Earthquake-prone Co Wexford has been shaken once again, after a minor tremor overnight that reached magnitude 2.2.
Yet all the seismic activity doesn’t have anything to do with being perched above a geological fault.
It is just the Earth’s surface continuing to rebound after the ice melted away after the last Ice Age, according to Tom Blake of the Dublin Institute for Advanced Studies.
But it might as well have been the "big one"given the magnitude of the social media response to the event .
“It created a Twitter sensation last night,” said Mr Blake, director of the Irish National Seismic Network based at the Institute.
"We can confirm 2.2 to 2.4 magnitude and the 'felt' reports were quite extensive," he said of the event which took place at 8.45pm last night. The earthquake's epicentre has been identified as about 11km offshore of the mouth of the Slaney.
The social media quake started minutes afterwards as people began asking whether anyone else had felt it. “I know we spoke to a lot of people in Wexford through various media,” Mr Blake said. “One radio station said they had registered 18,000 people reporting what they had felt.”
People took to social media to report feeling a “loud rumble” a “slight shake” and a “roar like thunder” in Rosslare, Barntown Enniscorthy and Wexford town.
Ireland is well used to earthquakes, even if only little ones. We have two quake hotspots in North Donegal and in the Wexford region, Mr Blake said. "What is happening here is we are seeing glacial rebound. The rapid removal of the ice layer after the ice age causes the land to rebound."
The “frequency envelope” tells seismologists it is rebound rather than slippage along a fault line, he said. The low rumble that is produced happens when the underground waves reach the surface.
“There is no threat whatsoever from an incident of this nature, no cause for alarm. These are events common, we maybe have them once or twice per year.”
Last year, there were back to back events in May and June off the Anglesey coastline. They reached a magnitude of about 3.8, he said.
“There is a perception it happens more frequently but there has been no increase in seismicity. It is the very effective reporting over social media. We see the role that social media is now playing in the distribution of information,” Mr Blake said.
Visit dias.ie for more information or fill in a "felt report" by searching for dias earthquake questionnaire
