Depression (geology)
In geology, a depression is a landform sunken or depressed below the surrounding area. Depressions form by various mechanisms.
Types
-related:- Blowout: a depression created by wind erosion typically in either a partially vegetated sand dune ecosystem or dry soils.
- Glacial valley: a depression carved by erosion by a glacier.
- River valley: a depression carved by fluvial erosion by a river.
- Area of subsidence caused by the collapse of an underlying structure, such as sinkholes in karst terrain.
- Sink: an endorheic depression generally containing a persistent or intermittent lake, a salt flat or dry lake, or an ephemeral lake.
- Panhole: a shallow depression or basin eroded into flat or gently sloping, cohesive rock.
- Sinkhole: a depression formed as a result of the collapse of rocks lying above a hollow. This is common in karst regions.
- Kettle: a shallow, sediment-filled body of water formed by melting glacial remnants in terminal moraines.
- Thermokarst hollow: caused by volume loss of the ground as the result of permafrost thawing.
- Impact crater: a depression created by an impact, such as a meteorite crater.
- Sedimentary basin: in sedimentology, an area thickly filled with sediment in which the weight of the sediment further depresses the floor of the basin.
- Structural basin: a syncline-like depression; a region of tectonic downwarping as a result of isostasy or subduction.
- Graben or rift valley: fallen and typically linear depressions or basins created by rifting in a region under tensional tectonic forces.
- Pull-apart basin caused by offset in a strike-slip or transform fault.
- Oceanic trench: a deep linear depression on the ocean floor. Oceanic trenches are caused by subduction of oceanic crust beneath either the oceanic crust or continental crust.
- A basin formed by an ice sheet: an area depressed by the weight of the ice sheet resulting in post-glacial rebound after the ice melts
- Caldera: a volcanic depression resulting from collapse following a volcanic eruption.
- Pit crater: a volcanic depression smaller than a caldera formed by a sinking, or caving in, of the ground surface lying over a void.
- Maar: a depression resulting from phreatomagmatic eruption or diatreme explosion.
List of depressions
- Aral–Caspian Depression
- Baetic Depression
- Bodélé Depression
- Caspian Depression
- Danakil Depression
- Eider-Treene Depression
- Georgia Depression
- Giurgeu-Brașov Depression
- Godzareh Depression
- Huancabamba Depression
- Kara Depression
- Karashor Depression
- Kuma–Manych Depression
- Kuznetsk Depression
- Mari Depression
- Mourdi Depression
- Qattara Depression
- Regen Depression
- Ronda Depression
- Táchira Depression
- Tunkin Depression
- Turan Depression
- Turpan Depression
- Tuva Depression
- Upemba Depression
- Weser Depression
- Wittlich Depression
- Wümme Depression