GeologyRocksKent Earthquake
The Kent earthquake comes as no real surprise to me. This area is one of the most active areas for large earthquakes in the UK, albeit with long return times. The most significant events were on 21st May 1382 and 6th April 1580, both estimated at Local Magnitude 5.8. The latter caused much damage in the southeast of England and is one of Britain's most fatal earthquakes with two apprentices being killed by falling masonry in a church in Newgate.
This region lies on the Artois (as in Stella) Axis, the lateral equivalent on the Variscan front that runs though South Wales and the Bristol Area - a fundamental lineament and a major zone of crustal weakness.
Note that at magnitude 4.3 today's earthquake was about 180 times less powerful than the historic events (1 unit on the magnitude scale = ~32 x increase in power [10x amplitude]).
Note also that I've not mentioned the 'Richter' word - it only works in California with a Wood-Anderson seismograph!
- hypocentre's blog
- Login or register to post comments
Send to friend
Comments
Rank:
Roles:
Contact:
About the structure down
Sun, 04/29/2007 - 08:23About the structure down there. If I remember correctly, some faults in southern UK were reactivated during the Alpine orgeny. However, I can't remember if those were Variscan faults or Jurassic extensional faults (or indeed both!). Anyone enlighten me?
Geologists are gneiss!!
Rank:
Roles:
Contact:
Southern Structure
Sun, 04/29/2007 - 08:30Both probably. The ones you are probably thinking about like the Isle of Wight monocline and Lulworth Crumple etc. are inversion on Mesozoic normal faults. However, the Variscan structures would be reactivated as well. Something has to bring the Carboniferous of the Kent Coalfield close to the surface.
Geologists like a nappe between thrusts