Technically known as an
earthquake swarm, the
Manchester earthquakes began on October 19th 2002, although the largest one was on October 21st, 2002 (measuring 3.9 on the
Ricter Scale and rating as a 5+ on the
European Macroseismic Scale (EMS) intensity scale). Earthquakes on this scale are rare in the UK, as the country is not situated on any major faultlines.
Earthquake swarms are sequences of earthquakes clustered in time and space without a clear distinction of main shock and aftershocks. Examples of such swarm activity in the UK are 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.
The Manchester sequence appears to be an earthquake swarm, since the difference in magnitude between the largest event in the sequence and the other events is not as significant as expected in a main shock – aftershock sequence. However, most of the energy during the sequence was actually released in the double-event on October 21 at 11:42. The clustering of these events in time and space does suggest that there is a causal relationship between the events of the sequence.
As a result of this (still ongoing) Manchester swarm, the British Geological Survey (BGS) have stationed three temporary seismograph stations within the city to compliment the two existing stations in the east and south-east. The temporary stations are located in Altrincham, one near Chaddington and one at Manchester University.
These stations have shown that the epicentres of each earthquake varies. The vast majority are located within a wide band running from the city centre out toward Ashton-Under-Lyne and from Gorton in the south to Collyhurst in the north.
Details of the swarm - as of 19 November 2002 (times in GMT).
Year Mo Dy Hr Mn Secs Lat Lon kmE kmN Depth Mag Int(EMS)
2002 11 19 02 31 45.3 53.486 -2.208 386.2 398.8 5.0 1.7
2002 11 19 01 00 31.0 53.491 -2.188 387.5 399.4 5.0 2.1 2+
2002 11 16 07 34 36.9 53.501 -2.205 386.4 400.5 5.0 2.1
2002 11 16 04 59 1.9 53.484 -2.179 388.1 398.6 5.0 2.5 3+
2002 11 16 04 57 46.7 53.490 -2.166 389.0 399.3 5.0 2.1 2+
2002 11 13 00 19 58.5 53.488 -2.201 386.7 399.1 5.0 1.6
2002 11 11 22 21 12.7 53.484 -2.162 389.3 398.6 5.0 1.8
2002 11 10 18 47 9.5 53.491 -2.222 385.3 399.4 5.0 2.0
2002 11 10 11 43 54.7 53.482 -2.172 388.6 398.4 5.0 2.0
2002 11 10 04 12 22.6 53.491 -2.222 385.3 399.4 5.0 2.3 3+
2002 11 09 23 36 42.7 53.481 -2.158 389.5 398.3 5.0 2.0
2002 11 09 01 54 33.2 53.480 -2.164 389.2 398.2 5.0 2.2 2+
2002 11 09 01 11 20.1 53.474 -2.167 388.9 397.5 5.0 2.1
2002 11 09 00 27 43.7 53.485 -2.137 390.9 398.7 5.0 1.9
2002 11 09 00 21 7.3 53.487 -2.178 388.2 398.9 5.0 1.7
2002 11 06 04 37 43.8 53.478 -2.107 392.9 398.0 5.0 1.7
2002 11 06 03 32 22.7 53.490 -2.101 393.3 399.3 5.0 1.8
2002 11 06 02 45 52.0 53.495 -2.175 388.4 399.9 5.0 1.6
2002 11 06 02 34 38.9 53.499 -2.082 394.6 400.2 5.0 1.7
2002 11 05 20 31 23.5 53.477 -2.163 389.2 397.9 5.0 1.9
2002 11 04 07 32 32.0 53.474 -2.159 389.5 397.6 5.0 2.7 3+
2002 11 04 07 29 12.8 53.481 -2.168 388.8 398.3 5.0 2.3 2+
2002 11 04 01 44 15.5 53.499 -2.165 389.0 400.2 5.0 1.1
2002 11 01 04 22 52.7 53.487 -2.217 385.6 399.0 5.0 1.5
2002 10 31 01 50 57.4 53.484 -2.211 386.0 398.6 5.7 2.3 2+
2002 10 31 00 07 15.0 53.469 -2.127 391.6 396.9 4.3 1.9
2002 10 29 17 32 15.9 53.487 -2.209 386.1 398.9 5.0 2.4 3+
2002 10 29 04 59 57.2 53.493 -2.212 386.0 399.7 5.0 1.6
2002 10 29 04 43 59.1 53.506 -2.178 388.2 401.1 5.0 1.8
2002 10 29 04 42 52.0 53.481 -2.198 386.9 398.3 5.0 2.6 3+
2002 10 29 00 07 53.7 53.486 -2.198 386.9 398.8 5.0 2.2 3+
2002 10 28 19 25 59.1 53.483 -2.201 386.7 398.6 5.0 2.3 3+
2002 10 28 03 27 51.1 53.494 -2.109 392.7 399.7 5.0 1.7
2002 10 28 03 08 14.1 53.494 -2.190 387.4 399.7 5.0 2.0
2002 10 26 22 35 35.5 53.504 -2.188 387.5 400.8 5.0 1.6
2002 10 26 21 14 26.6 53.492 -2.179 388.1 399.5 5.0 1.9
2002 10 25 17 24 48.1 53.485 -2.197 387.0 398.8 2.5 2.6 3+
2002 10 25 04 26 15.4 53.518 -2.250 383.4 402.4 5.0 1.6
2002 10 25 00 38 31.1 53.492 -2.121 392.0 399.5 5.0 1.6
2002 10 25 00 25 44.7 53.485 -2.212 385.9 398.8 5.0 2.3 2+
2002 10 25 00 20 39.7 53.488 -2.213 385.9 399.1 5.0 2.5 3+
2002 10 25 00 19 27.3 53.481 -2.204 386.5 398.4 5.0 2.5 3+
2002 10 25 00 02 51.0 53.505 -2.173 388.5 401.0 5.0 1.6
2002 10 24 23 07 51.6 53.496 -2.210 386.1 399.9 5.0 2.2
2002 10 24 19 13 18.6 53.482 -2.139 390.8 398.4 5.0 1.9
2002 10 24 19 00 45.8 53.489 -2.202 386.6 399.2 5.0 2.2 3+
2002 10 24 18 37 12.6 53.487 -2.213 385.9 399.0 5.0 2.6 3+
2002 10 24 16 34 38.8 53.493 -2.188 387.5 399.6 5.0 2.2
2002 10 24 15 46 44.2 53.482 -2.197 386.9 398.4 5.0 2.8 3+
2002 10 24 15 33 49.4 53.512 -2.229 384.8 401.8 5.0 1.9
2002 10 24 15 00 9.9 53.494 -2.206 386.3 399.8 5.0 1.8
2002 10 24 14 56 40.7 53.496 -2.194 387.2 400.0 5.0 2.1
2002 10 24 14 55 55.7 53.497 -2.201 386.7 400.1 5.0 1.9
2002 10 24 14 29 26.1 53.456 -2.182 387.9 395.5 5.0 1.7 2+
2002 10 24 12 20 28.4 53.495 -2.140 390.7 399.9 5.0 1.6
2002 10 24 10 45 13.9 53.480 -2.172 388.6 398.2 5.0 1.8
2002 10 24 10 26 55.8 53.490 -2.152 389.9 399.3 5.0 1.9
2002 10 24 09 46 54.6 53.492 -2.134 391.1 399.6 5.0 1.9
2002 10 24 09 36 5.5 53.493 -2.136 391.0 399.7 5.0 1.7
2002 10 24 09 18 5.1 53.503 -2.140 390.7 400.8 5.0 1.8
2002 10 24 08 42 36.7 53.499 -2.153 389.8 400.3 5.0 1.9
2002 10 24 08 24 54.7 53.485 -2.179 388.1 398.7 3.7 3.1 4+
2002 10 24 08 21 44.7 53.490 -2.180 388.1 399.3 5.0 2.0
2002 10 24 07 52 54.4 53.480 -2.173 388.5 398.2 5.0 2.6 3+
2002 10 24 06 38 26.5 53.473 -2.150 390.0 397.4 5.0 1.7
2002 10 24 05 53 54.5 53.482 -2.200 386.8 398.4 5.0 2.2
2002 10 24 04 38 36.9 53.479 -2.148 390.2 398.0 5.0 2.0 2+
2002 10 24 04 36 59.1 53.470 -2.161 389.3 397.1 5.0 2.3
2002 10 23 23 27 25.4 53.485 -2.174 388.4 398.8 5.0 1.9
2002 10 23 20 31 28.8 53.484 -2.172 388.6 398.6 5.0 2.5 3+
2002 10 23 20 20 56.7 53.499 -2.214 385.8 400.3 5.0 1.8
2002 10 23 20 16 31.7 53.477 -2.162 389.2 397.8 5.0 2.2 3+
2002 10 23 19 18 11.6 53.488 -2.164 389.2 399.1 5.0 2.0
2002 10 23 06 27 52.6 53.498 -2.137 390.9 400.2 5.0 2.0
2002 10 23 05 44 34.8 53.475 -2.125 391.7 397.6 3.6 1.9 2+
2002 10 23 04 46 21.1 53.514 -2.211 386.0 402.0 5.0 1.6
2002 10 23 03 57 47.6 53.493 -2.051 396.6 399.6 5.0 1.6
2002 10 23 01 53 28.8 53.477 -2.157 389.6 397.9 5.0 2.8 3+
2002 10 22 16 53 41.0 53.488 -2.145 390.4 399.1 5.0 2.4 2+
2002 10 22 13 38 27.9 53.491 -2.188 387.5 399.4 5.0 1.9
2002 10 22 12 51 59.6 53.468 -2.095 393.7 396.9 5.0 1.4
2002 10 22 12 28 8.4 53.473 -2.146 390.3 397.4 4.2 3.1 4+
2002 10 22 09 47 2.3 53.480 -2.147 390.3 398.2 5.0 1.7
2002 10 22 06 27 24.7 53.491 -2.079 394.8 399.4 5.0 1.7
2002 10 22 06 20 57.5 53.483 -2.202 386.6 398.6 5.0 2.0
2002 10 22 04 27 19.0 53.481 -2.133 391.2 398.3 5.0 1.3
2002 10 22 04 08 51.9 53.492 -2.121 392.0 399.5 5.0 1.5 2+
2002 10 22 04 02 45.9 53.484 -2.198 386.8 398.7 5.0 1.8
2002 10 22 03 54 2.4 53.464 -2.154 389.8 396.3 5.0 2.0 2+
2002 10 22 03 39 37.6 53.463 -2.219 385.5 396.3 5.0 2.9 4+
2002 10 22 00 41 49.9 53.502 -2.118 392.2 400.6 5.0 1.6
2002 10 22 00 24 22.0 53.471 -2.170 388.7 397.2 5.0 1.6
2002 10 21 22 34 38.3 53.472 -2.183 387.9 397.3 5.0 2.1
2002 10 21 17 02 42.1 53.502 -2.211 386.0 400.6 5.0 2.2
2002 10 21 16 22 21.8 53.480 -2.193 387.2 398.2 5.0 2.0
2002 10 21 11 56 46.0 53.441 -2.139 390.8 393.8 5.0 2.0
2002 10 21 11 42 56.9 53.478 -2.218 385.5 397.9 5.0 3.5 4+
2002 10 21 11 42 34.7 53.478 -2.196 387.0 398.0 2.8 3.9 5+
2002 10 21 11 15 6.6 53.490 -2.155 389.7 399.3 5.0 1.8
2002 10 21 08 04 58.7 53.497 -2.210 386.1 400.1 5.0 2.3 3+
2002 10 21 07 45 15.8 53.475 -2.196 387.0 397.6 5.0 3.2 4+
2002 10 21 07 29 20.4 53.490 -2.198 386.9 399.3 5.0 1.8
2002 10 19 01 44 59.5 53.504 -2.186 387.7 400.9 5.0 1.4
2002 10 19 01 21 26.6 53.506 -2.203 386.5 401.1 5.0 1.4
Key to the table.
Year Mo Dy - Year, month and day of event.
Hr Mn Secs - Time of occurrence of event in hours, mins and secs. All times are in Greenwich Mean Time.
Lat - Latitude of the event, positive latitude indicates north.
Lon - Longitude of the event, negative longitude indicates west.
kmE - UK National Grid Reference in kilometres east of grid origin.
kmN - UK National Grid Reference in kilometres north of grid origin.
Dep - Depth of the hypocentre in kilometres.
Mag - Richter local magnitude of the event.
Int - Maximum EMS intensity. 2+ indicates felt, no macroseismic details. 3+, 4+ etc indicates felt at 3 or 4, but no survey carried out. 3, 4, 5 etc describes the maximum EMS intensity produced by the event.
Source : http://www.quakes.bgs.ac.uk
I will update this node with further details of the earthquake swarm as and when necessary.