EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

An investigation on possibilty of creep on the Makran subduction zone based on deformation data

Homa Ghadimi Moghaddam1, Alireza Khodaverdian2, and Hamid Zafarani1
Homa Ghadimi Moghaddam et al.
  • 1International Institute of Earthquake Engineering and Seismology (IIEES), Seismology, Tehran, Iran, Islamic Republic of (
  • 2Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland

Long term crustal flow of the Makran subduction zone is computed with a kinematic finite element model based on iterated weighted least squares fits to data. Data include 91 fault traces, 56 fault offset rates, 76 geodetic velocities, 1962 principal stress azimuths, and velocity boundary conditions. Model provides long-term fault slip rates, velocity, and distributed permanent strain rates between faults in the Makran region from all available kinematic data. Due to low seismicity of western Makran compared to its eastern part we defined two models to evaluate the possibility of creep in the Iranian Makran subduction. One model assumes that geodetic velocities measured adjacent to the Makran subduction zone reflect a temporarily locked subduction zone will be referred to as the “seismic deformation model”. In contrast, another model called the “half creeping deformation model” assumes that the western part of Makran may creep smoothly without any locking. In order to verify the models, the estimates of fault slip rates are compared to slip rates from merely analysing geodetic benchmark velocities or paleoseismological studies or published geological rates which have not been used in the model. Our estimated rates are all in the range of geodetic rates and are even more consistent with geological rates than previous GPS-based estimates. Another verification for the model is comparison of the computed interseismic velocities at GPS benchmarks to GPS measurements. While neither model accurately predicts these interseismic velocities at benchmarks, the half creeping deformation model is more accurate for Chabahar station than the seismic deformation model. These results have important earthquake and tsunami hazard implications. For example, Fault slip rates are the main component of time-dependent seismic hazard studies and can be used to estimate activity rates for more sophisticated earthquake models.

How to cite: Ghadimi Moghaddam, H., Khodaverdian, A., and Zafarani, H.: An investigation on possibilty of creep on the Makran subduction zone based on deformation data, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-864,, 2019