GeologyRocks

I know it wasn't in the North Sea for starters. It was in Lincolnshire.

it was near though wat do u think it was then

It was a natural earthquake, and as Matt says, under Lincolnshire, well away from the gas fields (there are no oil fields in the southern North Sea).

The earthquake focal mechanism is strike-slip NW-SE compression, in line with pretty much all natural British earthquakes. There is no reason to think that it anything else.

I don't know. The BGS have said its focus was 18.6km deep, and after a quick look at the British Regional Geology book for the area, it doesn't look like anyone knows what's that deep. It's well well well below the base of the permian at any rate. The Aeromagnetic map shows Market Rasen to be at the centre of a broad high, so perhaps this is a fault-bound structure along which there was some movement. I'm just guessing here though. The Gravity anomaly map doesn't really pick out any structures.

The UK has a long and complex geological history. At England’s heart is a solid triangular Precambrian core - the Midlands Microcraton (with its upper apex somewhere near Manchester). Along the boundaries of the Midlands microcraton are a number of faults that have long and complex histories and tend to get reactivated by modern geological stresses.

To the west is the NE-SW trending Church Stretton / Pontisford Fault system (e.g. Bishop’s Castle 1990 earthquake), to the east is a NW-SE trending system (e.g. Market Rasen 2008, Dogger Bank Earthquake 1931). This triangle is also bisected by the N-S Malvern Line (e.g. Dudley Earthquake 2002)

So large earthquakes in the UK tend to be associated with lines of fundamental weaknesses in the English crust dating back to the Precambrian.

Didn't this happen a year ago as well? Same location? I'm wondering what actually lies under Lincolnshire- has anyone seen a fault map of this location? Be interested to know as my parent live right on top of it!

Marj 

Poetry Rocks and Rocks Rock

The BGS has a map of past seismicity here and there is nothing for last year as far as I can see.

I do have a fault map for the area, unfortunately not on this laptop. However, although you can get an overall idea of fault trend (WNW-ESE) because the 'quake was so deep (18.6km) trying to correlate it with anything at the surface is futile.

Actually, I just want to pick up on something in the first post.

The north sea is a proto-rift valley or failed rift system - the mid-Atlantic ridge is now the spreading centre. The rift structure in the North sea has made it suitable for genesis of oil and gas and hence there are oil and gas fields because of the rift feature. The rift feature is not because of the oil and gas fields.