What is Tellus?
Tellus is a ground and airborne geoscience mapping programme, collecting chemical and geophysical data that will inform the management of Ireland’s environment and natural resources. The project, run by the Geological Survey of Ireland, involves a low-flying survey aircraft and a ground-based sampling programme. New data will be joined with maps already available from these existing Tellus surveys and will be made available free of charge.
Where is the survey underway?
There are two airborne geophysical survey areas planned for 2017. The first survey will cover Co. Mayo (see survey area in the map below). This survey is set to commence early March and is set to continue for approximately 7 months, weather permitting.
The second survey will cover Co. Donegal (see survey area in the map below). This survey is also set to commence early March and continue for approximately 7 months, weather permitting.
Why do we need to do this survey?
The survey will give a comprehensive picture of the environment in the region today. This will help us sustainably manage the environment, natural resources and protect public health in the future. Previous Tellus surveys have:
- Provided improved data for the GSI to update geological maps for planning and research purposes
- Provided new data to improve radon risk mapping
- Assisted mineral exploration companies to invest locally
- Facilitated new third-level research on environmental pollution, agricultural productivity, peat and wetlands.
Where does the name "Tellus" come from?
In Roman mythology, Tellus was the goddess of the Earth.
Is Tellus anything to do with...
i. Mineral exploration?
Tellus isn’t engaged in commercial mineral exploration. The data collected will be impartial and freely available to all, including mineral exploration companies who may use the data to assist their exploration programmes and regulators responsible for permitting such activities. The data is likely to highlight areas which would be of interest to mineral exploration companies for further investigation, but the data alone cannot indicate where economic mineral deposits are present. Previous Tellus surveys have stimulated considerable investment into local economies from mineral exploration companies who use the data as part of their exploration programmes.
Tellus isn’t involved with the current shale gas or unconventional hydrocarbons hydraulic fracturing (or ‘fracking’) licensing or exploration in the region. The data collected will be impartial and freely available to all, including petroleum and mineral companies who may use the data to better understand the geology and assist their exploration programmes, researchers studying the possible effects of shale gas extraction on the environment, environmental groups, and regulators responsible for permitting such activities.
iii. Radon gas?
The rocks and soils across Ireland can naturally contain minerals which are radioactive and are a source of radon gas. The airborne survey will measure and map a range of radiogenic elements at a high resolution, and the data are used to map areas of potential radon gas risk. Research into this is being carried out in conjunction with the office of Radiological Protection, part of the Environmental Protection Agency.
iv. Bog conservation/ turf cutting?
Tellus collects data on the land and surface environment including areas covered by peat, however the project is not involved with the selection of bogs for conservation or the cessation of turf cutting. Previously research has been carried out using Tellus data in the border region on peat bogs to assess how much carbon is stored in peat and variation in peat deposit thickness.
v. Wind turbines?
Tellus is not involved with wind turbines.
Tellus is not involved with electricity pylons.
vii. Spectic tank inspection
Tellus is not involved with septic tank inspections.
viii. Water meters?
Tellus is not involved with installing or inspecting water meters or pipes.
What type of aircraft is being used in the airborne survey?
The aircraft is a De Havilland Twin Otter, operated by the specialist survey company, Sander Geophysics Ltd, based in Canada. The white, twin propeller plane has a red tail, dark blue stripe, and registration number C-GSGF.
At what height and speed does the survey aircraft fly? Why does it have to fly so low?
The aircraft flies at a safe height authorised by the Irish Aviation Authority. In rural areas this will be 60 m – about 8 times the height of a two storey house. In urban areas the height will be 240 m.
It flies at a low altitude because the instruments on board the plane can sense the properties of soil and rocks more accurately at a low altitude.
The speed of the aircraft is about 130 mph, and the sound of the aircraft passing overhead is similar to that of a passing lorry.
What equipment is the plane carrying? What do they measure, and are they dangerous?
The aircraft carries a range of instruments for navigation and for measuring geophysical properties of the ground. The navigation instruments carried on the aircraft include:
- A satellite navigation system;
- A radar altimeter for measuring altitude; and
- A video camera, which gives us a record of where the plane has flown. The video footage will not be used for any other purpose.
The geophysical instruments on board the plane comprise:
- A magnetometer which measures variations in the Earth’s magnetic field; mounted in a rod on the back of the plane.
- A gamma ray detector which measures the natural radioactivity of shallow soil and rocks; housed inside the plane.
- A frequency-domain (EM) system which measures variations in conductivity between different soils and rock; mounted in pods at the end of each wing.
The EM system is the only instrument which sends out a signal to the earth. The EM system on one wing pod sends a very weak signal, equivalent to the power of a light bulb, into the ground. A receiver in the other wing pod will measure small changes in this signal as it passes through different types of rocks and soil. The other instruments are passive — they don’t emit any signals.
Who is doing the work?
The project is funded by the Department of Communications, Climate Action & Environment (DCCAE). The project is being managed by the Geological Survey of Ireland which is a line division of the DCCAE.
The survey work is undertaken by qualified, highly specialised and experienced contractors on behalf of the Geological Survey Ireland. The airborne surveying is carried out by Sander Geophysics Ltd.
Where can I get more information?
Freephone: 1800 303 516
Postal mail may be addressed to:
Geological Survey of Ireland
Dublin D04 K7X4
Also, visit our contact us page to submit a message via our enquiry form.