Depression (geology)

A depression in geology is a landform sunken or depressed below the surrounding area. Depressions form by various mechanisms.

Erosion-related:

Collapse-related:

Impact-related:

Sedimentary-related:

Structural or tectonic-related:

Volcanism-related:

Aepyceros melampus petersi female 8014
A watering hole is a natural depression where water collects and animals come to drink
Λίμνη Στυμφαλίας
Karst closed depression with permanent lake Stymfalia, Peloponnese, Greece. Seasonal abundant precipitation drained by 3 sinkholes

See also

References

  1. ^ a b "Dictionary of Geologic Terms – B". US Geochemical. Retrieved 2017-09-09.
  2. ^ "Dictionary of Geologic Terms – K". US Geochemical. Retrieved 2017-09-09.
  3. ^ "Glossary of Important Terms in Glacial Geology – Peripheral Depression". Montana State University. 1999. Archived from the original on 2006-08-29. Retrieved 2006-08-25. Cites American Geological Institute's Glossary of Geology (3rd edition, revised in 1987).
  4. ^ "Dictionary of Geologic Terms – C". US Geochemical. Retrieved 2017-09-09.
Afar Triangle

The Afar Triangle (also called the Afar Depression) is a geological depression caused by the Afar Triple Junction, which is part of the Great Rift Valley in East Africa. The region has disclosed fossil specimens of the very earliest hominins, that is, the earliest of the human clade; and it is thought by some paleontologists to be the cradle of the evolution of humans, see Middle Awash, Hadar. The Depression overlaps the borders of Eritrea, Djibouti and the entire Afar Region of Ethiopia; and it contains the lowest point in Africa, Lake Asal, Djibouti, at 155 m (or 509 ft) below sea level.

The Awash River is the main waterflow into the region, but it runs dry during the annual dry season, and ends as a chain of saline lakes. The northern part of the Afar Depression is also known as the Danakil Depression. The lowlands are affected by heat, drought, and minimal air circulation, and contain the hottest places (year-round average temperatures) of anywhere on Earth.

The Afar Triangle is bordered as follows (see the topographic map): on the west by the Ethiopian Plateau and escarpment; to the north-east (between it and the Red Sea) by the Danakil block; to the south by the Somali Plateau and escarpment; and to the south-east by the Ali-Sabieh block (adjoining the Somali Plateau).Many important fossil localities exist in the Afar region, including the Middle Awash region and the sites of Hadar, Dikika, and Woranso-Mille. These sites have produced specimens of the earliest (fossil) hominins and of human tool culture, as well as many fossils of various flora and fauna.

Geology of the Falkland Islands

The geology of the Falkland Islands is described in several publications. The Falkland Islands are located on a projection of the Patagonian continental shelf. In ancient geological time this shelf was part of Gondwana, which around 400 million years ago broke from what is now Africa and drifted westwards relative to Africa. Studies of the seabed surrounding the islands indicated the possibility of oil. Intensive exploration began in 1996, although there had been some earlier seismic surveys in the region.

Godzareh depression

The Gowd-i zerrah, i.e., Zerrah Depression (Persian for "lake depression") is the lowest part of an inland drainage basin covering large parts of southern Afghanistan and Iran known as the Sistan Basin. The Sistan Basin is an endorheic basin and encompasses a complex system of rivers, shallow lakes, marshes and wetlands as its watershed, draining into the Hamun Lakes in southeastern Iran. Occasional outflows from these lakes are carried back into Afghanistan by the seasonal Shile river to the basin's terminus, the Godzareh depression in Afghanistan. The depression is flat and very shallow with fine textured sediment at its lowest portions. The lowest section of the Godzareh depression is 467 m above sea level. The depression only receives runoff water when the main tributaries are overflowing every 10 years on the average.In general, a geological depression is a landform that is sunken or lower than the surrounding area. The Godzareh depression is the lowest point in the Sistan Basin in Afghanistan and therefore is the terminus to which all the water flows.

Hole

A hole is a hollow place, an opening in/through a solid body, or an excavation in the ground. Holes occur through natural and artificial processes, and may be useful for various purposes, or may represent a problem needing to be addressed in many fields of engineering. Depending on the material and the placement, a hole may be an indentation in a surface (such as a hole in the ground), or may pass completely through that surface (such as a hole created by a hole puncher in a piece of paper). In construction, this describes the distinction between a blind hole and a through hole.

Kuznetsk Depression

Kuznetsk Depression (Russian: Кузнецкая котловина, Kuznetskaya kotlovina) is located among mountains of South-Central Siberia, including: Kuznetsk Alatau to the Northeast, Salair Ridge to the Southwest, and Mountainous Shoria to the South. It is within Kemerovo Oblast.

Manda Hararo

Manda Hararo is a group of basaltic shield volcanoes in east Africa whose last eruption was in 2009. The group is very large, spreading over 105 square kilometres (41 sq mi). At its northern end is a small example. South of this volcano is the Gumatmali-Gablaytu fissure system, an area dominated by fissure-fed lava flows. At the centre of the complex rise two volcanoes. Manda Hararo's large size is because it is a raised block from the end of a mid-ocean ridge spreading center. It is known for its rare basalts.

Nadir (topography)

In topography, a nadir is a point on a surface that is lower in elevation than all points immediately adjacent to it. Mathematically, a nadir is a local minimum of elevation. A nadir may be the lowest point of a dry basin or depression, or the deepest point of a body of water or ice. The nadir of a body of water is often called a "deep", as in the Challenger Deep, the nadir of the Earth's oceans.

Pseudo-atoll

A pseudo-atoll, like an atoll, is an island that encircles a lagoon, either partially or completely. A pseudo-atoll differs from an atoll as established by several authorities, such as how it is formed (not by subsidence, nor by coral). It is considered a preferable term to "near-atoll". There is a need for rigorous definition of "pseudo-atoll" before it can be accepted as a general term.

Tuva Depression

Tuva Depression (Russian: Тувинская котловина, tr. Tuvinskaya kotlovina) is located among mountains of South Central Siberia — the Tannu-Ola Mountains, Eastern Sayans and Western Sayans, and the Altay Mountains region. It is part of a region with a combination of raised lands and depressions.This Tuva Depression is within the Tuva Republic.

The elevation of the depression varies between 500–1,000 metres (1,600–3,300 ft).

Mountainous
Continental plain
Fluvial
Glacial
Oceanic and
coastal landforms
Volcanic
Aeolian
Artificial

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