The Huon Peninsula (Papua New Guinea) coral reef terraces re-visited with high-resolution topography and modeling
Abstract
Coral reef terraces (CRT) are key indicators of Quaternary sea level fluctuations, and have provided crucial insights within a wide spectrum of climatic and tectonic studies. The Huon Peninsula in Papua New Guinea was one of the first sites with an extensive CRT sequence to be mapped, measured and dated in detail, providing a basis for the earliest relative sea-level (RSL) curves. We re-visit the Huon CRTs to improve RSL constraints by using digital surface models calculated from 0.5m Pleiades satellite imagery. These allow us to assess the large-scale morphology and spatiotemporal uplift rate variations with unprecedented detail and provide a first order estimate of RSL-highstands. Unlike earlier studies, we find that large-scale tilting of the terrace sequence is generally N-directed, which implies RSL highstand estimates to be several meters higher than previously thought. We then use coral reef modeling to re-create the sequence morphology over the past few glacial-interglacial cycles, which allows us to consider 1) possible non-linear relationships between terrace elevations and RSL-highstands 2) the full possible range of RSL histories beyond only highstands. Our analysis shows that RSL at the Huon Peninsula was probably higher than most eustatic sea-level curves suggest, especially during peaks in MIS 3, 6 and 8. We discuss possible explanations for this discrepancy within the context of ice-sheet dynamics and eustatic sea-level cycles.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMPP015..06D
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHERE;
- 4556 Sea level: variations and mean;
- OCEANOGRAPHY: PHYSICAL;
- 4926 Glacial;
- PALEOCEANOGRAPHY;
- 4936 Interglacial;
- PALEOCEANOGRAPHY