Publications

An earthquake swarm on the Chagos-Laccadive Ridge and its tectonic implications


An unusual, isolated swarm of earthquakes occurred on the Chagos-Laccadive Ridge in the Central Indian Ocean between 1965 and 1970. Sixteen earthquakes were located at approximately 6.0" S, 7 1.3" E on the steep west facing scarp of the Chagos Bank. This swarm forms the only major seismic activity in the period 1963-76 on the otherwise aseismic ridge. The mechanisms of the three largest earthquakes were studied using body- and surface-wave data. All are extremely similar shallow normal fault events on an east-west fault plane. Such faulting is difficult to reconcile with that expected from either the trend of the Chagos-Laccadive Ridge or the spreading direction at the nearby Central Indian Ridge. The swarm may have occurred at depth on a cross fracture remaining from the breakup of the Chagos Bank and the Mascarene Plateau and the formation of the present Central Indian Ridge.
Authors
Stein S .
Year
1
DOI
10.1111/j.1365-246X.1978.tb05928.x
ISBN-13
0
Keywords
earthquakes
Link
http://gji.oxfordjournals.org/content/55/3.toc