Next steps

The GeoLaB project is divided into several project phases: The exploration phase is currently underway, followed later by the construction phase. Only then does the actual research begin.

Project phases| GeoLaB

Exploration phase

In the exploration phase, scientists will be carrying out investigations in Wald-Michelbach, Grasellenbach and Rimbach over the next few months. The question should be clarified: Is the area around the Tromm actually geologically suitable for the research laboratory?

Various investigations are planned, the approval of which will be applied for at the Hessian Mining Authority. They all help to learn more about the geological structures:

» Groundwater observation: Sampling and other measuring points relating to water for hydrogeological and hydrochemical data collection

» Seismic monitoring: passive monitoring of ground vibrations through seismometer measuring points

» With the help of sound waves that are generated by vibration, geology is examined (seismic). Measuring devices (geophones) record the reflected waves. You can find the information in the Seismic flyer or fold it out below.

Seismic truck in action on the Tromm.

» Sound waves generated by vibration are used to analyse the geology (seismics). Measuring devices (geophones) record the reflected waves. You can find the information in the seismic flyer or by clicking on it below.

Performing a gravimetric measurement. © Schätzler.

Geophysical measurements

» Additional geophysical measurements are used to determine the electrical and magnetic properties of the subsurface (geoelectrics and geomagnetics). In addition, the density of the rocks is examined using gravity measurement (gravimetry). You will find the relevant information bundled in this Geophysics flyer or fold it out below.

from October 2024

GEOPHYSICAL MEASUREMENTS IN GeoLaB
From September 2024, various measurements will be carried out on the Tromm for the GeoLaB project: Further measurements will be bundled in the geophysical measurement campaign, which will last about 8 weeks: gravimetry (gravity field measurement), magnetics and geoelectrics will be measured along 6 measurement profiles. The measurement campaign was planned by GeoLaB project partner KIT (Karlsruhe Institute of Technology). KIT has commissioned the company Geophysik GGD mbH and its partners, who have many years of experience in carrying out such measurement campaigns, to carry out the operational implementation.

MEASUREMENT METHODS
SURVEYING AND GRAVIMETRY
All measurement points are measured using a GPS (global positioning system) with high measurement accuracy. This enables precise determination of the positions and contributes to the improved interpretation of all other measurement data. Gravimetry measures changes in the Earth's gravitational field caused by density differences in the subsurface. A gravimeter is placed on the earth's surface and records minimal changes in gravity. By combining gravimetry and GPS, detailed maps of the density distribution underground can be created.

MAGNETICS
Magnetics is a geophysical method for measuring variations in the earth's magnetic field. These are caused by different magnetic properties of the ground and are measured with a magnetometer. The instrument is placed on the ground and measures for a few minutes to collect accurate data.

DC GEOELECTRICS
Geoelectrics is a method for investigating the electrical conductivity of the subsoil. An electric direct current (DC) is passed through the ground and the resulting voltage is measured. The electrical resistance of the subsoil is calculated from this. This method makes rocks and rock layers with different electrical properties visible. The following figure shows a typical set-up of a geoelectric measurement in which the electrodes are connected to a measuring unit via a cable.

Stainless steel spikes are used as electrodes, which are inserted into the ground by hand at regular intervals along the profile to a depth of a few centimeters. The entire measurement process is controlled by software.

PERMISSION
Permission is sought from the municipalities, HessenForst, other authorities, private owners and leaseholders for the inspection and use of paths, forest land and parcels of land. The company IPS Informations & Planungsservice GmbH has been commissioned by GeoLaB to obtain these permits.

WHAT DOES THIS MEAN FOR LOCAL RESIDENTS?
The surveying, gravimetry and magnetics are carried out using portable equipment. The measurements do not cause any noticeable effects or noise pollution. There are no disturbances or restrictions for local residents. To measure the geoelectrics, the electrodes must be placed in the ground and the cables laid for a measurement period of a few hours and a measurement distance of approx. 150 meters. The measurement setup can lead to minor disturbances within a limited area. All four measurement methods used do not affect the environment and do not cause any damage to buildings or infrastructure. They are carried out along the six measurement profiles around the Tromm, if necessary at different times.

The field work takes place Monday to Saturday between 7 am and 8 pm. There may be slight traffic restrictions due to the installation and collection of the measuring equipment. We ask for your understanding and will do our best to keep these to a minimum.

The measurement campaign will be carried out by the company Geophysik GGD mbH:
Geophysik GGD, Gesellschaft für Geowissenschaftliche Dienste m.b.H.
Tel: +49 341 58313 0, e-mail: info@geophysik-ggd.com

Contact person for licensing:
Tilo Hafner, IPS Informations & Planungsservice GmbH
Tel.: 05141 9771470, e-mail: t.hafner@ips-celle.de

Site plan of the GeoLaB-1 exploratory borehole southwest of the Tromm natural playground. © KIT, aerial photo Tromm Google Maps, 2024

Drilling site with acoustic barrier © KIT

Construction site with drilling rig © KIT

First core from the GeoLaB-1 borehole on the Tromm © GeoLaB

Exploratory drilling

» In addition, vertical boreholes will be drilled from the Tromm to explore the geological strata. The first of these boreholes will be 16 centimetres in diameter and approximately 500 metres deep. The drilling site is located south-west of the natural playground on the Tromm. Preparatory work began on 9 December 2024. The construction site was set up during the day in December.

In January, machine parking and storage areas were set up and containers for office work and personnel were installed. The drilling site was surrounded by a 10 metre high noise barrier. This is a requirement of the permitting authority to optimise noise protection for local residents and to combat African swine fever. Finally, the drilling rig was set up.

How long does the drilling take?

The drilling is carried out 24 hours a day and takes approx. 2 months.

Who is drilling?

KIT has commissioned the company Daldrup & Söhne AG to drill the borehole.

What is special about the borehole?

The borehole provides a precise view of the subsurface. We want to obtain information about the geological composition of the Tromm. To this end, the entire drill core from the 500 metre long borehole will be extracted, examined and stored at the HNLUG (Hessian State Agency for Nature Conservation, Environment and Geology) in the Villmar-Aumenau drill core storage facility for further investigations.

What will happen to the borehole after that?

Investigations and measurements are carried out in the borehole for about two weeks. The borehole will then be capped.

Should another borehole be drilled at this location?

Depending on the results of the first borehole, a further exploratory borehole will probably be drilled at this location in the course of 2025.

And afterwards?

The drilling site will be completely dismantled.

Construction phase

If the investigations during the exploration phase show that the Tromm area is a useful research location, planning will continue. The construction phase starts in 2026 and extensive questions need to be answered:

» Where could the tunnel be built?

» How can the construction site and access be set up?

Of course, approvals from the Hessian Mining Authority as the responsible authority are also required. Finally, the tunnel for the GeoLaB research laboratory will be built into the mountain.

During the construction phase of the tunnel there may be disruptions for residents, for example due to noise or traffic. Ways are being sought to avoid traffic, for example by using the waste on site. As soon as it is clear when the construction site will be set up and what consequences this will have for local citizens, they will be informed directly.

The laboratory is set up in the tunnel. A visitor ramp and later an information pavilion are intended to make GeoLaB accessible to the population and visitors to the Tromm region and make the fascinating world beneath our feet visible. There will be regular events there by the GeoLaB team and the researchers involved.