Webster, Jody M. (2008) Drowned reefs in the Great Barrier Reef and Hawaii: a new era in IODP coral reef drilling. In: Australian Earth Sciences Convention 2008. p. 251. From: Australian Earth Sciences Convention 2008, 20-24 July 2008, Perth, WA, Australia.

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Abstract

[Extract] The success of the recent IODP Tahiti Sea Level Expedition 310 has paved the way for a new era in shallow water carbonate drilling and research. This paper will summarize the scientific rationale and progresss towards IODP drilling of drowned reefs off the GBR and Hawaii. The site survey has now been completed for the GBR with EM300 bathymetry, seismic, AUV imaging and rock dredging data collected on a 2007 RV Southern Surveyor cruise. Similar to the Tahiti expedition, the scientific objectives of the GBR drilling are three fold; (1) to establish the nature of sea level rise since the last ice age about 20 ka; (2) reconstruct associated changes in sea surface temperature and salinity; and (3) determine how the GBR responded to these changes in terms of geometry, composition and community structure. Scientific drilling in the GBR will provide not only an important comparison with the Tahiti record but also a unique archive of Western Pacific sea level variability, climate change and reef evolution. Observational and numerical modeling data from the drowned Hawaiian reefs indicate that the internal stratigraphy and tops of the reefs are highly sensitive to sea-level and climate changes. Furthermore, as a direct result of Hawaii's rapid but constant subsidence, thick (100-200 m) expanded reef sequences are preserved. These reefs span important periods in Earth climate history that are either not available or are highly condensed, due to a lack of accommodation space and/or unfavorable shelf morphology, on stable (eg., GBR, Tahiti) or uplifted margins (eg., PNG, Barbados). The Hawaiian reefs grew throughout (albeit episodically) the majority of the last six glacial cycles. Therefore, scientific drilling through these reefs will generate a new record of sea-level and associated climate variability during several controversial and poorly understood periods over the last 500 kyr.

Item ID:	27805
Item Type:	Conference Item (Abstract / Summary)
ISSN:	0729-011X
Date Deposited:	30 Jul 2013 05:24
FoR Codes:	04 EARTH SCIENCES > 0403 Geology > 040305 Marine Geoscience @ 100%
SEO Codes:	97 EXPANDING KNOWLEDGE > 970104 Expanding Knowledge in the Earth Sciences @ 100%
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