woody
24-10-2002, 11:28 AM
just thoguht you might find this interesting...:thumbs:
The Manchester earthquake swarm
The recent events in the Manchester area since 19 October 2002 are unusual in the UK in that they appear to be a sequence of earthquakes of moderate magnitude without a distinctive mainshock event of magnitude very much larger than the other events. This type of activity is called an ‘earthquake swarm’. Though they are unusual, earthquake swarms have happened before in other regions of the UK. Examples include Comrie (1788-1801, 1839-46), Glenalmond (1970-72), Doune (1997) and Blackford (1997-98, 2000-01) in central Scotland, Constantine (1981, 1986, 1992-4) in Cornwall, and Johnstonbridge (mid1980s) and Dumfries (1991,1999) in the Borders. Such activity can continue for periods ranging from weeks to years. The largest recorded earthquake within such a series in the UK has not exceeded magnitude 5, approximately the magnitude of the 2002 Dudley earthquake, which only caused minor damage to chimneypots and a church spire. Unlike Japan, Turkey or California, the UK is not located near a plate boundary, where destructive earthquakes of magnitude 7+ can occur. It also has no history of catastrophically destructive earthquakes. Thus such swarm activity should not be interpreted as a precursor to a large destructive earthquake.
Earthquakes detected in Manchester since 19 October 2002:
19 OCT 2002 01:21 UTC (02:21 BST) 1.4 ML
19 OCT 2002 01:44 UTC (02:44 BST) 1.5 ML
21 OCT 2002 07:45 UTC (08:45 BST) 3.2ML
21 OCT 2002 08:04 UTC (09:04 BST) 2.3ML
21 OCT 2002 11:42 UTC (12:42 BST) 3.9ML
21 OCT 2002 11:42 UTC (12:42 BST) 3.5ML
21 OCT 2002 11:56 UTC (12:56 BST) 2.0 ML
21 OCT 2002 17:02 UTC (18:02 BST) 2.2 ML
21 OCT 2002 22:34 UTC (23:34 BST) 2.1 ML
22 OCT 2002 00:41 UTC (01:41 BST) 1.3 ML
22 OCT 2002 03:39 UTC (04:39 BST) 2.9 ML
22 OCT 2002 03:54 UTC (04:54 BST) 2.0 ML
22 OCT 2002 04:02 UTC (05:02 BST) 1.8 ML
22 OCT 2002 04:08 UTC (05:08 BST) 1.5 ML
22 OCT 2002 04:27 UTC (05:27 BST) 1.3 ML
22 OCT 2002 06:27 UTC (07:27 BST) 1.7 ML
22 OCT 2002 12:28 UTC (13:28 BST) 3.2 ML
22 OCT 2002 16:53 UTC (17:53 BST) 2.4 ML
23 OCT 2002 01:53 UTC (02:53 BST) 2.8 ML
(plus the one from this morning!)
The Manchester earthquake swarm
The recent events in the Manchester area since 19 October 2002 are unusual in the UK in that they appear to be a sequence of earthquakes of moderate magnitude without a distinctive mainshock event of magnitude very much larger than the other events. This type of activity is called an ‘earthquake swarm’. Though they are unusual, earthquake swarms have happened before in other regions of the UK. Examples include Comrie (1788-1801, 1839-46), Glenalmond (1970-72), Doune (1997) and Blackford (1997-98, 2000-01) in central Scotland, Constantine (1981, 1986, 1992-4) in Cornwall, and Johnstonbridge (mid1980s) and Dumfries (1991,1999) in the Borders. Such activity can continue for periods ranging from weeks to years. The largest recorded earthquake within such a series in the UK has not exceeded magnitude 5, approximately the magnitude of the 2002 Dudley earthquake, which only caused minor damage to chimneypots and a church spire. Unlike Japan, Turkey or California, the UK is not located near a plate boundary, where destructive earthquakes of magnitude 7+ can occur. It also has no history of catastrophically destructive earthquakes. Thus such swarm activity should not be interpreted as a precursor to a large destructive earthquake.
Earthquakes detected in Manchester since 19 October 2002:
19 OCT 2002 01:21 UTC (02:21 BST) 1.4 ML
19 OCT 2002 01:44 UTC (02:44 BST) 1.5 ML
21 OCT 2002 07:45 UTC (08:45 BST) 3.2ML
21 OCT 2002 08:04 UTC (09:04 BST) 2.3ML
21 OCT 2002 11:42 UTC (12:42 BST) 3.9ML
21 OCT 2002 11:42 UTC (12:42 BST) 3.5ML
21 OCT 2002 11:56 UTC (12:56 BST) 2.0 ML
21 OCT 2002 17:02 UTC (18:02 BST) 2.2 ML
21 OCT 2002 22:34 UTC (23:34 BST) 2.1 ML
22 OCT 2002 00:41 UTC (01:41 BST) 1.3 ML
22 OCT 2002 03:39 UTC (04:39 BST) 2.9 ML
22 OCT 2002 03:54 UTC (04:54 BST) 2.0 ML
22 OCT 2002 04:02 UTC (05:02 BST) 1.8 ML
22 OCT 2002 04:08 UTC (05:08 BST) 1.5 ML
22 OCT 2002 04:27 UTC (05:27 BST) 1.3 ML
22 OCT 2002 06:27 UTC (07:27 BST) 1.7 ML
22 OCT 2002 12:28 UTC (13:28 BST) 3.2 ML
22 OCT 2002 16:53 UTC (17:53 BST) 2.4 ML
23 OCT 2002 01:53 UTC (02:53 BST) 2.8 ML
(plus the one from this morning!)