glacial

Bacteria trapped in glacial ice for thousands of years could help humans live to 140, scientists claim.

Braided streams are common in both deserts and glacial environments because both produce abundant sediment.

Over the past two million years, colder glacial periods have alternated with warmer interglacial periods.

Climatic changes at the end of the glacial period 13,000 years ago have been proposed to account for the emergence of farming.

Interglacial periods are, typically periods of time between Ice Ages, when the climate warms, and the glacial ice retreats for a time, before things cool off again and another Ice Age begins.

In all these diverse regions, Agassiz saw signs of glacial erosion and sedimentation.

The heterogeneous material of the drift (sand, clay, and rocks deposited there) convinced him of its glacial origin.

It soon became clear that there were multiple glacial ages during the Pleistocene, with warmer interglacial intervals between them.

As geologists mapped glacial deposits in the late nineteenth century, they became aware that there were several layers of drift, the lower ones corresponding to earlier ice ages.

Between the older layers of glacial material were well-developed soils containing fossils of warm-climate plants.

Ocean sediments presented a much more complete geologic record of the Pleistocene than continental glacial deposits did.

Isotopic analysis of shells allowed geologists to measure another glacial effect.

The oxygen isotope ratio of the ocean changes as a great deal of water is withdrawn from it by evaporation and is precipitated as snow to form glacial ice.

From this analysis of marine sediments, geologists have learned that there were many shorter, more regular cycles of glaciation and deglaciation than geologists had recognized from the glacial drift of the continents alone.

With additional time, pressure, and refrozen meltwater from above, the small firn granules become larger, interlocked crystals of blue glacial ice.

The glacial system is governed by two basic climatic variables: precipitation and temperature.

A surplus allows snow to accumulate and for the pressure of snow accumulated over the years to transform buried snow into glacial ice with a depth great enough for the ice to flow.

When snowfalls on high mountains or in polar regions, it may become part of the glacial system.

Until the early 1970s,most archaeologists did not consider the coast a possible migration route into the Americas because geologists originally believed that during the last Ice Age the entire Northwest Coast was covered by glacial ice.

The water was always laden with pebbles, gravel, and sand, known as glacial outwash, that was deposited as the flow slowed down.

Her glacial beauty is magnetic.