Earth:Abyssal hill
An abyssal hill is a small hill that rises from the floor of an abyssal plain. They are the most abundant geomorphic structures on Earth, covering more than 30% of the ocean floor.[1] Abyssal hills have relatively sharply defined edges and climb to heights of no more than a few hundred meters. They can be from a few hundred meters to kilometers in width. A region of the abyssal plain that is covered in such hill structures is termed an "abyssal-hills province". However, abyssal hills can also appear in small groups or in isolation.[2]
The greatest abundance of abyssal hills occurs on the floor of the Pacific Ocean.[1] These Pacific Ocean hills are typically 50–300 m (160–980 ft) in height, with a width of 2–5 km (1.2–3.1 mi) and a length of 10–20 km (6.2–12.4 mi).[3] They may be created along the flanks of the tectonically active East Pacific Rise as horst-and-graben features, then become stretched out with the passage of time.[1] Abyssal hills may also be areas of thicker oceanic crust that were generated at the mid-ocean ridge during times of increased magma production.
References
- ↑ 1.0 1.1 1.2 Kennish, Michael J. (2001). Practical handbook of marine science. Marine science series (3rd ed.). CRC Press. p. 282. ISBN 0-8493-2391-6.
- ↑ Heezen, Bruce C.; Laughton, A. S. (1963). "Abyssal Plains". in M. N. Hill. Earth Beneath Sea History Sea. Sea: Ideas and Observations on Progress in the Study of the Seas. 3. Harvard University Press. p. 312. ISBN 0-674-01730-7.
- ↑ Dilek, Y. (1998). "Structure and tectonics of intermediate-spread oceanic crust drilled at DSDP/ODP Holes 504B and 896A, Costa Rica Rift". in Adrian Cramp. Geological evolution of ocean basins: results from the Ocean Drilling Program. Geological Society special publication. 131. Geological Society. p. 194. ISBN 1-86239-003-7.
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