GeoMôn hosts ‘Raspberry Shake’ seismometer in its visitor centre, the Watch House
GeoMôn hosts ‘Raspberry Shake’ seismometer – meaning that GeoMôn has joined the Raspberry shake network by installing one of their seismometers in the Watch House. This location is ideal being well away from disturbances like heavy lorries driving past. This was kindly supplied by Prof David Healy of the University of Aberdeen. The tiny device records earth tremors from all across the world. Wherever an earthquake occurs, shock waves travel through the planet and are recorded by seismometers all over the world. The time a wave takes to arrive together with some basic geometry helps plot how far away the earth quake was. Using several station to triangulate the wave arrivals enables geophysicists to plot the actual location and even the depth below the surface where the earthquake originated. Over time, with many earthquakes, geologists can begin to model the interior structure of the earth. 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. Now GeoMôn is ready to record them!
The seismogram below shows both P and S waves arriving from an earthquake in the Norwegian Sea on March 21 2022.
The Raspberry shake website explains all about seismometers and their network. It also displays the record from our seismometer as it happens, by the day and has the facility to look back over previous days.
