Environment around 90,000 BC

The Globe

 If we consider where the equator was 90,000 years ago, we discover that this line was very close to many famous archaeological sites like Hoggar in Algeria; Tibesti in Chad; the southern part of Egypt; Bahrein and Dilmun in the Persian Gulf; Sumer and Akkad in Mesopotamia; the southern part of Persia; the Indus valley; Angkor, in Cambodia; Malekula, in the New Hebrides; Rapa, in Polynesia; Easter Island, in the South Pacific; Pisco Bay and the Nasca plateau in Peru; Tiahuanaco, in Bolivia; and the Amazon delta. (Our Cosmic Ancestors)

What is now clear is that during the last ice age, and the period that followed it, the climate was much more chaotic than it has been in recent millennia. Generally, the climate was much more variable. Sudden changes occurred from time to time. Collapse of parts of the ice sheets, or release of meltwater lakes that built up behind the ice, led to cataclysmic changes. Armadas of icebergs or floods of icy freshwater swept out into the North Atlantic altering the circulation of the ocean at a stroke and with it the climate of the neighbouring continents. With a flick of the climatic switch, Europe and much of North America could be plunged back into icy conditions, having only just emerged from the abyss of the preceding millennia. Conversely, the stability of the glacial conditions could be interrupted by a re-establishment of the flow of warm water to higher latitudes in the North Atlantic, bringing surprising temporary warmth to the northern continents. (Climate Change in Prehistory)

...the isotopic temperature records show some 20 interstadials, ...between 15 and 100 kya. Typically the events start with an abrupt warming of Greenland of some 5 to 10°C over a few decades or less. This warming is followed by a gradual cooling over several hundred years, and occasionally much longer. This cooling phase often ends with an abrupt final reduction of temperature back to cold ('stadial') conditions. (Climate Change in Prehistory)

Changes in the sea level during the last 100 kyr. (Climate Change in Prehistory)

The last earth crust displacement occurred 11,600 years ago when all three astronomical cycles meshed, ushering in the present interglacial epoch. The dominant cycle relating to these events is that of the earth’s tilt (now thought to move from the minimum of 21.8° to the maximum of 24.4° every 41,000 years).6 We believe other earth crust displacements occurred during the last glacial epochs at 11,600, 52,600, and 93,600 years ago. (Atlantis Beneath the Ice)

Africa

In the Middle East the most important consequence of the cold conditions around 87 kya was extreme desiccation. The expansion of the deserts here may well have driven out any humans living there at the time. What little evidence there is of climatic conditions in Africa at this time also points to drier conditions. The record of desert-dune formation across southwestern Africa shows that at least part of this period was extremely arid. Desert conditions seem to have existed over a large area west of about 15°E, and south of about 18°S. (Climate Change in Prehistory)

Southwest Asia

 In the Middle East the most important consequence of the cold conditions around 87 kya was extreme desiccation. The expansion of the deserts here may well have driven out any humans living there at the time. What little evidence there is of climatic conditions in Africa at this time also points to drier conditions. The record of desert-dune formation across southwestern Africa shows that at least part of this period was extremely arid. Desert conditions seem to have existed over a large area west of about 15°E, and south of about 18°S. (Climate Change in Prehistory)

Egypt

 

Indus Valley

 

China

 

Europe

 

South America

 

Mesoamerica

 

North America

Several lines of solid evidence suggest that during the last ice age the North Pole was located in or near Hudson Bay. ...the best guess for the site of the pole seems to be approximately 60 degrees North Latitude and 83 degrees West Longitude. The first line of evidence that the last North American ice cap was a polar ice cap is based on the shape, size, and peculiar geographical location of the ice sheet. (Path of the Poles)

MacNeish’s find is important because it confirms that migration to North America from Siberia was possible between 91,600 BCE and 50,600 BCE and again after the next earth crust displacement at 50,600 BCE. This displacement dragged eastern North America into the polar zone but left islands off the Pacific coast free of ice. The Arctic Circle then lay over Hudson Bay. Greenland remained in the polar zone. Theoretically, from 91,600 BCE to 9600 BCE, people travelling in boats could have moved from Siberia to America along the Pacific Coast where they could navigate between the ice-free islands. (Atlantis Beneath the Ice)

Other