Abstract
An earthquake swarm that occurred in the vicinity of the island of Tobago during the latter half of 1982 was monitored in the near-field by a five-station seismograph network. The monitoring of the swarm eventually led to the issuing of a potential earthquake hazard alert, 3 days prior to the major energy release (earthquake magnitude mb=5.2). We discuss the reasons for issuing this alert. In particular, daily monitoring of the changing b value and energy release was used to constrain estimates of future earthquake behaviour. The aftershock seismicity showed activity in a direction trending west to WNW. This is in good agreement with the focal mechanism of the main earthquake which showed right-lateral strike-slip motion along and E-W fault plane dipping steeply (71°) to the north. This active fault appears to form part of the previously unrecognized Southern Tobago Fault System for which there is evidence in the geology of the Late Neogene rocks of the island. -Authors
Original language | English |
---|---|
Pages (from-to) | 1550-1562 |
Number of pages | 13 |
Journal | Bulletin of the Seismological Society of America |
Volume | 78 |
Issue number | 4 |
Publication status | Published - 1 Jan 1988 |