Controls of seismogenic zone width and subduction velocity on interplate seismicity: Insights from analog and numerical models

Abstract

Correlations between geodynamic parameters and interplate seismicity characteristics in subduction zones are generally weak due to the short instrumental record and multiparameter influences. To investigate the role of subduction velocity Vs and the width of the seismogenic zone W on maximum magnitude Mmax, seismic rate τ, characteristic recurrence rate τc, and moment release rate MRR, we use synthetic data sets from simplified analog and numerical models to gain insight into natural subduction zones seismicity. Our models suggest that Mmax increases with W and is unaffected by Vs, τ increases with Vs, τc increases with Vs/W, and MRR increases with Vs × W. In nature, only the positive correlation between Vs and τ is significant. Random sampling of our time series suggest that the positive correlation between Vs and τ can be observed with short observation time windows. Other correlations, including Mmax versus W, become clear only for time window lengths longer than 1/τc