The great Sumatra fault (SF) is one of the most prominent examples for large strike­slip fault systems developing along subduction zones. The 1900 km long dextral slip SF accommodates a significant amount of the trench­parallel component of the oblique convergence between the Indo­ Australien and Eurasien plates. The location of the SF approximately coincides with the distribution of main arc volcanism in Sumatra. Another interesting feature of the SF is the presence of 19 pull­ apart basins, which were formed in response to regional changes in plate motion rates and directions, and resulting segmentation of the fault system. The SF is of importance not only as a prominent geodynamic structure, but is also of relevance for the evaluation of hazard by large earthquakes and volcanic activity. Furthermore, Indonesia is one of the leading nations in geothermal exploitation, and the SF is considered as a key target for future geothermal development because of its potential for enhanced transport of heat and fluids from greater depth. In geothermal exploration, there is a very close linkage required between different topics such as geodynamics, structural geology, volcanology, hazard, exploration geology and reservoir engineering.

We suggest a passive seismological experiment in northern Sumatra, close to the city of Banda Aceh, which strongly suffered from the 2004 Tsunami earthquake. The study area is located around roughly know seismicity (located from larger, sparser networks) in apparent vicinity to the SF and volcanoes close­by. The purpose is a pilot study to evaluate the feasibility to image geological structures, map seismicity for geothermal exploration and simultaneous hazard evaluation as an decision criterion before geothermal production.

The proposed project would contribute to major POF topics such as (1) subduction zones and large shear zones, and relationship to arc volcanism, (2) hazard by large earthquakes and volcanoes, and (3) geothermal exploration. The project is based on well­established networking at GFZ (International Centre for Geothermal Research, Indonesia project for geothermal development, GITEWS) and international partnerships (e.g. Aceh University, BMKG).

Time Frame

• 05/2014 - 05/2015 (fieldwork)

Funding

• GFZ - Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences

Principal Investigators

• Dr. Muksin Umar (GFZ Potsdam)
• Dr. Muzli (BMKG)
• Dr. Trond Ryberg (GFZ Potsdam)
• Dr. Klaus Bauer (GFZ Potsdam)
• Dr. Christian Haberland (GFZ Potsdam)

Cooperations

• Syiah Kuala University, Banda Aceh
• BMKG

Methods & Equipment

• DATA - CUBE3 (three component)

Publications/Results

• Muksin, U., Bauer, K., Muzli, M., Ryberg, T., Nurdin, I., Masturiyono, M., Weber, M. (2019): AcehSeis project provides insights into the detailed seismicity distribution and relation to fault structures in Central Aceh, Northern Sumatra. - Journal of Asian Earth Sciences, 171, 20-27, doi.org/10.1016/j.jseaes.2018.11.002