Stress evolution and slip deficit on the North Anatolian Fault (Turkey) in the Marmara Sea: insights from paleoseismicity, seismicity and geodetic data

<p>The North Anatolian Fault experienced large earthquakes with 250&#8211;400 years recurrence time. In the Marmara Sea region,<br>the 1999 (Mw=7.4) and the 1912 (Mw =7.4) earthquake ruptures bound the Central Marmara Sea fault segment. Using<br>historical-instrumental seismicity catalogue and paleoseismic results (&#8771; 2000-year database), the mapped fault segments, fault<br>kinematic and GPS data, we compute the paleoseismic-seismic moment rate and geodetic moment rate. A clear discrepancy<br>appears between the moment rates and implies a signifcant delay in the seismic slip along the fault in the Marmara Sea. The<br>rich database allows us to identify and model the size of the seismic gap and related fault segment and estimate the moment<br>rate defcit. Our modelling suggest that the locked Central Marmara Sea fault segment (even including a creeping section)<br>bears a moment rate defcit 6.4 &#215; 1017 N.m./year that corresponds to Mw &#8771; 7.4 for a future earthquake with an average<br>&#8771; 3.25 m coseismic slip. Taking into account the uncertainty in the strain accumulation along the 130-km-long Central fault<br>segment, our estimate of the seismic slip defcit being &#8771; 10 mm/year implies that the size of the future earthquake ranges<br>between Mw=7.4 and 7.5.</p><p>Reference:</p><p>[1] Meghraoui, M., Toussaint, R. & Aksoy, M.E. The slip deficit on the North Anatolian Fault (Turkey) in the Marmara Sea: insights from paleoseismicity, seismicity and geodetic data. <em>Med. Geosc. Rev.</em> <strong>3, </strong>45&#8211;56 (2021). https://doi.org/10.1007/s42990-021-00053-w</p>