SURFACE RUPTURE

Fault ruptures commonly occur in the deep subsurface with no ground breakage at the surface

Surface fault rupture associated with the El Asnam (Algeria) earthquake on October 10, 1980. (Photograph from the Godden Collection, EERC, University of California, Berkeley.)

Surface fault rupture associated with the Izmit (Turkey) earthquake on August 17, 1999. (Photograph by TomFumal, USGS.)

Fault displacement; relative movement of the two sides of a fault, measured in a specific direction (Bonilla 1970).

11 m (35 ft) of vertical displacement in the Assam earthquake of 1897.9 m (29 ft) of horizontal movement during the Gobi-Altai earthquake of 1957.

length of surface faulting in the 1964 Alaskan earthquake varied from 600 to 720 km

Damage Caused by Surface RuptureOverview of a dam damaged by surface fault rupture associated with the Chi-chi (Taiwan) earthquake on September 21, 1999. (Photograph from the Taiwan Collection, EERC, University of California, Berkeley.)

REGIONAL SUBSIDENCEIn addition to the surface fault rupture, another tectonic effect associated with the earthquake could be uplifting or regional subsidence.

A graben is defined as a crustal block that has dropped down relative to adjacent rocks along bounding faults.

LIQUEFACTIONsubsurface soil condition that is susceptible to liquefaction is loose sand, with a groundwater table near ground surface.

Sand boil in Niigata caused by liquefaction during the Niigata (Japan) earthquake of June 16, 1964. (Photograph from the Steinbrugge Collection, EERC, University of California, Berkeley.)

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