geo 2.1

Geomorphology and Glaciers

• The zone of illuviation refers to the recrystallization of minerals or deposition of fine materials that occurs directly below the zone of eluviation.
• A landscape consisting of overlapping alluvial fans along a mountain front is called a bajada.

Deserts and Atmospheric Circulation

• The Sahara Desert in Africa is best associated with the descending air of the subtropical high-pressure cell of the three-cell model of atmospheric circulation.

Aeolian Sediment Transport

• Saltation is an aeolian sediment transport process that requires the sediment to remain in contact with the surface at all times.

Cultural Revolution of Agriculture

• The cultural revolution of agriculture (horticulture) began around 10,000 years ago.

Glaciers and Meltwater

• When meltwater accumulates at the base of a glacier, providing a lubricant between the underlying rock and the glacier, the glacier moves through the process called basal sliding.

Glacial Formation and Composition

• After the transition from snow to firn, additional compaction results in more air being squeezed out, resulting in a dense material with ice crystals aligned to each other, making up approximately 90% of the solid mass.
• The gradual thickening, compaction, and recrystallization of snow and water over time form a feature called ice.
• The part of the glacier where snow melts is called the ablation zone.
• Freshly fallen snow is roughly 20% air.