Welcome ...
.... I'm a geophysicist at Bristol University with an interest in small earthquakes, engineering geophysics and Distributed Acoustic Sensing. I live in the South-West of England with my wife, Cassie, and two miniature versions of myself. I'm also a caver and a core member of Mendip Cave Rescue (https://www.mendipcaverescue.org/).
I've been fortunate enough to move back into the academic life in 2014, and spend my time combining research, student fieldwork teaching and consultancy. Prior to academia, I practised my trade looking for unexploded ordnance at the UK Ministry of Defence and engineering and environmental geophysics at TerraDat UK Ltd.
I've put tried to put together information on this site that I hope might be of interest, and includes some case studies on some of the projects that I've been involved with.
News and interesting things ...
Exploring the structure of the Ascension Island
In October '24 I visited the Ascension Island as part of a collaborative research project investigating the recovery of rare earth elements (REEs) from volcanic sedimentary rocks (www.earth.ox.ac.uk/article/new-research-investigate-recovery-rare-earth-elements-ascension-island). The volcanic island is located in the South Atlantic, 7 degrees south of the equator, and is less than 10km in diameter. As part of the project, we acquired four electrical resistivity profile lines, which allowed us to image to a maximum depth of 1km.
Medical training with the Mendip Cave Rescue
I recently qualified as a MREW Remote Rescue Medical Technician (previously known as "Cas Care"), which allows the provision of advanced first aid to people in remote environments. This course has been running since the start of the year, with several training sessions to cover all the skills that are required. The final series of training sessions was held on the 28th of September in Goughs Cave, Cheddar (https://www.mendipcaverescue.org/index.php/mcr-training/training-29092024).
Seismometers deployed in Boulby Mine
During February 2024 we had that opportunity to deploy seismometers within Boulby Mine, North Yorkshire. Boulby is a polyhydrite and salt mine located at a depth of ~1km within the Zechstein Formation, and a portion of the mine extends underneath the southern North Sea. It is also home to the STFC Boulby Underground Laboratory (www.boulby.stfc.ac.uk), which hosts ultra-low background and deep underground science projects. The sesimic data provides that opportunity to understand seimic noise levels and seismic activity within the area. The instruments with deployed alongside the University of Oxford with support from ICL, and is part of the BOPS research consortium.
DarkSeis
The DarkSeis project is a UKRI-funded research project investigating the use of fibre-optic Distributed Acoustic Sensing (DAS) acquisition to provide geophysical imaging in the urban subsurface. The project will utilise fibre-optic telecommunications cables that run under the city of Bristol, using active seismic sources and passive seismic methods to acquire geophysical images of the subsurface below the city. These images will have a broad range of applications, including: prospecting for geothermal sources of energy; identifying old abandoned mines; geotechnical planning; and characterising flooding risk.
DarkSeis is a collaboration between the University of Bristol, the University of Oxford, and the British Geological Survey. https://www1.gly.bris.ac.uk/DarkSeis/index.html
New Discoveries in Gibbet Brow
On Thursday 16th November 2023 we finally broke through in Gibbets Brow. During what seemed like an unhopeful pumping session, Sam Hill managed to breach the mud plug we have been digging for the last 2 years. We returned the following day and discovered ~100m of new cave passage, most of which is spacious in size. The current far end of the cave heads east and extends 50-60m beyond Valentines passage into a blank space on the map. It ends in two ways. One is a small hole in the floor which the water flows through. The other is a muddy choked passage with 6 inches of air space. This has a very strong draft through it. We’re now focused on attacking the various leads, so hopefully there might be more passage to come. One of the benefits of the breakthrough is that we (currently) no longer have an issue with water, so we’re now unimpeded by the weather and can return to regular Thursday night sessions.
DigiMon - Digital Monitoring of CO2 storage:
DigiMon Concludes
At the start of 2023, the DigiMon project concluded after a 3 year period which straddle Covid-19. The project comprised of a strong international and interdisciplinary consortium with leading research institutions and industry from Norway, the Netherlands, Germany, United Kingdom, USA, Romania and Greece, with professional capabilities and skills from both natural and social sciences.
The project sought to integrate of a broad range of technologies for MMV at CO2 storage sites (i.e. distributed fibre-optic sensing technology (DxS), seismic point sensors and gravimetry). The DigiMon project has involved development and integration of system components that are available at intermediate to high Technology Readiness Levels (TRLs) and raising them to a uniformly high TRL. DigiMon succeeded in bridging technology and social science research, particularly through development of the Societal embeddedness Level (SEL) methodology for evaluating social readiness or maturity of CCS projects.
SeismoArt Project - Bacon Hole, Gower
During March 2023 we deployed a seismometer within a sea cave called Bacon Hole, located in the Gower, Wales, as part of a SeismoArt project led by Kate Aster. The aim was to create sound recordings of the ground motion within the cave, which you could then interact with using an audio player which played recodings when contact was made with the rock. We were able to recorded several storm surges, which generated significant tidal energy. Along with the ground motion created by the waves, we also recorded higher frequency signals generated by reverberations within the rock mass. Below is an example of 12 days of recording which have been filtered using a 10Hz highpass filter.
OFD Cave Rescue
During the 2021 bonfire weekend, myself and several hundred other cavers were called to assist an injured caver in OFD, South Wales. It's an area that several cohorts of Bristol undergraduates should know well, as it is a regular field trip location for 3rd years to develop their geophysical surveying skills. OFD is one of the largest cave systems in the UK, with multiple entrances of varying sizes and difficulties. Unfortunately for George (the casualty), a rock gave way under him while he as traversing a section of passage in one of the more difficult places to get rescued from. He fell 8m, badly injuring most of the right side of his body, which meant that he had to come the long way out via the larger Top Entrance. Most of this exit route is along streamway passage against the water flow, and our group entered at 3am Monday morning to haul him along the final wet section of the cave. George's injuries required him to be carried out in a stretcher, and in the streamway he was also wrapped in inflatable air mattresses which allowed us to float him along the wider sections. In the more difficult parts, the stretcher needed to be slid over legs braced across the passage, or delicately carried over natural obstacles, like in the photo below. I can be seen in the bottom left of the image with the muddy white helmet, and prior to it being taken, had acted as a human ramp to raise him onto the ledge. Our shift ended after he was taken out of the streamway into the upper passages, and here we handed over to the next wave of cavers coming in. We exited around midday, after 8/9 hours underground, into the Welsh mist and a bit of a media circus, neither of which had been there the night before.
It took around 54 hours to get George to the surface, the longest cave rescue in the UK, which required around 300 volunteers from all over the UK. Alongside those underground, there was also significant surface support co-ordinating and fuelling the rescue. All were there voluntarily with the sole aim of helping a fellow caver who was in trouble. I personally found it a hugely heart-warming, if not slightly tiring, experience. George was very unlucky to suffer this accident and should, hopefully, fully recover.