Dr Bird, who lives in Jesmond, Newcastle and is a visiting scholar at Northumbria University, says the last glacial period
lasted for 100,000 years.
Of the six dusty periods recorded in Antarctic ice cores that cover the last 420,000 years, four immediately preceded the end of the four glacial periods
recognized during that time.
during the 100,000-year cycles have been characterised by a very slow build-up of ice which took thousands of years, the result of ice volume responding to orbital change far more slowly than the ocean temperatures reacted.
He wrote 'there appear to have been glacial periods
of world-wide extent'.
This transition marked a global climate change with the beginning of glacial periods
lasting 100,000 years, in comparison to the gradual intensification of glacial cycles occurring in the three million years immediately before, when periods lasted 41,000 years.
But before the glacial period
, geological evidence indicates that the site was in shallow water.
Even if Earth was sliding in and out of glacial periods
back then, there still would have been a large amount of liquid water in equatorial regions, just like today," he said.
The Pleistocene ice age is really a succession of 17 or more glacial periods
separated by warmer times, called interglacial periods, when the ice retreats.
They have determined there were at least three major glacial periods
occurring about every 10,000 years.
Anatolia is considered to be one of the most important refugia in southern Eurasia during glacial periods
Increased mixing in the Pacific and Indian oceans during glacial periods
could have increased the amount of water moved by the Antarctic Circumpolar Current by about 30 percent, the authors suggest.
The wind is not having such effects now because the climate is different, Kapp indicates, suggesting the westerly winds shift north during interglacial periods like that of the current climate and toward the equator during glacial periods
The large steps were made during various glacial periods
many hundreds of thousands of years ago when the glaciers melted during global warming periods and the sea level rose by hundreds of feet (Swansea and environs up to and including Clydach below water) only to drop again during the next ice age.
2] stored in deep-sea reservoirs during glacial periods
, although this remains an open question.
The study says about 430,000 years ago, the glacial periods
started to lengthen and interglacials started to shorten.