GeoScience complete an updated sub-surface heat flow map for the Southwest
In January 2022, GeoScience gained funding from the 'Deep Digital Cornwall' Research and Innovation Project, led by the Camborne School of Mines (CSM) with the Institute for Data Science and Artificial Intelligence at the University of Exeter, to update and progress existing investigations into the heat flow properties of the Southwest.
CSM worked with three delivery partners: Cornish Lithium, Cornwall Resources Limited (CRL) and the South West Centre of Excellence in Satellite Applications (SWCoESA), and received grant funding from the European Regional Development Fund.
Our project, named 'Digital Cornwall Heat Flow Map' has now been completed, and after two study phases we have an updated understanding of the geothermal resource in Cornwall.
Phase 1 - Data collection and collation
Phase one of the project concentrated on collecting new subsurface temperature and rock thermal conductivity data throughout the Southwest and collating it with the existing data from the Beamish and Busby study done first in the 1980's and re-evaluated in 2016. Through collaboration with other Cornish SMEs, a temperature dataset was compiled from boreholes and mine workings from three hundred sites across the Southwest to depths of up to 4800m. In situ temperature measurements were recorded to depths of up to 850m using either in-house equipment (Solinst) or contracted services (European Geophysical Services (EGS)).
Above are images of measuring temperatures in boreholes and mine shafts
We also recorded thermal conductivity measurements on core samples from forty-nine sites across the Southwest, producing a database of 1850 points. Core samples analysis was produced from our in-house specialist equipment (C-Therm Trident) to measure the thermal conductivity of granite and killas samples.
Phase 2 - Producing the Digital Cornwall Heat Flow Map
The second phase involved assigning thermal conductivity values to litho-types encountered in the Southwest. Surface heat flow figures were calculated using the temperature data, modern paleoclimatic corrections and in-house subsurface temperature modelling capabilities to produce a revised heat flow map of Cornwall.
In June 2023, Jos Thio presented the results of our Digital Cornwall Heat Flow Map Project at the DDC showcase event at Tremough Campus. These results are combined with Deep Digital Cornwall’s 3D geological model in their visualisation suite which opened in May 2023. The DDC project funded a variety of different projects which has allowed them to develop a brand-new model of Cornwall using subsurface, surface, aerial and satellite data.
From this work we have a better understanding and constrain of the region’s heat flow and thermal properties, which will help to actively develop the geothermal resources across SW England where there is huge potential for a variety of heat users to harness this significant energy source.
We would like to thank Deep Digital Cornwall and all the research partners that have collaborated with us on this project.