Monday, 24 September 2018
Getting that sinking feeling: engineering geology in the Vale of York and Ripon...by Hannah Gow
The Friday evening kicked off with an evening reception meal and talks given by Holger Kessler, Callum Irving (TSP Projects), Dr Vanessa Banks and myself (Hannah Gow). We gave an overview of the Quaternary history, mapping and modelling of the areas we were going to be visiting over the next two days. The talks went on quite late into the evening and some think we may have beat a BGS record, anyone else given a presentation later than 11pm on a Friday evening?!
Even after a late evening, we were all raring to go on Saturday morning and we started off the day with site visits to overlook the Escrick Moraine. The day was led by Jon Ford, Holger Kessler and Callum Irving, providing an in-depth narrative of the geological history and engineering properties of the ground in the area.
As typical for a field visit, it rained for most of the day and we came away with an extra couple of inches height due to the clay that stuck to the bottom of our wellingtons at Wilberfoss Quarry! It is a good job us geologists are a hardy lot!
The Sunday was led by Dr Tony Cooper and he took us to various sites around Ripon to look at sinkholes. Our first stop of the day was a sinkhole that had opened up very recently, within the last five months, one to add to the BGS records! At first glance, you could mistake it for a lovely village pond, if it were not for all the orange fencing around it and the fact that holes like that seem to appear quite a lot in Ripon! Ripon has a history of sinkholes due to the gypsum under the ground. Gypsum dissolves in water causing cavities to open and the ground above it can collapse to form a sinkhole. It is believed that the sinkholes in Ripon, may have even been the inspiration behind Alice in Wonderland falling down a deep hole following the white rabbit! In the afternoon, Dave Morgan gave us all a demonstration of the passive seismic techniques being used to give us a better understanding of how and why sinkholes form.
It was an interesting and informative weekend with lots of discussion surrounding the engineering geology of the region. I think we have all come away with new friends in the geology world and ideas that we can apply to our own work/research.
Click here to find out more about the EGGS.
Click here for further information on gypsum and Ripon.
Photos courtesy of Craig Parry (Atkins) and Hannah Gow (BGS)