Aftershock strikes near Jersey
Magnitude 2.0, near Jersey, Channel Islands
A minor earthquake struck south-west of Jersey in the Channel Islands, with reports sent to the British Geological Survey of people on the island of Jersey feeling the tremor. It is another aftershock of the magnitude 4.3 earthquake which struck on the 11th July this year.
The magnitude 2.0 earthquake struck at 9:49pm, and had a focal depth of 7 kilometres. Previous seismicity in this area since the magnitude 4.3 earthquake on the 11th July have struck at depths of between 6 and 12 kilometres along a north-south striking line. Although the immediate conclusion is this line may well represent the features of a fault, it has yet to be confirmed that this is the case. In fact very little information has been forthcoming regarding the July earthquake from BGS, something which is rather bizarre for the largest earthquake to strike the Channel Islands since 1932.
The Channel Islands have a long recorded history of felt earthquakes on or near the islands. The earliest known earthquake to have been felt on the Channel Islands occurred in 1091 and this tremor brought down the copper cock on the spire of Coutances Cathedral in France; it quite likely also brought down stones from the church at Angers. Since this quake there have been numerous large quakes in the Channel Islands or adjacent parts of France, including numerous shakes in April 1773, a large earthquake offshore of Caen in 1878, another large earthquake offshore of Caen in 1889, two earthquakes in 1926 and 1927 east of Jersey of large magnitudes, and the 1932 earthquake.
Further earthquake in the Channel Islands over the next two or three decades are to be expected. Due to the lack of recent earthquake of significance, it is unknown what sort of magnitudes to expect, but in general magnitude of 5.5 at maximum are not to be dismissed for the Channel Islands themselves, and magnitude 6 earthquakes in the Cotentin or southern Brittany near Vannes are distinct possibilities.
The magnitude 2.0 earthquake struck at 9:49pm, and had a focal depth of 7 kilometres. Previous seismicity in this area since the magnitude 4.3 earthquake on the 11th July have struck at depths of between 6 and 12 kilometres along a north-south striking line. Although the immediate conclusion is this line may well represent the features of a fault, it has yet to be confirmed that this is the case. In fact very little information has been forthcoming regarding the July earthquake from BGS, something which is rather bizarre for the largest earthquake to strike the Channel Islands since 1932.
The Channel Islands have a long recorded history of felt earthquakes on or near the islands. The earliest known earthquake to have been felt on the Channel Islands occurred in 1091 and this tremor brought down the copper cock on the spire of Coutances Cathedral in France; it quite likely also brought down stones from the church at Angers. Since this quake there have been numerous large quakes in the Channel Islands or adjacent parts of France, including numerous shakes in April 1773, a large earthquake offshore of Caen in 1878, another large earthquake offshore of Caen in 1889, two earthquakes in 1926 and 1927 east of Jersey of large magnitudes, and the 1932 earthquake.
Further earthquake in the Channel Islands over the next two or three decades are to be expected. Due to the lack of recent earthquake of significance, it is unknown what sort of magnitudes to expect, but in general magnitude of 5.5 at maximum are not to be dismissed for the Channel Islands themselves, and magnitude 6 earthquakes in the Cotentin or southern Brittany near Vannes are distinct possibilities.
This article was written on the 4th October 2014 by J H Gurney.
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