Deciphering aseismic deformation along submarine fault branches below the eastern Sea of Marmara (Turkey): Insights from seismicity, strainmeter, and GNSS data

The recently observed slow transients in the Sea of Marmara are important to quantify the seismic hazard and risk for the greater Istanbul metropolitan region. In this study, we analyze and characterize a slow slip event that occurred in the Eastern Sea of Marmara in 2016. To characterize the temporal history and the location of this event, we combine for the first time in this region different types of geodetic data (strainmeters and GNSS stations) and seismicity. We propose two interpretations to explain the observations: either the slow event initiated on the western part of the Armutlu fault and then propagated approximately 40 km eastward, or it initiated on the western section of the Armutlu fault, and then jumped onto a perpendicular fault after propagating ca. 15 km. We deduce these interpretations from forward modeling of the strain and displacement data. In addition, our results also suggest that this slow event triggered seismicity on a neighboring perpendicular fault. (C) 2022 Elsevier B.V. All rights reserved.