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Glacier Formation

the accumulation of snow compacted into ice over time. The three necessary factors for glacier formation are cold temperatures, snowfall exceeding snowmelt, and time for compaction.

Firn

partially compacted snow that is one step away from becoming glacial ice. It forms through the process of snow accumulation, compaction, and recrystallization over several years.

Glacier Movement

move due to internal deformation and sliding at their base. can vary from a few centimeters to several meters per day.

Glacial Features

Eskers are winding ridges of sediment deposited by meltwater streams in or under glaciers. Moraines are accumulations of rock debris carried and deposited by glaciers. Kettles are depressions formed by melting ice blocks. Cirques, hanging valleys, arêtes are landforms shaped by glacial erosion.

U-shaped Valleys

Glaciers carve due to their ability to erode and transport large amounts of rock and sediment.

Moraines

ridges of glacial debris left behind as the glacier advances or retreats. They are significant as they provide evidence of past glacier activity and can help reconstruct glacial history.

Pleistocene Ice Age

The Pleistocene Ice Age was a period of repeated glaciations that occurred from about 2.6 million to 11,700 years ago. It was characterized by the presence of extensive ice sheets and cooler global temperatures.

Insolation and Ice Ages

Insolation refers to the solar radiation received on Earth's surface, which varies due to changes in Earth's orbit and axial tilt (Milankovitch cycles). These variations in insolation are linked to the onset and retreat of ice ages.

CO2 and Climate Change

influences Earth's climate. Natural sources include volcanic eruptions, while human activities like burning fossil fuels contribute to increased levels. Greenhouse gases trap heat in the atmosphere, leading to global warming.

Geologic Time

refers to the sequence of events in Earth's history without specific dates, while absolute provides actual dates using radiometric dating. Uniformitarianism is the principle that geological processes observed today have operated similarly throughout Earth's history.