An unusual occurrence of a moderately sized earthquake (Ml 4.2) on the Irish continental shelf and passive margin
Abstract
On June 06th, 2012, at UTC 07:58:13, a magnitude 4 earthquake occurred at 54.151N, 10.904W and was felt over a wide area of County Mayo in Western Ireland. The epicentre was 100 km off Ireland's West Coast in the region of the Erris-Slyne Trough. The event was recorded by the five Irish National Seismic Network (INSN) broadband stations currently in operation across the island and by eighteen of the broadband stations of Ireland Array (a long-term temporary deployment). This event, although not large in global terms, is the largest local event recorded by the INSN in recent times. It is significant as no events have ever been located in this region since recording began in 1978. This earthquake occurred along the Irish continental shelf proximal to a region of moderate Mesozoic crustal extension of Caledonian crystalline basement. It is located landward of tectonically hyper-extended crust in the deep-water Rockall Trough, near a region of slope failure related to Pleistocene climate change. The largest local event ever recorded by the INSN occurred on the other side of the island, in the Irish Sea, off the Llwyn Peninsula in Wales on July 19th, 1984, and measured magnitude 5.4. We discuss the significance of the recent event in the context of the overall tectonics of Ireland and north-eastern Atlantic and explore its implications for seismicity and hazard assessment in the region.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.S53A2476B
- Keywords:
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- 7230 SEISMOLOGY / Seismicity and tectonics;
- 7299 SEISMOLOGY / General or miscellaneous