DIG at IGRM 2023

The 66th Irish Geological Research Meeting took place at the Ulster Museum in Belfast from 3rd – 5th March 2023. There were a range of great talks and posters spanning all elements of geological research taking place in Ireland including presentations on peat bog coverage, seismicity in Ireland and mineral deposits.

Emma Chambers presented on behalf of DIG updated temperature maps for all of Ireland. She showed improvements in the maps with temperatures in the model more accurately reflecting direct borehole temperature measurements. This work has built on many years of geothermal projects in Ireland, without which the model couldn’t have been made. We hope to publish these updated temperature maps in the coming months.

Thanks to all the organisers and funders of the event. It was a great success and we had fun presenting. Looking forward to next year!

IGRM program page taken from GSNI tweets

DIG Seismic Fieldwork Dec 22/Jan 23

On Dec 29th, Meysam and Colin scouted and confirmed 4 site locations in the eastern side of Mallow city, along the MT Line 2 on both sides of the river and the Killarney-Mallow fault.

Meysam and Dave then returned from 4th – 6th January 4-6th to deploy 4 broadband stations running on solar and battery at those 4 sites. The weather was mixed with some pretty wet days as you can see from the photos.

Dave installing a seismometer in Mallow.

Our sensors need to be secured from water. To do this the team had an ingenious setup to protect the electronics. First they dug a 50-70cm deep hole and poured concrete in the bottom. They then pushed a plastic drum into the concrete and added cement to this to make a level floor for the sensor.

Digging the hole to place the drum and checking it is the right depth. This allows us to have the best coupling with the ground while also keeping our sensor and equipment dry.

Once the cement is dry they leveled the sensor orienting them North so that we can work out the direction of our seismic waves. After this all the cables were connected and sealed inside the bin. The cables from the sensor go to a connection box and connect to the power, in this case a solar panel and battery.

Dave adding a solar panel and connecting it to the seismic sensor.
Finished site installation after a very wet day of fieldwork

The DIG team will be back in early February to check everything is working appropriately and if the solar panel can charge the batteries in the Irish winter!

The aim is to leave the seismometers recording for the next year and collect the data every few months to process and image the subsurface beneath each site. Once the work is complete, all materials including concrete will be removed and the land left as we found it.

Finished site as we leave it for the next few months.
Installing another solar panel at a different site.

National Geothermal Energy Summit – November 2022

DIG were invited to present at the National Geothermal Energy Summit hosted at the Technological University Dublin, Grangegorman campus and organised by the Geological Survey Ireland. We were based in St Lawrence’s, a former church.

St Lawrence’s, The venue for the National Geothermal Energy Summit

Emma L. Chambers gave a talk on “Improving Temperature and Heat Flow Models in Ireland” as part of session 3 “Quantifying our Geothermal Potential.” After the presentation, there was a panel question and answer session with Emma, Rory Dunphy (GSI/ CGC), Koen Torremans (UCD) and John Walsh (UCD), with Sean Finlay (Geoscience Ireland) moderating the session.

The TU Dublin Grangegorman site is the location of a 1 km borehole in Dublin with plans to drill an additional 3 km borehole for future geothermal energy extraction. In the future it will heat the whole campus.

Thanks to GSI and TU Dublin for organising an excellent summit and we can’t wait to see the progress made by the next one!

DIG MT Fieldwork August 2022

In August 2022 researchers commenced the second phase of MT fieldwork adding another profile to the original survey.

We added 16 stations to the original 12. We tried to mitigate noise sources and be in quiet locations. Below are some of the noise sources we encounter but we can filter the data to remove these signals.

Noise sources in and around Mallow

We’re currently processing the data to see what the subsurface structure looks like. Watch this space for results!

Geological map of the two completed MT profiles. The original profile was extended to image depths >5 km and a second profile was included to check the consistency of features laterally along the fault zone.

DIG MT and Seismic Fieldwork March 2022

Following the success of the preliminary MT fieldwork, researchers from DIAS traveled back to Mallow to test other sites around Mallow off profile and to reoccupy existing sites.

Tao setting the parameters for the MT acquisition

They also deployed 3 new nodal arrays consisting of 11 instruments each around Mallow to determine noise sources, including west of Mallow train station. The fieldwork takes a few days for seismic with a return several days after deployment to gather the data. In contrast the MT fieldwork takes a bit longer as the equipment needs to be buried in trenches and has a lot more components!

Typical setup of the MT equipment

These new arrays are being used to design the large scale survey which will occur later in the year

The views from our MT base station
Another shot of the base station near Gougane Barra

We should all be out in spring/summer 2022 to collect the large datasets for the DIG project. Let’s hope for weather as good as this trip!

Gougane Barra on a particularly clear and calm day

All photo credit to Colin Hogg (DIAS).

DIG MT Fieldwork 2021

Last week we completed the first magnetotelluric fieldwork for the DIG project. Several of us travelled to Munster Basin, Co. Cork, a known area of high heat flow and the location of the Mallow warm springs.

Our base station was near the beautiful location of Gougane Barra. A remote area with less anthropogenic noise than our main profile.

After establishing a base, we deployed a mix of long and short period instruments along a 5 km long profile. This profile is a short test profile to give us an overview of the lithospheric structure in this location and plan a denser and more targeted deployment in the future.

The mian profile is noisier than the base station with noise from electric fences and water pumps but this can be removed in future processing steps when we clean up the data.

Members of the team also deployed seismic nodal instruments. These are again a pilot study to understand the directionality of seismic noise sources in the area. These will again be scaled to a targeted study of the Munster basin.

This stage of fieldwork took ~ 2 weeks and we expect the next stage of data collection to occur in the first half of 2022.

Photos courtesy of Colin Hogg and Emma Chambers

vEGU 2021

This week we’re at the Virtual European Geosciences Union Conference presenting the first outputs of the DIG project. See below for a presentation on the latest update of Work Package 1:

EGU Abstracts

Click on the links below to see the DIG 2021 EGU abstracts:

DIG: A New Project to De-risk Ireland’s Geothermal Energy Potential 

Imaging the temperature beneath Ireland and Britain using massive, broadband surface-wave datasets and petrological inversion

Fieldwork Autumn 2020

Having joined the DIG project in August 2020, I immediately got the opportunity to gather data from seismic stations around Ireland. This involved travelling to sites all around Ireland from Malin’s head, Donegal, to Cork and Waterford. Each location is in a secured area with a seismic instrument, recording device and power. My colleagues and I checked the instrument was in good working order and downloaded available data from the stations. Back at base, this dataset was quality controlled, preprocessed and incorporated with data from previous service runs. It is now being used to investigate the velocity structure beneath Ireland as part of the DIG project. All fieldwork was carried out following strict coronavirus procedures. Below are some photos from the trip.

Servicing a site at Roches Point. Setup in the meteorological centre the equipment stays dry and we have access to power. Great site setup and the view wasn’t bad either!
Servicing another station in Sligo. The orange cover provides insulation for the seismometer and below that is a further casing. This reduces noise s we can record a cleaner signal.
View from one of the seismic sites in Sligo of Ben Bulben.