Quaternary morphology and paleoenvironmental records of carbonate islands
Citable URI
https://hdl.handle.net/1912/6315Location
Tahaa, French PolynesiaGreat Bahama Bank
DOI
10.1575/1912/6315Keyword
Biogeochemical cycles; PaleogeographyAbstract
Here I use a simple numerical model of reef profile evolution to show that the presentday
morphology of carbonate islands has developed largely in response to late
Pleistocene sea level oscillations in addition to variable vertical motion and reef accretion
rates. In particular, large amplitude ‘ice-house’ sea-level variability resulted in long
lagoonal depositional hiatuses, producing the morphology characteristic of modern-day
barrier reefs. Reactivation of carbonate factories, transport of coarse reef material and
rapid infilling of shallow water accommodation space since deglaciation makes these
unique sites for reconstructing Holocene climate.
Integration of new tropical cyclone reconstructions from both backbarrier reef (central
Pacific) and carbonate bank (the Bahamas) settings with existing storm archives suggests
a coordinated pattern of cyclone activity across storm basins since the late Holocene.
Seesawing of intense tropical cyclone activity between the western Pacific (~0-1000 yrs
BP) and North Atlantic/Central Pacific (~1000-2500 yrs BP) appears closely tied with
hydrographic patterns in the tropical Pacific and El Niño-like variability. Decoupling of
North Atlantic (inactive) and South Pacific (active) tropical cyclone patterns during the
mid-Holocene suggests precession driven changes in storm season insolation may
constrain ocean-atmosphere thermal gradients and therefore cyclone potential intensity
on orbital timescales.
Description
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2014
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Suggested Citation
Thesis: Toomey, Michael R., "Quaternary morphology and paleoenvironmental records of carbonate islands", 2014-02, DOI:10.1575/1912/6315, https://hdl.handle.net/1912/6315Related items
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