Fault rupture mapping of the February 6, 2023 earthquake sequence, eastern Türkiye

The powerful earthquake that struck eastern Türkiye on February 6th 2023 is the most devastating earthquake of the past century in the region. Here we present our first-hand field measurements of the ground offsets and the high resolution (centimeter level) drone-mapped surface ruptures 10 days after the first shock. It is clear that the initial rupture was on the Dead Sea fault zone (DSFZ), yet maximum displacements and energy release (Mw 7.8) occurred 24 sec later when rupture transferred to the East Anatolian fault zone (EAFZ). Seven hours later, a Mw 4.5 aftershock at the junction of the EAFZ with the east-west striking Çardak-Sürgü fault (Ç-SF) triggered the second large (Mw 7.5) earthquake, causing another round of the damage in the region. The maximum ground offsets are around 47.5 kilometers away from the epicenter in this event on the EAFZ. The surface ruptures directly cut young basins and mountains, as well as activating some pre-existing surfaces. Our observation provides important data on surface deformation during large continental strike-slip earthquakes, rupture propagation mechanisms, and how slip may be transferred between complex fault systems. We also provide insight into how slip along linked fault systems accommodates global plate motions.