New Insights Into Crustal Properties of Anatolia and Its Surroundings Inferred From P‐Coda Autocorrelation Inversions. Issue 12 (22nd December 2021) - Eken, Tuna
Abstract: Constraints on crustal and uppermost mantle structure provide key information for understanding the geodynamic processes that have shaped the geological expressions and are currently causing deformation in Anatolia. We apply a novel method of Bayesian inversion of autocorrelated teleseismic P‐wave coda data to retrieve the crustal and uppermost mantle structures beneath Anatolia and southeast Europe. Our inversion provides estimates of Moho depth variations and crustal velocity structure (e.g., Vp, Vs, and Vp/Vs ratio). The Moho architecture in the study area can be summarized by (a) an overall west‐to‐east increase in the Moho depth from Greece to eastern Anatolia, (b) a homogeneously thin crustal structure beneath Greece, (c) complex, small‐scale crustal features and variations in western and central Anatolia, and (d) relatively long‐wavelength variations, but overall thick crust in eastern Anatolia. The apparent relation between the Moho depth variations and suture/fault zones implies a dominant control of structural inheritance on the past deformation in Anatolia. The overall Moho architecture appears to correlate well with the topography in Anatolia, although with some exceptions, in particular at smaller wavelength. These local inconsistencies in the topography‐Moho depth relation suggest a more complex, wavelength‐dependent isostatic state compared to what is expected from simple Airy isostasy. The observed deviations may originate from elastic effects, lithospheric density changes, or sub‐lithospheric dynamic effects. Obvious large lateral variations in Vp, Vs and Vp/Vs ratio estimates in our model can relate to such density variations within the crust especially between tectonic domains. Plain Language Summary: Reliable knowledge of the physical properties and architecture of Earth's crust is of utmost importance for providing key information for understanding the geodynamic processes that have shaped the geological expression of and that are currently causing deformation in various tectonic settings. We apply a novel method of Bayesian inversion of auto‐correlated teleseismic P‐wave coda data to retrieve information on the crust and uppermost mantle in Anatolia and surrounding areas. Our new findings indicate crustal complexity, primarily in central Anatolia, throughout all crustal depths. The observed correlation between Moho depth variations and suture/fault zones suggests a dominant role of structural inheritance on the past deformation in Anatolia. There is an evident consistency between crustal thickness and the topography in Anatolia. However, notable local inconsistencies at smaller wavelengths that cannot be explained by simple Airy isostasy may be associated with elastic effects, lithospheric density changes in the crust and mantle lithosphere, or sub‐lithospheric dynamic effects. Key Points: The crust is complex, particularly in central Anatolia Moho topography is related to sutures and fault zones The overall Moho architecture appears to correlate well with the topography in Anatolia, although with some exceptions at smaller wavelength