Mapping N Wales Earthquakes
We are taught that earthquakes ae caused by motion between plates, yet this website is mapping N Wales earthquakes. Anglesey – and N Wales in general – is in the centre of a plate, miles from any boundaries, and the nearest plate boundary out near Iceland, is a a constructive boundary or mid-ocean ridge nomrally characterised by shallow, gentle quakes.
There are, however, lots of minor tremors within plates. As the plates move, small quakes occur along old faults, a kind of gentle settling down, relieving stress. There have been several such in N Wales; this website from Seismic Explorer, shows where they have occured.
GeoMôn UNESCO Global Geopark has a seismograph – part of the “raspberry shake network”. This is vital to understanding things like plate tectonics and plate boundaries. reconstructing much of Anglesey’s geology is dependent on both unraveling past plate movements Precambrian to Carboniferous rocks] and relatively recent issues [Tertiary dolerite dykes]. Not to mention explaining those seemingly random earthquakes around Anglesey at the present day – such as the event in 1984 off Lleyn measuring 5.4 on the Richter scale it last for 12 seconds and the British Geological Survey (BGS) later declared it the largest onshore earthquake in the UK in the 20th century. Or the event in 1990 which measured 5.1 on the Richter scale. There are many ancient fault systems embedded in the rocks of Anglesey and Snowdonia which occasionally move slightly. The seismogram below was recorded on our device.
