A 4 magnitude earthquake was recorded Wednesday morning about 30 miles outside of Mayo off the Western coast of Ireland. Local people reported feeling slight tremors as well as light structural damage. This is the first earthquake in the area since recordings began in 1978.
RTE News reports that the British Geological Survey confirmed the small earthquake which occurred just before 9am on Wednesday. The quake hit at a depth of around three kilometers.
A spokesperson for the British Geological Survey said the earthquake was a "rare and unusual" event, but also added that around 200 small earthquakes happen around Ireland every year.
People around Mayo and Sligo reportedly felt tremors and heard a loud noise from the quake. Reports of light damage, including cracked chimneys, were received though not yet confirmed.
Wednesday’s tremors come close to the July 1984 quake felt when a 5.4 magnitude earthquake struck off the coast of Wales, causing some damage on the eastern coast of ireland.
Brian McConnell of the Geological Survey of Ireland told Midwest Radio that "There are good geological reasons for it happening in that area.”
"There's a large fault system which runs down the west coast of Ireland, and which drops the Rockall trough down from the Irish continental shelf, down into much deeper water off the west.”
"That fault system has been active for many millions of years - it still is active. So small, gradual stresses have been building up over time. And today is when the rocks just couldn't take the stress anymore and they just slipped a bit to create this earthquake."
Additionally, the recently-installed seismometer at the Cliffs of Moher in County Clare also picked up the earthquake, described as the second “significant” earthquake Ireland has experienced in recent years.
In May 2010, a 2.7-magnitude trembler struck in Lisdoonvarna, Co Clare just 6 miles from the Cliffs of Moher, and remains the strongest onshore earthquake recorded in Ireland since records began in 1978.
The 2010 quake was also the first earthquake to be recorded in the southwest of the country since records began in 1978, when the Dublin Institute for Advanced Studies (DIAS) began modern seismic recordings. The Irish National Seismic Network (INSN) now features five permanent stations in Dublin, Kerry, Galway, Donegal and Wexford, along with 55 other seismometers around the country. For more see www.dias.ie.
Tom Blake, INSN Director and Experimental Officer with the School of Cosmic Physics at DIAS, said of today’s offshore quake that: “This is the first event recorded in this area and was felt onshore by quite a number of people. There are some reports of minor structural damage, which have not been confirmed.”
Blake added that “Although Ireland does not sit on any major plate margin, it is still susceptible to earthquakes as we saw in may today and in Clare in 2010. The Cliffs of Moher seismometer would certainly was well placed to register and record this week’s earthquake.”
“This was a very important seismic event as it was the first time that a tremor had occurred in this region since records began.”