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|Title:||The 'Darwin Point' of Pacific Ocean atolls and guyots: a reappraisal||Contributor(s):||Flood, Peter Gerard (author)||Publication Date:||2001||DOI:||10.1016/S0031-0182(01)00390-X||Handle Link:||https://hdl.handle.net/1959.11/10531||Abstract:||The 'Darwin Point', where atolls drown, has been redefined as a function of climate, sea-level history, paleolatitude, seawater temperature and light. During the last 34 Ma, in the Hawaiian-Emperor Chain, the Darwin Point has been shown to shift at least between 24 and 30°N latitude. Atoll drowning there is correlated with decreased seawater temperature and light and depends on sea-level history as well as the elevation of atoll summits at the time of sea-level transgressions. If the atoll top falls below 30 m with respect to sea level and the rate of sea-level rise is more than 15 mm/yr, the atoll will drown. Results of the Ocean Drilling Program legs 143 and 144, which investigated the histories of several NW Pacific guyots, indicate that the demise of the shallow-water carbonate platforms there was related to either a temporal (110-100 Ma) eustatic sea-level event, the paleolatitude location (0-10°S) of nutrient-rich water, and/or increased seawater temperature (greenhouse effect) unconducive to the production of calcium carbonate by shallow-water organisms. Hence, the Darwin Point phenomena of atolls and guyots cannot be viewed as a manifestation of any single factor, rather, it results from a combination of factors including: decreased water temperature and light related to higher latitude; the amplitude and rate of sea-level changes; presence of nutrient-rich waters; and/or elevated seawater temperatures. It is indeed dynamic, both in time, space, and cause.||Publication Type:||Journal Article||Source of Publication:||Palaeogeography, Palaeoclimatology, Palaeoecology, 175(1-4), p. 147-152||Publisher:||Elsevier BV||Place of Publication:||The Netherlands||ISSN:||0031-0182
|Field of Research (FOR):||040601 Geomorphology and Regolith and Landscape Evolution||Peer Reviewed:||Yes||HERDC Category Description:||C1 Refereed Article in a Scholarly Journal||Statistics to Oct 2018:||Visitors: 295
|Appears in Collections:||Journal Article|
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