3D Karoo

Speculation on the existence of "cheap" shale gas energy in the Karoo in South Africa heats up the discussion on exploration and production. An moratorium on shale gas exploration opens a 5-year science window to obtain a basic understanding of the geology, petrology, and hydrology of the Karoo sedimentary basin. Without background knowledge, the possible pollution of groundwater and the destruction of the ecosystem by fracking or the extraction of shale gas can not be estimated. The research required is divided into seven sub-programs supported and funded by the Eastern Cape Provincial Government, the Africa Earth Observatory Network (AEON) and the Nelson Mandela University's Earth Stewardship Science Research Institute (AEON-ESSRI) in Port Elizabeth. Two GFZ projects are concerned with shallow drilling for scientific purposes, geophysical imaging of shallow and deep subsoil and groundwater movement studies. In November 2014, a group of researchers around Dr. Ute Weckmann started an magnetotelluric (MT) experiment with nearly 4.5 tons of geophysical instruments that were shipped to the eastern Karoo. The experimental layout consisted of a 50km x 50km area with more than 100 MT stations. Thereby we aim to map both the top kilometers of the potentially shale-gas-bearing Karoo sedimentary basin by means of a three-dimensional underground model of electrical conductivity and include the new measurement results in an already existing regional MT profile. In addition to the shale gas formations, another focus is the mapping of the different groundwater layers and their interconnection. This high-resolution experiment is complemented by a Airborne Geophysics Observatory, which provides high-resolution magnetic, radiometric and digital surface model data.

Time frame

  • 1/2015 - 12/2018

Funding

Principal Investigators

  • PD Dr. Ute Weckmann
  • Prof. Moctar Doucouré

Personnel

  • Anna Platz
  • Jade Grave

Cooperations

  • Nelson Mandela University, Port Elizabeth, South Africa
  • AEON, South Africa

Methods & Equipment

  • MT (Metronix induction coils, Ag-AgCl electrodes, S.P.A.M. IV data logger)

Publications/Results

Acknowledgements

We would like to thank

  • The Geophysical Instrument Pool Potsdam for providing the instruments
  • Farmers of the Karoo for giving land access
  • Barry Morkel for permitting support
  • Lucien Bezuidenhout, Sarah Brina, Ashton Dingle, Bastien Linol, Cedric Patzer, Manfred Schüler & Viera Wagener for their help during the field experiment
Ute Weckmann
Group Leader
Priv. Doz. Dr. Ute Weckmann
Near-surface Geophysics
Telegrafenberg
Building E, Room 426
14473 Potsdam
+49 331 288-2824
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