Learn About The Ice Age
The last ice age may have come and gone, but according to recent research, it has left behind quite icy footprints on the landscapes of certain unglaciated parts of North America. Jill A. Marshall, an assistant professor of geosciences in the University of Arkansas, has made this research available via a journal called the Geophysical Research Letters.
The layer of the earth from the point where it supports vegetation above it to the lowest parts of the bedrock within the surface of the earth’s crust, is regarded as a critical zone, a key player in the regulation of our natural habitat, and extremely susceptible to the effects of various geological processes.
In such extremely freezing areas as Alaska for example, solid rocks edging close to the earth’s surface can be cracked by the pressure from a build up of ice, and eventually broken down into sediments. The result is a flattening of previously elevated landscapes, or the emergence of sloping structures from the points of solid rock structures down to the broken down, now sandy areas.
Think of the numerous instances of deliberate human activity, including breaking of rocks, aimed at levelling various natural habitats to flatlands for their own occupation. Only this time, ice is the villain.
A frost-weathering model was used to observe and record temperature changes throughout the Last Glacial Maximum, or LGM, which is the name given to the most recent period during which ice sheets on the earth’s surface reached their maximum total mass, and is calculated to have been about 21, 000 years ago.
It was discovered that large sections of North America, such as Oregon, Texas and Arkansas were affected by these processes. These periglacial areas, though not directly undergoing permanent freezing like the Arctic, however still experienced extremely cold conditions during the ice age.
And even though factors such as fresh vegetation and other continuous geological processes may have concealed proof of these landscape changing processes, results from the research indicate that possible weathering induced by the presence of ice during these cold conditions affected a far larger area than even the permanently frozen areas.
The research further suggests that future influence of these processes on present landscapes is to be expected. The thickness of the soil can be affected by how much breakdown of rock occurs thus, and how swiftly the particles travel across the surface of the earth aided by ice.