Since December the 10th 2013 and up to 31st of January 2014 the Ollerton region has experienced 38 earth tremors all induced by man-made activity.
The cause is suspected, according to the British Geological Survey, the Natural Environment Research Council, to be colliery mining from Thoresby Colliery in neighbouring Edwinstowe but as of yet this hasn’t been confirmed by Thoresby.
The tremors originate between 1km to 3km down, a shallow depth in comparison to natural tectonic earthquakes, and have a magnitude generally in the area of 1.5.
I have personally experienced around 20 of the tremors now as I often work upstairs.
Sometimes you feel the tremor as a passing rumble that makes the floorboards creak under pressure, make wardrobes slightly shudder and window panes and doors make cracking noises in their frames.
Other times they come as short sharp jolts like something big slamming into the side of your house.
Most of the tremors happen on a Monday, Tuesday, Thursday and Friday with the least activity being on Wednesday and the weekend.
The tremors happen on an almost daily basis, sometimes twice a day but over the holidays between the 23rd of December and the 30th there wasn’t a single tremor. Again highly suggestive that they are caused by mining activity.
The main clustering of the epicenters are in the Ollerton area, the Maun Valley and Sherwood Forest.
I believe Thoresby Colliery practices retreat mining where they head out to a source of coal say in the Welbeck and Ollerton areas and then mine back to Thoresby.
Whether this is the cause of the tremors I do not know, I am no geologist nor work for any mine but I would be interested in hearing from any experts on this type of mining, whether such a practice can cause the tremors or induce older workings from the ex-collieries to collapse.
These shakes essentially are unsettling when you experience them and even more so when you repeatedly experience them and like falling sick, where you imagine the very worst until you hear of a diagnosis for your condition, it would put some people’s minds to rest to know what exactly is going on beneath our feet from those experts in the know.
It is all well and good for someone to say there is nothing to worry about but when you go from around 19 tremors in the last 13 years to 38 in the last 7 weeks one begins to wonder what is happening below you, and when you can’t see what is happening or have any knowledge about it then it can be worrisome.