Sentences with phrase «during glacial periods when»

The researchers found that during glacial periods when the atmosphere was colder and sea ice was far more extensive, deep ocean waters came to the surface much further north of the Antarctic continent than they do today.

Not exact matches

The tools were found beneath glacial deposits laid down during a period 450,000 years ago when the region was blanketed in ice, so they must be older than this.

The sand was blown up onto the island during the last glacial period when the water levels were very low.

It seems increasingly clear that D - O events must involve major sea ice changes (and there is not much sea ice left, by comparison with what was present during the glacial period (20000 + years ago, when these events happened), so D - O events are increasingly unlikely in the future).

The Last Glacial Maximum is a period when ice sheets during the last northern hemisphere ice age were at their highest extent.

Arctic climatic extremes include 25 °C hyperthermal periods during the Paleocene - Eocene (56 — 46 million years ago, Ma), Quaternary glacial periods when thick ice shelves and sea ice cover rendered the Arctic Ocean nearly uninhabitable, seasonally sea - ice - free interglacials and abrupt climate reversals.

Carbon starvation, which apparently sometimes occurs during glacial periods due to the low levels of CO2 that are reached, has the same effect on C3 plants * trees, shrubs, and such) as do warm, dry conditions when the warm is excesaive.

This fossilized coral reef was alive about 20,000 years ago, during the height of the last glacial period, a time when Earth was around 9 degrees Fahrenheit (5 degrees Celsius) cooler than it is now, and the city of Chicago was buried beneath an ice sheet almost 2 miles (3 kilometers) thick.

Well drained and rocky substrate there creates a glade ecosystem where sloping ground can encourage the growth of prickly pear cacti and other desert and prairie species such as the collared lizard, Crotaphytus that last covered the whole area around 7,000 years ago in the Hypsithermal Interval, during the Holocene Period, when warming dried out much of the glacial Northern Hemisphere.