EGU2020-18112, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-18112
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

A geodetic exploration of the behavior of aseismic slip along the central section of the North Anatolian fault

Jorge Jara1, Alpay Ozdemir2, Angelique Benoit1, Romain Jolivet1, Ziyadin Çakir3, Semih Ergintav4, and Ugur Dogan2
Jorge Jara et al.
  • 1Ecole Normale Superieure, Laboratoire de Geologie, Department of Geosciences, Paris, France (jara@geologie.ens.fr)
  • 2Yildiz Technical University, Department of Geomatic, Istanbul, Turkey
  • 3Istanbul Technical University, Department of Geology, Maslak, Turkey
  • 4Bogazici University, Kandilli Observatory and Earthquake Research Institute, Istanbul, Turkey

Many geodetic evidence suggest aseismic slip along active faults is more common than previously thought. Furthermore, aseismic slip during the interseismic period seems to be made of intermittent slow slip events, corresponding to episodes of loading and releasing of tectonic stress over time. However, although our capabilities of detection and location of aseismic deformation have significantly increased together with the growth in available geodetic data, the physical mechanisms governing slow slip remain unknown.

We explore the spatial and temporal behavior of aseismic deformation in the vicinity of the small town of Ismetpasa, located along the central section of the North Anatolian Fault (Turkey). We combine InSAR and GNSS data acquired over the last 10 years to locate and quantify aseismic slip in the subsurface. We process SAR images (ALOS and Sentinel-1) acquired from 2007 to 2018 to build time series of ground deformation and maps of ground velocity. We confirm the presence of a 100 km-long creeping section, at rates of 10-20 mm/yr. Along this section, slip is not constant and decreases over time as formerly observed over the last 60 years. Furthermore, via a detailed analysis of our geodetic time series, we detect 3 major episodes of aseismic slip between 2015 and 2018, with durations ranging from 6 months to 1 year and magnitudes between 4.6 - 5.2. These results are compared with time series obtained from a network of GNSS permanent stations we have installed in the region (17 stations, period 2016 - 2019). As a conclusion, aseismic slip along this section of the North Anatolian Fault is characterized by slow slip events rather than by a constant, steady-state aseismic slip rate. We discuss the potential implications in terms of mechanics of slow slip along the NAF.

How to cite: Jara, J., Ozdemir, A., Benoit, A., Jolivet, R., Çakir, Z., Ergintav, S., and Dogan, U.: A geodetic exploration of the behavior of aseismic slip along the central section of the North Anatolian fault, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18112, https://doi.org/10.5194/egusphere-egu2020-18112, 2020