← Back to Sessions

Complex Martinique Intermediate Depth Earthquake Hints at Early Atlantic Break-Up

Description: 

Earthquake rupture is the result of complex physical properties and stresses. In the last decade, more and more observations were reported that large earthquakes consist of multiple ruptures on a network of faults within the continental crust and oceanic lithosphere. Similar observations are lacking for intermediate-depth (70 - 300 km) earthquakes posing the question if multiple fault ruptures are hindered by the physical properties and stresses in subducting lithosphere. On November 29, 2007, an Mw7.4 earthquake struck the central islands of the Lesser Antilles Island Arc close to the island of Martinique. The earthquake occurred at a depth of ∼150 km near the lower end of the Wadati-Benioff-Zone (WBZ) of the Lesser Antilles subduction zone. Restricted by limited coverage and unfavorable distribution of regional seismic stations at the time of the earthquake, a detailed examination of the rupture process of the Martinique event was challenging if not impossible. Here, we compile seismic data from different studies and perform regional moment tensor (RMT) inversion to show that the earthquake is a doublet consisting of at least two oblique fault planes. Our analysis suggests that the earthquake ruptured along a re-activated ridge-transform fault at the plate boundary between the subducting Atlantic/Proto-Caribbean lithosphere.

Session: Structure and Properties of Subducting Slabs and Deep Earthquakes [Poster]

Type: Poster

Date: 4/19/2023

Presentation Time: 08:00 AM (local time)

Presenting Author: Andreas Rietbrock

Student Presenter: No

Invited Presentation: 

Authors