4.7 Article

Two hundred thirty years of relative sea level changes due to climate andmegathrust tectonics recorded in coral microatolls of Martinique (FrenchWest Indies)

Journal

JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
Volume 121, Issue 4, Pages 2873-2903

Publisher

AMER GEOPHYSICAL UNION
DOI: 10.1002/2015JB012406

Keywords

-

Funding

  1. Agence Nationale de la Recherche (Project EQUIPEX ASTER-CEREGE)
  2. ANR CATTELL SUBSISMANTI
  3. INSU (CT3 ALEAS)

Ask authors/readers for more resources

We sampled six coral microatolls that recorded the relative sea level changes over the last 230 years east of Martinique, on fringing reefs in protected bays. The microatolls are cup-shaped, which is characteristic of corals that have been experiencing submergence. X-ray analysis of coral slices and reconstructions of the highest level of survival (HLS) curves show that they have submerged at rates of a few millimeters per year. Their morphology reveals changes in submergence rate around 1829 +/- 11, 1895, and 1950. Tide gauges available in the region indicate a regional sea level rise at a constant mean rate of 1.1 +/- 0.8 mm/yr, which contrasts with our coral record, implying additional tectonic subsidence. Comparing our coral morphology with that of synthetic corals generated with Matlab by using the Key West tide gauge record (Florida), we show that their growth was controlled by tectonics and that a sudden relative sea level increase drowned them around 1950. Simple elastic models show that this sudden submergence probably occurred during the 21 May 1946 earthquake, which ruptured the plate interface in front of Martinique, in the mantle wedge, in an area of sustained seismic activity. The 1839 M8+ earthquake probably occurred in the same area. Long-term subsidence of microatolls indicates that this deep portion of the megathrust is probably locked down to 60 km depth during the interseismic period. Our oldest coral recorded a long-lasting period (50 years) of stable relative sea level after the 1839 earthquake, indicating that transient interseismic strain rate variations may occur in the Lesser Antilles.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available