NGA-Sub source and path database

Abstract

We describe source and path attributes of the Next Generation of Ground-Motion Attenuation for Subduction zones (NGA-Sub) project relational database. The database contains 991 earthquakes between 1937 and 2016 that meet quality assurance standards and have assigned event types (mostly interface or intraslab). Data curation emphasized large magnitudes: 73% of events have M > 5 and 13 events have M > 8. Event attributes in the database can be broadly divided into those related to the moment tensor, those related to rupture surface geometry (referred to as finite-fault parameters), and categorizations by type (e.g. interface, intraslab) and sequence classification (mainshock, aftershock). Earthquake information and moment tensor parameters compiled from earthquake catalogs include event date and origin time, hypocenter location, seismic moment, and the strike, dip, and rake angles of nodal planes. Finite-fault parameters include along-strike length, down-dip width, and depth to top-of-rupture for one or more rectangles used to parameterize rupture surface geometry. These are modified from models in literature where available, and otherwise are simulated using procedures customized for subduction earthquakes. Rupture distance and other metrics are computed using finite-fault representations of sources, and (as applicable) are partitioned into forearc and backarc components. Forearc and backarc regions are defined based on volcano locations, and are assigned to events and sites.