Sunda Shelf

Geologically, the Sunda Shelf is an extension of the continental shelf of Southeast Asia, covered during interglacials by the South China Sea, which isolates as islands Borneo, Sumatra Java and smaller islands. [Zvi Ben-Avraham, "Structural framework of the Sunda Shelf and vicinity" "Structural Geology" (January 1973) [http://hdl.handle.net/1912/1265 abstract] .] During glacial periods, the sea level falls, and great expanses of the Sunda Shelf are exposed as a marshy plain. [The rise of sea level during a meltwater pulse 14.6 to 14.3 kbp was as much as 16 meters within 300 years. Till Hanebuth, Karl Stattegger and Pieter M. Grootes, "Rapid Flooding of the Sunda Shelf: A Late-Glacial Sea-Level Record", "Science" "288" 12 May 2000:1033-35.] The seas and bays that cover the Sunda Shelf are less than 100 m deep.

Steep undersea gradients separate the Sunda Shelf from the Philippines, Sulawesi and the Lesser Sunda Islands, where the dividing line, passing between Bali and Lombok, is marked by a major discontinuity in fauna that is known as the Wallace Line from Alfred Russel Wallace, the biologist who first recognized it in the 19th century.

The complicated history of island formation on the Sunda Shelf and changing landbridge connections with mainland Southeast Asia have resulted in a high degree of endemism and local distribution discontinuities, discussed at Sundaland, the biogeographical province that has resulted from these changes.

The exposure of the Sunda Shelf during eustatic sea level changes has effects on the El Niño oscillation. [Andrew B. G. Bush and Richard G. Fairbanks, "Exposing the Sunda shelf: Tropical responses to eustatic sea level change", "Journal of Geophysical Research" 108 (2003).]

Notes

External Web Pages

*Voris, H., and C. Simpson, 2000 and 2006, [http://www.fieldmuseum.org/research_collections/zoology/zoo_sites/seamaps/ Pleistocene Sea Level / Paleogeography Maps of Sunda Shelf] The Field Museum, Chicago, Illinois.