Distance

In OpenSHA, Distance refers to the distance between an Earthquake Rupture and a Site. However, many Attenuation Relationships use different criteria to define distance. These are the currently supported definitions:

DistanceRup

The shortest distance from a site to a rupture surface.

DistanceSeis

The shortest distance from a site to a point on a rupture surface that is deeper than some minimum seismogenic depth.

DistanceJB

The Joyner-Boore distance defined as the shortest distance from a site to the surface projection of the rupture surface.

DistanceX

The shortest horizontal distance from a Site to a line defined by extending the fault trace (or the top edge of the rupture) to infinity in both directions. Values on the hanging-wall are positive and those on the foot-wall are negative.

(distRup - distJB) / distRup

The difference between DistanceRup and DistanceJB (normalized by DistanceRup).

(distRup - distX) / distRup

The difference between DistanceRup and DistanceX (normalized by DistanceRup).

See entry on Earthquake Rupture for definition of terms: rupture surface, seismogenic depth, fault trace, hanging-wall, foot-wall