High‐resolutionS r/C a ratios in aP orites luteacoral fromL akshadweepA rchipelago, southeastA rabianS ea: An example from a region experiencing steady rise in the reef temperature
| Autor: | Steffen Hetzinger, Miriam Pfeiffer, Wolf-Christian Dullo, Syed Masood Ahmad, Dieter Garbe-Schönberg, Netramani Sagar |
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| Rok vydání: | 2016 |
| Předmět: |
010504 meteorology & atmospheric sciences
Coral bleaching Coral Porites 010502 geochemistry & geophysics Oceanography Monsoon 01 natural sciences Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) 14. Life underwater Reef 0105 earth and related environmental sciences geography geography.geographical_feature_category biology Coral reef biology.organism_classification Sea surface temperature Geophysics 13. Climate action Space and Planetary Science Climatology Archipelago Environmental science |
| Zdroj: | Journal of Geophysical Research: Oceans. 121:252-266 |
| ISSN: | 2169-9291 2169-9275 |
| DOI: | 10.1002/2015jc010821 |
| Popis: | Here we present the first record of Sr/Ca variability in a massive Porites lutea coral from the Lakshadweep Archipelago, Arabian Sea. The annual mean sea surface temperature (SST) in this region and the surrounding areas has increased steadily in the recent past. During some major El Nino events, SSTs are even higher, imposing additional thermal-stress on corals, episodically leading to coral bleaching. We infer from the coral-Sr/Ca record (1981-2008) that during some of these events high and persistent SSTs lead to a dampening of the temperature signal in coral-Sr/Ca, impairing the coral's ability to record full scale warming. Thus, coral-Sr/Ca may provide a history of past El Nino Southern-Oscillation (ENSO) induced thermal-stress episodes, which are a recurrent feature also seen in cross-spectral analysis between coral-Sr/Ca and the Nino3.4 index. Despite the impact of episodical thermal-stress during major El Nino events, our coral proxy faithfully records the seasonal monsoon-induced summer cooling on the order of approximate to 2.3 degrees C. Calibration of coral-Sr/Ca with instrumental grid-SST data shows significant correlation to regional SST and monsoon variability. Hence, massive Porites corals of this region are highly valuable archives for reconstructing long-term changes in SST, strongly influenced by monsoon variability on seasonal scales. More importantly, our data show that this site with increasing SST is an ideal location for testing the future effects of the projected anthropogenic SST increase on coral reefs that are already under thermal-stress worldwide. |
| Databáze: | OpenAIRE |
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