The 1978 Santa Barbara earthquake (also known as the Goleta earthquake), occurred on August 13, 1978, 3:54 p.m. ( PDT) with its epicenter beneath the

Santa Barbara Channel The Santa Barbara Channel is a portion of the Southern California Bight and separates the mainland of California from the northern Channel Islands. It is generally south of the city of Santa Barbara, and west of the Oxnard Plain in Ventura Co ...

. The magnitude of the earthquake was estimated at 5.1 according to the

Southern California Seismic Network The Southern California Seismic Network (SCSN) is a cooperative project of Caltech and the United States Geological Survey. The SCSN has benefited from numerous upgrade projects. TERRAscope, funded by the L. K. Whittier and ARCO Foundations, and NS ...

; however, it may have been as high as 5.6 . There were no deaths from the event; however, 65 people sustained mild to moderate injuries.

Tectonic setting

Santa Barbara is part of

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, which is known for its very high level of seismic activity, the second highest in all of the United States only behind

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

. The Santa Barbara area is affected by numerous faults, inland within the mountainous ridges on the Santa Ynez Range down to the coastal plains and beneath the Santa Barbara Channel. The Santa Barbara Channel lies within the

Transverse Ranges The Transverse Ranges are a group of mountain ranges of Southern California, in the Pacific Coast Ranges physiographic region in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie within Santa Ba ...

block where the transform boundary between the

North American North America is a continent in the Northern and Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the sou ...

and Pacific plates takes on a

transpression In geology, transpression is a type of Strike-slip fault, strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. ...

al character associated with the "Big Bend" in the

San Andreas Fault The San Andreas Fault is a continental Fault (geology)#Strike-slip faults, right-lateral strike-slip transform fault that extends roughly through the U.S. state of California. It forms part of the tectonics, tectonic boundary between the Paci ...

. The faults beneath the channel trend mainly west–east and are mainly thrusts with associated

folding Fold, folding or foldable may refer to: Arts, entertainment, and media * ''Fold'' (album), the debut release by Australian rock band Epicure * Fold (poker), in the game of poker, to discard one's hand and forfeit interest in the current pot *Abov ...

. Santa Barbara was previously hit by a much larger earthquake in 1925, with estimated magnitude between 6.5 and 6.8 , causing $8 million (1925 rate) in damage and killing 13 people.

Earthquake

According to initial records it measured 5.1–5.7 and is still being debated today. The fault that caused the tremor has still been unidentified however surface ruptures were found facing Northwestward around the epicenter focused beneath the Santa Barbara Channel. Seismograph monitors in the campus of the

University of California, Santa Barbara The University of California, Santa Barbara (UC Santa Barbara or UCSB) is a Public university, public Land-grant university, land-grant research university in Santa Barbara County, California, United States. Tracing its roots back to 1891 as an ...

(UCSB) measured 0.45 ''g'', another monitor at the top of the North hall on the other hand recorded accelerations as high as 0.94 ''g''. Other local seismographs claim that 0.40 ''g'' was recorded in Goleta and only 0.23 ''g'' was recorded in Santa Barbara. Coincidentally, just a day before the earthquake struck, four seismographs were installed near the most affected areas. The newly installed instruments helped determine the focal mechanism;

thrust fault A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. I ...

ing with a small component of left-lateral

strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

Damage

Despite having a relatively moderate magnitude, it generated unusually strong ground movements. The city of Goleta suffered the greatest damage due to its location nearest to the epicenter. Items were thrown out off shelves at shops, glass windows on buildings shattered, walls cracked and one roof reportedly collapsed.

Rockslide A rockslide is a type of landslide caused by rock failure in which part of the bedding plane of failure passes through compacted rock and material collapses ''en masse'' and not in individual blocks. Note that a rockslide is similar to an ava ...

s were triggered, one of them blocking

California State Route 154 State Route 154 (SR 154) (also known as the Chumash people, Chumash Highway or unofficially as San Marcos Pass Road after the signage) is a state highway in the U.S. state of California that runs from Los Olivos, California, Los Olivos to Santa ...

, 5 km southeast of the

San Marcos Pass San Marcos Pass (Chumash: ''Mistaxiwax'') is a mountain pass in the Santa Ynez Mountains in southern California. It is traversed by State Route 154. The pass crosses the Santa Ynez through a southwestern portion of Los Padres National Forest, ...

, forcing a closure for 30 hours. Other landslides occurred nearby the San Marcos Pass, and along south of U.S. Highway 101. The airport terminal at the

Santa Barbara Municipal Airport Santa Barbara Municipal Airport is west of downtown Santa Barbara, California, United States. The airfield covers of land and has three runways. It is near the University of California, Santa Barbara, and the city of Goleta. The airport wa ...

leaned, and a nearby

freight train A freight train, also called a goods train or cargo train, is a railway train that is used to carry cargo, as opposed to passengers. Freight trains are made up of one or more locomotives which provide propulsion, along with one or more railroad ...

from Goleta derailed. At the library of the UCSB, some 400,000 volumes or about one third of all books were thrown out of shelves. The total damage was at $15 million, in the UCSB it was at $5.5 million alone.

References

{{Earthquakes in the United States Earthquakes in California 1978 earthquakes 1978 in California

Tectonic setting

Earthquake

Damage

See also

References