| Abstrakt: |
Knowledge of earthquake source faults is crucial for the calculation of robust Coulomb stress models. However, source faults are often poorly constrained, especially for pre‐instrumental events, and these historical earthquakes are commonly studied with little or no consideration of other nearby events. We introduce an approach using Coulomb Stress Transfer (CST) modeling to investigate historical earthquake sequences and constrain possible source faults. Using historical and instrumental records from the Büyük Menderes Graben, western Türkiye, we create an ensemble of earthquake sequences featuring multiple rupture scenarios for individual earthquakes, and model both coseismic and interseismic CST. We filter and evaluate the models based on criteria to gain knowledge on historical earthquakes and their source faults and assess the current stress state and related seismic hazard of the investigated fault network. For our study area, the results provide further constraints on the source faults of several historical earthquakes, including the destructive MW 7.0 earthquake in 1899. The approach presented herein is applicable to other tectonically active areas where the causative faults of historical earthquakes are poorly constrained from existing data sets (e.g., paleoseismology, damage records), providing a new tool to help decipher historical earthquake sequences and improve modeling studies. Plain Language Summary: Earthquakes do not occur independently, instead they are influenced by nearby earthquakes which can promote or delay them due to static stress transfers within the crust. However, to model stress transfer and fault interactions accurately, it is important to know which fault caused the earthquake. This can be difficult for earthquakes that occurred hundreds of years ago when instrumental records were unavailable, so instead we rely on the availability (and accuracy) of historical documents or evidence from archeology or geology. In this study we use stress models to try and provide new limits on the locations of historical earthquakes in western Türkiye. For several earthquakes, we do not know which fault moved, so we model the stress transfer for multiple possible earthquake scenarios. Then we add the different stress models together to create a range of possible earthquake sequences. We use knowledge about stress triggering behavior to filter our modeled earthquake sequences to determine which sequences and modeled scenarios are more plausible. In addition, our models can be used to estimate the stress state and possible earthquake hazard of the study area. Our approach is a new way of using stress calculations for historical earthquake studies. Key Points: We present a novel approach to evaluate possible source faults of destructive historical earthquakes using Coulomb stress modelingResults constrain the extent of historical ruptures in W Türkiye, particularly the 1899 earthquake which affected a ∼100 km wide areaAreas of positive Coulomb stress in the Büyük Menderes Graben and Denizli Basin broadly correlate with instrumental seismicity [ABSTRACT FROM AUTHOR] |
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