Sinkholes Tellus Border Earthquake - Geological Survey of Ireland

Earthquakes shake East Coast
Geology Matters: Summer 2013
Dr Brian McConnell, Bedrock Programme
Two earthquakes recently
occurred just off the coast
of the Llyn peninsula, North
Wales. The first was at 3.16am
on Wednesday 29th May,
Magnitude is variably reported
as between 3.8ML and 4.2ML
at a depth of 8km. The second
of magnitude 2.8ML took place
in almost the same location at
22.28 on the 26th of June.
The earthquakes were
produced by movements on
the Menai Straits fault system,
which runs across the Irish
Sea from Anglesey to South
Wexford. This fault has had
a long geological history of
movement and is a locus
of small earthquakes to the
present day.
Shaking of buildings was
reported across SE Ireland,
from counties Wexford to
Dublin. In Britain, the tremors
were felt in many communities
in North Wales and even in
Douglas, Isle of Man and
Southport, Lancashire.
Location of recent earthquakes,
courtesy of BGS.
In 1984 the Llyn Peninsula
was also the site of the largest
earthquake felt in Ireland in
recent times, which measured
5.4ML.
Image captured on May 29th by Seismograph based at the
Geological Survey of Ireland
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