Geodetic Strain Observations and Return Period of the Strongest Earthquakes of a Given Seismic Source Zone

摘要

We present the basis for a method for estimating the return period of large and medium earthquakes that is independent of current deterministic and probabilistic approaches. The two standard techniques of seismic hazard assessment—probabilistic seismic hazard assessment (PSHA) and deterministic seismic hazard assessment (DSHA)—suffer from limited knowledge of seismic prehistory. A further weakness of PSHA is its requirement of homogeneous seismic activity within a seismic zone. Moreover, PSHA and DSHA were developed for seismically active areas and, thus, cannot reliably be used in areas of medium and low activity. In this paper we propose the combined use of geodetic strain rate data and the seismic moment data set determined for past seismic events. This combination represents a new and independent approach to estimation of future seismic activity. Using a modified version of Kostrov’s (Phys Solid Earth 1:23–40, 1974) equation and the catalogue of seismic moments, the minimum return period of the strongest earthquakes of a source area is estimated.