Earthquake!

A very loud rumbling noise with some shaking of the house occurred at 9.15 this morning lasting several seconds. I don't yet know how widely it was felt, but certainly in Bruichladdich, Port Charlotte and Kilchoman, and I assume right across the island. The trace below is from a seismological station in Northern Ireland and taken from the British Geological Survey website. There was a second, smaller, rumble, about 10 minutes later. The immediate thought of myself and those I have spoken to was of a very large truck rumbling past on the road or even crashing off the road! Or perhaps of a very large building close by falling down! Fortunately, neither of those have happened, but that was the impression we had.
According to the BGS website, the tremor registered 2.8 on the Richter Scale, and the second one 2.1.
We appear to be in a very active period, as several tremors have been registered this month with the two today making a total of six this month with five in the last 10 days. Quite a number of people felt the one at 5.35 am on 20th Feb, though I have to confess that it failed to wake me up!

Date                Time               Lat           Long   Depth (km)  Richter scale
2012/02/29     09:25:08.1     55.791     -6.348       9                    2.1          ISLAY, ARGYLL/BUTE
2012/02/29     09:14:26.0     55.777     -6.326     10                    2.8          ISLAY, ARGYLL/BUTE   
2012/02/27     08:20:47.3     55.776     -6.301     12                    1.6          ISLAY, ARGYLL/BUTE   
2012/02/20     07:18:20.0     55.750     -6.317       9                    1.4          ISLAY, ARGYLL/BUTE   
2012/02/20     05:35:48.9     55.780     -6.349     12                    2.6          ISLAY, ARGYLL/BUTE
2012/02/05     15:15:03.3     55.801     -6.368       6                    1.5          ISLAY, ARGYLL/BUTE  


Malcolm

What happened last night? Was it an earth tremor?

At around 22.45hrs last night lots of people heard/felt something on Islay - but there are no reports of an earth tremor on the net, not that we have been able to find anyway.  Some people describe 'feeling' something, others heard a loud noise/rumble.

Does anyone know what it was?  Suggestions include an earth tremor, explosion, thunder, a strong gust of wind - or an aircraft breaking the sound barrier.  We once heard the Space Shuttle coming in  to land at Edwards Air Force Base in California and when it passed overhead in the San Fernando Valley it made a similar (actually louder) noise...

Carl

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