Exploratory models of long-term crustal flow and resulting seismicity across the Alpine-Aegean orogen

Abstract

[1] Long-term crustal flow is computed with a kinematic finite element model based on iterated weighted least squares fits to data and prior constraints. Data include 773 fault traces, 106 fault offset rates, 510 geodetic velocities, 2566 principal stress azimuths, and velocity boundary conditions representing the rigid parts of the Eurasia, Africa, and Anatolia plates. Model predictions include long-term velocities, fault slip rates, and distributed permanent strain rates between faults. One model assumes that geodetic velocities measured adjacent to the Aegean Trench reflect a temporarily locked subduction zone; in this case, longterm subduction velocity averages 45 mm/yr and rapid crustal extension is predicted in the southern Aegean Sea. Another model assumes steady creeping subduction; in this case, subduction velocity averages only 29 mm/yr, and the eastern Aegean Seafloor is predicted to be more nearly rigid. Long-term seismicity maps are computed for each model on the basis of the SHIFT hypotheses and previous global calibrations of plate boundary earthquake production. Retrospective comparisons to seismic catalogs are encouraging: map patterns, spatial distribution functions, and total earthquake counts are all comparable. While neither model accurately predicts earthquake rates at all magnitudes, the creeping subduction model is more accurate for strong m6+ events, which dominate the seismic hazard. Citation: Howe, T. M., and P. Bird (2010), Exploratory models of long-term crustal flow and resulting seismicity across the Alpine-Aegean orogen, Tectonics, 29, TC4023,

Integrating geologic fault data into tsunami hazard studies

“…Chiarabba et al, 2008) and dips to the northwest. Convergence rates are in the order of 35 mm yr −1 in the Hellenic Arc (Reilinger et al, 2006) and 1-5 mm yr −1 in the Calabrian Arc (D' Agostino and Selvaggi, 2004;Devoti et al, 2008;Howe and Bird, 2010;Serpelloni et al, 2010;D'Agostino et al, 2011). Wide and thick accretionary wedges developed in both zones as a consequence of the subduction processes thereby deforming the thick sediment cover accumulated over time onto the Ionian crust.…”

Neotectonic Deformation in Central Eurasia: A Geodynamic Model Approach

“…We use the recent crustal and lithospheric structure model by Robert et al (2015) and the results from Jiménez-Munt et al (2008) and Tunini et al (2015 and2016). The thin-sheet approach has proven to be useful for studying both the present-day (neotectonic) deformation in collisional settings (Barba et al, 2010;Bird, Liu, & Rucker, 2008;Cunha et al, 2012;England & Molnar, 1997;Howe & Bird, 2010;Jiménez-Munt et al, 2001Liu & Bird, 2002;Marotta et al, 2001;Negredo et al, 2002;Negredo, Jiménez-Munt, & Villaseñor, 2004;Neres et al, 2016) and its evolution through time (England & Housemann, 1989;Garcia-Castellanos & Jiménez-Munt, 2015;Jiménez-Munt, Garcia-Castellanos, & Fernandez, 2005;Jiménez-Munt & Platt, 2006;Robl & Stüwe, 2005;Sobouti & Arkani-Hamed, 1996;Sternai et al, 2016).…”

Fault slip rates for the active External Dinarides thrust‐and‐fold belt

“…Computed fault‐locked horizontal velocities (red arrows) compared to GPS measurements (green arrows) from Caporali et al [2009, 2011], Devoti et al [2008], Bennett et al [2008] and Howe and Bird [2010]. GPS velocities are shown with their 90% confidence ellipses.…”

“…Despite the fact that geological data, GPS measurements and seismicity show the ED to be an active thrust belt, just little research on better understanding the rheological setting and slip rates of active faults is available. Recently a series of finite element methods have been applied to study active tectonics of the Central Mediterranean, revealing the importance of mantle flow in predicting crustal stress patterns [ Barba et al , 2008; Ismail ‐ Zadeh et al , 2010] as well as the kinematic behavior of faults [ Howe and Bird , 2010], but none of them addressed the ED in detail.…”