A Worldwide and Unified Database of Surface Ruptures (SURE) for Fault Displacement Hazard Analyses

Fault Displacement Hazard Assessment is based on empirical relationships from historic fault ruptures. These relationships establish the likelihood of co-seismic fault displacements values, for on-fault (i.e. along the primary earthquake fault) and off-fault (i.e. distributed surface rupture off the primary rupture) displacements, for a given earthquake magnitude. These relationships are useful when trying to predict future fault displacements at, and close to an active fault, when surface rupture hazard is expected at a site (for land use planning and/or structural design of infrastructure and critical facilities located on, or close to, an active fault line). The current equations are based on sparsely populated datasets, including a limited number of mainly pre-2000 events.

In 2015 an international effort started to constitute a worldwide and unified surface co-seismic displacements database (SURE) to improve further fault displacements estimations. To date, two workshops have been held and discussions on how to build such a database started. Outcomes from these discussions area: (1) the first is step should be to unify the existing datasets; and (2) the future database will include recent cases which deformation have been captured and measured with modern techniques. New parameters which are relevant to properly describe the rupture will also be required. This common effort would imply a large and open community of earthquake geologists to create a free and open access database.

This poster is an update of a previous version, and was presented in Barcelona in June 2019, after submission of the so-called SURE database and companion paper in Seismological Research Letters. The database encompasses (in 2019) 45 earthquakes from magnitude 5 to 7.9, with more than 15,000 coseismic surface deformation observations (including slip measurements) and 56,000 of rupture segments. Twenty earthquake cases are from Japan, 15 from the USA, 2 from Mexico, Italy and New Zealand, 1 from Kyrgystan, Ecuador, Turkey and Argentina. Twenty four earthquakes are strike-slip faulting events, eleven are normal or normal-oblique, and ten are reverse faulting.