2000),

or the Antarctic ice shelf from Australia (Bonnichsen, 2001); or (3) sailing or pad-

dling directly across the ocean (Terrell, 1998; Dixon, 2000). But despite the limited

number of options and many decades of effort by an army of scientists in a wide array

of disciplines, none of the choices can be unequivocally accepted or rejected.The Beringian hypothesis has long been the standard paradigm by which others

are measured. Today, however, there are probably more reasons for doubting its

veracity than there are for accepting it (Wyatt, 2002). Consequently, first American

studies appear to be in the midst of a paradigm shift. Yet it is unclear to what alter-

native the shift should be made. Existing archaeological evidence fails to correlate

unambiguously with any of the proposed options. All things consideredenviron-

Geoarchaeology: An International Journal, Vol. 19, No. 6, 511529 (2004)

2004 Wiley Periodicals, Inc.

Published online in Wiley Interscience (www.interscience.wiley.com). DOI:10.1002/gea.20008


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VOL. 19, NO. 6512

ment and technology at temporally crucial points being perhaps the most determi-

nativeany or all routes affording the opportunity to exploit new resources likely

would have been used (Wyatt, 2002). But which did the very first Americans use?

Addressed here is perhaps the most controversial of the proposed answers tothat question: transoceanic seafaring, or more specifically, transpacific voyaging

from the Old World to the New via the islands of Oceania. Although judging the fea-

sibility of such an epic journey deep in antiquity requires consideration of myriad pri-

mary and ancillary issues, space limitations permit focusing primarily on only one

in this paper. Even so, the issue detailed may well be the most salient and introduces

a new, potentially far-reaching factor in the debate: the possible existence of now inun-

dated but previously exposed islands in the mostly landless eastern South Pacific

Ocean. A chain of islands in that vast expanse revealed by late Pleistocene glacially-

induced sea level lowering and other geological phenomena could have provided

facilitating stepping-stones for completing the culminating leg of a transpacific migra-

tion to America, just as extant islands aided the exploration of Oceania. Before pur-suing this idea in detail, a brief review of the controversial concept of ancient sea-

faring itself might be useful.

Evidence of Ancient Mariners

Humans almost unquestionably arrived in the New World during the late

Pleistocene. However, considering the perishable nature of the materials likely used,

direct evidence for seafaring or watercraft use of any kind dating to that epoch is

essentially nonexistent anywhere in the world (Wyatt, 2002). Nonetheless, it is con-

ceivable that crude rafts could have been employed very early by coastal dwellers.

Adopted initially as expedient transportation for accessing nearshore resources,they may have later been found adequate as an intermittent and rapid means of tran-

siting from one resource patch to the next.

The concept of rafting over water is certainly not difficult to grasp; a fallen tree

floating offshore demonstrates the necessary principles. And indeed, hominids

apparently have had more than ample opportunity to observe and experiment with

those principles. Large shellfish middens found at Terra Amata in France (ca.

400,000 yr B.P.) and the Klasies River Mouth Caves in Africa (ca. 150,000 yr B.P.),

for example, suggest coastal dwellers have had the opportunity for many thou-

sands of years (Yesner, 1980).

More definitive evidence of ancient seafaring, albeit still circumstantial, is found

in the western South Pacific. Australias more than 60,000 years of settlement history

is most notable. Presumably this island continent had to have been colonized by

mariners, since it was never connected by land bridge to mainland Asia some 90 km

distant (Meltzer, 1995; Morwood et al., 1998; Terrell, 1998; Dixon, 1999; Nemecek,

2000). Similarly, the equally detached Solomon Islands were reached by at least 30,000

years ago (Bellwood, 1997; Terrell, 1998). Most fascinating, though, is testimony from

the small Indonesian island of Flores, where archaeologists found stone tools dating

to some 800,000 years ago (Bellwood, 1997; Morwood et al., 1998). Such a discovery

is exciting on its own merits, but, remarkably, faunal and floral proxy records insinuate


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that even when sea level reached its nadir, this island, too, was stranded from the

mainland. The implication is profound: hominids predating modernHomo sapiens may

have been the first seafarers (Bellwood, 1997; Morwood et al., 1998).

Ostensibly then, mariners have been moving among the islands of the westernSouth Pacific, if not elsewhere, for tens or hundreds of millennia. And that they

spread throughout Oceania in this manner during some period in prehistory is unde-

niable, since the Polynesian, Melanesian, and Micronesian archipelagos were fully

populated before European contact (Conniff, 1993). But a serious chronological

shortcoming exists for Oceanian researchers attempting to project the early mar-

itime exploration and settlement history of the far western archipelagos into

Polynesia: Archaeological records are totally unsupportive (Dixon, 1993; Terrell,

1998; Finney, 1999; Kirch, 2002).

Although Australia and the Solomons apparently were reached by seafarers well

back in the Pleistocene, archaeological evidence suggests that the islands of Polynesia

were settled only within the last 3000years or so (Dixon, 1993; Terrell, 1998; Finney,1999; Kirch, 2002). Furthermore, it appears that the eastern-most Polynesian islands

were reached just within the past 1600 years (Conniff, 1993; Finney, 1999; Kirch,

2002). Such a time differential is quite puzzling and remains to be reconciled. Did the

incipient migration throughout Oceania inexplicably cease for a prolonged period,

or are these findings only a function of the nascent state of Polynesian archaeology

(Terrell, 1998)? If the answer falls in the latter category, it is quite possible that the

oldest sites have simply yet to be found.

But regardless, even if the prehistory of Polynesia is eventually extended into the

late Pleistocene, it does not automatically follow that ancient mariners would have

continued their explorations to America. Rafting between relatively closely spaced

islands, as is typical of much of Oceania, is much different from sailing across thou-sands of kilometers of open ocean as is required to reach the New World. While in

the former situation ones destination may not be visible before embarking, it typi-

cally does appear ahead before land is lost behind (Irwin et al., 1990); in the latter

case, land may not be visible in any direction for weeksa sobering thought for

emigrant families confined in small vessels.

Transoceanic Voyaging

Theories promoting early transoceanic voyaging are not new (Dixon, 1999;

Bonnichsen, 2001). For decades some researchers have cited early seafaring as a pos-

sible explanation for several mysteries surrounding the peopling of the New World,

including how lower North America could have been settled before the glaciers

receded (Meltzer, 1995), why South American sites consistently date older than

North American sites (Dillehay, 1997; Meltzer et al., 1997; Dixon, 1999; Gruhn, 2000),

and why DNA studies continue to tentatively identify genetic affinities among Native

Americans, Polynesians, Australians, and Southeast Asians (Hall, 1996; Powledge

and Rose, 1996). Most recently, a transatlantic voyage was proposed as an expla-

nation for the dearth of Clovis technology antecedents in Beringia (Dorfman, 2000;

Hall, 2000).

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL

ANCIENT TRANSPACIFIC VOYAGING TO THE NEW WORLD

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Undoubtedly, protracted ocean journeys in unsophisticated watercraft were pos-

sible. They have been accomplished on several occasions historically both by acci-

dent and also by design for the specific purpose of proving that high-tech boats and

equipment were not a prerequisite (Finney, 1999, 2000).Kon Tikis ill-founded 1947voyage from Peru to the Tuamotu Islands is one well-known example; the 1976 voy-

age of theHokulea from Maui to Tahiti is another (Finney, 1999). But these suc-

cesses notwithstanding, the most pertinent question still remains unanswered: Was

transoceanic voyaging a feasible method for first initiating and then maintaining a

New World colony in antiquity?

Attempting to answer this question pragmatically involves a slew of cross-disci-

pline considerations. Outside of psychological factors, the success or failure of most

human endeavors is governed by the interaction of elements falling under four broad

classifications: technology, biology, culture, and environment (Wyatt, 2002). Regarding

the first, for this study it was assumed a priori that marine-oriented groups pos-

sessing somewhat more than basic rafting technology existed in the South Pacific dur-ing the late Pleistocene. As outlined already, this supposition is supported by cir-

cumstantial evidence and, to some degree, by experimentation.

An assessment of biological and cultural factors (e.g., the logistics of obtaining food

and fresh water at sea, and the difficulties of an isolated founding population in

maintaining reproductive viability) revealed that they would not have necessarily

had a negative impact on oceanic exploration (Wyatt, 2002). From a feasibility stand-

point, that is, there were no definitive reasons among biological or cultural factors

alone to unequivocally declare impossible or even inconceivable successful settle-

ment enterprises via the ocean. Technology, biology, and culture aside, then, left

only environmental issues to cast the deciding vote (Wyatt, 2002).

Subsumed under environmental elements for this research were varying oceano-graphic factors throughout the South Pacific with the potential for extensively affect-

ing extended ocean voyages. Two somewhat obvious primary factors stood out as

most influential: (1) prevailing sea surface currents and winds; and (2) landfall fre-

quency (Wyatt, 2002).

Moving freely about the sea is dictated mostly by the nautical skill of a boats crew

and on prevailing ocean currents and winds. The contemporary trend of the latter in

the South Pacific between the equator and about 30S latitudethe zone of Trade

Winds in which most of Polynesia liesblows from east to west. Surface currents (the

upper 10% of ocean waters) flow counterclockwise within the confines of the South

Pacific basin in a more or less circular motion (called a gyre) due to the combined

forces of wind, solar heating, the Coriolis effect, and gravity. Like the Trade Winds,

the east to west flowing northern limb of this circulation (the South Equatorial Current)

also falls between the equator and about 30S latitude (Figure 1). Mariners wishing to

travel east in these latitudes, then, must sail both into the wind and against the oceans

surface currents. Of course, eastbound mariners could have dropped farther south

into the zone of west to east blowing Westerlies above 30S latitude and picked up the

easterly flowing South Transverse Current (Figure 1). But temperatures generally

become decidedly colder and the seas much stormier as one approaches Antarctica

(Finney, 1999), thus making an already difficult journey more perilous still.

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Neither ocean currents nor winds are by any means static, however. Due to the

complex nature of the oceanatmosphere system, several seasonal and anomalous

phenomena occur today (e.g., monsoonal periods and El Nio episodes) that tend

to reverse the normal or prevailing trend of winds and currents, especially in the

zone of Trade Winds (Diaz and Markgraf, 1992; OLenic, 1994; Finney, 1999). If

these or similar phenomena also occurred during the late Pleistoceneanother

controversial, yet feasible proposition (Sandweiss et al., 1996, 1999; Wells et al.,

1996; Heusser and Sirocko, 1996; Keefer et al., 1998)they could have provided

savvy seafarers a practical means for exploring to the east (Irwin et al., 1990).

Hence, it cannot be assumed unequivocally, as Heyerdahl did, that eastbound

mariners island-hopping across the Pacific always would have had to buck winds

and currents. Intervals of abnormal west to east blowing winds with coincident

adjustments in current flow may have been normal for long periods in the past

(Irwin et al., 1990; Finney, 1999).

PLEISTOCENE LANDFORMS

Arguably, the single most important element affecting ocean voyaging is the dis-

tance from one landfall to the next. Nearness of ones destination ameliorates all



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Figure 1. Generalized flow pattern of present-day prevailing sea surface currents and winds in the South

Pacific Ocean: (a) Equatorial Counter Current; (b) South Equatorial Current; (c) South Transverse Current;

(d) Antarctic Circumpolar Current (West Wind Drift); (e) Peru Current; and (f) East Australian Current.

The east to west blowing Trade Winds occur in the zone between the equator and about 30S. latitude;

the west to east blowing Westerlies occur between 30and 60S latitude.


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other applicable issues. The countless, relatively closely spaced islands character-

istic of the western two-thirds of the South Pacific, for example, provided conven-

ient steppingstones for more readily colonizing that area (Finney, 1999). Today, how-

ever, once an eastbound sailor reaches Pitcairn Island in the hinterlands of Polynesia,

only six tiny atolls interrupt the ensuing 5000 km or so of sea between it and South

America (see Figure 2). Even with a high level of sailing expertise and favorable

winds, the sheer vastness of such a journey without periodic landfall seems a tremen-

dous undertaking for family groups in simple, probably rather cramped watercraft.

Indeed, lack of layover islands could well have been the most serious deterrent to

consummating an early transpacific voyage to the New World (Wyatt, 2002). But has

this space always been devoid of land?

One of the major geological impacts of late Pleistocene glaciation was a sub-

stantial lowering of eustatic sea level. During the last glacial maximum (LGM) some

20,000 years ago, sea level is thought to have waned by as much as 100150 m or more

due to the enormous quantity of water impounded by the formation of massive con-

tinental ice sheets (Masters and Flemming, 1983; Garrison, 1993; Meltzer, 1995;

Dixon, 1999). The result was an 18% increase in global terrestrial surface area

(Garrison, 1993). Appearance of the Bering Land Bridge and exposure of the con-

tinental shelves are perhaps the most notorious examples of this event; both

American coasts extended many kilometers farther seaward at that time (Meltzer,

1995). But might there be other now submerged landforms that could have been

similarly exposed during Ice Age glaciationlatent islands in the worlds oceans,

for example?

While perhaps vaguely reminiscent of a mythological lost continent of Atlantis, this

notion is not a fantasy. In fact, many vital details of seafloor morphology are only now

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Figure 2. Limits of research area showing existing islands in the region.


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being revealed. For instance, the rather extensive Foundation Seamounts located

southwest of Easter Island were discovered just within the past decade or so. And

importantly here, some of the shallower peaks of that group exhibit features (e.g.,

sandy beaches), suggesting that they may have protruded above the sea in the past(see Paradises Lost inDiscovery, 1995, 16(9), 28). Similarly, rounded cobbles

dredged from the seafloor near the Galapagos Islands appear to have been shaped

in a terrestrial environment sometime in the distant past (Weiner, 1994).

A procession of latent Pleistocene islands punctuating the eastern third of the

South Pacific could represent the propitious terrestrial missing link that might

have allowed island-hopping explorers to continue an eastward migration toward the

New World. A voyage to America under those circumstances would have been little

different from any other in Oceania. Moreover, an island chain surfacing in that

region presumably would have altered regional ocean currents. Possibly so, but the

first step in testing any aspect of a latent Pleistocene island theory would be identi-

fying prospective islands, and therein lies a problem.Merely estimating sea level drop due to Ice Age glaciation and attempting to

reconstruct paleoshorelines by tracing specific isobaths naively ignores concur-

rent geological processes bearing on ocean basin morphology. Besides obvious vol-

umetric relationships between glacial ice and sea level, for example, plate tecton-

ics, climate, and Earths rheological responses to changes in ice- and water-mass

distribution are also critical contributory mechanisms. Rheological responses, espe-

ciallywhich may have operated on the same order of magnitude as apparent sea

level fluctuationsin concert with the complexities of plate tectonics prevent a

simple delineation of antediluvian landmass boundaries (Masters and Flemming,

1983). These factors may have actually conspired at times to cause relative sea lev-

els to be simultaneously lower in some areas and higher in others (Fedje andChristensen, 1999). In short, no single curve can adequately trace the course of sea

level through time because a stable datum from which to measure absolute eusta-

tic oscillations apparently does not exist (Masters and Flemming, 1983).

Nonetheless, despite this inherent, incessant unknown, the fact remains that one

manifestation of various geological phenomena was exposure of certain landforms

during the LGM (e.g., the Bering Land Bridge) that are submerged tens or even hun-

dreds of meters below the sea today. Overall too, paleoshorelines in nonglaciated

regions, like the South Pacific, may well have been largely a consequence of sea

level change alone (Fedje and Christensen, 1999). Thus, with these caveats in mind,

a comparison of available seafloor elevations with a range of sea level differentials

still might provide intriguing fodder for future research.

METHODOLOGY

Many of the thousands of extant islands in the South Pacific are the decaying

remnants of seamounts. These once active volcanoes, born of hot spots beneath

tectonic plates or at convergent plate boundaries, spewed forth sufficient quan-

tities of lava in the past to raise their peaks above the oceans surface, as in Hawaii

today. Similarly, the summits of other seamounts lofty enough to be exposed if sea



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level fell appreciably, as it did periodically during late Pleistocene glaciation,

would also be islands. These were the landforms sought and focused on by this

research.

Pleistocene islands in the South Pacific Ocean would have been most useful to east-bound seafaring explorers if located in the landless void between about 130W lon-

gitude and South America. The search in that rather large swath of ocean began with

a preliminary examination of seafloor topography using the ETOPO-5 bathymetric

database obtained from the National Geophysical Data Center (1988). ETOPO-5 data

are provided on a comparatively large-scale 5-minute-square grid. From these data

it was concluded that the most promising region for detecting latent islands fell

between 20 and 30S latitude and between 130 and 80W longitude along the Sala-

y-Gmez and Nazca Ridges (Figure 2).

A more detailed digital database (referred to here as TOPEX) available online

from the World Data Center for Marine Geology and Geophysics (Smith and

Sandwell, 1997a) was used to acquire seafloor elevations within the establisheddomain. Smith and Sandwell (1997b) used TOPEX data derived from a combina-

tion of depth soundings and high-resolution marine gravity data from the Geosat and

ERS-1 satellites to produce a digital bathymetric map of the seafloor on a 2-minute-

square grid. Although gaps in coverage required interpolation of topography in some

areas to complete the TOPEX elevation matrix, detailed testing found that most

intermediate- and large-scale seafloor structures were identifiable to a reasonable

degree of accuracy (Smith and Sandwell, 1997b). The reader may wish to consult

Smith and Sandwells (1997b) report on this database for design details and further

assessments of its overall accuracy.

A depth value of 500 m below sea level (mbsl) maximum was selected as an indi-

cator of possible latent islands. This value is greater than most estimates of the com-bined effects of sea level drop and other Ice Age-related geological processes.

However, due to uncertainties in those factors, uncertainties in the database itself,

and the relatively wide spacing of the database grid (2 minutes of arc equals approx-

imately 4 km along the Earths surface at 25 latitude), 500 mbsl seemed an equi-

table starting point. Even so, elevations less than 200 mbsl were noted individually

as well. Allowing for some structural elevation loss over time because of subsidence

and erosion (see Discussion in this paper), this value probably most closely aligns

with current theories on glacial sea level fluctuations (Wyatt, 2002). TOPEX-acquired

elevations below these target values were noted and tabulated along with their lat-

itude and longitude coordinates.

RESULTS

Besides those elevations identifying existing islands within the studys scope,

approximately 450 additional sub-500 mbsl elevations were noted in the TOPEX

data. A cursory comparison of their latitude and longitude coordinates revealed

34 fairly distinct elevation groupings, each of which was assumed to represent a

potential island. However, subsequent plotting of the elevations graphically dis-

closed that there were actually 43 individual islands. Twenty-three of the 43 fell

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below 200 mbsl, and 15 of those were less than 100 mbsl. All existing islands were

identified by 1 mbsl readings or as positive elevations. As examples, TOPEX data

identifying Sala-y-Gmez Island are shown in Table I, and data identifying poten-

tial island number 26 are shown in Table II. Table III lists the longitude and lati-

tude coordinates of the minimum depth below current sea level elevation (MIN)

of all 43 islands, and Figure 3 depicts their approximate geographic location. For

a more detailed view, the topography of nine islands based on TOPEX data is

illustrated in Figure 4.

DISCUSSION

This analysis implies that east of about 110W longitude, as many as 43 addi-

tional islands could have been exposed in the eastern South Pacific during

Pleistocene sea level fluctuations (Wyatt, 2002). Although it is tempting to make

such an assertion, crucial unknowns still exist that must be resolved before declar-

ing unequivocally that these potential islands ever actually broke the seas surface.

What was the true measure of Ice Age isostatic adjustments in the South Pacific, if

any? And how low did eustatic sea level really drop at the LGM? Moreover, even if

these islands or others did exist, it is as yet unknown whether they could have pro-



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Table I.An example of TOPEX elevation data in the area of Sala-y-Gmez Island.a

Longitude ( west) Latitude ( south) Elevation (mbsl)

105.5500 26.4564 1.00

105.4834 26.4564 1.00

105.4834 26.4266 262.00

105.4500 26.4564 1.00

105.4500 26.4266 292.00

105.4167 26.4564 109.00

105.4167 26.4863 363.00

105.3833 26.4564 75.00

105.3833 26.4863 101.00

105.3500 26.4564 75.00

105.3500 26.4863 95.00

105.3500 26.4266 326.00

105.3167 26.4564 95.00105.3167 26.4266 123.00

105.3167 26.4863 177.00

105.2834 26.4863 28.00

105.2834 26.4564 96.00

105.2834 26.4266 205.00

105.2834 26.5161 433.00

105.2500 26.4564 390.00

aLongitudes and latitudes are in degrees and decimals of degrees west of the prime meridian and south

of the equator, respectively. Elevations are in meters below sea level (mbsl).


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vided useful steppingstones for human explorers. Were they large enough to pro-

vide safe haven? Were they replete with effectual resources? A tiny, lifeless rock pro-

truding sharply from the ocean would scarcely benefit seafaring emigrants. Sala-y-

Gmez, for example, is reduced to a mere 70 m in length at high tide and is so

constantly swept by salt spray that only four plant species are able to sustain life

on it (Finney, 2000). Finally, while the bathymetric data used here are among the most

precise available to date, their overall accuracy remains questionable. High-tech,

detailed seafloor studies are relatively new and, among other possible deficiencies,

have yet to achieve complete, dependable coverage. Thus, topography in some

areas may be subject to both estimation and speculation (Smith and Sandwell,

1997b). The reality of latent Pleistocene islands, then, must also remain speculative.

Nevertheless, the results are intriguing, especially when an additional variable is

considered. Again, many of the existing islands in the South Pacific are the pro-

truding peaks of ancient volcanoes. Weathering and isostatic adjustments unrelated

to glaciation (e.g., volcanic subsidence) take their toll on these massive structures

over time causing them to gradually sink or erode away once they become inac-

tive. One could argue, in fact, that perhaps many more former islands of this nature

have eroded or subsided to a point at which they can no longer be considered rea-

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VOL. 19, NO. 6520

Table II.An example of TOPEX elevation data in the area of potential Pleistocene island number 26.a

Longitude ( west) Latitude ( south) Elevation (mbsl)

85.5167 25.6179 200.0085.5167 25.6479 246.00

85.5167 25.5878 276.00

85.5167 25.6780 334.00

85.5167 25.7080 490.00

85.4833 25.7080 4.00

85.4833 25.6780 50.00

85.4833 25.6479 96.00

85.4833 25.5878 108.00

85.4833 25.6179 120.00

85.4833 25.7380 182.00

85.4833 25.5577 310.00

85.4500 25.6780 149.0085.4500 25.6479 161.00

85.4500 25.7080 181.00

85.4500 25.6179 185.00

85.4500 25.5878 229.00

85.4500 25.7380 245.00

85.4500 25.5577 257.00

85.4167 25.6780 142.00

85.4167 25.6479 196.00

aThe geographic location of island number 26 is noted in Figures 3 and 4. Longitudes and latitudes are

in degrees and decimals of degrees west of the prime meridian and south of the equator, respectively.

Elevations are in meters below sea level (mbsl).


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Table III. Potential Pleistocene islands in the research area as located by the longitude and latitude

coordinates of the point of minimum depth below current sea level (MIN) of each as discerned from

TOPEX elevation data.a

Island # Longitude ( west) Latitude ( south) Min Depth (mbsl)

1 110.2500 26.9626 415

2 106.5167 26.3669 273

3 106.2167 26.6651 265

4 102.9500 26.1876 4

5 101.7834 26.2474 438

6 99.6833 25.1360 4

7 99.4500 25.1058 486

8 98.9833 25.5267 130

9 98.7834 25.1058 50

10 98.7167 25.1360 96

11 97.4833 25.0454 72

12 97.3834 25.1360 68

13 95.4167 25.8281 372

14 94.9500 25.7080 246

15 94.6167 25.6780 102

16 93.0500 25.5267 4

17 91.1167 25.0454 132

18 90.3500 25.1360 458

19 89.2167 25.5276 22

20 88.6167 24.9580 340

21 88.3834 25.0454 392

22 87.2500 25.5276 10

23 86.6167 25.7080 4

24 86.2167 25.7981 98

25 85.4833 24.7128 31326 85.4833 25.7080 4

27 85.1500 25.3470 374

28 84.7500 23.9839 303

29 84.6500 25.8281 210

30 84.3500 25.9480 4

31 84.2500 25.4976 392

32 83.9500 25.8281 124

33 83.3500 23.4346 364

34 83.3167 25.7680 470

35 82.9500 25.7380 138

36 82.4833 25.6179 163

37 82.3834 25.5577 175

38 82.1833 23.3122 32639 82.0500 25.0454 334

40 81.8500 25.4073 66

41 81.6833 21.4941 4

42 81.2834 22.1439 154

43 80.8834 20.8101 497

aLongitudes and latitudes are in degrees and decimals of degrees west of the prime meridian and south

of the equator, respectively. MIN is in meters below sea level (mbsl). The islands are numbered accord-

ing to their longitudes beginning with the most westerly and stepping east; they are plotted geographi-

cally in Figure 3.


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sonable candidates for exposure by late Pleistocene sea level lowering. The rates of

subsidence and erosion are critical components of that argument and theoretically,subsidence at least, can be approximated indirectly.

Those islands in the South Pacific that are not of volcanic origin are typically

atolls. Atoll-forming coral reefs often form around volcanic islands sinking at

about the same rate as reefs grow. Today, the growth rate of coral in the South

Pacific is estimated to be about 1 cm per year (Garrison, 1993). At that rate, over

a period of 50,000 years, a subsiding island would lose only about 500 m in height

an amount that would still leave its peak within the tolerance of the indicator

value used here (i.e., 500 mbsl). Hence, a much greater rate of subsidence than 1

cm per year would have been necessary to remove volcanic islands from the range

of this inspection.

On the other hand, accounting for a change in elevation due only to subsidence

(i.e., not including erosion or sea level drop) at a rate of 1 cm per year since the LGM

(ca. 20,000 yr B.P.) would result in many of the potential islands identified here pro-

truding not only above the estimated lowered sea level of that period, but also well

above current sea level (1 cm per year 20,000 years 200 m; a review of Table III

finds that the MIN of 23 of the listed islands is less than 200 m). Subsidence in tan-

dem with sea level change seems a more complete explanation for latent Pleistocene

islands than inundation by a rising sea alone.

WYATT

VOL. 19, NO. 6522

Figure 3.Approximate geographic location of existing islands and the 43 potential Pleistocene islands

located by this research. TOPEX elevation data for Sala-y-Gmez Island are listed in Table I and for poten-

tial island number 26 in Table II. Longitude and latitude coordinates and minimum depth below present

sea level elevations (MIN) of each island are listed in Table III. Topography of islands within the rec-

tangle delimited by a double line is shown in Figure 4.


13/19

Because neither the actual rate of subsidence (SUB) nor the magnitude of sea

level drop (SLD) since and at the time of the LGM is known, Table IV provides a

varying comparative relationship between these two factors (again, not including

erosion which may have had significant consequences as well) to demonstrate their

combined hypothetical impact on the potential islands listed in Table III. Figure 5

depicts the elements of Table IV graphically. Using column one of Table IV as an

example, if a seamount has subsided at an average rate of 0.5 cm per year (upper half

of row one) since the LGM, it would be 100 m lower today than at the LGM relative

to current sea level (lower half of row one: 0.5 cm per year 20,000 years 100 m;

SUB in Figure 5). And if SLD at the LGM totaled 50 m relative to current sea level (row

two; SLD in Figure 5), the combination of the two phenomena would have had the

equivalent effect on the seamount-elevation/sea level relationship at the LGM as low-

ering current sea level by 150 m would on that relationship today (row three: 100 m

of SUB 50 m of SLD 150 m). In other words, this particular combination of SUB

and SLD implies that any potential island lying less than 150 mbsl today could have

been exposed at the LGM. This can be demonstrated mathematically by the equation



523

Figure 4. Topography, as determined by TOPEX elevation data, of potential islands delimited by the

double-lined rectangle in Figure 3. For reference, TOPEX data for island number 26 are listed in Table

II. The longitude and latitude coordinates and minimum depth below present sea level (MIN) of all nine

islands illustrated here are listed in Table III.


14/19

WYATT

VOL. 19, NO. 6524

TableIV.

Thecombinedvariableeffectsofsealeveldrop(SLD)a

ndsubsidence(SUB)ontheelevation

softhepotentialPleistoceneislands

locatedby

thisresearch.a

SUB(cm/year)

0.5

0.5

0.5

0.5

1.0

1.0

1.0

1.0

1.5

1.5

1.5

1.5

2.0

2.0

sinceLGM(

m)

100

100

100

100

200

200

200

200

300

300

300

300

400

400

SLDatLGM(

m)

50

100

150

200

50

100

150

200

50

100

150

200

50

100

SUB

SLD(m)

150

200

250

300

250

300

350

400

350

400

450

500

450

500

Numberofislands

20

23

25

27

25

27

32

37

32

37

39

43

39

43

possiblyexposed

aTheelementsofthistable

areshowngraphicallyinFigure5.Ro

woneisdividedintoupperandlowerhalves:Theupperhalfindicatesarangeofpro-

posedratesofSUB(centim

etersperyear)forthe20,0

00yearper

iodsincethelastglacialmaximum(L

GM);thebottomh

alfistheproductoftheupper

half(cm/year

20,0

00years)andrepresentstherelativeheighta

djustmentinmetersofapotentialisla

ndduetoSUBsincetheLGM(

SUBin

Figure5).

Rowtwo,

SLDattheLGM,providesarangeofSLDvaluesinmetersbelowpresentsealevel(SLDinFigure5).Rowthreeisthesum(

inmeters)ofthe

lowerhalfofrowone(SUB

sincetheLGM)androwtwo(SLDa

ttheLGM)andisthenumberfromw

hichapotentialislandsminimumde

pthbelow

currentsealevel(MINfrom

TableIIIandFigure5)issubtractedtodeterminetheislandsrelationshiptosealevelattheLGM(

ELVinFigure5;ifELV

isapositivevalue,

thepote

ntialislandroseabovesealevelattheLGM;ifELVisanegativevalue,

the

islandwasnotexposedattheLGM

).Thebot-

tomr

owindicateshowmanyofthe43potentialislandslistedin

TableIIIcouldhavebeenexposedby

eachcombinationofSUBandSLDastotaledin

rowthree(basedontheirM

IN).SeetheexampleinthetextunderDiscussionformoredetail.


15/19

SUB

SLD

MIN

ELV

where ELV (see Figure 5) represents the actual height or depth of a potential island

above (if ELV is a positive value) or below (if ELV is a negative value) sea level at the

LGM. Perusing Table III reveals that 20 potential islands have a MIN less than 150 m

and, therefore, could have been exposed at the LGM under the prescribed condi-

tions (bottom row in Table IV). To exemplify further, this combination of values

would have resulted in potential island number 10 (from Table III, MIN 96 mbsl)

protruding some 54 m above sea level at the LGM (100 m SUB50 m SLD 96 m MIN

54 m ELV); potential island number 36 conversely (from Table III, MIN 163

mbsl) would not have been exposed because it lies more than 150 m below current

sea level (100 m SUB

50 m SLD

163 m MIN13 m ELV).Besides providing additional landfall for seafarers, another presumed byproduct

of an exposed island chain in the eastern South Pacific would have been modifica-

tion of regional sea surface currentspossibly more favorably for eastward sailing

(Wyatt, 2002). While it is unclear what the actual extent of such an alteration could

have been, Figure 6 illustrates one speculative example and describes how an east-

ward flowing current may have been produced. Simulating the proposed archipel-

ago configuration and surface current flow on a stream table or by computer mod-

eling might provide greater insight into this part of the theory.



525

Figure 5. Graphic representation of elements discussed in Table IV. LGM last glacial maximum; SLD

sea level drop at the LGM in meters below current sea level; SUB subsidence of a potential island

in meters since the LGM; MINminimum depth in meters below current sea level of each potential island

listed in Table III; and ELV the elevation of a potential island in meters above (a positive value) or below

(a negative value) sea level at the LGM as calculated using the equation: SUB SLDMIN ELV.


16/19

CONCLUSIONS

Although presently it cannot be demonstrated conclusively that mariners disem-

barked on the shores of America late in the Pleistocene, it is evident that the sea may

not have presented an insurmountable barrier to their doing so (Wyatt, 2002). Clearly,

the data presented here suggest that a now-submerged island chain in the eastern South

Pacific Ocean could have been exposed during glacially-induced sea level lowering in

combination with a moderate rate of volcanic subsidence and erosion (Wyatt, 2002). It

should be noted, too, that, though the temporal period of the LGM was chosen here to

model the hypothesis, glaciers, and consequently sea level, waxed and waned through-

out the 80,000 or so years of the Wisconsin Glacial Stage of the late Pleistocene (Meltzer,

1995). Hence, the proposed island chain and its attendant conditions and possible ben-

efits to seafarers may have appeared and disappeared correspondingly.

WYATT

VOL. 19, NO. 6526

Figure 6. Speculative illustration of sea surface current modifications resulting from a chain of islands

exposed by Pleistocene sea level lowering as suggested by this research. In this conjectural example, the

northward flowing Peru Current (e) is split by the hypothetical chain; its western arm (g) is deflected west-

ward along the southern periphery of the chain until intercepting an existing southward flowing sub-current (h) in the mid South Pacific gyre. The northern portion of the subcurrent (h) likewise is split by

the hypothetical island chain; its eastern arm (i) is deflected eastward along the northern periphery of the

chain until rejoining the Peru Current (e).


17/19

Whenever it may have emerged, a string of islands could have provided both

facilitating layover points for eastbound seafaring explorers and favorable current

modifications. These factors, combined with seasonably variable and anomalous

wind and current shifts, imply that sailing to America from the Old World duringthe late Pleistocene may have been quite feasible if the technology existed (Wyatt,

2002). In this regard, though there is no direct evidence, the early settlement of

Australia (ca. 60,000 yr B.P.) and other western South Pacific islands suggests

that watercraft of some sort had been discovered well before the LGM. If so, it

seems illogical to conclude that humans living in a maritime environment would

not have continued to improve, refine, and exploit this valuable tool over the

ensuing millennia.

Even so, the lack of late Pleistocene-aged archaeological sites in Polynesia is wor-

risome if this hypothesis is to have any merit. Some argue that this deficiency is sim-

ply a function of the infant state of Polynesian archaeology (Terrell, 1998), while

others are confident that earlier sites are unlikely to be found (Kirch, 2002). Pastarchaeological missteps, however, suggest it would be prudent not to become too

complacent or secure in any particular conviction. If latent islands do exist in the east-

ern third of the South Pacific, as proposed here, others may also exist in the west-

ern two-thirds. Conceivably it could be on those hypothetical islands or on the now

inundated shorelines of existing islands that the most ancient evidence of Polynesian

settlement will eventually be found. Only additional archaeological research can

resolve this issue.

Accordingly, proving any aspect of the subject hypothesis requires accomplishing

at least three important geological and archaeological tasks. First, the potential

islands identified here must be physically located/mapped and their actual depths

below sea level determined by more direct means. Second, if they are found to exist,they must be physically inspected for evidence of a past terrestrial existence. And

third, to verify that humans ever landed on their shores, human artifacts or other

archaeological evidence must be found on them. In addition, to show that the islands

may have also been part of a larger migratory scheme, corroborating archaeological

evidence must be found in adjacent areas both in the Americas and in Oceania. Only

after these criteria have been satisfied, at a minimum, will ancient transpacific voy-

aging to America by island-hopping be anything more than a chimera.

Be that as it may, Figure 7 illustrates a comparison between the hypothesized

island chain suggested here and the approximate location of Paleoindian archaeo-

logical sites located to date along South Americas coast. Perhaps it is only coinci-

dental that there appears to be a large concentration of sites near the eastern terminus

of the proposed island pathway, where it might be expected that seafaring colonists

following that route could have first come ashorebut then again, perhaps it is not.

I am most grateful to Leland Bement, Patricia Gilman, and Douglas Elmore of the University of Oklahoma,

Norman, for their assistance in preparing the original thesis from which this paper was derived. In its pres-

ent form, I am particularly indebted to Leland Bement, Mary Wyatt, the reviewers for Geoarchaeology:

An International Journal, and David Hurt for his expert assistance with the illustrations. Any errors or

misrepresentations, however, are my responsibility alone.



527


18/19

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Figure 7.Approximate location of existing and potential Pleistocene islands in the eastern South Pacific

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Received February 1, 2003Accepted for publication July 7, 2003



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Wyatt Ancient Transpacific Voyaging Americas

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