Chapter 1: Full-Glacial Arctic Tundra

In what kind of a climate, on what kind of a plant-cover has the woolly mammoth lived in northwestern North America and northern Siberia? Some scientists believe: This elephant has lived in the Far North in ice and snow, just like the reindeer and the muskox of today. It has lived up there during the height of the Last Glaciation, when it was much colder than now. The mammoth has lived up there on a zonal dry steppe, stretching from Western Europe across Northern Siberia to Northern Canada. This zonal dry steppe has grown there also during the height of the Last Glaciation. This they have proved now through many carbon-14 dates, done with the newest up-to-date methods.

Is that true? Does that agree with the new scientific findings? What observational and experimental proof is there? In what kind of a climate has this mammoth steppe grown in the Far North? How large was there the annual precipitation? And how much aboveground dry plant matter was growing there per year? Could it have fed herds of elephants, bison and wild horses? What have scientists found out now about this?

"Snapshot" of full-glacial environment

on Northern Seward Peninsula, Western Alaska

At the westernmost part of Alaska, at the Bering Strait, scientists have found now something very interesting, on the northern part of Seward Peninsula: Soil, with its plant-cover, suddenly buried under a thick layer of volcanic ash. According to carbon-14 dating, this happened at the height of the Last Glaciation. This is a rare "snapshot" of the full-glacial environment on Northern Seward Peninsula, Western Alaska, they say. We may compare it with the South Italian City of Pompeii, which was suddenly buried by the volcanic ash of the Vesuv.

Claudia Höfle, Mary E. Edwards, David M. Hopkins, and Daniel Mann were working then at the Alaska Quaternary Center, University of Alaska, Fairbanks, Alaska. They report about their findings in, "The Full-Glacial Environment of the Northern Seward Peninsula, Alaska, Reconstructed from the 21,500-Year-Old Kitluk Paleosol", in Quaternary Research 53, 143-153 (2000):

"Paleoenvironmental conditions are reconstructed from soils, buried under volcanic ash ca. 21,500 years ago on the Seward Peninsula. Soil development was minimal, reflecting the continuous regional deposition of loess, which originated from river flood-plains and the exposed Chukchi shelf. Cryoturbated (= changed through very low temperature) soil horizons, ice wedges, and ice-lens formation indicate a permafrost environment and mean annual temperatures below –6° to –8°C. Shallow active layers (average 45 cm), minimal evidence for chemical leaching of soils, and the presence of earth hummocks indicate a cold and seasonally dry climate. Neither steppe nor polar desert soils are appropriate analogues for these zonal soils of loess-covered central Beringia." - Höfle, C. et al. (2000:143).

"As Quaternary sea level fluctuated with glacial cycles, the shallow Bering and Chukchi shelves intermittently formed a land connection between Asia and North America: the Bering land bridge. During the last glacial maximum (ca. 21,500 years ago), the land bridge lay at the center of a largely ice-free land mass (Beringia), which stretched between the Kolyma and Mackenzie rivers." - Höfle, C. et al. (2000:143)

"At the last glacial maximum, much of lowland Beringia was characterized by accumulation of loess. A widely cited model for the full-glacial environment is the ‘arctic steppe’ or ‘mammoth-steppe’ hypothesis, which is based on diverse and abundant Pleistocene mammalian fossils, many of which have been retrieved from loess or loess-derived deposits. Large grazers, such as mammoth, bison, and horse, predominate in these assemblages. In this paper, we describe the full-glacial soil and land surface of 10 localities on the northwestern Seward Peninsula." - Höfle, C. et al. (2000:143, 144)

"Study area: The study area is located within the boundaries of the Bering Land Bridge National Preserve on the tundra-covered coastal plain of northern Seward Peninsula. It is bounded by Kotzebue Sound on the east and the shore of the Chukchi Sea to the north (Fig. 2). Relief is low, and altitudes are mostly below 60 m. At Kotzebue, ca. 60 km to the northeast, January mean temperature is ca. –20°C, July ca. 12°C, and mean annual temperature is ca. –6°C. Precipitation averages 230 mm, with more than half falling in the summer and early fall (U.S. Weather Service data). Permafrost is present; measured modern active-layer depths range [surface of frozen soil thawing in summer] between 30 and 58 cm under shrub-tussock tundra on silty substrates and sedge-meadow tundra on peat.

"About 21,500 cal yr (18,000 ¹⁴C yr) ago, a maar eruption created two large craters, now occupied by Devil Mountain Lakes. The resultant Devil Mountain Lakes tephra covered about 2,500 km² of the surrounding area, in many places to depths of >1 m. The eruption probably continued over a period of weeks or months, with the tephra falling cold. The plume direction was north and west, as indicated by the thickest cover of tephra.”

Comment: A maar is a volcano, which under a high internal pressure suddenly explodes, and which throws up then the upper layers of rock like an exploding bomb.

"With a thick tephra layer, insulating the former surface after the eruption, the frost table must have moved rapidly upward. The soil and vegetation beneath the ash froze, preserving features of the ancient surface and, were subsequently exposed, providing a unique ‘snapshot’ of the full-glacial landscape. The landscape – low interfluves and shallow valleys, slightly elevated above major flood-plains – was probably typical of a considerable portion of full-glacial central Beringia, and as such probably supported zonal vegetation and soils. We named the buried soil, associated with this event, the Kitluk Paleosol.

"No large mammals, other than caribou, are directly associated with the paleosurface, although various large-mammal remains, including mammoth, have been recovered from other late-Pleistocene deposits on northern Seward Peninsula. Mammoth remains are also known from Wisconsin-age sediments on nearby Baldwin Peninsula." - Höfle, C. et al. (2000:145).

Results

The six AMS dates (Table 2) cluster tightly and average 18,070 ± 60 ¹⁴C yr B.P, or 21,570 cal yr B.P. Thus, the eruption occurred shortly before 21,500 yr ago (18,000 ¹⁴C yr). Two conventionally dated samples, taken farther below the paleosurface, date to ca. 19,300 ¹⁴C yr B.P. All samples have a silt-loam texture (average 18% sand, 71% silt, 11% clay), reflecting derivation from loess. - Höfle, C. et al. (2000:146).

Site Localities and Active Layer Depths of Kitluk Paleosol

Latitude 66°33´45" North latitude, 164°27´40" W Longitude, Lake Rhonda 1

Paleoactive-layer depth (cm) 30-60 cm

Estimates of active layer depth beneath the KP range from 30 to 64 cm and average 45 cm.

"With the deposition of loess (ca. 0.5 mm/yr), .... rates are similar to those estimated for loess accumulation in middle Wisconsin time in the Fairbanks area (0.75-0.375 mm/yr (Hamilton et al., 1988).

"Circumstantial evidence suggests, that the eruption occurred during the spring. We interpret the clear, flat-top ice, with intact plant material, as frozen puddles and the opaque ice with an uneven surface as snow. The snow was evidently patchy, suggesting a landscape during break-up. Based on modern analogues, the puddles would have formed from runoff that froze nightly. ... Goetcheus et al. (1994) report an intact nest of M. miurus on the paleosurface, which also suggests winter or spring, as nests become dispersed during the summer." Höfle, C. et al. (2000:149).

Biotic Environment

What kind of a plant-cover was growing at the height of the Last Glaciation on Seward Peninsula? How much aboveground plant matter was growing there per year? Could it have fed the mammoth?

"The paleovegetation of the KP (Kitluk Paleosol) surface, as described by Wolf and Birks (in press), is characterized by graminoids and forbs, with arctic willow confined to certain areas, probably snowbeds. The sedge Kobresia myosuroides is dominant .... the vegetation is interpreted as a dry tundra or meadow tundra, probably closed, with a continuous acrocarpous moss layer. Wolf and Birks (in press) suggest, that the best physiognomic modern analogues for this vegetation are the dry meadow and Kobresia meadow communities of Yurtsev (1982), although species composition differs. D. Walker (personal communication, 1997) has pointed out the physiognomic similarities between moist, nonacidic tundra of the Alaskan North Slope (Walker et al., 1998) and the paleo-vegetation, although again, species composition is different.

"Collared lemmings are browsers; today they eat primarily willow leaves and Dryas (the latter being absent from the sampled paleovegetation). They are commonly found in dry, open-ground, drifted-snow conditions, with a minimum snow cover of 20-30 cm." Höfle, C. (2000:150).

Paleoclimatic Inferences

"The KP (Kitluk Paleosol) developed in a cold, permafrost environment. ... A mean annual air temperature at least as cold as –6°C to –8°C is indicated by the growth of ice wedges (Washburn, 1980). Snow cover was probably thin, but with drifts of at least 20-30 cm, as indicated by the mammalian remains. ... Thorson and Guthrie (1992) estimate that in loess-affected interior Alaska the active layer may have been as little as 20 cm deep..." (2000:150)

Modern Analogues for the KP

Where is this type of plant-cover growing now? Was it a zonal dry steppe?

C. Höfle et al. (2000:151): "At the one extreme would be sparse, dry tundra, perhaps akin to polar semi-desert on extremely dry soils (Bliss and Richards, 1982). At the other would be productive, grass-dominated vegetation on warm, permafrost-free soils, such as that described by Laxton et al. (1996), which could today be described as azonal steppe. Based on KP data and the partial analogues, we suggest that the KP and its associated vegetation lies somewhere in the middle of this continuum and that it represents a cooler, shorter, and drier growing season, than that of the region today."

"The KP soil is not a typical steppe soil, nor do Wolf and Birks (in press) interpret the vegetation as steppe vegetation. The paleoclimatic inferences from the KP data suggest, that the soil formed under climatic conditions, that today would be associated with tundra." Höfle, C. et al. (2000:151)

We have found out:

·         The plant-cover on Seward Peninsula was covered by volcanic ash during the height of the Last Glaciation, according the radiocarbon dates.

• This place on Seward Peninsula lies in Western Alaska, close to the Bering Strait and near the middle of Beringia.

·         The mean annual air temperature was lower than 6°-8°C, as indicated by the growth of the ice wedges in the ground. They are growing in continuous permafrost.

• Onto this plant-cover, the wind was blowing loess from the near by river flats.
• This plant-cover was not a grass steppe. The vegetation was not steppe vegetation. And it was not growing on typical steppe soil. It grew in a tundra climate.
• It is a mixture of two different types of plant-cover: (1) A sparse, dry tundra, perhaps akin to polar semi-desert on extremely dry soils (Bliss and Richards, 1982). (2) A productive grassland on warm, permafrost-free soils, such as that described by Laxton et al. (1996), which could today be described as azonal steppe.
• The growing season of the plants was cooler, shorter, and drier, than that of Seward Peninsula today.

Polar semi-desert and aboveground plant production

How much aboveground vegetation is growing now on the polar semi-desert on Banks Island, Melville Island, and on the other Canadian High Arctic Islands, north of the Canadian mainland? We are looking for a plant-cover, which is similar to the plant cover on the northern Seward Peninsula, western Alaska, at the Bering Strait. Volcanic dust has suddenly covered it at the peak of the Last Glaciation, according to carbon-14 dating. Would the mammoth have found up there enough to eat?

Standing crop and production estimates of some Polar Semi-desert sites of Melville, Banks, and Victoria Islands, N.W.T. Adapted from J. Svoboda (1977:206) Table 12.

In such a polar desert, the poor mammoth would have had to live during the height of the Last Glaciation, near the rim of the continental ice sheets, if the ice-age experts were telling the truth. The elephant would have pitifully starved, thirsted and frozen there to death within a few weeks, if not days. The elephant is still able to live, where 250 g DM/m² yr have grown during 8-9 wet months, followed by 3-4 dry months. During the great drought of 1970-71 in Tsavo East N. Park, East Africa, about 5000 elephants and several hundred black rhinos have starved to death with a full stomach, where only 200 gDM/m² had grown per year from 255 mm of rain. (Phillipson, J. 1975:176). The asserted adaptation of the woolly mammoth to severe arctic cold is not science, only science-fiction. It has nothing to do with serious scientific research.