Late Pleistocene and Holocene Paleoenvironments of the North Pacific Coast

LATE PLEISTOCENE AND HOLOCENE PALEOENVIRONMENTS OF THE NORTH PACIFIC COAST

DANIEL H. MANN* and THOMAS D. HAMILTON? *Alaska Quaternary Center; University of Alaska Museum, 907 Yukon Drive, Fairbanks, AK 99775, U.S.A. I-US. Geological Survey, 4200 University Drive, Anchorage, AK 99508, U.S.A.

Abstract - Unlike the North Atlantic, the North Pacific Ocean probably remained free of sea ice during the last glacial maximum (LGM), 22,000 to 17,000 BP. Following a eustatic low in sea level of ca. -120 m at 19,000 BP, a marine transgression had flooded the Bering and Chukchi shelves by 10,000 BP. Post-glacial sea-level history varied widely in other parts of the North QSR Pacific coastline according to the magnitude and timing of local tectonism and glacio-isostatic rebound. Glaciers covered much of the continental shelf between the Alaska Peninsula and British Columbia during the LGM. Maximum glacier extent during the LGM was out of phase between southern Alaska and southern British Columbia with northern glaciers reaching their outer limits earlier, between 23,000 and 16,000 BP, compared to 15,00&14,000 BP in the south. Glacier retreat was also time-transgressive, with glaciers retreating from the continental shelf of southern Alaska before 16,000 BP but not until 14,000-13,000 BP in southwestern British Columbia. Major climatic transitions occurred in the North Pacific at 24,000-22,000, 15,000-13,000 and 11,OOO-9000 BP. Rapid climate changes occurred within these intervals, including a possible Younger Dryas episode. An interval of climate warmer and drier than today occurred in the early Holocene. Cooler and wetter conditions accompanied widespreadNeoglaciation, beginning in some mountain ranges as early as the middle Holocene, but reaching full development after 3000 BP.

INTRODUCTION calcareous microfossils such as foraminifera contained in deep sea cores. The North Pacific Ocean borders the Asian and North We review here the late Pleistocene (25,000-10,000 American continents along an intricate coastline arcing BP) and Holocene (10,000-O BP) paleoclimate and between Japan and California (Fig. 1). Unlike the paleogeography of the coastal regions bordering the Atlantic Ocean, the North Pacific is virtually barred from North Pacific from northern Japan, through Alaska, and the Arctic Ocean, being connected only through the down the northwest coast of North America through shallow and narrow Bering Strait. Across this strait and British Columbia into Washington state. Emphasis is surrounding parts of the Bering Platform, the fauna and placed on coastal areas of Alaska, the areas we know flora of Asia and North America have mingled. By this best. All ages are expressed as uncalibrated radiocarbon route, humans probably first entered the New World years before present. (Meltzer, 1993). Biotic interchange between continents is The reader is cautioned that the wide geographical one reason why the paleoclimates and paleogeography of separation of data sites introduces assumptions about spa- the North Pacific coastline are of special interest. tial scales into the paleogeographic reconstructions we Another reason is that, like the North Atlantic, the North present. As the distance between data sites increases, so Pacific greatly affects the climate and weather over the does the uncertainty in the reconstructed image of the surrounding landmasses, especially downwind in North paleolandscape. The patch size relevant to an organism, America (e.g. Charles et al., 1994). Past and future whether human or spruce tree, can be far smaller than the climatic changes are intimately tied to oceanographic and resolution of our reconstructions. Scale problems also climatic processes in the Pacific Ocean. derive from the available temporal control since most Although the largest of the three major oceans, the studies rely on radiocarbon chronologies whose resolu- Pacific is poorly understood in terms of its late tions range from hundreds to thousands of years. Rates of Pleistocene history. This lack of information is especially climatic or geographic changes, which may have been notable in the Russian sectors of the coast. critical in determining species survival or extinction, Paleoceanographic research has lagged in the North generally are inadequately known at present. Pacific because the carbonate-compensation depth, the water depth where calcareous microfossils dissolve, is THE NORTHWEST PACIFIC OCEAN above the bottom over large reaches of this deep ocean (Archer and Maier-Reimer, 1994). In other oceans, most The northwest Pacific Ocean stretches from Hokkaido notably in the North Atlantic, our reconstructions of pale- to the Commander Islands and includes the Sea of oceanography and paleotemperature are largely based on Okhotsk and the Sea of Japan (Fig. 1). Today this sector

449 450 Quaternary Science Reviews: Volume 14

FIG. 1. North Pacific region, showing landmasses, continental shelves (light grey), and major ocean currents (arrows). The Tsushima Current flows northward through the Sea of Japan and into the Pacific Ocean through Tsugaru Strait south of Hokkaido.

of the Pacific, lying beneath the shifting border between summer, and allowing surface waters to warm in summer cool Siberian air masses and warmer maritime air, is the (L.E. Heusser and Morley, 1985). Boreal-forest vegeta- birthplace of many of the cyclonic storms that travel to tion dominated by Picea, Abies, Tsuga and Pinus spread the North American coastline along the prevailing west- downslope and southward to cover most of the Japanese erlies (Wendland and Bryson, 1981; Terada and archipelago (Tsukada, 1983, 1985). Mean annual temper- Hanzawa, 1984). Hence the paleoclimatology of this atures in the northern archipelago may have been as region is of key interest in understanding the climatic his- much as 8-9OC below present values and mean annual tory of other sectors of the North Pacific coastline. precipitation may have been one-third lower during the Paleoclimatic events before 15,000 BP are poorly LGM (Tsukada, 1986; Kerschner, 1987; Morley and understood in the northwest Pacific. During the last Heusser, 1989). Temperatures and precipitations predict- glacial maximum (LGM), the Polar Front was displaced ed by global circulation modeling for the LGM in this perhaps 5” of latitude further south (CLIMAP, 198 1; region have similar signs and magnitudes as estimates Morley and Heusser, 1989). Steepening of temperature based on the field data (Winkler and Wang, 1993). gradients along the coast of northeastern Asia probably In northeastern Siberia during the LGM, subpolar caused an intensification of wind speeds at the 500 mb desert and montane tundra (Grichuk, 1984) covered the level and a more zonal orientation of the subpolar jet lowlands between mountain massifs supporting isolated stream (Kutzbach et al., 1993). The Japanese archipelago ice caps and valley glaciers (Glushkova, 1994). Open was much cooler and drier than today as maritime air forests of spruce and birch grew on the southern tip of masses were displaced south and eastwards and replaced Kamchatka and in the Amur River region (Fig. 2). At the by the Siberian High for much of the year (Morley and same time, the upper Kolyma River valley supported Heusser, 1989; Winkler and Wang, 1993). With lowered Arremisia-Gramineae tundra growing on poorly-devel- sea level, Japan was connected to the Asian mainland. oped, frost-disturbed soils (Lozhkin et al., 1993). Seasonal temperature contrasts were greater than today, The first indications of climatic amelioration in the probably because low-salinity surface waters stabilized upper Kolyma valley occurred ca. 12,500-12,000 BP the water column, preventing deep convection in with a transition from herb tundra to Betula shrub-tundra D.H. Mann and T.D. Hamilton: Paleotinvironments of the North Pacific Coast 451

i/ 60°N- Sea

‘Kamchatka

fl\-1’00 m bathymetric

FIG. 2. Vegetation zones of northeast Asia during the last glacial maximum (LGM) ca. 22,000-18,000 BP as inferred by Grichuk (1984). Heavy lines depict modem coastline; black areas represent glaciers.

(Lozhkin et al., 1993). Larix duhurica forests became A possible late Glacial cold episode analogous to the established ca. 11,600 BP indicating summer tempera- Younger Dryas in the North Atlantic is currently a topic tures of at least 12°C. The last major element of the mod- of active research in the northwest Pacific. Chinzei et al. em vegetation to arrive, the stone pine (Pinus pumilu), (1987) and Kallel et al. (1988) interpret isotope and reached the upper Kolyma River about 9000 BP. The foraminifera data to indicate a re-advance of subpoiar autecology of this conifer implies an amelioration in win- water along the Japanese coast between 11,000 and ter conditions that may have included deeper snow packs 10,000 BP, correlative with the re-advance of the polar and warmer temperatures (Lozhkin et al., 1993). Pollen front in the North Atlantic during the Younger Dryas. A accumulation rates suggest that altitudinal treeline may Younger Dryas signal may be present in the Chinese have risen in the Kolyma area between 9000 and 7000 loess record (An et al., 1993) and possibly in pollen BP (Lozhkin et al., 1993) accompanying a northward records near Beijing (Liu, 1988). However, Keigwin and advance in latitudinal treeline on the Kolyma plain (Kind, Gorbarenko (1992) ascribe possible Younger Dryas 1967). analogs near northern Japan to an episode of freshwater Deep-sea sediment records indicate that full-glacial discharge from the Sea of Japan. conditions persisted in the northwest Pacific Ocean until During the early Holocene, sea-surface temperatures ca. 14,000-13,000 BP, when the first of three abrupt were 1-4”C lower than today (L.E. Heusser and Morley, changes in water temperature and/or salinity occurred 1990). The final warming step occurred in the deep (Fig. 3). A major influx of ice-rafted debris between waters of the northwest Pacific between 8000 and 6000 13,000 and 12,000 BP signaled rapid retreat of calving BP (Fig. 3). Temperate forest communities reached their glaciers somewhere in the North Pacific basin (Keigwin maximum abundance around the Sea of Okhotsk during et al., 1992). After about 3000 years of stable or slowly- the middle Holocene, whereas the spread of spruce forest declining temperature, water temperature warmed rapidly after 4000 BP probably accompanied regional cooling around 10,500 BP (Keigwin et al., 1992). (Morley and Heusser, 1991). Northern expansion in the 452 Quaternary Science Reviews: Volume 14

range of Cryptomeria japonica, a tree requiring moisture delta “0 do0 from heavy winter snowfall, also occurred after 4000 BP, suggesting cooler, wetter winters after that time (Tsukada, 1986). On Sakhalin Island, shrub birch, larch and Pinus h OTcl-41;.;r:t were replaced by spruce after 10,000 BP Ii pumila (Khotinskiy, 1984). Deciduous tree species reached their greatest Holocene abundance between 9500 and 8500 BP suggesting that summers were warmer than today. Historical records of climate in northern China document declining temperatures corresponding to the onset of Neoglaciation after 5000 BP (Zhang, 1991) or, alternate- ly, after 3000-4000 BP (Liu, 1988; Winkler and Wang, 1993). Low temperatures in these Chinese records between 1200 and 1900 A.D. (Zhang, 1991) record the occurrence of Little Ice Age cooling in northeast Asia (Fig. 4). Marginal seas (the Okhotsk, Japan and Bering Seas) (Fig. 1) comprise much of the coastline of the northwest and northern Pacific. The paleoenvironmental histories of these seas were, in some cases, quite different from events in the open Pacific. The late Pleistocene history of the Japan Sea illustrates the potential complexity of climatic and oceanographic changes in the marginal seas 15) -- caused by interactions between changing sea level and cooler warmer shallow straits. The Japan Sea today experiences a PIG. 3. Oxygen isotope values of foraminifera from a deep-sea continuous inflow of warm water from the Tsushima core taken southwest of Kamchatka (Keigwin et al., 1992). Current, a western branch of the Kuroshio Current. Shaded areas mark intervals of rapid warming at 14,000-13,000 However, during the LGM, falling sea level cut off the BP, 10,500-10,000 BP, and again ca. 7000 BP. The term ‘ka Tsushima Current, causing sea surface temperatures to BP’ signifies millennia before 1950 A.D. drop and salinity to decline under the influence of increased freshwater input from the diverted Amur River (Oba et al., 1991; Keigwin and Gorbarenko, 1992). Primary productivity fell in the Japan Sea because the cold, low-salinity surface waters prevented deep convection Sometime between 20,000 and 10,000 BP, the cold Oyashio Current entered the northern Japan Sea restoring

3000 2000 1000 0 500 1000 1500 1750 1800 1900 1950 B.CjA.D. Calendar Years PIG. 4. Historical records of late-Holocene temperature fluctuations in China (redrawn from Zhang, 1991). This curve depicts temperature changes during the Neoglacial Interval (ca. 3000-O B.C.), including the Little Ice Age (ca. 1200 to 1900 A.D.). D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 453 deep ventilation and productivity (Oba et al., 1991). The After a low stand of about -120 m, reached ca. Oyashio Current was excluded and flickering inflow of 18,000 BP (Fig. 5), eustatic sea level rose rapidly and the Tsushima Current began after 10,000 BP. Modern reached near-modern levels by 4000 BP (Mason and oceanographic conditions were not established until after Jordan, 1993). Rising sea level progressively flooded 8000 BP (Oba et al., 1991). Sea level was l-l.5 m higher the Bering Strait separating Chukotka and Alaska than present in the Sea of Japan during a mid-Holocene between 11,000 and 8500 BP (Elias et al., 1992). Only warm interval dated by thermophilous bivalves between after 8500 BP could the modern circulation patterns 5000 and 7000 BP (Jones et al., 1994). between the Bering, Chukchi and Beaufort Seas have become established. In contrast to the relative tectonic BERING SEA REGION stability of the Bering Platform, the Aleutian Arc is seismically active and the relative sea-level history is in During the last ice age, global sea level fell to ca. part controlled by tectonism (Hamilton and Thorson, -120 to -130 m (Fairbanks, 1989; Bard et al., 1990), 1986; Taber et cd., 1989). Hence it is unwise to apply exposing large portions of the continental shelf beneath Fairbank’s (1989) eustatic sea-level curve to this por- the shallow Bering and Chukchi Seas. Exposure of the tion of the Bering Sea. continental shelf had two major effects in the Bering Sea During the LGM, the southeastern Bering Sea and Sea region: it made the climates on Chukotka and western of Okhotsk had ice cover for perhaps 9 months of the Alaska more continental and it unified terrestrial habitats year (Sancetta, 1983; Sancetta et al., 1985). During the on both sides of the Bering Strait. At a hemispheric scale, summer, ice floes were advected across the southern changes in the amount of relatively fresh Pacific water Bering Sea and Sea of Okhotsk into the northwest Pacific flowing northwards through Bering Strait into the Arctic Ocean, creating a surface layer of cold, low-salinity Ocean possibly influenced North Atlantic thermohaline water that prevented vertical mixing and lowered primary circulation and climate (Shaffer and Bendtsen, 1994). productivity (Sancetta, 1983). According to Sancetta’s

Sea Level 20

Shpanberg Straft

40 ong / Herald I E 3nadyr Straits <. rc ; 6o

0 2 4 6 8 10 12 14 16 18 AGE (ka B.P.) FIG. 5. The bathymetry of the Bering Strait region (panel a) (redrawn from Porter, 1988) and global (eustatic) sea level approximated by the Barbados sea-level data of Fairbanks (1989) (panel b). In panel b, horizontal lines are the sill altitudes of straits within the Bering and Chukchi Seas: L = Long Strait, H = Herald Strait, A = Anadyr Strait, B = Bering Strait, and S = Shpanberg Strait. The Chukchi Sea lies north of the Bering Strait and the Bering Sea lies to the south. In panel a, vertical arrows point to the probable date these straits were flooded in postglacial times. The dark circle and arrowhead represent the age of terrestrial peats presently at a depth of -50 m in the Chukchi Sea (Elias et al., 1992). Time scale is in radiocarbon years BP See Bard et al. (1990) for the slightly revised, Barbados sea-level chronology in U-Th years BP 454 Quaternary Science Reviews: Volume 14 model, cooling of North Pacific waters may have intensi- ranges of beavers, tree birch, and cattails (McCulloch fied the Polar Front and shifted it southward. This caused and Hopkins, 1966; Hopkins, 1982) and thickening of increased storminess in the mid-latitude North Pacific, the active layer above permafrost (McCulloch and decreasing evaporation from the higher latitude Pacific, Hopkins, 1966). Extra-limital Populus wood in northern and consequently decreasing precipitation in Beringia Alaska dates between 11,300 and 8400 BP (Hamilton during the LGM. Ocean circulation in the southern and Fulton, in press, Table 4b). Unfortunately the exist- Bering Sea was radically different during the LGM. ing age estimates bracketing the Populus peak in pollen Lowered sea levels and expanded glaciers over the diagrams are from bulk radiocarbon dates of dubious Aleutians and the Alaska Peninsula prevented the Alaska accuracy from lake sediments often low in organic con- Coastal Current from entering the southeastern Bering tent. Beetle remains dated to 11,300-l 1,000 BP from Sea as it does today (Fig. 1) through passes in the eastern terrestrial peats on the Chukchi shelf suggest that Aleutians. While the shelf was subaerial, the Yukon and summer climate was appreciably warmer than today Kuskokwim Rivers entered the southern Bering Sea (Elias et al., 1992). rather than having most of their water shunted northward The Bering and Chukchi coastlines did not experience through the Bering Strait as they do today (Sancetta et the subsequent episode of increased summer warmth ca. al., 1985). The resulting fresh water lid would have 8500-5500 BP that caused treeline in Keewatin, on the intensified sea-ice formation. The Pleistocene to MacKenzie Delta (Ritchie and Hare, 1971), and on the Holocene transition was accompanied by decreasing sea Kolyma plain (Kind, 1967) to advance hundreds of kilo- ice and re-entry of the Alaska Coastal Current into the meters. Ritchie and Hare (197 1) suggest that the nortb- southeastern Bering Sea (Sancetta and Robinson, 1983). ward shift of the average position of the Polar Front in Plankton productivity increased with the disappearance western Alaska during this interval is consistent with of the freshwater lid around 10,000 BP (Sancetta et al., increased onshore flow of cool, cloudy, maritime air from 1985). the Bering and Chukchi Seas. Lozhkin ef al. (1993) sug- Full-glacial, terrestrial climate was drier and colder gest the flooding of the Bering and Chukchi platforms in than today, reflecting in part the increased continentality the early Holocene caused a transition from continental caused by the vastly increased land area of the exposed to maritime climate. Certainly the timing of the interval Bering shelf. Dry, windy climate caused widespread of maximum post-glacial warmth seems to have been deposition of loess, sand dunes, and sand sheets through- time-transgressive in the Beringia region. out Beringia (Hopkins, 1982; Lea and Waythomas, 1990; Forests along the eastern coast of the Bering and Hamilton and Ashley, 1993). In modem loess-dominated Chukchi Seas developed their modem distribution and ecosystems on the Arctic Coastal Plain of northern species composition by ca. 6000-5000 BP (Anderson. Alaska, continual disturbance by loess and eolian-sand 1985, 1988). On St. Paul Island, no vegetation change is deposition maintains the vegetation in an early succes- evident in the pollen record since 9500 BP. However, on sional state with a significant component of grass species St. George Island, slight changes in the pollen record dur- (Walker and Everett, 1991). From pollen records. ing the middle to late Holocene may record a shift to Colinvaux (1986) and Matthews (1982) advocate a topo- cooler Neoglacial climate in the southern Bering Sea graphically- and regionally-complex mosaic of shrub- region (Ager, 1982). and herb-tundra vegetation across Beringia during the Existing spit complexes on the coast of northwestern LGM, whereas Guthrie (1990), reinterpreting much of Alaska originated as sea level stabilized after 4400 BP the same data, advocates a widespread, steppe-tundra (Mason and Jordan, 1993; Plug and Mann, 1994). biome with no clear modem analogs. Disconformities and truncations in many of these com- Pollen records from western Alaska indicate that plexes may be the results of erosion during intervals of major climatic changes occurred 14,000- 13,000 and increased summer storminess between 3300-l 700 BP 11 ,OOO-9000 BP in the Bering-Chukchi Sea region and 1200-900 BP (Mason and Jordan, 1993 ). These (Ager, 1982, 1983; Ager and Brubaker, 1985; Anderson authors correlate increased storminess in the Bering and and Brubaker, 1993). Pollen diagrams from the Yukon Chukchi Seas with northward shifts in Pacific storm delta, Norton Sound, and Kotzebue Sound areas docu- tracks. Mason and Jordan’s (1993) intervals of increased ment a shift from predominately herbaceous tundra vege- storminess show weak correspondence to intervals of tation to mesic, shrub-birch tundra ca. 14,00&13,000 BP dune activity and cirque-glacier expansion in northern (Lozhkin et al., 1993). Alaska (Galloway and Carter, 1993). Maximum post-glacial warmth occurred in notthwest- We have no information on changes in the extent and em Alaska before 8000 BP and possibly before 10,000 seasonal persistence of sea ice during the Holocene in the BP (Brubaker et al., 1983; Lozhkin et al.. 1993; Edwards Bering and Chukchi Seas. Both these phenomena vary and Barker, 1994) perhaps in response to a solar-radiation according to regional climatic patterns, including strength maximum centered on 10,000 BP (Ritchie et al., 1983; and persistence of the Siberian High and strength and ori- Barnosky et al., 1987; Bartlein et al., 1991). This warm entation of the Aleutian Low (Niebauer et al., 1989). interval saw the establishment of Populus woodland in Polynyas, areas of open water or thin ice found at pre- areas beyond the present range of this species (Brubaker dictable, recurrent locations within the regional cover of et al., 1983; Ager and Brubaker, 1985; Anderson, 1988; sea ice, presently occur in the lee of islands and capes in Anderson et al., 1990), as well as expansions in the the Bering and Chukchi Seas. Polynya geography is D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 455 closely related to settlement patterns& the eastern biota ,was blocked by glacier barriers even when the Canadian High Arctic (Schlederman, 1980), and prob- Bering platform was dry land. However, preliminary ably affected settlement in the Bering Sea region as well. mapping of moraines in Chukotka suggest that the exten- Polynya locations depend on wind intensity and direction sive mountain-glacier complex hypothesized by Hughes (Stringer and Grove, 1991). and Hughes (1994) did not exist during the LGM Three alternative reconstructions exist for glacier (Glushkova, 1994; Heiser and Roush, 1994). extent during the LGM in Beringia. In the most widely General circulation models suggest that the Aleutian accepted view, glaciers were limited to high mountains Low intensified during the LGM and shifted southwards on both sides of the northern Bering Sea and Chukchi from its present position (Manabe and Hahn, 1977; Sea during the LGM (Velichko er al., 1984; PCwt, 1975; Kutzbach et al., 1993). Modeling also suggests that the Hamilton, 1994). On the Seward Peninsula, snowlines elevated mass of the Cordilleran and Laurentide Ice fell to 300-600 m above present sea level (Kaufman and Sheets caused a split in the polar jet stream during the Hopkins, 1986) but most glaciers terminated within last ice age, with a northern branch streaming northeast- mountain valleys. Along the southern margin of the ward over the Bering Strait region (Kutzbach, 1987; Bering Sea, local ice caps inundated the Aleutian Islands, Bamosky et al., 1987; Bartlein et al., 1991; Kutzbach et coalescing within island groups and possibly forming a al., 1993). However, actual field evidence for this split jet floating ice shelf in the southern Bering Sea (Thorson is lacking or contradictory. For instances, the orientation and Hamilton, 1986). of full-glacial dune fields in Alaska indicates that the pre- In an alternate model, Gros’vald and Vozovik (1984) dominant, dune-forming winds blew out of the northeast and Gros’vald (1988) advocate a marine-based ice sheet (Hopkins, 1982; Lea and Waythomas, 1990). Also, snow- covering the southern Bering Shelf and flowing south- line altitudes in glaciated areas in southeastern Beringia ward through the Aleutian Islands. However, no field during the LGM were lower but of similar regional pat- data exist to support this hypothesis, and evidence against tern as today, implying that LGM storm tracks were like the marine ice-sheet model is presented by Hopkins et al. those of today (Hamilton and Thorson, 1983; Detterman, (1992). The third model is a modified marine ice-sheet 1986; Mann and Peteet, 1994). hypothesis described by Hughes and Hughes (1994). It states that a continuous mountain-glacier complex SOUTHWEST ALASKA rimmed the Bering Sea coast northeast of Kamchatka during the LGM, merging with a marine ice sheet in the Southwest Alaska (Fig. 6) extends from the mouth of Beaufort and Chukchi Seas. Both the Hughes and the Cook Inlet to Unimak Pass in the inner Aleutian Islands, Gros’vald models predict that exchange of terrestrial and includes the mountainous Kodiak archipelago in the

- \ il60"E u

North Pacific Ocean sland .-I .”

@C% Trinity IslaAds

,. -. I) . . _*.._* * . . . - . . . edge “’ ...... *. . * . . . . . * ($I+ 16O’W ___i_ -- FIG. 6. Southwestern Alaska. Large lakes presently dammed behind moraines left by late Pleistocene glaciation are shown in black. 456 Quaternary Science Reviews: Volume 14

Gulf of Alaska, the Alaska Peninsula, and the low-lying faces available as refugia would have been steep, alpine shores of Bristol Bay. Southwest Alaska was the extreme ridges with a total surface area of ca. 900 km2 (Mann southeastern comer of Beringia when sea level was low- and Peteet, 1994). To the east, the ice covering the ered to -120 m (Fairbanks, 1989) during the LGM. Alaska Peninsula merged with other parts of the Fluctuating glaciers in southwest Alaska acted as an ice Cordilleran glacier complex. To the west, along the inner gate that opened and shut between the unglaciated low- Aleutian Islands, it probably continued as a narrow belt lands of western and central Beringia and the Gulf of of small interconnected, island ice caps (Thorson and Alaska coastline. Hamilton, 1986). During the LGM, the Alaska Peninsula was largely The last glacial maximum was reached in southwest covered by an elongate glacier complex fed by snow Alaska after 23,000 BP, when ice advancing toward the catchment areas along the crest and southern flank of the outer continental shelf dammed valleys on western Aleutian Range as well as in the mountains of Kodiak Kodiak Island and impounded proglacial lakes (Mann Island (Fig. 7). Ice was more extensive on the Gulf of and Peteet, 1994). Glaciers had retreated from the Low Alaska side of the peninsula than on the Bristol Bay side. Cape area of southwestern Kodiak Island before 14,700 The Gulf of Alaska was the major source of precipitation BP (Mann and Peteet, 1994). The Kodiak Island ice cap then, as it is today. Snowlines rose from ca. 350 m on expanded to a late-glacial maximum at 13,400 BP, Kodiak Island to more than 900 m on the north side of retreated an unknown distance, and then expanded to a the Alaska Peninsula, representing a lowering of the slightly less extensive position at 11,900 BP (Mann and snowline about 300-600 m below present-day values Peteet, unpublished d&z). By 10,000 BP the Kodiak ice (Detterman, 1986; Mann and Peteet, 1994). cap had undergone final collapse and the inner fjords of Reconstruction of ice thickness using trimline and the island were ice free (Mann and Peteet, unpublished moraine altitudes onshore, bathymetric charts on the data). In the Katmai area on the Alaska Peninsula, glaci- continental shelf, and theoretical calculations of basal- ers re-advanced sometime between 12,000 and 10,000 shear stress indicate that the glacier complex covering BP and perhaps again between 9800 and 9500 BP the Alaska Peninsula and Kodiak Island flowed to the (Pinney and Beget, 1991). outer edge of the continental shelf where it calved ice- A drier than modem climate is suggested by pollen bergs into the open Pacific (Fig. 7). Low ice saddles analysis of peat deposited near sea level on western connected the mountains of Kodiak Island to the main- Kodiak Island between 15,000 and 10,000 BP (Peteet and land and bridged the entrance of lower Cook Inlet. Small Mann, unpublished data). Vegetation was probably mesic ice-free areas persisted through the last glacial maximum tundra dominated by mosses and ericad shrubs, with on southwest Kodiak Island (Karlstrom, 1969; Mann and much open ground in near-coastal environments where Peteet, 1994). However, the ice-free areas on Kodiak sand-sheet sediments accumulated. Widespread peat Island were largely filled by proglacial lakes and the sur- accumulation began on the Kodiak archipelago after

I ice-surface 5 Ice-tree areas El contours Cmx 100) y~;,~xocler

160 “w _.~ -.__. I __. ~_

FIG. 7. Maximum extent of glaciers in southwest Alaska during the last glacial maximum, 22,000--18,ooO BP. From Mann and Peteet (1994). D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 457

13,000 BP Macrofossil and pollen evidence suggests an in the, North Pacific are closely linked to sea surface 800 year interval of cooler, drier climate between ca. temperatures (Namias, 1970; Emery and Hamilton, 10,800 and 10,000 BP, perhaps correlative with the 1985). High coastal mountains bordering the Gulf of Younger Dryas episode (Peteet and Mann, 1994). Pollen Alaska pose major barriers to these storms, which dump and macrofossils record the sudden establishment of their precipitation and release large amounts of latent modem plant communities on western Kodiak Island at heat. The combined result of the ocean and atmospheric 10,000 BP circulation systems is presently a wet, maritime climate On the southeastern slopes of the Ahklun Mountains which is comparatively mild given the region’s latitude. north of Bristol Bay (Fig. 6), mesic herb tundra domi- Temperatures and precipitation tend to increase from nated the landscape ca. 13,000-9800 BP (Hu et al., west to east across the northern Gulf of Alaska (Wilson 1995). A climate reversal perhaps correlative with the and Overland, 1987). Younger Dryas episode occurred between 10,800 and Some aspects of the present climatic regime were 9800 BP Alder arrived and became important in the veg- probably also present during the LGM. For instance, etation by ca. 7400 BP. White spruce arrived in the sea-surface temperature reconstructions indicate that sea region 5500-4000 BP and reached its modem distribu- ice was never present in the Gulf of Alaska (CLIMAP, tion by ca. 2000 BP (Ager, 1983; Hu et al., 1995). 1981). However, near-surface waters were of lower Peat sections from the Shumagin Islands and the salinity during LGM summers than today, retarding Alaska Peninsula west of Kodiak Island record a major convection and lowering sea-surface temperatures vegetation change at 10,000 BP from grass/ (Zahn e? al., 1991). Sea-surface temperatures at the Artemisialwillow to birch/Empetrumlgrass-dominated LGM in the Gulf of Alaska were probably 34°C lower vegetation (C.J. Heusser, 1983a). Shrub alder (Alms than at present (CLIMAP, 1981). Global circulation sinuata) reached the Shumagin Islands around 5000 BP modeling hypothesizes that during the LGM both but persisted in relatively low numbers until the last January and July temperatures over the northern Gulf of several centuries when it increased markedly (C.J. Alaska were 2-4”C cooler than today (Kutzbach et al., Heusser, 1983a). 1993). Although sea ice probably was absent, icebergs were common, especially during periods of glacier THE GULF OF ALASKA retreat (Keigwin et al., 1992). Reconstructions of sea- surface temperatures based on microfossils suggest that The Yakataga Formation, which is exposed along the the North Pacific Polar Front shifted southward by only coastline of the eastern Gulf of Alaska, documents the 5” of latitude or less between the present and 18,000 BP onset of tidewater glaciation during latest Miocene time (Thompson, 198 1), however, ocean circulation intensi- that accompanied the uplift of the coastal mountains fied and thermal gradients steepened along the front (Eyles et al., 1991; Lagoe et al., 1993). Initial tidewater (Moore et al., 1980; Sancetta, 1983). Although agreeing glaciation occurred about 6.7-5.0 Ma, and a major in suggesting an intensification of the Aleutian Low increase in the intensity of glaciation began between 2.48 during the LGM, global circulation models hypothesize and 3.5 Ma following a mid-Pliocene warm interval a southerly shift in the Polar Front and its associated (Lagoe et al., 1993). Bottom sediments in the Gulf of storm tracks by 10-20” latitude during the LGM Alaska record numerous episodes of subsequent iceberg (Manabe and Hahn, 1977; Kutzbach, 1987; Kutzbach et dispersal from calving glaciers (von Huene et al., 1976; al., 1993). The precipitation now nourishing glaciers von Huene, 1989; Carlson, 1989). Large glacial troughs and raising temperatures in the eastern Gulf of Alaska that extend to the outer continental shelf offshore of would have been diverted further south into the western major fjord systems indicate extensive glaciations whose United States at that time (Bamosky et al., 1987). The ages are poorly constrained (Carlson, 1989; Carlson er GCM models further suggest that an anti-cyclone over al., 1982; Molnia, 1986). the North American ice sheets created a southerly flow, The present climate of this large, sea-ice free sector drawing relatively warm, maritime air masses north- of the Pacific Ocean stretching between Kodiak Island ward into the eastern Gulf of Alaska (Manabe and and the Queen Charlotte Islands is dominated by inter- Broccoli. 1985; Kutzbach, 1987; Kutzbach et al., 1993). actions between ocean-current systems (Fig. 1) and the Hopefully, further studies of marine microfossils will prevailing westerly winds. Oceanographic and atmos- resolve the discrepancy between computer simulations pheric events here are critical to climates in downwind and field data. North America. The northward-flowing Alaska Current/ Oceanographic and atmospheric processes in the Gulf Alaska Coastal Current (Reed and Schumacher, 1987) of Alaska control climate along its shoreline yet the exact transports large amounts of heat into the coastal mechanisms and actual chain of prehistoric events remain environments of southern and southeastern Alaska. obscure. For instance, dendrochronologies from coastal Current systems in the Gulf of Alaska are sensitive to sites between western Washington and Kamchatka record small changes in sea surface temperature and frontal a cooling of the North Pacific in the mid- to late 1800s positions (Reed and Schumacher, 1987; Royer, 1989; AD (Jacoby et al., 1994) that probably caused glacier Ebbesmeyer and Ingraham, 1992). Heat is also trans- advances throughout southern and southeast Alaska ported into the region by cyclonic storms traveling (Wiles and Calkin, 1994). Throughout the Holocene, northeastward in the prevailing Westerlies. Storm tracks changes in the seaward influence of continental high 458 Quaternary Scienc:e Reviews: Volume 14 pressure over northern British Columbia and the southern placements are separated by gradual interseismic move- Yukon may have modulated the frequency of storms ments of the crust, usually in the direction opposite to the moving onshore in southeastern Alaska (M. M. Miller coseismic displacement (Plafker, 1969). Great earth- and Anderson, 1974). The frequency of these blocking quakes tend to be spaced ca. 1000 years apart (Plafker et highs (Wilson and Overland, 1987) over the eastern Gulf al., 1992; Combellick, 1993). of Alaska in winter could have exerted an important con- During the LGM, glaciers virtually covered the Kenai trol over the timing of Neoglaciation in southeastern Peninsula and filled Cook Inlet (Karlstrom, 1964; Alaska. Hamilton, 1994; Reger and Pinney, in press). The only ice-free areas not covered by proglacial lakes were small- COASTAL, SOUTH-CENTRAL ALASKA upland areas northwest of the Kenai Mountains. The largest ice bodies in Cook Inlet flowed eastward across We define coastal, south-central Alaska as the region the inlet from sources in the Alaska and Aleutian Ranges between Cook Inlet and Yakutat Bay (Fig. 8). This is a (Schmoll and Yehle, 1986). They extended onto the high-wave-energy coast closely backed by the Kenai, Kenai Lowland, where they locally merged with ice from Chugach, and St. Elias Mountains, which include some of the Kenai Mountains and blocked drainages to impound a the highest near-coastal peaks in the world. This region chain of lakes (Reger and Pinney, in press). Although no contains the most extensive present-day glaciers in Alaska, dates on this event are available from Cook Inlet, they including two vast Piedmont ice bodies - Bering Glacier probably are close to the bracketing ages of ca. 25,000 and Malaspina Glacier. Protected shorelines are rare com- and 17,000 BP on the last glacial maximum (McKinley pared to southwest Alaska, the Bering Sea, or the Seas of Park I Stade) of the central Alaska Range (Ten Brink and Japan and Okhotsk. The exception is Prince William Waythomas, 1985). Sound, a glacially-scoured fjordland of numerous rocky The glacier complex in Cook Inlet began to break up islands protected from the open Pacific by Montague and before 16,500-16,000 BP, when marine waters invaded Hinchinbrook Islands. From Montague Island westward, the lower inlet (Reger and Pinney, in press). Relative sea the coastline is primarily rocky and eastward it is mostly level was at least 25 m above its present position at that composed of sand and gravel originating from the Copper time, owing to glacial-isostatic depression of at least River and near-coastal, Piedmont glaciers. 112 m. During a subsequent stillstand or re-advance prior The ongoing tectonism associated with subduction of to 14,900 BP, glaciers from the north and east coalesced the Pacific plate along the eastern end of the Aleutian in uppermost Cook Inlet while marine waters invaded to Trench (von Huene, 1989; Page et al., 1991) is an impor- present-day Anchorage (Reger and Pinney, in press). tant factor in relative sea-level history in south-central During a final glacial re-advance into Cook Inlet, which Alaska. Along much of the western portion of this coast- occurred sometime between 14,000 and 11.700 BP line, the land is presently subsiding while farther east it is (Schmoll et al., 1972), glaciers extended into upper Knik rising (Plafker, 1969, 1990). Coseismic uplift or down- and Tumagain Arms but did not coalesce (Schmoll and warp ranges up to several meters, and these abrupt dis- Yehle, 1986; Reger and Pinney, in press). Glacier retreat

FIG. 8. Coastal. south-central Alaska, showing existing glaciers. D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 459 from Knik Arm was nearly complete by 11,400 BP and response to lower summer temperatures (Wiles and from Tumagain Arm by 10,700 BP (Regei and Pinney, ih Catkin, 1994). These differential responses may be press). Spruce forest invaded the region by about 8400 common to glaciers throughout the gulf coast and com- BP (Ager and Sims, 1984). plicate the interpretation of glacier behavior in terms of The extent of glaciers onto the continental shelf off of climate. south-central Alaska during the LGM is a topic of contin- The oldest continuous pollen record in coastal south- ued speculation (Pew& 1975; Coulter er al., 1965) LGM central Alaska comes from Hidden Lake on the Kenai ice probably flowed to the outer edge of the continental Peninsula and dates to 14,000 BP (Ager, 1983; Ager and shelf in the Gulf of Alaska given the probable extent of Sims, 1984; Anderson and Brubaker, 1993). Initial herb ice in the Kodiak region (Mann and Peteet, 1994), the tundra with a few shrubs of willow and ericads was abundant evidence for high-altitude glacial erosion on replaced by shrub tundra dominated by birch in the inter- Knight and Montague Islands in Prince William Sound val 13,700-10,300 BP Between 11,000 and 8000 BP, the (Mann, unpublished observations), and submarine fea- vegetation changed to a mixture of shrub tundra and tures suggestive of glacial origin on the continental shelf deciduous forest communities dominated by poplar and (von Huene, 1966; Carlson et al., 1982; Carlson, 1989; willow. Alder invaded the area between 9000 and 8000 Molnia, 1986; Sirkin and Tuthill, 1987). BP (Ager, 1983). This ice mass had broken up and retreated out of the Sedge, willow, and ferns were the earliest plants colo- inner fjords of Prince William Sound by about 14,000 BP nizing the inner fjords of Prince William Sound ca. (Sirkin and Tuthill, 1987; Reger, 1991). Some coastal 10,000 BP (C.J. Heusser, 1983b, 1985). In Port Wells, glaciers may have persisted until nearly 10,000 BP (Ager, alder become widespread after 8300 BP Sitka spruce and 1992). The interval lO,ooo-6ooo BP was probably slight- mountain hemlock arrived only ca. 3000 BP (C.J. ly warmer and drier than today in coastal south-central Heusser, 1983b), although they may have entered the Alaska with glaciers persisting in retracted positions near outer islands of Prince William Sound much earlier. Only or upvalley from their present positions (Calkin, 1988; after 2000 BP did Sitka spruce, mountain hemlock, and Wiles and Calkin, 1990). western hemlock assume an important role in the vegeta- Three major intervals of Neoglaciation in the Southern tion of the inner fjords of Prince William Sound (C.J. Kenai Mountains are documented by Wiles and Calkin Heusser, 1985). (1990, 1993, 1994). The earliest advance occurred about At Icy Cape, in the eastern Gulf of Alaska near 3700-3600 BP A subsequent interval of expansion was Mount St. Elias, peat accumulation began around 10,800 underway by about 500 A.D. and ended around 900 A.D. BP under a vegetation of coastal tundra dominated by The latest and best-documented phase of glacier expan- sedges and crowberry (Empetrum nigrum) (C.J. Heusser, sion occurred between ca. 1200 A.D. and 1890 A.D. dur- 1960). Tundra was replaced by alder and ferns ca. ing the Little Ice Age, when equilibrium-line altitudes 10,000 BP (Peteet, 1986). A Hypsithermal Interval, (roughly equivalent to late summer snowlines) were warmer and drier than today, occurred at Icy Cape depressed loo-150 m below present levels. The most between ca. 9000 and 7500 BP (Peteet, 1986). Sitka recent maximum position of glaciers in the Kenai fjords spruce arrived ca. 7600 BP, mountain hemlock ca. 5000 was reached in the late 1800s A.D. and was followed by BP, and western hemlock ca. 3800 BP (Peteet, 1986). general retreat. These arrival times probably were affected by immigra- Near-synchronous glacial advances during the last two tion lags caused by long-distance dispersal from full- millennia in Icy Bay were reported by Porter (1989), who glacial refugia in western Washington (C.J. Heusser, dated the outermost recognizable moraine complex 1985; Peteet. 1991). between 400-850 A.D. Little Ice Age advances probably began in the 13th century in upper parts of Icy Bay, and SOUTHEAST ALASKA they culminated in the early 1800s A.D. Glacier retreat began in Icy Bay by the 1880s A.D. (Porter, 1989). Southeast Alaska is the ‘panhandle’ region of Alaska Pollen records support the glacial data in showing wetter that extends from Yakutat Bay southward to Dixon and cooler climates associated with the Neoglacial Entrance (Fig. 9). Most of this region consists of the Interval (Heusser, 1985). Alexander Archipelago: mountainous, glacially-scoured Interpretation of Holocene dynamics of alpine glaci- islands crisscrossed by deep fjords originating in the ers on the Gulf of Alaska coastline is complicated by Coast Mountains. The extreme northwest part of the two factors. Calving glaciers are subject to non-climati- Alaskan panhandle is a narrow-coastal foreland running cally controlled instabilities causing advances and along the seaward flank of the Fait-weather Range and retreats not affecting landbased glaciers (Mann, 1986a; including the fjord systems of Lituya Bay and Yakutat Meier and Post, 1987). Second, glaciers seem to have Bay. differed in their responses to climate change depending The Quatemary history of southeast Alaska is poorly on their geographical position. Glaciers on the seaward understood. During the LGM, coalescing ice caps flowed flank of the Kenai Mountains seem to have advanced in westward out of the Coast Mountains and the island mas- response to the increased winter precipitation occurring sifs of the Alexander Archipelago onto the continental during relatively warm intervals over the last 2000 shelf of the Gulf of Alaska. Large outlet glaciers occu- years while glaciers on the western flank advanced in pied what are today the major fjord systems in southeast 460 Quaternary Science Reviews: Volume 14

Holocene marine transgression culminating ca. 8500 BP. A transgression of similar duration and magnitude occurred on the Queen Charlotte Islands, possibly in response to a migrating forebulge created when mantle material that had been displaced westward during maximum ice loading diffused back towards the mainland after deglaciation (Clague, 1975, 1983; Clague et al., 1982). In contrast, sea level around Prince of Wales Island reached near-modem levels before 9000 BP and no subsequent transgression was detected. Mobley’s (1988) findings point out the complexity of sea-level changes over short distances in southeast Alaska, which are probably due to interactions between glacial history, crustal response to ice loading, and tectonism. Tectonic factors are certainly a major factor in sea-level dynamics in this region today (Hudson et al., 1982; von Huene, 1989). Herb-tundra vegetation colonized the lowlands of southeast Alaska following glacier retreat and the subsequent marine transgression. Lodgepole pine and alder reached the northern archipelago by 12,500 BP (Engstrom et al., 1990; Cwynar, 1990; Anderson and Brubaker, 1993). A climate reversal, perhaps correlative with the Younger Dryas episode in northwestern Europe. ;Q”**d occurred between 10,800 and 9800 BP when lodgepole Charlottei Islands I pine parkland was replaced by shrub- and herb-dominated tundra (Engstrom et al., 1990). After 10,000 BP, FIG. 9. Southeastern Alaska, the region between Yakutat Bay Sitka spruce, western hemlock, and mountain hemlock and Dixon Entrance and seaward of the Coast Mountains. arrived in that order. Tree arrival times were time-transgressive along the coast because of the time it took them Alaska (Goldthwait, 1987). Reconstruction of glacier to spread northward from southern refugia (Peteet, 1986, extent on the continental shelf around Lituya Bay and 1991; Cwynar, 1990). Cross Sound, based on ice flow models and onshore map- Western red cedar, an important tree for northwest ping of glacial features (Derksen, 1976; Mann, 1986b), coast cultures in historic times, expanded its range into suggests that glaciers reached only the inner continental the south part of southeast Alaska only during the middle shelf in areas lying between major fjord entrances during Holocene (Hebda and Mathewes, 1984). The northward the LGM. Though undocumented to date, it is possible that migration of tree taxa was only complete in the northern areas lying between Piedmont ice lobes on the continental part of southeast Alaska by ca. 4000 BP (Peteet. 1986; shelf remained ice-free and subaerial during the LGM. C.J. Heusser, 1985; Cwynar, 1990). Despite the presence Deglaciation probably was rapid in southeast Alaska, of small ice-free areas along the outer coast of Glacier with iceberg calving causing glacier termini to retreat to Bay and probably on the outer continental shelf (Worley, near their modem positions by about 13,500 BP, even in 1980; Mann, 1986b), the consistent trend of trees arriving some of the inner fjords like Glacier Bay (McKenzie and later at more northwesterly sites across southeast and Goldthwait, 1971; Goldthwait, 1987). Rapid ice retreat south-central Alaska suggests that no tree species sur- was followed by a marine transgression reaching .50- vived the LGM in local refugia. Evidently climate was 230 m above present sea level on the isostatically- too extreme during the LGM for the survival of arboreal depressed coast (R.D. Miller, 1972, 1973a,b, 1975). At vegetation. the south end of the Chilkat Peninsula, three raised ter- Opinions vary about the timing of an interval of races indicate a complex relative sea-level history warmer and/or drier climate in southeast Alaska during between 13,000 and 10,ooO BP (Ackerman et ul., 1979). the early Holocene. Initial reconstructions from pollen Based on the rates of isostatic rebound in southwest diagrams suggested a time of maximum warmth and British Columbia (Clague, 1989; Easterbrook, 1992), minimum precipitation between 5000 and 2000 BP modem sea level was probably reached by 9000 BP in (Heusser, 1960). However, temperature and precipita- most areas of southeast Alaska not affected by tectonic tion trends deciphered by transfer functions using pollen uplift or subsidence. However, such generalized predic- data suggest the Hypsithermal Interval occurred tions may be premature. For instance, Mobley (1988) between 9000 and 6000 BP with a precipitation mini- found major differences over a distance of less than mum occurring at 8000 BP (Heusser et al., 1985). 100 km in the sea-level histories of Heceta and Prince of Wetter and cooler climate definitely is registered by Wales Islands in the southern Alexander Archipelago. pollen records after ca. 3300 BP (C.J. Heusser, 1985; The more seaward Heceta Island experienced an early C.J. Heusser et al., 1985). D.H. Mann and T.D. Hamilton: Paleoenvironmentsof the North Pacific Coast 461

Neoglaciation began on the western slopes of the fjordlands and associated strand flats is bordered to the Fairweather Mountains ca. 6000 BP and resulted in three west by the Pacific Ocean and to the east by the Coast distinct glacial maxima 6000-5000 BP, 3500-2500 BP Mountains and Cascade Range (Fig. 10). These near- and 1800-1900 A.D. (Mann and Ugolini, 1985; Mann, coastal mountains support numerous glaciers today and 1986b). However, glaciers in Glacier Bay were still during the Pleistocene comprised the heartland of the retracted behind their present-day positions at 6000 BP Cordilleran Ice Sheet and its ancillary fringe of alpine ice (McKenzie and Goldthwait, 1971; Goodwin, 1988). caps and glaciers. Around 5000 BP, glaciers in the West Arm of Glacier The Cordilleran Ice Sheet advanced twice in south- Bay began an advance which, though interrupted by still- west British Columbia during the interval 25,000- stands and minor retreats, was to carry the terminus to the 10,000 BP (Clague, 1991; Ryder et al., 1991; mouth of the bay by ca. 1700 A.D. (Goldthwait, 1966). Easterbrook, 1992) (Fig. 11). The first glacier maximum Glaciers in Muir Inlet had joined this advance by 2700 was reached during the Evans Creek stade (Coquitlam BP (Goodwin, 1988; Goldthwait, 1966). After a brief stade in British Columbia) between ca. 22,000 and retreat ca. 2000 BP, the coalescing glaciers continued to 19,000 BP probably in response to a short-lived (< 1000 advance towards the mouth of the bay until ca. 900 BP when another stillstand or minor retreat occurred (Goodwin, 1988). Sometime after 850 BP a final advance occurred to the mouth of Glacier Bay. After ca. 1750 A.D., the glacier that filled Glacier Bay underwent a rapid retreat from its maximum Little Ice Age position (Goldthwait, 1966; Field, 1975; Clague and Evans, 1993). This retreat perhaps was initiated by climatic amelioration but was certainly exaggerated by the rapid calving of icebergs in the deep waters of this fjord. In Glacier Bay, biota has rapidly colonized the land exposed by retreating glaciers over the last 250 years. The rates and patterns of this recolonization, especially by vegetation and by salmonid fish, may be partly analogous to prehistoric events in older deglaciated areas. Salmonids do not colonize cold and turbid streams heading in glaciers (Milner and Bailey, 1989). Even after the disappearance of glacial ice, rapid downcutting in recently-deglaciated stream systems discourage large salmon runs (Benda er al., 1992). However, channels stabilize and suspended sediment load decline following deglaciation as streams approach equilibrium profiles and large woody debris accu- mulates. As streams become clear and water temperatures rise, salmon rapidly colonize them. In Glacier Bay, Oncorrhynchus nerka (sockeye salmon) and 0. kisutch (coho salmon) established runs in Nunatak Creek less than 15 years after the watershed was deglaciated (Milner and Bailey, 1989). However, the rapid colonization of Glacier Bay streams following the Little Ice Age may not be analagous to salmon recolonization following the LGM. Glacier Bay after the Little Ice Age was a small area of newly-exposed terrain within a large region of stream systems already containing salmon. Following the rapid retreat of LGM glaciers in coastal areas, large numbers of streams were created in a region devoid of established salmon runs. We can only speculate that salmon populations took longer, perhaps centuries rather than decades, to colonize late Pleistocene streams as their spawning populations increased explosively in formerly ice-covered areas.

COASTAL BRITISH COLUMBIA AND WASHINGTON

Puget Sound in Washington marks the southern limit of a landscape unit that reaches its northern limit in the Alexander Archipelago. This region of glacially-scoured FIG 0. Western British Columbia and western Washington. 462 Quaternary Science Reviews: Volume 14

existing icefields I I \

FIG. 11. The changing extent of the Cordilleran Ice Sheet over southwest British Columbia and Washington after 25.000 BP (after Clague, 1981). Alpine glaciers in the Cascade Range and in the Olympic Mountains are not shown.

years) but severe drop in regional snowline to as low as Moody interstade (Hicock and Armstrong, 1985) when 1000 m above sea level (Booth, 1986, 1987). This fall in ice retreated into the inner fjords and mountain valleys of snow line probably accompanied a temperature depres- the Coast Mountains (Clague et al., 1988). sion > 6°C (Porter et al., 1983). Ice failed to reach the Retreat of ice was rapid after 14,000 BP and involved Pacific coast on western Vancouver Island and left much iceberg calving of glaciers into the deep water of the iso- of Puget Sound ice-free during the Evans Creek stade statically depressed Puget Sound and Straits of Georgia (Ryder and Clague, 1989). The second, more extensive (Ryder and Clague, 1989; Easterbrook, 1992). The subse- advance, culminated ca. 14,500-14,000 BP in southern quent Sumas re-advance between 11,500 and 11,000 BP Puget Sound during the Vashon stade (Thorson. 1989; was followed by the final collapse of the southwestern Ryder and Clague, 1989; Easterbrook. 1992). During the portion of the Cordilleran Ice Sheet before 10,000 BP. Vashon stade, snowline depression was less than during Fjords bordering the Straits of Georgia were ice-free by the Evans Creek stade but lasted longer, probably for sev- 11,000 BP (Ryder and Clague, 1989). eral thousand years (Booth, 1987, 199 I ). Lowered Farther north, outlet glaciers draining the Coast Vashon stade snowlines probably were associated with Mountains between Vancouver Island and the Queen increased precipitation (Mathewes, 199 1) accompanying Charlotte Islands terminated in calving margins along the increased storminess along a southward-displaced polar outer edge of the continental shelf during the LGM jet stream (Bamosky et al., 1987). Glaciers reached the (Blaise et al., 1990; Josenhans, 1992). Cordilleran ice open Pacific during the Vashon stade along the west coast advanced onto the eastern and northern shores of the of Vancouver Island (Anderson, 1968; Alley and Queen Charlotte Islands between 23,000 and 21,000 BP Chatwin, 1979) and buried the inner fjords and straits (Clague et al., 1982; Blaise et al., 1990). Mainland- under thick ice (Ryder and Clague, 1989). The Evans derived glaciers retreated from the Queen Charlottes Creek and Vashon advances were separated by the Port before 15,000 BP following a maximum advance that D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 463

127”W 125’W 51”N

47-N

0 2000 4000 6000 8000 1 Calibrated Radiocarbon Years B.P. FIG. 12. Holocene sea-level histories for three areas of coastal, southwestern British Columbia. Datum is mean tide level. Redrawn from Hutchinson (1992).

culminated before 16,000-15,500 BP (Clague et al., The west coasts of Vancouver Island and northwest 1982; Warner et al., 1982; Blaise et al., 1990). By 13,000 Washington experienced a distinctive sea-level history BP, ice had retreated to the inner fjords of the mainland strongly influenced by tectonism (Hutchinson, 1992). (Ryder and Clague, 1989). Post-glacial marine limits were relatively low, 20-25 m Postglacial sea-level changes along the British along the outer coast of Vancouver Island (Clague, 1989; Columbia and Washington coasts varied in a complex Friele and Hutchinson, 1993). In response to isostatic fashion according to ice-loading history, eustatic sea-level rebound, sea level fell in the early Holocene to a low- history, and local tectonism (Hutchinson, 1992). In areas stand varying from +5 to -10 m relative to present sea bordering the eastern shores of the Strait of Georgia that level. After isostatic recovery from ice loading was com- were deeply buried by Late Wisconsin ice, sea level fell pleted lO,OOO-8000BP, eustatic sea level rose, causing a between the time of deglaciation and the early Holocene as marine transgression that culminated in the middle to late isostatic rebound uplifted land formerly covered by hun- Holocene, 2-5 m above present sea level. As eustatic sea dreds of meters of ice and outstripped the rise in eustatic level equilibrated in the middle Holocene, tectonic uplift sea level. Isostatic rebound following ice unloading was became the dominant control over sea level causing a fall the major determinant of post-glacial sea level in these in relative sea level over the last 4000 years (Friele and areas. Post-glacial marine limits were reached before Hutchinson, 1993). 11,000 BP at altitudes as high as 200 m above present sea More is known about Pleistocene sea-level history level in fjords along the inner coastline of British from the Queen Charlotte region than from any other sec- Columbia (Clague, 1981). Sea level stabilized between tor of the coast. Sea level was below that of the present 11,000 and 6ooo BP (Clague, 1989; Hutchinson, 1992) as day from at least 15,000 to ca. 10,000 BP (Clague, 1989). isostatic rebound slowed, matching the rate of eustatic rise. Around 10,600 BP, sea level stood near -100 m and In areas close to the margin of the Cordilleran Ice exposed large areas of the floor of Queen Charlotte Sheet, post-glacial marine limits also lie tens to hundreds Sound (Lutemauer et al., 1989). These areas may have of meters above modem sea level (Clague et al., 1982; remained subaerial until ca. 10,000 BP. The Holocene Thorson, 1989). However, isostatic rebound ended earlier sea-level history of the Queen Charlotte Islands resem- than in the inner fjords allowing a marine transgression bles that of western Vancouver Island. Modem sea level of 5-10 m between ca. 8000 and 3000 BP caused by was probably reached by 9000 BP after a rapid transgres- eustatic sea-level rise (Eronen et al., 1987; Hutchinson, sion (Josenhans, 1992). Sea level then rose more gradual- 1992; Dragovich et al., 1994). Slowing of eustatic sea- ly in a transgression culminating between 8500 and 7500 level rise after ca. 5000 BP allowed expression of tecton- BP with levels as much as 15 m above the modem, per- ic effects on relative sea level in western Washington haps in response to the eastward flow of a forebulge in (Bucknam et al., 1992; Hutchinson, 1992). Areas south the underlying mantle (Claglie, 1983). Falling sea level of the Cordilleran Ice Sheet in Washington and Oregon on the Queen Charlotte Islands since ca. 7500 BP may be that were beyond the effects of ice loading experienced due to tectonic uplift (Clague, 1989). Certainly the active monotonic submergence overprinted by tectonic move- tectonic setting of the British Columbia coast makes large ments (Atwater, 1992) as eustatic sea level rose follow- vertical-crustal movements likely (von Huene, 1989; ing a late Pleistocene lowstand (Hutchinson, 1992). Rogers and Homer, 199 1). 464 Quaternary Science Reviews: Volume 14

Pollen evidence suggests that climate in southern than today (Pellatt and Mathewes, 1994). The warmer British Columbia was colder and drier than today and drier climates of this Hypsithetmal interval gradually between 25,000 and 16,000 BP, although several major were replaced by cooler and wetter conditions that climatic oscillations occurred within this interval. During accompanied the expansion of western hemlock and the Evans Creek stade (ca. 22,000-19,000 BP), mean western red cedar in the forests of southwestern British annual temperature was 5-8°C lower and annual precipi- Columbia (Mathewes, 1985). tation 700-1000 mm less than today (Hicock et al., 1982; Neoglaciation began in the Canadian Cordillera as Whitlock, 1992; Thompson et al., 1993). At this time, early as 5000 BP (Luckman et al., 1993). Widespread subalpine parkland and possibly alpine plant communi- glacier expansion was underway by 3500 BP (Ryder, ties covered the lowlands of eastern Vancouver Island 1989; Luckman et al., 1993) to maxima that were possi- (Clague and MacDonald, 1989). Pollen, beetle remains, bly time transgressive, occurring between ca. 3300 and and plant macrofossils suggest a relatively warm and 1900 BP (Denton and Karlen, 1977; Ryder and moist interval between 19,000 and 18,000 BP during the Thompson, 1986; Osborn and Luckman, 1986, 1988; Port Moody interstade (Hicock et al., 1982; Mathewes, Clague and Matthews, 1992). Maximum Holocene 1991). At this time, surprisingly diverse vegetation exis- extent of many glaciers occurred during the Little Ice ted in the coastal areas of southwestern British Columbia Age. Little Ice Age advances in the Coast Mountains that later were overwhelmed by Vashon stade ice. Near and Cascade Range began ca. 1350 A.D. and ended ca. the city of Vancouver, subalpine fir-Engelmann spruce 1900 A.D. with the onset of widespread glacier retreat forest and parkland grew under a cold-humid continental (Burbank, 1981; Heikkinen, 1984; Ryder, 1989). climate (Hicock et al., 1983; Clague and MacDonald, 1989). SYNTHESIS Climate became warmer and wetter in coastal British Columbia after 16,000 BP (Nelson and Coope, 1982; In rough synchrony with the worldwide LGM, the Mathewes, 1991), although pollen data suggest it was North Pacific region saw a maximum extent of glaciers still cooler and drier than today as late as 10,000 BP between 22,000 and ca. 17,000 radiocarbon years BP. (Mathewes, 1985). At ca. 15,000 BP, non-arboreal herb- Due to regional patterns of precipitation and topogra- and shrub-tundra covered the lowlands of the Queen phy, the northeastern (North American) margin of the Charlotte Islands (Warner et al., 1982). At 14,000 BP, Pacific Ocean was more heavily glaciated than the ice-free areas on northwest Vancouver Island supported northwestern (Asian) margin. Subsequent deglaciation heaths, grass-sedge-herb meadows, and spatially-restric- was rapid in coastal areas where glaciers that were ted conifer vegetation (Hebda, 1992). Significant warm- grounded below rising sea levels collapsed rapidly ing occurred between 12,000 and 10,000 BP when through iceberg calving. The continental shelf of south- conifers rapidly invaded deglaciated areas (Sugita and em Alaska near Kodiak Island (Mann and Peteet, 1994) Tsukada, 1982). Southwestern coastal British Columbia and lower Cook Inlet (Reger and Pinney, in press) were was recolonized by plants ca. 13,500 BP with trees arriv- deglaciated before ca. 14,700 and 16,000 BP respective- ing ca. 13,000 BP (Clague and MacDonald, 1989). ly. The timing of deglaciation was similar on the Queen Lodgepole pine and poplar probably were the first tree Charlotte Islands where ice originating on mainland colonists on the Queen Charlotte Islands, arriving about British Columbia had withdrawn before 15,000 BP 12,000 BP, followed by spruce immigration ca. 11,200 (Blaise et al., 1990). By inference, the intervening BP (Warner et al., 1982). Summer temperatures in shal- coastline of south-central and southeast Alaska may low ponds on the Olympic Peninsula may have reached also have been deglaciated by this date, at least on the modern values at 12,000 BP (Petersen et al., 1983). continental shelf. Inner fjords in places like Prince Several pollen diagrams suggest a reversion to cold con- William Sound and the easternmost parts of the ditions between 11,500 and 10,000 BP at the time of the Alexander Archipelago may have retained glaciers at Younger Dryas episode in northwest Europe (Mathewes least slightly more extensive than today until ca. 10,000 et al., 1993). BP. Rapid warming occurred at ca. 10,000 BP in south- The LGM was accompanied by a ca. 120 m drop in western British Colombia. Forests dominated by Douglas global (eustatic) sea level which exposed large portions fir and alder were established during an interval that was of the unglaciated continental shelves in the Bering- drier and as warm or warmer during the summer than Chukchi Seas and northeast Asia. Following degiacia- today and lasted until ca. 6000 BP (L.E. Heusser, 1983; tion, eustatic sea level rose until ca. 4ooo BP (Fairbanks, C.J. Heusser, 1985). Climatic conditions at 9000 BP were 1989). Generalized curves of eustatic sea-level change the driest of the Holocene with pronounced summer are not applicable to many areas around the North Pacific droughtiness (Thompson et al., 1993). Treeline in the due to strong interference from post-glacial tectonism southeastern Coast Mountains was between 60 and and/or glacio-isostatic rebound. As a result, there is no 130 m higher than today during the interval 9100 to 8200 universal sea-level curve for the North Pacific region. BP (Clague and Mathewes, 1989). Western hemlock Within formerly-glaciated areas and in areas of ongoing (Tsuga heterophylla [Raf.] Sarg. trees grew at higher than tectonism, detailed reconstructions of sea-level history modern elevations in the Queen Charlotte Islands are necessary at a local (ca. 1000 km2) scale. An excep- between 9600 and 8700 BP, suggesting warmer climate tion to this caution may be the Bering and Chukchi D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 465 basins where tectonism and glacial isostasy have been the post-glacial marine transgression may have prevented relatively minor over the last 15,000 years as evidenced drier and warmer conditions during the early Holocene by the similar altitudes (8-12 m) of the Isotope Stage 5e, (Lozhkin et al., 1993). Glaciers remained in retracted Pelukian shoreline on the Alaskan coast of the Chukchi positions throughout the coastal mountains rimming the Sea (McCulloch, 1967; Brigham, 1985; Brigham-Grette Gulf of Alaska until after 6000 BP and Hopkins, 1995). Comparisons between the Fairbanks Neoglaciation began in the American Cordillera in (1989) sea-level record and the bathymetry of the Bering response to cooler and probably more moist conditions and Chukchi Seas suggest that the Bering land bridge after the middle Holocene (Calkin, 1988; Wiles and probably was not flooded until ca. 10,000 BP, a timing Calkin, 1993; Ryder, 1993). Neoglaciation probably substantiated by radiocarbon dates on submerged terres- accompanied regionally synchronous shifts in tempera- trial peats (Elias et al., 1992). ture and precipitation, however these events were of Pollen and plant macrofossils provide an important smaller magnitude than during the LGM to Holocene source of paleoclimatic data in the North Pacific region. transition and consequently are recorded with varying During the onset of the last glacial maximum, forests sensitivity by pollen and glacier records. The history of retreated southward in northeast Asia, but were extirpat- the Little Ice Age, which spanned roughly the last millen- ed in Alaska and the Yukon where their retreat was nium, is recorded by both the historical record and by blocked by glaciated mountains and the ocean. During glacier and pollen proxy records. the LGM, northern Japan and the Asian mainland north of the Amur River was a mostly treeless tundra (Grichuk, 1984; Lozhkin et al., 1993). Beringia probably supported ACKNOWLEDGEMENTS a steppe-tundra vegetation lacking any clear modern We thank Dorothy Peteet, Paul Carlson, John Clague, Julie analogs but capable of supporting a diverse large-mam- Brigham-Grette, and Dick Reger for constructive comments on mal fauna of unknown population size (Guthrie, 1990). earlier drafts of this review. Owen Mason and Patricia Heiser Following the LGM, important changes in vegetation provided useful discussions and references. occurred throughout the region in response to the jerky shift of the global ocean-climate system from glacial into interglacial mode and the retreat of glaciers. With the REFERENCES retreat of glaciers from the northeast Pacific coastline, Ackerman, R.E., Hamilton, T.D. and Stuckenrath, R. (1979). biota began to move northward from refugia in Early culture complexes on tire northern Northwest Coast. Washington. Similar northward shifts must have occurred Canadian Journal of Archaeology, 3, 195-209. along the Russian coast during the Holocene. Forest veg- Ager, T.A. (1982). Vegetational history of western Alaska dur- etation similar to today’s was established by 4000 BP in ing the Wisconsin glacial interval and the Holocene. In: Hopkins, D.M., Matthews, J.V., Schweger, C.E. and Young, the northern Alexander Archipelago (Peteet, 1986; S.B. (eds), Paleoecology of Beringia, pp. 75-93. Academic Cwynar, 1990) and by 5000 BP in northwest Alaska Press, New York. along the Chukchi Sea coast (Anderson, 1985, 1988). Ager, T.A. (1983). Holocene vegetational history of Alaska, In: Plant colonization of terrain deglaciated more than Wright, H.E. Jr (Ed.), Late Quatemary Environments of the 10,000 years ago continues at present in south-central United States, Vol. 2, The Holocene, pp. 128-141. University of Minnesota Press, Minneapolis. and southwest Alaska (Peteet, 1991; C.J. Heusser, 1985). Ager, T.A. (1992). Ecosystem development in topographically Despite several decades of discussion, no indisputable complex south-central Alaska during the late Quatemary. In: evidence exists for the persistence of glacial refugia International Conference on Arctic Margins, Anchorage, along the seaward margin of the Cordilleran Ice Sheet in AK. September 1992, Abstracts, p. 1. Canada or Alaska (C.J. Heusser, 1989). Ice-free areas did Ager, T.A. and Brubaker, L. (1985). Quatemary palynology and vegetational history of Alaska. In: Bryant, V.M. and persist near Lituya Bay (Mann, 1986), in the Caribou Holloway, R.G. (eds), Pollen Records of Late Quatemary Hills east of lower Cook Inlet (Reger and Pinney, in North American Sediments, pp. 353-384. American press), and on southwest Kodiak Island (Karlstrom and Association of Stratigraphic Palynologists, Dallas, TX. Ball, 1969; Mann and Petett, 1994), but they probably Ager, T.A. and Sims, J.D. (1984). Postglacial pollen and tephra contained depauperate, tundra communities of little records from lakes in the Cook Inlet region, southern Alaska. U.S. Geological Survey Circular, 868, 103-105. importance in the recolonization of the forested, post- Alley, N.F. and Chatwin, S.C. (1979). Late Pleistocene history glacial landscape. and geomorphology, southwestern Vancouver Island, British Early Holocene climates were warmer and drier than Columbia. Canadian Journal of Earth Science, 16, today in most regions around the North Pacific. As a con- 1645-1657. sequence, treeline was higher and glaciers were in An, Z., Porter, S.C., Zhou, W., Lu, Y., Donahue, D.J., Head, M.J., W., X., Ren, J. and Zheng, H. (1993). Episode of retracted positions between ca. 9500 and 7000 BP in the strengthened summer monsoon climate of Younger Dryas Coast Mountains of British Columbia (Clague et al., age on the loess plateau of central China. Quaternary 1992). Interior areas seem to have warmed early in post- Research, 39,45-54. glacial times in response to a peak in high-latitude solar Anderson, F.E. (1968). Seaward terminus of the Vashon conti- radiation centered on ca. 10,000 BP (Barnosky et al., nental glacier in the Strait of Juan de Fuca. Marine Geology, 6,419-438. 1987). In coastal areas in western Alaska and Chukotka, Anderson, PM. (1985). Late Quatemary vegetational change in as well as coastlines in the Gulf of Anadyr and the Sea of the Kotzebue Sound area, northwestern Alaska. Quotemary Okhotsk, flooding of nearby continental shelves during Research, 24.307-321. 466 Quaternary Science Reviews: Volume 14

Anderson, P.M. (1988). Late Quatemary pollen records from Bucknam, R.C., Hemphill-Haley, E. and Leopold, E.B. (1992). the Kobuk and Noatak River drainages, northwestern Abrupt uplift within the past 1700 years at southern Puget Alaska. Quaternary Research, 29,263-276. Sound, Washington. Science, 258, 1611-1614. Anderson, P.M. and Brubaker, L.B. (1993). Holocene vegeta- Burbank, D.W. (1981). A chronology of late Holocene glacier tion and climate histories of Alaska. In: Wright, H.E. Jr, fluctuations on Mount Ranier, Washington. Arctic and Kutzbach, J.E., Webb, T., III, Ruddiman, W.F., Street- Alpine Research, 13, 369-386. Perrott, EA. and Bartlein, P.J. (eds), Global Climates since Calkin, F?E. (1988). Holocene glaciation in Alaska (and adjoin- the Last Glacial Maximum, pp. 386-400. University of ing Yukon Territory, Canada). Quaternary Science Reviews, Minnesota Press, Minneapolis. 7, 159-184. Anderson, P.M. and Brubaker, L.B. (1993). Vegetation history Carlson, P.R. (1989). Seismic reflection characteristics of of northcentral Alaska: A mapped summary of Late- glacial and glacimarine sediments in the Gulf of Alaska and Quatemary pollen data. Quaternary Science Reviews, 13, adjacent fjords. Marine Geology, 85, 391-416. 71-92. Carlson, P.R., Burns, T.R., Molnia, B.F. and Schwab, W.C. Anderson, P.M., Bartlein, P.J. and Brubaker, L.B. (1994). Late (1982). Submarine valleys in the northeastern Gulf of Quaternary history of tundra vegetation in northwestern Alaska: Characteristics and probable origin. Marine Alaska. Quaternary Research, 41, 306-315. Geology, 47,2 17-242. Anderson, P.M., Reanier, R.E. and Brubaker, L.B. (1990). A Charles, C.D., Rind, D., Jouzel, J., Koster, R.D. and Fairbanks, 14,000-year pollen record from Sithylemenkat Lake, north- R.G. (1994). Glacial-interglacial changes in moisture central Alaska. Quaternary Research, 33,400-404. sources for Greenland: Influences on the ice core record of Archer, D. and Maier-Reimer, E. (1994). Effect of deep-sea sed- climate. Nature, 263,508--5 11. imentary calcite preservation on atmospheric COz concen- Chinzei, K., Fujioka, K., Kitazato, H., Koizumi. I., Oba, T., tration. Nature, 367,26&263. Oda, M., Okada, H., Sakai, T. and Tanimura, Y. (1987). Atwater, B.F. (1992). Geologic evidence for earthquakes during Postglacial environmental change of the Pacific Ocean off the past 2000 years along the Copalis River, southern coastal the coasts of central Japan. Marine Micropaleonrology, 11, Washington. Journal of Geophysical Research, 97, 273-291. 1901-1919. Clague, J.J. (1975). Late Quaternary sea level fluctuations, Bard, E., Hamelin, B., Fairbanks, R.G. and Zindler, A. (1990). Pacific coast of Canada and adjacent areas. Geological Calibration of the “‘C timescale over the past 30,COOyears Survey of Canada Paper, 75lC, 17-21. using mass spectrometric U-Th ages from Barbados corals. Clague, J.J. (1981). Late Quatemary geology and geochron- Nature, 345,405-410. ology of British Columbia. Part 2: Summary and discussion Bamosky, C.W., Anderson, P.M. and Bartlein, P.J. (1987). The of radiocarbon-dated Quatemary history. Geology Survey of northwestern U.S. during deglaciation: Vegetational history Canada, Papec 80-35. and paleoclimatic implications. In: Ruddiman, W.F. and Clague, J.J. (1983). Glacio-isostatic effects of the Cordilleran Wright, H.E. (eds), North America and Adjacent Oceans Ice Sheet, British Columbia, Canada. In: Smith, D.E. and During the Last Degiaciation, pp. 289-321. The Geology of Dawson, A.G. (eds), Shorelines and lsostasy, pp. 321-343. North America, Vol. K-3, Geological Society of America, Academic Press, London. Boulder, CO. Clague, J.J. (1989). Quaternary sea levels (Canadian Bartlein, P.J., Anderson, P.M., Edwards, M.E. and McDowell, Cordillera). In: Fulton, R.J. (ed.), QualernaT Geology qf P.F. (1991). A framework for interpreting paleoclimatic vari- Canada and Greenland, pp. 43-45. The Geology of North ations in eastern Beringia. Quaternary Inremarional, 10-12, America, Vol. K- 1, Geological Society of America, Boulder, 73-83. co. Benda, L., Beechie, T.J., Wissmar. R.C. and Johnson, A. Clague, J.J. (1991). Quatemary glaciation and sedimentation, (1992). Morphology and evolution of salmonid habitats in a In: Gabrielse, H. and Yorath, C.J. (eds), Geology of the recently deglaciated river basin, Washington state, USA. Cordilleran Orogen in Canada, pp. 419-434. The Geology Canadian Journal of Fisheries and Aquatic Science, 49. of North America, Vol. G-2, Geological Society of America, 1246-1256. Boulder, CO. Blaise, B., Clague, J.J. and Mathewes, R.W. (1990). Time of Clague, J.J. and Evans, S.G. (1993). Historic retreat of Grand maximum Late Wisconsin glaciation, west coast of Canada. Pacific and Melbern Glaciers, Saint Elias Mountains, Quatemary Research, 34,282-295. Canada: An analogue for decay of the Cordilleran ice sheet Booth, D.B. (1986). Mass balance and sliding velocity of the at the end of the Pleistocene? Journal of Glaciology, 39. Puget Lobe of the Cordilleran Ice sheet during the last 619-624. glaciation. Quaternary Research, 25. 269-280. Clague, J.J. and MacDonald, G.M. (1989). Paleoecology and Booth, D.B. (1987). Timing and processes of deglaciation along paleoclimatology (Canadian Cordillera). In: F&on. R.J. the southern margin of the Cordilleran Ice Sheet. In: (ed.). Quaternary Geology of Canada and Greenland, The Ruddiman, W.F. and Wright, H.E. (eds), North America and Geology of North America, Geological Society of America, Adjacent Oceans During the Last Deglaciarion, pp. 71-90. Vol. K- 1, Geological Society of America, Boulder, CO. The Geology of North America, Vol. K-3, Geological Clague, J.J. and Mathewes, R.W. (1989). Early Holocene ther- Society of America, Boulder, CO. mal maximum in western North America: New evidence Booth, D.B. (1991). Glacier physics of the Puget Lobe, south- from Castle Peak, British Columbia. Geology, 17,277-280. west Cordilleran Ice Sheet. GCographie physique et Clague, J.J. and Mathewes, W.H. (1992). The sedimentary Quatemaire, 45,301-315. record and Neoglacial history of Tide Lake, northwestern Brigham, J. (1985). Marine Stratigraphy and Amino Acid British Columbia. Canadian Journal of Eurth Sciences. 29, Geochronology of the Gubik Formation, Western Arctic 2383-2396. Coastal Plain, Alaska. Unpublished Ph.D. Dissertation, Clague, J.J., Harper, J.R., Hebda, R.J. and Howes, D.E. (1982). University of Colorado, Boulder. Late Quatemary sea levels and crustal movements, coastal Brigham-Grette, J. and Hopkins, D.M. (1995). Emergent marine British Columbia. Canadian Journal of Earth Sciences, 19, record and paleoclimate of the last interglaciation along the 597-618. northwest Alaskan coast. Quotemar?/ Research (in press). Clague, J.J., Mathewes, R.W., Buhay, W.M. and Edwards, Brubaker, L.B., Garfinkel, H.L. and Edwards, M.E. (1983). T.W.D. (1992). Early Holocene climate at Castle Peak, A late Wisconsin and Holocene vegetation history from southern Coast Mountains, British Columbia, Canada. the central Brooks Range: Implications for Alaskan Palaeography, Palaeoclimatologq, Palaeoecology, 95, paleoecology. Quaternary Research, 20, 194-2 14. 153-167. D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 467

Clague, J.J., Mathewes, R.W. .and Warner, B,q._ (1982). Late Field, W.O. (1985). Glaciers of the St. Elias Mountains. In: Quaternary geology of eastern Grahain Island, Qaeen Field, W.O. (ed.), Mountain Glaciers of the Northern Charlotte Islands, British Columbia. Canadian Journal of Hemisphere, pp. 143-297. Volume 2. Hanover, New Earth Sciences, 19, 1786-1795. Hampshire, Cold Regions Research and Engineering Clague, J.J., Saunders, I.R. and Roberts, M.C. (1988). Ice-free Laboratory. conditions in southwestern British Columbia at 16,000 years Friele, P.A. and Hutchinson, I. (1993). Holocene sea-level B.P. Canadian Journal of Earth Sciences, 25,938-941. change on the central west coast of Vancouver Island, CLIMAP (1981). Seasonal reconstructions of the Earth’s sur- British Columbia. Canadian Journal qf Earth Science, 30, face at the last glacial maximum. The Geological Society of 832-840. America Map and Chart Series MC-36. Galloway, J.P and Carter, L.D. (1993). Dune activity on the Colinvaux, P.A. (1986). Plain thinking on the Bering Land western Arctic Coastal Plain of Alaska coincident with Bridge vegetation and mammoth populations. Quaterly Neoglacial cirque-glacier expansion in the Brooks Range. Review of Archaeology, 7, 8-9. In: 23rd Annual Arctic Workshop, Columbus, Ohio, Combellick, R.A. (1993). The penultimate great earthquake in Abstracts, p. 35. Columbus, Ohio State University, Byrd southcentral Alaska: Evidence from a buried forest near Polar Research Center, Miscellaneous Series M-322. Girdwood. In: Short Notes on Alaskan Geology, State of Glushkova, 0. Yu (1994). Paleogeography of Late Alaska Division of Geological and Geophysical Surveys, Pleistocene glaciation of northeastern Asia. In: Thurston, Professional Report, 113,7-16. D.K. and Fujita, K. (eds), Proceedings of the 1992 Coulter, H.W., Hopkins, D.M., Karlstrom, T.N.V., PkwC, T.L., International Conference on Arctic Margins, pp. 339-344. Wahrhaftig, C. and Williams, J.R. (1965). Map showing Mineral Management Service, Outer Continental Shelf extent of glaciations in Alaska. U.S. Geological Survey Region Study 94-0040, U.S. Department of the Interior, Miscellaneous Geologies investigations Map I-415, scale Anchorage. l:2,5oo,ooo. Goldthwait, R.G. (1966). Glacial History. In: Mirsky, A. (ed.), Cwynar, L.C. (1990). A late Quatemary vegetation history from Soil Development and Ecological Succession in a Deglaci- Lily Lake, Chilkat Peninsula, southeast Alaska. Canadian ated Area of Muir Inlet, Southeast Alaska, pp. l-1 7. Institute Journal of Botany, 68, 1106-l 112. of Polar Studies Report 20. Ohio State University, Denton, G.H. and Karl& W. (1977). Holocene glacial and tree- Columbus, OH. line variations in the White River Valley and Skolai Pass, Goldthwait, R.P. (1987). Glacial history of Glacier Bay Park Alaska and Yukon Territory. Quatemary Research, 7,63-l 11. area. In: Anderson, F!J., Goldthwait, R.P. and McKenzie, Derksen, S.J. (1976). Glacial geology of the Brady Glacier G.D. (eds), Observed Processes of Glacial Deposition in region. Ohio State University. Institute of Polar Studies Glacier Buy, Alaska. Miscellaneous Publication 236, Byrd Report, 60,97 pp. Polar Research Center, Columbus, OH. Dettennan, R.L. (1986). Glaciation of the Alaska Peninsula. In: Goodwin, R.G. (1988). Holocene glaciolacustrine sedimenta- Hamilton, T.D., Reed, K.M. and Thorson, R.M. (eds), tion in Muir Inlet and ice advance in Glacier Bay, Alaska, Glaciation in Alaska, pp. 151-170. Alaska Geological U.S.A. Arctic and Alpine Research, 20,55-69. Society, Anchorage. Grichuk, V.P. (1984). Late Pleistocene vegetation history. In: Dragovich, J.D., Pringle, PT. and Walsh, T.J. (1994). Extent Velichko, A.A. (ed.), Late Quaternary Environments of the and geomeuy of the Mid-Holocene Osceola Mudflow in the Soviet Union, pp. 155-178. University of Minnesota Press, Puget Lowland - implications for Holocene sedimentation Minneapolis, MN. and paleogeography. Washington Geology, 22,3-26. Gros’vald, M.G. (1988). An Antarctic-style ice sheet in the Easterbrook, D.J. (1992). Advance and retreat of Cordilleran ice northern hemisphere: Towards a new global glacial theory. sheets in Washington, U.S.A. Geographic physique et Polar Geography and Geology, 12,239-267. Quatemaire, 46,s l-68. Gros’vald, M.G. and Vozovik, Y.N. (1984). A “marine” ice cap Ebbesmeyer, C.C. and Ingraham, W.J. (1992). Shoe spill in the in south Beringia (a working hypothesis). Polar Geography North Pacific. EOS, 73,361-365. and Geology. 8, 128-146. Edwards, M.E. and Barker, E.D. Jr (1994). Climate and vegeta- Grove, J. (1988). The Little Ice Age. Methuen, London. tion in northeastern Alaska 18,000 yr B.P.-Present. Guthrie, R.D. (1990). Frozen Fauna of the Mammoth Steppe. Palaeogeography, Palaeoclimatology, Palaeoecology, 109, The University of Chicago Press. 127-135. Hamilton. T.D. (1994). Late Cenozoic glaciation of Alaska. In: Elias, S.A., Short, SK. and Phillips, R.L. (1992). Paleoecology Plafker. G. and Berg, H.C. (eds), The Geology of Alaska. of Late-Glacial peats from the Bering Land Bridge, Chukchi The Geology of North America, Vol. G-l, Geological Sea Shelf region, northwestern Alaska. Quaternary Society of America, Boulder, CO. Research, 38,37 l-378. Hamilton, T.D. and Ashley, G.M. (1993). Epiguruk: A late Emery, W.J. and Hamilton, K. (1985). Atmospheric forcing of Quatemary environmental record from northwestern Alaska. interannual variability in the northeast Pacific Ocean: Geological Society of America Bulletin, 105,583-602. Connections with El Nino. Journal of Geophysical Hamilton, T.D. and Fulton, R.J. (1994). Middle and Late Research, 90,857-868. Wisconsin environments of eastern Beringia. In: Engstrom, D.R., Hansen, B.C.S. and Wright, H.E. (1990). A Bonnichsen, R., Frison, G.C. and Tummire, K. (eds), Ice- possible Younger Dryas record in southeastern Alaska. Age Peoples of North America, Texas A&M University, Science, 250, 1383-1385. College Station, TX. (in press). Eronen, M., Kankinen, T. and Tsukada, M. (1987). Late Hamilton, T.D. and Thorson, R.M. (1983). The Cordilleran Ice Holocene sea-level record in a core from the Puget Lowland, Sheet in Alaska. In: Wright, H.E., Jr and Porter, S.C. Washington. Quatemary Research, 27, 147- 159. (eds), Lute Quatemary Environments of the United States, Eyles, C.H., Eyles, N. and Lagoe, M.B. (I 991). The Yakataga pp. 38-52, Vol. 1. University of Minnesota Press, Formation - a late Miocene to Pleistocene record of tem- Minneapolis, MN. perate glacial marine sedimentation in the Gulf of Alaska. Hebda, R.J. (1992). Fraser-age environments of Vancouver In: Anderson, J.B. and Ashley, G.M. (eds), Glacial Marine Island and adjacent mainland British Columbia (Abstract). Sedimentation, pp. 159-l 80. Geological Society of America Quaternary Research Center Spring Conference on: Special Paper 26 1. Chronology and Paleoenvironments of the Western and Fairbanks, R.G. (1989). A 17,000 year glacio-eustatic sea level Southern Margins of the Cordilleran Ice Sheet during the record: Influence of glacial melting rates on the Younger Dryas Last Glaciation (25,000-10,000 years ago), University of event and deep-ocean circulation. Nature, 342.637-642. Washington. 468 Quaternaty Science Reviews: Volume 14

Hebda, R.J. and Mathewes, R.W. (1984). Holocene history of Hughes, B.A. and Hughes, T.J. (1994). Transgressions: cedar and native Indian cultures of the North American Rethinking Beringian glaciation. Palaeogeography, Pacific coast. Science, 225,7 I 1-7 13. Palaeoclimatology, Palaeoecology, 110,275-294. Heikkinen, 0. (1984). Dendrochronological evidence of varia- Hutchinson. I. (1992). Holocene sea level change in the Pacific tions of Coleman Glacier, Mount Baker, Washington, U.S.A. Northwest: A catalogue of radiocarbon dates and an atlas of Arctic and Alpine Research, 16.53-64. regional sea level curves. Institute of Quaternary Research, Heiser, PA. and Roush, J.J. (1994). Pleistocene glacier extent in Simon Fraser University, Occasional Paper Number 1, 100 Chukotka, Russia: Moraine mapping using satellite synthetic PP. aperature radar imagery, p. A-309. Geological Society of Jacoby, G.C., Wiles, G.C.. D’Arrigo, R.D., Gostev, M.E.; America, Abstracts with Programs, Annual Meeting, Seattle, Vjatkina, M. $nd Khomentovsky, P.A.‘( 1994)‘.Coastal trees Washington. as high-resolution indicators of North Pacific Paleoclimate. Heusser, C.J. (1960). Late-Pleistocene Environments of North Abstracts, 45th Arctic Science Conference, Anchorage, Pacific North America. American Geographical Society Alaska and Vladivostok, Russia. Book 1, p. 53. Far East Special Publication No. 35,308 pp. Branch, Russian Academy of Sciences and American Heusser, C.J. (1983a). Pollen diagrams from the Shumagin Association for the Advancement of Science. Vladivostock, Islands and adjacent Alaska Peninsula, southwestern Alaska. Russia. Boreas, 12,279-295. Jones, G.A., Elder, K.L., Kuzmin, Y.V. and Rakakov, V.A. ( 1994). Heusser, C.J. (1983b). Holocene vegetation history of the Chronology and paleoenvironment of the Holocene climatic Prince William Sound region, south-central Alaska. optimum in Peter the Great Gulf, Sea of Japan. Abstracts, 45th Quaternary Research, 19,337-355. Arctic Science Conference, Anchorage, Alaska and Heusser, C.J. (1985). Quaternary pollen records from the Vladivostok, Russia. Book 1, p. 63. Far East Branch, Russian Pacific-Northwest coast: Aleutians to the Oregon-California Academy of Sciences and American Association for the border. In: Bryant, V.M. and Holloway, R.G. (eds), Pollen Advancement of Science. Vladivostock, Russia. Records of Late-Quaternary North American Sediments, Josenhans, H.W. (1992). No Younger Dryas on the Canadian PP. 141-165. American Association of Strati- Pacific rim continental shelf: Evidence for full-glacial graphic Palynologists Foundation, pp. 353-387, Dallas, retreat and local lowering of sea level to -110 m by 10,600 TX. yr BP (Abstract). Chronology and Paleoenvironments of the Heusser, C.J. (1989). North Pacific coastal refugia - The Western and Southern Margins of the Cordilleran Ice Sheet Queen Charlotte Islands in perspective. In: Scudder, G.G.E. during the Last Glaciation (25,000-10,000 years ago). and Gessler, N. (eds), The Outer Shores. Queen Charlotte Quatemary Research Center, University of Washington. Islands Museum, Sk&g&e, British Columbia. Kallel, N., Labeyrie, L.D., Arnold, M., Okada, H., Dudley. Heusser, C.J., Heusser, L.E. and Peteet, D.M. (1985). Late- WC. and Duplessy, J.-C. (1988). Evidence of cooling during Quaternary climatic change on the American North Pacific the Younger Dryas in the western Pacific. Oceanologica Coast. Nature, 315,485-487. Acta, 11,369-375. Heusser, L.E. (1983). Palynology and paleoecology of post- Karlstrom, T.N.V. (1964). Quaternary geology of the Kenai glacial sediments in an anoxic basin, Saanich Inlet, British lowland and glacial history of the Cook Inlet region, Alaska. Columbia. Canadian Journal of Earth Sciences, 20, U.S. Geological Survey Professional Paper 443,69 pp. 873-885. Karlstrom, T.N.V. (1969). Regional setting and geology. In: Heusser, L.E. and Morley, J.J. (1985). Pollen and radiolarian Karlstrom, T.N.V. and Ball, G.E. (eds). The Kodiak Island records from deep-sea core RCl4- 103: Climatic reconstruc- Refugium, Ryerson Press, Boreal Institute. University of tions of northeast Japan and the Northwest Pacific for the Alberta, Calgary, Alberta. last 90,000 years. Quatematy Research, 24.60-72. Karlstrom, T.N.V. and Ball. G. (1969). The Kodiak Zsland Heusser, L.E. and Morley, J.J. (1990). Climatic change at the Refugium. Ryerson Press, Boreal Institute, University of end of the last glacial maximum in Japan inferred from Alberta, Calgary, Alberta. pollen in three cores from the northwest Pacific Ocean. Kaufman, D.S. and Hopkins, D.M. (1986). Glacial history of Quatemary Research, 34, 101-110. the Seward Peninsula. in: Hamilton. T.D., Reed, K.M. and Hicock, S.R. and Armstrong, J.E. (1985). Vashon Drift: Defini- Thorson, R.M. (eds), pp. 5 l-78. Alaska Geological Society. tion of the formation in the Georgia Depression, southwest Anchorage. British Columbia. Canadian Journal of Earth Science, 22, Keigwin, L.D. and Gobarenko, S.A. (1992). Sea level, surface 748-757. salinity of the Japan Sea, and the Younger Dryas Event in Hicock, S.R., Hebda, R.J. and Armstrong, J.E. (1982). Lag of the northwestern Pacific Ocean. Quaternaty Research, 37, Fraser glacial maximum in the Pacific Northwest: Pollen 346360. and macrofossil evidence from western Fraser Lowland, Keigwin, L.D., Jones, G.A. and Froelich, P.N. (1992). A 15,000 British Columbia. Canadian Journal of Earth Sciences, 19, year paleoenvironmental record from Meiji Seamount, far 2288-2296. northwestern Pacific. Earth and Planetary Science letters, Hopkins, D.M. (1982). Aspects of the paleogeography of 111,425-440. Beringia during the late Pleistocene. In: Hopkins, D.M., Kerschner. H. (1987). A paleoprecipitation model for full Matthews, J.V., Schweger, C.E. and Young, S.B. (eds), glacial Hokkaido as inferred from paleoglaciation data. In: Paleoecology of Beringia, pp. 3-28. Academic Press, New Abstracts of the XII International Congress of the York. International Union for Quaternary Research, p. 200. Hopkins, D.M., Benson, S., Brigham-Grette, J., Heiser, PA. and Ottawa, Canada, July, 1987. lvanov, V. (1992). Ice sheets on the Bering shelf?, p. 27, Khotinskiy, N.A. (1984). Holocene vegetation history. In: Abstracts. International Conference on Arctic Margins, Velichko, A.A. (ed.), late Quaternary Environments of the Anchorage, Alaska, September 1992. Soviet Union, pp. 179-200. University of Minnesota Press. Hu, ES., Brubaker, L.B. and Anderson, P.M. (1995). Postglacial Minneapolis, MN. vegetation and climate change in the northern Bristol Bay Kind, N.V. (1967). Radiocarbon chronology in Siberia. In: region, southwestern Alaska. Quaternary Research (in Hopkins, D.M. (ed.), The Bering Land Bridge, pp. 172-192. press). Stanford University Press, Stanford, CA. Hudson, T., Dixon, K. and Plafker, G. (1982). Regional uplift in Kutzbach, J.E. (1987). Model simulations of the climatic pat- southeastern Alaska. In: Coonrad, W.L. (ed.), The United terns during the deglaciation of North America. In: States Geological Survey in Alaska: Accomplishments dur- Ruddiman, W.F. and Wright, H.E., Jr (eds), The Geology of ing 1980. U.S. Geological Survey Circular, 844, 132-l 35. North America. North America and Adjacent Oceans D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 469

During the Last Deglaciation. The Geology of North McCulloch, D.S. and Hopkins, D.M. (1966). Evidence for an America, Vol. K-3, The Geological Society of America, early Recent warm interval in northwestern Alaska. Boulder, CO. Geological Society of America Bulletin 77, 1089-l 108. Kutzbach, J.E., Guetter, P.J., Behling, PJ. and Selin, R. (1993). McKenzie, G.D. and Goldthwait, R.G. (1971). Glacial history Simulated climatic changes: Results of the COHMAP cli- of the last eleven thousand years in Adams Inlet, southeast- mate-model experiments. In: Wright, H.E. Jr, Kutzbach, ern Alaska. Geological Society of America Bulletin 82, J.E., Webb, T. III, Ruddiman, W.F., Street-Petrott, EA. and 1767-1782. Bartlein, P.J. (eds), Global Climates since the Last Glacial Meier, M.F, and Post, A.S. (1987). Fast tidewater glaciers. Maximum, pp. 24-93. University of Minnesota Press, Journal of Geophysical Research 92B, 9051-9058. Minneapolis, MN. Meltzer, D.J. (1993). Pleistocene peopling of the Americas. Lagoe, M.B., Eyles, C.H., Eyles, N. and Hale, C. (1993). Evolutionary Anthropology, 1, 157-169. Timing of late Cenozoic tidewater glaciation in the far North Miller, M.M. and Anderson, J.H. (1974). Out-of-phase Pacific. Geological Society of America Bulletin, 105, Holocene climatic trends in the maritime and continental 1.542-l 560. sectors of the Alaska-Canada Boundary Range. In: Lea, PD. and Waythomas, C.F. (1990). Late-Pleistocene eolian Mahaney, W.C. (ed.), Quaternary Environments: sand sheets in Alaska. Quaternary Research, 34,269-28 1. Proceedings of a Symposium, Geographical Monographs no. Liu Kam-biu (1988). Quaternary history of the temperate 5, pp. 33-58. York University. forests of China. Quatemary Science Reviews, 7, l-20. Miller, R.D. (1972). Surficial geology of the Juneau urban area Lozhkin, A.V., Anderson, P.M., Eisner, W.R., Ravako, L.G., and vicinity, Alaska, with emphasis on earthquakes and Hopkins, D.M., Brubaker, L.B., Coiinvaux, PA. and Miller, other geological hazards. U.S. Geological Survey Open-file M.C. (1993). Late Quaternary lacustrine pollen records from Report 517. 108 pp. southwestern Beringia. Quatematy Research, 39.314-324. Miller, R.D. (1973a). Two diamictons in a landslide scarp on Luckman, B.H., Holdsworth, G. and Osborn, G.D. (1993). Admiralty Island, Alaska, and the tectonic significance of an Neoglacial glacier fluctuations in the Canadian Rockies. intervening peat bed. U.S. Geological Survey Journal of Quatemary Research, 39, 144-153. Research, 1,309-3 14. Lutemauer, J.L., Clague, J.J., Conway, K.W., Barie, J.V., Blaise, Miller, R.D. (1973b). Gastineau Channel Formation, a com- B. and Mathewes, R.W. (1989). Late Pleistocene terrestrial posite glaciomarine deposit near Juneau, Alaska. U.S. deposits on the continental shelf of western Canada: Geological Survey Bulletin 1394-C, Cl-C20. Evidence for rapid sea-level change at the end of the last Miller, R.D. (1975). Surficial geologic map of the Juneau glaciation. Geology, 17, 357-360. urban area and vicinity, Alaska. U.S. Geological Manabe, S. and Hahn, D.G. (1977). Simulation of the tropical Survey Miscellaneous Investigations Map I-885, scale climate of an Ice Age. Journal of Geophysical Research, 82, 1:48,000. 3889-3911. Milner, A.M. and Bailey, R.G. (1989). Salmonid colonization of Manabe, S. and Broccoli, A.J. (1985). The influence of conti- new streams in Glacier Bay National Park, Alaska. nental ice sheets on the climate of an ice age. Journal of Aquaculture and Fisheries Management, 20, 179-192. Geophysical Research, 90,2 167-2 190. Mobley. CM. (1988). Holocene sea levels in southeast Alaska: Mann, D.H. (1986a). Reliability of a fjord glacier’s fluctuations Preliminary results. Arctic, 41,261-266. for paleoclimatic reconstructions. Quaternary Research, 25. Molnia, B.F. (1986). Glacial history of the northeastern Gulf of 1O-24. Alaska - a synthesis. In: Hamilton, T.D., Reed, K.M. and Mann, D.H. (1986b). Wisconsin and Holocene glaciation of Thorson, R.M. (eds), Glaciation in Alaska, pp. 219-235. Southeast Alaska, pp. 237-265. In: Hamilton, T.D., Reed, Alaska Geological Society, Anchorage, Alaska. K.M. and Thorson, R.M., Glaciation in Alaska, pp. Moore, T.C. (1980). The reconstruction of sea surface tempera- 237-265. Alaska Geological Society, Anchorage, AK. tures in The Pacific Ocean of 18,000 B.P. Marine Mann, D.H. and Peteet, D.M. (1994). Extent and Time of the Micropaleontology, 5, 2 15-247. Last Glacial Maximum in Southwest Alaska. Quaternac Morley, J.J. and Heusser, L.E. (1989). Late Quatemary atmos- Research, 42, 136-148. pheric and oceanographic variations in the western Pacific Mann, D.H. and Ugolini, EC. (1985). Holocene glacial history inferred from pollen and radiolarian analyses. Quatemary of the Lituya District, southeast Alaska. Canadian Journal Science Reviews, 8, 263-276. of Earth Sciences, 22,9 13-928. Morley, J.J. and Heusser, L.E. (1991). Late Pleistocene/ Mason, O.K. and Jordan, J.W. (1993). Heightened North Pacific Holocene radiolarian and pollen records from sediments in storminess during synchronous late Holocene erosion of the Sea of Okhotsk. Paleoceanography, 6, 12 1- 13 1. Northwest Alaska beach ridges. Quaternary Research, 40, Namias, J. ( 1970). Macroscale variations in sea-surface temper- 55-69. atures in the North Pacific. Journal of Geophysical Mathewes, R.W. (1985). Paleobotanical evidence for climatic Research, 75.565-583. change in southern British Columbia during Late-Glacial Nelson, R.E. and Coope, G.R. (1982). A late-Pleistocene insect and Holocene time. Syllogeus, 55,397-422. fauna from Seattle, Washington, p. 146. Seventh Annual Mathewes, R.W. (1991). Climatic conditions in the western and American Quaternary Association Meeting, Seattle, northern Cordillera during the last glaciation: Paleoecologi- Abstracts. cal evidence. Geographic physique et Quaternaire, 45, Niebauer, H.J. and Day, R.H. (1989). Causes of interannuai 333-339. variability in the sea ice cover of the eastern Bering Sea. Mathewes, R.W., Heusser, L.E. and Patterson, R.T. (1993). Geojoumal, 18,45-59. Evidence for a Younger Dryas-like cooling event on the Oba. T., Kato, M., Kitazato, H., Koizumi, I., Omura, A., Sakai, British Columbia coast. Geology, 21, 101-104. T. and Takayama, T. (1991). Paleoenvironmental changes in Matthews, J.V. Jr (1982). East Beringia during Late Wisconsin the Japan Sea during the last 85,000 years. time: A review of the biotic evidence. In: Hopkins, D.M., Paleoceanography, 6,499-5 18. Matthews, J.V., Schweger, C.E. and Young, S.B. (eds), Osbom, G. and Luckman, B.H. (1988). Holocene glacier fluctu- Paleoecology of Beringia, pp. 127-150. Academic Press. ations in the Canadian cordillera (Alberta and British New York. Columbia). Quatematy Science Reviews, 7, 115-128. McCulloch, D.S. (1967). Quaternary geology of the Alaskan Page, R.A., Biswas, N.N., Lahr, J.C. and Pulpan, H. (1991). shore of the Chukchi Sea. In: Hopkins, D.M. (ed.), The Seismicity of continental Alaska. In: Slemmons, D.B., Bering Land Bridge, pp. 91-120. Stanford University Press, Engdahl, E.R., Zoback, M.D. and Blackwell, D.D. (eds), Stanford. Neotectonics of North America, Geological Society of 470 Quaternary Science Reviews: Volume 14

America, Decade of North American Geology Map Volume Ritchie, J.C., Cwynar. L.C. and Spear, R.W. (1983). Evidence 1, Boulder, CO. from north-west Canada for an early Holocene Milankovitch Pellat, M.G. and Mathewes, R.W. (1994). Paleoecology of post- thermal maximum. Nature. 305, 126-128. glacial tree line fluctuations on the Queen Charlotte Islands, Rogers, G.C. and Homer, R.B. (1991). An overview of western Canada. Ecoscience, 1,71-81. Canadian seismicity. In: Slemmons, D.B., Engdahl, E.R.. Peteet, D.M. (1986). Vegetational history of the Malaspina Zoback, M.D. and Blackwell, D.D. (eds), Neotecronics of Glacier District. Quaternary Research, 25, 100-120. North America. Decade of North American Geology Map Peteet, D.M. (1991). Postglacial migration history of lodgepole Volume 1. Geological Society of America, Boulder, CO. pine near Yakutat, Alaska. Canadian Journal of Botany, 69, Royer, T.C. (1989). Alaskan oil spill. Science, 245,243 (letter). 786-796. Ryder, J.M. (I 989). Holocene glacier fluctuations (Canadian Peteet, D.M. and Mann, D.H. (1994). Late-glacial vegetational, Cordillera): In: Fulton, R.J. (ed.), Quaternar?, Geology of tephra, and climatic history of southwestern Kodiak Island, Canada and Greenland, pp. 74-76. The Geology of North Alaska. Ecoscience, 1,255-267. America, Vol. K-l, Geological Society of America, Boulder. Petersen, K.L., Mehringer, PJ., Jr and Gustafson, C.E. (1983). co. Late-glacial vegetation and climate at the Manis Mastodon Ryder, J.M. and Clague, J.J. (1989). British Columbia site, Olympic Peninsula, Washington. Quaternary Research, (Quaternary stratigraphy and history, Codilleran Ice Sheet). 20,215-231. In: Fulton, R.J. (ed.), Quaternary Geology of Canada and PCwC, T.L. (1975). Quaternary geology of Alaska. U.S. Greenland, pp. 48-58. The Geology of North America, Vol. Geological Survey Professional Paper 835. K- 1. Geological Society of America, Boulder, CO. Pinney, D.S. and Beg&, J.E. (1991). Late Pleistocene volcanic Ryder, J.M., Fulton, R.J. and Clague, J.J. (1991). The deposits near the Valley of Ten Thousand Smokes, Katmai Cordilleran Ice Sheet and the glacial geomorphology of National Park, Alaska. Short Notes on Alaskan Geology, southern and central British Columbia. Geographic physique State of Alaska Division of Geological and Geophysical et Quatemaire, 45,365-377. Surveys, Professional Report 111.45-53. Ryder, J.M. and Thompson, B. (1986). Neoglaciation in the Plafker, G. (1969). Tectonics of the March 27, 1964 Alaska southern Coast Mountains of British Columbia: Chronology Earthquake. U.S. Geological Survey Professional Paper prior to the late Neogiacial maximum. Canadian Journal of 543-L 74 pp. Earth Sciences, 23, 273-287. Plafker, G. (1990). Regional vertical tectonic displacement of Sancetta, C. (1983). Effect of Pleistocene glaciation upon shorelines in south-central Alaska during and between great oceanographic characteristics of the North Pacific Ocean earthquakes. Northwest Science, 64.250-258. and Bering Sea. Deep-Sea Research, 30,85 l-869. Plafker, G., Lajoie, K.R. and Rubin, M. (1992). Determining Sancetta, C. and Robinson, S.W. (1983). Diatom evidence on the recurrence intervals of great subduction zone earth- Wisconsin and Holocene events in the Bering Sea. quakes in southern Alaska by radiocarbon dating. In: Taylor, Quaternary Research, 20,232-245. R.E., Long, A. and Kra, R.S. (eds), Radiocarbon Dating Sancetta, C., Heusser, L., Labeyrie, L., Naidu, A.S. and after Four Decades, pp. 436-452. Springer, New York. Robinson, S.W. (1985). Wisconsin-Holocene paleoenviron- Plug, L.J. and Mann, D.H. (1994). The development of ground ments of the Bering Sea: Evidence from diatoms, pollen, oxy- ice features and ponds in a northwestern-Alaska beach ridge gen isotopes, and clay minerals. Marine Geology, 62,55-68. wetland. Abstracts, 45th Arctic Science Conference, Schledermann, P. (1980). Polynyas and prehistoric settlement Anchorage, Alaska and Vladivostok, Russia. Book 2, p. 27. patterns. Arctic. 33, 292-302. Far East Branch, Russian Academy of Sciences and Schmoll, H.R., Szabo, B.J., Rubin, M. and Dobrovolny. E. American Association for the Advancement of Science. (1972). Radiometric dating of marine shells from the Vladivostock, Russia. Bootlegger Cove Clay, Anchorage area, Alaska. Geological Porter, S.C., Pierce, K.L. and Hamilton, T.D. (1983). Late Society of America Bulletin, 83, 1107-I 113. Wisconsin mountain glaciation in the western United States. Schmoll, H.R. and Yehle, L.A. (1986). Pleistocene glaciation of In: Porter, S.C. (ed.), Late Quaternary Environments of the the upper Cook Inlet basin. In: Hamilton, T.D., Reed, K.M. United States, Vol. I: The Late Pleistocene;pp. 71-l 14. and Thorson, R.M. (eds), Glaciation in Alaska, pp. 193-2 18. University of Minnesota Press, Minneapolis, MN. Alaska Geological Society, Anchorage. Porter, S.C. (1988). Landscapes of the last ice age in North Shaffer, G. and Bendtsen, J. (1994). Role of the Bering Strait in America. In: Carlisle, R.C. (ed.), Americans before controlling North Atlantic ocean circulation and climate. Columbus: Ice-Age Origins, pp. l-25. Ethnology Nature, 367,354-357. Monographs Number 12, Department of Anthropology, Sirkin. L. and Tuthill, S.J. (1987). Late Pleistocene and University of Pittsburgh, Pittsburgh, PA. Holocene deglaciation and environments of the southern Porter, SC. (1989). Late Holocene fluctuations of the fjord Chugach Mountains, Alaska. Geological Society ofAmerica glacier system in Icy Bay, Alaska, U.S.A. Arctic and Alpine Bulletin, 99, 376-384. Research, 21,364-379. Stringer, W.J. and Grove, J.E. (1991). Location and a real extent Reed, R.K. and Schumacher, J.D. (1987). Physical ocean- of polynyas in the Bering and Chukchi Seas. Arctic, 44, graphy. In: Hood, D.W. and Zimmerman, S.T. (eds), The 164-171. Gulf of Alaska: Physical Environment and Biological Sugita, S. and Tsukada, M. (1982). The vegetation history in Resources, pp. 57-75. National Oceanic and Atmospheric western North America 1. Mineral and Hall Lakes. Japanese Administration, Washington, DC. Journal of Ecology, 32.499-5 15. Reger, R.D. (1991). Deglaciation of the Allison-Sawmill Creeks Taber, J.J., Billington, S. and Engdahl, E.R. (1991). Seismicity area, southern shore of Port Valdez, Alaska. Short Notes on of the Aleutian Arc. In: Slemmons, D.B., Engdahl, E.R., Alaskan Geology, State of Alaska Division of Geological Zoback, M.D. and Blackwell, D.D. (eds), Neotectonics of and Geophysical Surveys, Professional Report 111. 55-62. North America, Decade Map Volume 1. Geological Society Reger, R.D. and Pinney, D.S. (in press). Late Wisconsin of America, Boulder, CO. Glaciation of the Cook Inlet region with emphasis on Kenai Ten Brink, N.W. and Waythomas, C.F. ( 1985). Late Wisconsin lowland. In: Davis, N.Y. and Davis, W.E. (eds), The glacial chronology of the north-central Alaska Range: A region- Anthropology of Cook Inlet: Proceedings from a al synthesis and its implications for early human settlements. Symposium. Cook Inlet Historical Society, Anchorage. National Geographic Society Research Reports, 19, 15-32. Ritchie, J.C. and Hare, F.K. (1971). Late-Quatemary vegetation Terada, K. and Hanzawa, M. (1984). Climate of the North and climate near the Arctic tree line of northwestern North Pacific Ocean. In: Van Loon, H. (ed.), Climates of the America. Quatemary Research, 1.331-342. Oceans. pp. 431-504. Elsevier, Amsterdam. D.H. Mann and T.D. Hamilton: Paleoenvironments of the North Pacific Coast 471

Thompson, P.R. (1981). Planktonic foraminifera in the western Prudhoe Bay. Ecological Monographs, 61.437-464. North Pacific during the past 150,000 years: Comparison of Warner, B.G., Mathewes, R.W. and Clague, J.J. (1982). Ice-free modern and fossil assemblages. Palaeogeography, conditions on the Queen Charlotte Islands, British Palaeoclimatology, and Paleaoecology, 35,241-279. Columbia, at the height of Late Wisconsin glaciation. Thompson, R.S., Whitlock, C., Bartlein, P.J., Harrison, S.P. and Science, 218,675-677. Wendland, W.M. and Bryson, R.A. (1981). Northern hemi- Spaulding, W.G. (1993). Climatic changes in the western sphere airstream regions. Monthly Weather Review, 109, United States since 18,000 yr B.P. In: Wright, H.E., Jr, 255-270. Kutzbach, J.E., Webb, T., III, Ruddiman, W.F., Street- Whitlock, C. (1992). Vegetation history of the Cordilleran ice Perrott, EA. and Bartlein, P.J. (eds), Global Climates Since Sheet (Abstract). Quaternary Research Center Spring the Last Glacial Maximum, pp. 468-513. University of Conference on: Chronology and Paleoenvironments of the Minnesota Press, Minneapolis, MN. Western and Southern Margins of the Cordilleran Ice Sheet Thorson, R.M. (1989). Glacio-isostatic response of the Puget during the Last Glaciation (25,000-10,000 years ago), Sound area, Washington. Geological Society of America University of Washington. Bulletin, 101,1163-1174. Wiles, G.C. and Calkin, PE. (1990). Neoglaciation in the south- Thorson, R.M. and Hamilton, T.D. (1986). Glacial geology of ern Kenai Mountains, Alaska. Annals of Glaciology, 14, the Aleutian Islands. In: Hamilton, T.D., Reed, K.M. and 3 19-322. Thorson, R.M. (eds), Glaciation in Alaska, pp. 171-191. Wilkes, G.C. and Calkin, PE. (1993). Neoglacial fluctuations Alaska Geological Society, Anchorage. and sedimentation of an iceberg-calving glacier resolved Tsukada, M. (1983). Vegetation and climate during the last with tree rings (Kenai Fiords National Park. Alaska). glacial maximum in Japan. Quaternary_ Research, 19, Quatemaly InTemXational,i8, 3542. 212-235. Wiles, G.C. and Calkin, P.E. (1994). Late Holocene, high-reso- Tsukada, M. (1985). Map of vegetation during the last glacial lution glacial chronologies and climate, Kenai Mountains, maximum in Janan. Ouatemarv Research. 23.369-381. Alaska. Geological Society of America Bulletin, 106, Tsukada, M. (198’6). Gtitudinal’and latitudinal migration of 281-303. Cryptomeria japonica for the past 20,000 years in Japan. Wilson, J.G. and Overland, J.E. (1987). Meteorology. In: Hood, Quaternary Research, 26, 135-152. D.W. and Zimmerman, S.T. (eds), The Gulf of Alaska: Velichko, A.A., Isayeva, L.L., Makeyev, V.M., Matishov, G.G. Physical Environment and Biological Resources, pp. 3 l-56. and Faustova, M.A. (1984). Late Pleistocene glaciation of National Oceanic and Atmospheric Administration. the Arctic shelf and reconstruction of Eurasian ice sheets. In: Washington, DC. Velichko, A.A. (ed.), Late Quaternary Environments of the Winkler, M.G. and Wang, PK. (1993). The Late-Quatemary Soviet Union, pp. 35-44. University of Minnesota Press, vegetation and climate of China. In: Wright, H.E., Jr, Minneapolis, MN. Kutzbach, J.E., Webb, T., III, Ruddiman, W.F., Street- von Huene, R. (1966). Glacial-marine geology of Nuka Bay, Perrott, EA. and Battlein, P.J. (eds), Global Climates Since Alaska and the adiacent continental shelf. Marine Geology,-. the Last Glacial Maximum, pp. 221-264. University of 4.291-304. - Minnesota Press, Minneapolis, MN. von Huene, R. (1989). Continental margins around the Gulf of Worley, IA. (1980). Ancient environments and age of non- Alaska. In: Winterer. E.L.. Hussone. D.M. and Decker. R.W. glaciated terrain in southeastern Alaska. National (eds), The Eastern Pacific Ocean &d Hawaii, pp. 383-401. Geographic Society Research Reports, 12,733-747. The Geology of North America, Vol. N. Geological Society Zahn, R., Pederson, T.F., Bornhold, B.D. and Mix, A.C. of America, Boulder, CO. (1991). Water mass conversion in the glacial subarctic von Huene, R., Crouch, J. and Larson, E. (1976). Glacial advance Pacific (54 N, 148 W): Physical constraints and the benth- in the Gulf of Alaska area implied by ice-rafted material. ic-planktonic stable isotope record. Paleoceanography. 6, Geological Society ofAmerica Memoir, 145,41 l-422. 543-560. Walker, D.A. and Everett, K.R. (1991). Loess ecosystems of Zang. D. (199 1). Historical records of climate change in China. northern Alaska: Regional gradient and toposequence at Quatemav Science Reviews, 10.551-554.