Glaciers can leave behind unique landforms as they move across, including mountain peaks, ribbon lakes and rock drumlins.
But which term best characterizes glacial erosion? This depends on which process is involved, so let’s take a closer look at these processes and their impact on landscapes.
Rocks embedded within glaciers churn against it as it moves, much like how wood surface would react when touched with sandpaper. This erosion produces many distinctive glacial landforms such as faceted clasts (rocks which have been smoothed off by colliding against other rocks), grooves and scarps called striations as well as glacial pavements that scrape across bedrock surfaces.
Glacial abrasion is an integral component of glacial lake formation, as ice with its loads of rocks erode the soft sedimentary bedrock beneath.
Abrasion contributes to the formation of corries, aretes, pyramidal peaks and u-shaped valleys known as troughs; it also forms whalebacks and mountainous rocks called roches moutonnees. Abrasion rates tend to be very low beneath polar glaciers; most erosion that occurs here comes from freeze-thaw weathering processes rather than direct abrasion.
As glaciers erode rock below them, they do so through two mechanisms: abrasion and plucking. Plucking involves breaking off chunks of bedrock called joint blocks via pressure or freeze-thaw weathering processes, with those rocks later carried downstream and deposited as moraines.
Glacial abrasion occurs when glacier clasts rub against bedrock and one another while moving along the ground, producing long, deep scratch marks called striations that show which direction the glacier moved in.
Glaciers also sculpt the landscape by carving hanging valleys, cirques, aretes, and horns into the landscape, creating hanging valleys, cirques, aretes and horns from U-shaped valleys carved by multiple glaciers eroding one mountain side at once. Ribbon lakes, truncated spurs and moraines can also form due to glaciers’ erosion on U-shaped valleys; other features may include ribbon lakes truncated spurs moraines.
Landscape systems (including glacial ones ) can be thought of as being composed of inputs, stores, transfers and outputs. Rock material enters glacial systems through rockslides, rockfall, erosion of glacier paths valley sides or bedrock and redistributed throughout the landscape.
Freeze-thaw weathering is a physical/mechanical process in which water percolates into cracks in exposed rocks, freezes and expands in winter temperatures before freezing again when temperatures warm again, widening existing cracks further and stressing out rock over time – leading it to break apart by repeated freeze-thaw cycles.
An important erosive process, wind erosion plays an integral part in landscape evolution and ecosystem succession. Pioneer plant species often colonise new habitat created by this process and help ensure its success, contributing to ecosystem succession. At a regional scale, climate can have some influence over erosion rates due to its impact on geology environment; on a continental ice sheet scale however, internal ice-dynamic related switches play a more dominant role as an erosion driver.
Erosion refers to the generalized wear-and-tear process that results in landform change and modification by wind, fluvial (river), marine, and glacial processes; wind erosion speeds this up considerably due to global warming causing riverine processes to carry rock away downstream; however, global warming will exacerbate erosion rates further and cause devastating results on coastal regions.
Glacier erosion creates many fascinating landforms, from mountains and peaks, lakes, to nunatuks (landforms with interesting names). Glacial erosion occurs through processes of abrasion, plucking, freeze-thaw weathering and freeze-thaw weathering.
Abrasion occurs when the surface of a glacier rubs against bedrock underneath, grinding rock fragments to powder or leaving long scratches called striations that indicate its direction of movement. As soon as a glacier melts it leaves behind deep depressions called cirque basins in its wake while multiple glaciers working to erode one mountain peak create pointed shapes known as horns – signs that these processes should stop.