Do seismic slip deficits indicate an underestimated earthquake potential along the Vienna Basin Transfer Fault System?

Abstract

AbstractSeismic slip rates of about 0.2 mm yr−1 calculated from cumulative seismic moments of earthquakes along the Vienna Basin Transfer Fault (VBTF) between the Alps and the Carpathians are very low compared to geologically and geodetically determined slip rates of 1–2 mm yr−1, proving a significant seismic slip deficit. Additional seismic slip calculations for arbitrarily selected fault sectors reveal large differences along strike ranging from c. 0.02 to 0.5 mm slip yr−1. As the earthquake frequency distribution suggests seismically coupled deformation, these variations might indicate locked fault segments. Results suggest that (1) the seismic cycle of the VBTF exceeds the length of available seismological observation, and (2) larger earthquakes than those recorded may occur along the fault. Thus, current local seismic hazard estimates, which are solely based on this historical database, probably underestimate the earthquake potential of the fault system.