2.3 Magnitude Earthquake Recorded In Irish Sea

A 2.3 magnitude earth tremor was recorded in the Irish sea off North Wales last night.

The earthquake of the 7 February occurred at 22:41 UTC, with an epicentre approximately 12 km southwest of Caernarfon, Gwynedd.

The instrumental magnitude was determined at 2.3 ML, and is located approximately 10 km north of the magnitude 5.4 earthquake that occurred on the Lleyn peninsula on 26 July 1984. The latter quake was the largest ever recorded earthquake on mainland Britain and was felt throughout Ireland's east coast, Wales and England. Aftershocks from the quake measured up to 4 on the Richter scale.

According to the British Geological Survey (BGS): "The estimated area over which an earthquake with a magnitude of 2.3, and depth of 13 km, would be felt was calculated to be a distance of up to 30 km from the epicentre. Analysis of the results from an automatic online questionnaire survey agreed with this. So far, some 110 felt reports have been received out of a total of 135 completed questionnaires. Of those 110 felt reports, the majority came from populated areas up to 30 km northeast of the epicentre, particularly from the towns of Caernarfon and Bangor and surrounding hamlets. Around a dozen reports were received from beyond this area with the furthest afield being from near Abersoch (28 km to the SSW), Porthmadog (22 km to the SE) and near Harlech (34 km to the SE)."

Most people described the shaking strength of the earthquake to be weak, with a few reporting it as moderate, and most describing the sound strength to be moderate. Reports described “I just heard loud rumbling, at first I thought it was thunder”, “roar didn't last very long but it was so loud I turned the teli volume off”, “rumbling sound that seemed to come from underneath my feet with slight shaking”, “sounded so loud that thought there was a train heading toward me”.

It is unlikely the effects of earth tremor were felt on Ireland's east coast.

A magnitude 2.7 earthquake was recorded off the northwest coast of Ireland on November 21st last.

On June 6th 2012, a magnitude 4.0 earthquake was recorded off the coast of County Mayo, close to the Corrib gas field.  The quake happened at 9am, 60km west of Aughleam near Belmullet.

The most significant land tremor to be recorded in recent years occurred in May 2012 when a 2.7 quake hit Lisdoonvarna in County Clare in May 2010.   It also was the first tremor or earthquake to be recorded in the west of Ireland in modern times.

Seismologist, Davie Galloway, on BBC Radio Wales, discusses the 2.3 M earthquake HERE
See the TMT earthquakes map HERE
More info from IRIS