Gravity surveys in County Antrim

May 2025

Members of the Geological Survey of Northern Ireland (GSNI) are carrying out a survey to take measurements of gravity around Ballymena, Randalstown, Antrim and Ballyclare. The survey begins on 19th May 2025 and is expected to finish in September 2025. You may see a team of two or three researchers taking measurements (see photo). They will be surveying along road verges, tracks and footpaths, and occasionally in fields (with permission).

What is a Gravity survey? We can accurately measure the Earth's gravitational field using an instrument called a gravimeter – this portable survey equipment passively collects data without electricity or noise and does not impact the environment. Differences in the gravity readings indicate differences in the density of the rocks below the surface. By analysing the data, these variations in gravitational pull help researchers identify features like faults and folds in the rock or changes in rock type which we cannot see above ground.

Gravity data can be combined with other data and pre-existing geological understanding to help determine which locations might be suitable, for example, to use geothermal energy for heating.

When we do this at regularly spaced points across an area, we can build up a 3D picture of the geology. For the Antrim area, there will be around 600 measurements taken a few hundred metres apart from each other.

If you see our colleagues in the area over the next few months, feel free to ask questions about their work and the GEMINI project.

Geophysical surveying, County Antrim

March 2025

Scientists from the Dublin Institute for Advanced Studies (DIAS) and Geological Survey of Northern Ireland (GSNI) have begun a geophysical survey within County Antrim, Northern Ireland for the GEMINI project. They are currently installing around 30 seismometers (which detect distant earthquakes) throughout the areas of Ballymena, Randalstown, Antrim and Ballyclare. If you meet our colleagues as they are installing the seismic equipment (with landowners’ permission), please feel free to ask them questions about the project.

Update 25 April 2025:  Just two more seismic stations to be installed! Read Duygu and Giuseppe's blog to find out what this survey can tell us about the subsurface.

Welcoming the launch of the GEMINI project, Minister for the Environment, Climate and Communications, Eamon Ryan, T.D., said:

I am pleased to announce my Department’s commitment to supporting the GEMINI geothermal energy project. This project will help bring us closer to our 2030 and 2050 emission targets by supporting the Geothermal Energy and District Heating policies led by my Department to decarbonize the heating and cooling sector, which is a critical element of the Irish Government’s Climate Action Plan.

Importantly the GEMINI project will do more than just deliver infrastructure in the short term. It will also build essential capacity in our planning, education, research and energy design systems, along with best practice for community engagement. This will deliver long term solutions and sustainable impact beyond the four-year project. Along with my colleagues in Northern Ireland, I look forward to seeing the outputs of this ambitious and timely collaborative project.”

Economy Minister Conor Murphy said:

Decarbonisation is a cornerstone of my economic plan. As an alternative to fossil fuels, geothermal energy has a pivotal role to play in decarbonising heat. The Gemini project will demonstrate and promote the benefits of geothermal across the island.

Important partnership work has made this project possible, and I commend the partners involved for their ongoing collaboration with the public sector in the north. The public sector is our largest energy consumer, and I welcome GEMINI’s commitment to reduce its carbon emissions by unlocking our island’s deep geothermal potential and supporting our move away from imported fossil fuels”.

The GEMINI project will support the development of the geothermal sector and accelerate the uptake of geothermal energy through four real-world pilot installations, 3 shallow (<500m) in Sligo and Belfast, and one deep (approx. 2km) in Grangegorman, Dublin. Additional data will also be collected for potential future sites, thereby ensuring that the GEMINI work will have wider impacts for the island by increasing and improving our knowledge of the sub-surface and our island’s potential geothermal resources. This information will also help to inform new policies, guidelines and supports for the sector through geological heat potential maps, cross-border policy recommendations, toolkits for decision makers (homeowners, planners, developers and local government), community engagement guidelines, and business and skills development activities.

SEUPB Chief Executive Gina McIntyre:

Promoting renewable, sustainable, and greener energy is a really important way to create a better future for everyone right across this island.

“Geothermal is one of the most exciting opportunities that exists for utilising our natural resources safely and responsibly to enhance energy production. This is an industry in which organisations in Northern Ireland and Ireland can make a significant impact and we are proud to support this important sector through PEACEPLUS.”

7th November 2024