Seismic gaps and intraplate seismicity around Rodrigues Ridge (Indian Ocean) from time domain array analysis

  • Rodrigues Ridge connects the Réunion hotspot track with the Central Indian Ridge (CIR) and has been suggested to represent the surface expression of a sub-lithospheric flow channel. From global earthquake catalogues, the seismicity in the region has been associated mainly with events related to the fracture zones at the CIR. However, some segments of the CIR appear void of seismic events. Here, we report on the seismicity recorded at a temporary array of 10 seismic stations operating on Rodrigues Island from September 2014 to June 2016. The array analysis was performed in the time domain by time shifting and stacking the complete waveforms. Event distances were estimated based on a 1-D velocity model and the travel time differences between S and P wave arrivals. We detected and located 63 new events that were not reported by the global networks. Most of the events (51) are located off the CIR and can be classified as intraplate earthquakes. Local magnitudes varied between 1.6 and 3.7. Four seismic clusters were observed that occurred to the west of the spreading segment of the CIR. The Rodrigues Ridge appeared to be aseismic during the period of operation. The lack of seismic activity along both Rodrigues Ridge and the sections of the CIR to the east of Rodrigues may be explained by partially molten upper-mantle material, possibly in relation to the proposed material flow between the Réunion plume and the CIR.
Author:Manvendra SinghORCiDGND, Georg RümpkerORCiD
Parent Title (English):Solid earth
Publisher:Copernicus Publ.
Place of publication:Göttingen
Document Type:Article
Date of Publication (online):2020/12/23
Date of first Publication:2020/12/23
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2021/01/21
Page Number:12
First Page:2557
Last Page:2568
© Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
Institutes:Geowissenschaften / Geographie / Geowissenschaften
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften
Open-Access-Publikationsfonds:Geowissenschaften / Geographie
Licence (German):License LogoCreative Commons - Namensnennung 4.0