The GIAME (Geociencia Integral de Los Andes de Mérida - Integrated Geosciences in the Merida Andes) project,  funded by the Venezuelan Ministry of Science, Technology and Innovation,  started in February 2013 with a focus on active seismic, gravimetric and geological investigation. The Venezuelan Foundation of Seismological Research (FUNVISIS) has a coordinating role.

The Mérida Andes (MA) are the main mountain chain of western Venezuela, a NE-trending intracontinental orogen that started to rise from the middle Miocene due to the lateral strike-slip convergence between the Caribbean and South American Plates. Results of this interdisciplinary geological and geophysical research will help to address the seismic hazard in Western Venezuela, as well as to constrain the development of the petroleum bearing basins on both flanks of the Andes. They also should help to clarify the role of the Maracaibo block, and the Caribbean and Nazca plates in the regional deformation history of the Northern Andes. 

GFZ acquired two 240 km and 160 km long magnetotelluric profiles in March and April 2015. A total of 90 stations were deployed in the central and southern Mérida Andes, representing the first successful broadband MT acquisition carried out in Venezuela (see Figure).

Time frame (experiment)

• March/April 2015

Funding

• Funding of field experiments by FUNVISIS
• Ministerium für Wissenschaft, Technologie und Innovation - Venezuela

Principal Investigators

• Oliver Ritter (GFZ Potsdam)

Personnel

• Jose Cruces (GFZ Potsdam)

Cooperations

• Prof. M. Schmitz (FUNVISIS)
• Venezuelan Foundation of Seismological Research (FUNVISIS)
• Los Andes University (ULA)
• Venezuelan Central University (UCV)
• Simón Bolívar University (USB)
•  Venezuelan State Oil Company (PDVSA)

Methods & Equipment

• SPAM 4 real-time data acquisition instruments for broad band measurements
• Induction coils (Metronix)
• Non-polarisable Ag-AgCl electrodes (GFZ)

Publications/Results

• Cruces-Zabala, J., Ritter, O., Weckmann, U., Tietze, K., Meqbel, N., Audemard, F., Schmitz, M. (2022): Three-dimensional magnetotelluric imaging of the Mérida Andes, Venezuela. - Journal of South American Earth Sciences, 114, 103711.
  https://doi.org/10.1016/j.jsames.2022.103711
• Ritter, O.; Cruces-Zabala, J.; Weckmann, U.; Tietze, K.; Schmitt, R.; Schmitz, M. (2021): Magnetotelluric measurements in the Mérida Andes, western Venezuela. GFZ Data Services.
  https://doi.org/10.5880/GIPP-MT.201527.1
• Ritter, O., Cruces-Zabala, J., Weckmann, U., Tietze, K., Schmitt, R., Schmitz, M. (2021): Magnetotelluric measurements in the Mérida Andes, western Venezuela - Report on the magnetotelluric data in the project/repository folder: GIAME.2015.
• Cruces-Zabala, J., Ritter, O., Tietze, K., Weckmann, U., Schmitz, M. (2020): Magnetotelluric imaging of the Mérida Andes and surrounding areas in Venezuela. - Geophysical Journal International, 222, 3, 1570-1589. https://doi.org/10.1093/gji/ggaa266
• Cruces-Zabala, J., Ritter, O., Weckmann, U., Tietze, K., Schmitz, M. (2018): The Mérida Andes of Venezuela: Magnetotelluric forward modelling and comparison with real data. - In: Becken, M., Hölz, S. (Eds.), - Protokoll über das 27. Schmucker-Weidelt-Kolloquium für Elektromagnetische Tiefenforschung: Breklum, 25.-29. September 2017, 27. Schmucker-Weidelt-Kolloquium für Elektromagnetische Tiefenforschung (Breklum 2017), 104-104.
• Cruces, J., Ritter, O., Weckmann, U., Tietze, K., Schmitz, M. (2017, March). A magnetotelluric profile across the Mérida Andes (Venezuela) - preliminary results and directionality analysis. Poster session presented at the annual Deutsches Geophysikaliches Gesellschaft Conference (DGG 2017), Potsdam, Germany.

Acknowledgement

• Funding Jose Cruces by the German Academic Exchange Service (DAAD)
• All magnetotelluric instruments are provided by the magnetotelluric component of the geophysical instrument pool (GIPP-MT).