The Seismic Hazard Mapping Act ("The Act") was enacted by the

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

legislature in 1990 following the

Loma Prieta earthquake The 1989 Loma Prieta earthquake occurred on California's Central Coast on October 17 at local time. The shock was centered in The Forest of Nisene Marks State Park in Santa Cruz County, approximately northeast of Santa Cruz on a section of t ...

of 1989. The Act requires the California State Geologist to create maps delineating zones where data suggest amplified ground shaking,

liquefaction In materials science, liquefaction is a process that generates a liquid from a solid or a gas or that generates a non-liquid phase which behaves in accordance with fluid dynamics. It occurs both naturally and artificially. As an example of the ...

, or

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

-induced landsliding may occur ("seismic hazard zones"). The Act requires responsible agencies to approve only projects within seismic hazard zones following a site-specific investigation to determine if the hazard is present and inclusion of appropriate mitigation(s) if so. The Act also requires disclosure by real estate sellers and agents at the time of sale if a property is within one of the designated seismic hazard zones. The Act called for the creation of an advisory board to the State Mining and Geology Board to advise on the Act's implementation. In a 2004 update to the seismic hazard zone mapping guidelines, this advisory body concluded the amplified

ground motion Ground motion is the movement of the earth's surface from earthquakes or explosions. Ground motion is produced by seismic waves that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the earth a ...

hazard was already sufficiently addressed by the 2001 California Building Code. Consequently, zones for this hazard are not being mapped by the State Geologist.

External links

Law.justia.com: Seismic Hazards Mapping Act
California statutes Earthquakes in California Earthquake and seismic risk mitigation 1989 in law 1989 in California California Geological Survey Disaster preparedness in the United States {{Seismology-stub