Santa Barbara County Notables

Santa Barbara Earthquakes

PRINCIPAL EARTHQUAKES

Source:
http://projects.crustal.ucsb.edu/sb_eqs/SBEQCatlog/SBEQCATINTRO.html

from:

CATALOG OF SANTA BARBARA EARTHQUAKES - 1800 TO 1960

compiled and edited by Arthur Gibbs Sylvester, 2001

The Santa Barbara area has been affected by three major earthquakes and several lesser ones during the time covered by the catalog: 1812, 1925, and 1927.

The earthquake of 1812 is regarded as one of the largest earthquakes in California history, based evidently on the size of the felt area, the extensive destruction to missions in Santa Barbara County, and the report of seismic sea waves.

The assigned magnitude of this earthquake is 7.0 (Toppozada et al., 1981; Evernden and Thompson, 1985). The data for this earthquake are meager unfortunately, and permissive arguments can be presented which not only raise doubts about the existence of any seismic sea waves (Grauzinis, et al., 1965), but also downgrade the probable magnitude and scope of the earthquake (Sylvester, 1978).

The great Fort Tejon earthquake of 1857 (M 8), which accompanied the rupture of the San Andreas fault for a distance of about 300 km from Parkfield to Cajon Pass, was "sensibly felt" in Santa Barbara but did not cause significant damage according to fairly extensive and detailed press reports. The effects were considerably stronger in the Santa Clara River valley and were described in detail in the Santa Barbara newspapers.

The earthquake of 29 June 1925 (M 6.3) was Santa Barbara's most destructive earthquake in terms of loss of life and property. Indeed, the property damage was so extensive, that much of the downtown part of the city had to be rebuilt, and was rebuilt according to the dictates of an architectural plan adopted by the City only weeks after the earthquake, resulting in the attractive Spanish style that characterizes the City today. Thus the earthquake forced one of the first urban renewal projects in California.

More significantly, the Santa Barbara earthquake exposed inadequacies of contemporary building design and construction, prompting much discussion and little remedial legislative action statewide until the general lessons learned were confirmed by the 1933 Long Beach earthquake.

The heavy damage to public schools in Long Beach, coupled with the realization of the enormous loss of life that might have occurred if the earthquake had taken place only an hour or so earlier, led to the formulation and enactment of the Field Act in 1993 by the State Legislature. That act gave jurisdiction to the State Division of Architecture to regulate the design and construction of public school facilities.

Significant expansion of the codes to cover other kinds of public buildings, such as hospitals, fire and police stations, did not happen until after the 1971 San Fernando earthquake.

The 1927 Pt. Arguello earthquake (Byerly, 1930), Ms and Mw = 7.0; Mo=3 x 1026 ( Helmberger et al. 1992; Satake and Somerville, 1992), generated the only truly documented seismic sea waves by a local earthquake (Satake and Somerville, 1992). The epicenter was about 45 km due west of Pt. Conception (Helmberger et al., 1992). The earthquake damaged nearby coastal cities of Lompoc and Santa Maria.

Other noteworthy earthquakes that strongly affected Santa Barbara and vicinity include the Los Alamos earthquakes of 1902 and 1915, and the Santa Barbara earthquake of 1941. The strongest intensities in both the 1902 and 1915 earthquakes were clearly centered in the Los Alamos area, and their location, together with numerous reports of small earthquakes before and since in the same area, indicate that the central part of the Santa Maria basin is a zone of active faulting at depth (Sylvester and Darrow, 1979).

The earthquake of 1941 (M 5.9) was centered in the Santa Barbara Channel about 10 km south of the City of Santa Barbara and caused much window breakage and cracking of walls in the downtown part of the City where the damage was so extensive in 1925.

Reports of earthquakes emanate from Ojai during the period of the catalog as well as from Ventura and nearby areas. The Ventura reports probably reflect activity offshore of Pt. Mugu. This judgment is based on the similarity of felt reports of numerous earthquakes believed to have been generated in that area with felt reports from the 1973 Pt. Mugu earthquake (M 5.3).

~~~~~~~~~~

The 1812 Santa Barbara Earthquake

Source:
http://projects.crustal.ucsb.edu/sb_eqs/1812/1812.html

In 1812, Mission La Purisima, situated in the bucolic setting of Lompoc Valley, was typical of the nineteen Spanish missions that were spread throughout California. But on the morning of December 21, around 10:00 or 10:15, the quiet of that mission was upset when the earth underneath Mission La Purisima began to shake. The strong earthquake frightened the mission's residents-- padres, Indians, and soldiers--who rushed out of the mission buildings. Luckily for the mission residents, they were too scared to reenter the buildings, because the first shock turned out to be only a foreshock.

About fifteen minutes later, a stronger earthquake struck. The shaking was so intense that the mission's church bells rang out, the adobe walls of the mission buildings were shattered, were thrown out of plumb, and in some instances collapsed, reducing Mission La Purisima to "rubble and ruin, presenting the picture of a destroyed Jerusalem." Severe damage from the earthquake was also reported from Mission Santa Ines, Mission Santa Barbara, the Santa Barbara Presidio, Mission San Buenaventura (Ventura), and Mission San Fernando, covering a distance of over 100 miles.

~~~~~~~~~~

The 1857 Fort Tejon Earthquake

Source:
http://projects.crustal.ucsb.edu/sb_eqs/1857/1857.html

Many people think that the 1906 San Francisco earthquake was the largest earthquake to strike California in historical times, but that distinction actually belongs to the shaker that rocked southern and central California on January 9, 1857, uprooting trees in the San Bernardino Mountains and causing the Kern River to flow backwards for a time. Because of the small population in the state in 1857 (perhaps 350,000 people), there were only two fatalities, one near Fort Tejon, where many buildings were destroyed.

The earthquake was strongly felt from Los Angeles to San Francisco. The rupture on the surface of the earth can still be traced to this day, extending from near Parkfield, California, to near San Bernardino, California, over a distance of roughly 225 miles. Strong shaking from the earthquake was said to last from 1 to 3 minutes.

The earthquake occurred along the San Andreas fault, the major fault in California. The latest estimate of the size of this earthquake is magnitude 7.9. An earthquake of this size will certainly recur along the San Andreas fault, with devastating results given California's population today. The average recurrence interval for this earthquake has been estimated at 140 years 40 years. Since it is already 144 years since the last earthquake, the next one may not be too far in the future.

Despite the size of the earthquake, it occurred far enough away that only minor damage occurred in Santa Barbara, although the earthquake was strongly felt in that city.

~~~~~~~~~~

The 1902 Los Alamos Earthquakes

Source:
http://projects.crustal.ucsb.edu/sb_eqs/1902/1902.html

"Terror reigns in Los Alamos valley!" blasted the August 1st, 1902, edition of the San Francisco Chronicle, reporting on a series of earthquakes that struck the small town of Los Alamos in northern Santa Barbara County. The newspaper accounts portrayed a town which had been nearly destroyed:

With the first shock this morning, buildings in every part of the town tumbled down. ... It was preceded by a rumbling like that of distant thunder, which increased until the earth began to rock and twist and the hills began to tremble. ... Los Alamos is now being deserted as fast as railroads and other means of transportation can be pressed into service. ... Churches have been leveled to the ground ... frame buildings thrown from their foundations ... telegraph and telephone wires have been broken. ... the villiage is almost entirely deserted.

The Chronicle went on to report that huge fissures, 15 miles long and 4 miles wide, had been opened by the earthquakes. The earthquakes themselves were said to be the result of a nearby volcano.
The reality of what happened in Los Alamos was much less sensational, as the Chronicle was forced to admit the following day:

The reports of damage done have been swelled beyond all reason, and the stories of panic so distorted as to be almost absolute lies. Considerable feeling is manifested throughout the entire region against the author of the sensational reports sent out from Los Alamos.

The paper did go on to say, however, that "those who have had time for such occupation claim to have counted 75 separate shocks." And although the accounts of the panic were exaggerated, the earthquakes were frightening enough that an evacuation of about 60 people from the town did occur.

~~~~~~~~~~

The 1925 Santa Barbara Earthquake

Source:
http://projects.crustal.ucsb.edu/sb_eqs/1925/1925.html

On June 28, 1925, the residents of the city of Santa Barbara climbed into bed on an uncomfortably warm, humid, and still night. Used to a cooling breeze from the ocean, many people tossed and turned in their sleep. At 3:27 AM, the pressure gauge at the Santa Barbara Water Department recorded slight tremors from a small earthquake. At about the same time, the city manager, Herbert Nunn, awoke from his sleep to the strong odor of crude oil seeping onto the beach 85 feet below his bluff-top house.

The pressure gauge at the Water Department continued to record small tremors, off and on, for over three hours. Then, at 6:44 AM, a magnitude 6.3 earthquake woke up those Santa Barbara residents who weren't already awake from the heat. Most homes survived the earthquake in relatively good shape, although nearly every chimney in the city crumbled.

Commercial buildings did not ride out the earthquake as well as the residences. In the downtown area, along State Street, the rubble was so thick in the middle of the street that travel by car was impossible. Several hotels partially collapsed, some other buildings completely collapsed, and the Sheffield Dam, within city limits, cracked apart, sending a wall of water to the ocean. Thirteen people were killed, many fewer than would have been had the earthquake occurred several hours later.

In an odd twist of fate, by leveling much of Santa Barbara's commercial district, the earthquake proved a boon to Santa Barbara's businesses. City officials seized the opportunity that the earthquake gave them to enforce a stricter building code, requiring commercial buildings along State Street to conform to a Spanish-Moorish style of architecture. Thus the 1925 earthquake is responsible for the distinctive architecture in the city that has made Santa Barbara a popular tourist destination for over 70 years.

Crumbled bell tower of the Santa Barbara Mission after the 1925 earthquake.

This image is from the
Earthquake Engineering Research Center at the University of California, Berkeley.

~~~~~~~~~~

The 1927 Lompoc Earthquake

Source:
http://projects.crustal.ucsb.edu/sb_eqs/1927/1927.html

Late in the morning of November 4, 1927, Captain Williamson of the S. S. Floridian was startled to discover great quantities of dead or stunned fish floating on the surface of the Pacific Ocean, a few miles from Point Arguello. Captain Williamson was unaware of it at the time, but he was viewing the aftermath of an earthquake that had struck underneath the waters of the Pacific some five hours earlier.

The first signs of the impending trouble came an hour after midnight on the fourth, when residents of the coastal community of Casmalia were awakened by a small earthquake. Others soon followed, including an earthquake at 3:10 that was strong enough to awaken most of the inhabitants of Lompoc, and that was followed by three smaller earthquakes within half an hour. Finally, at 5:51 AM, stresses that had been building within the earth for decades were violently released.

The earthquake shook ships in the Pacific Ocean, and was felt with greatest intensity along the coast of the Pacific, in western Santa Barbara County. Several hundred thousand cubic feet of sand underneath the tracks of the Southern Pacific Railroad were shaken loose and fell to the beach below. One person asleep near the coast was thrown from his bed, highways cracked, a bridge was thrown out of line, and there were numerous rock and dirt falls.

Further inland, in the towns of Lompoc, Santa Maria, and Los Alamos, people were awakened and rushed into the streets in their night clothes, chimneys collapsed, goods were thrown from shelves, windows cracked, and cornices of buildings fell.

Besides the dead fish noticed by Captain Williamson, there are a number of other peculiar effects from this earthquake, including a small tsunami that rolled in a few minutes after the largest earthquake.

~~~~~~~~~~

The 1978 Goleta Earthquake

Source:
http://projects.crustal.ucsb.edu/sb_eqs/1978/1978.html

Starting in March of 1978 and continuing sporadically through July, 1978, a swarm of small earthquakes--called microearthquakes-- occurred underneath the northeastern end of the Santa Barbara Channel. This swarm did not arouse much concern, however, since microearthquakes occur frequently underneath the Santa Barbara Channel. Toward the end of the microearthquake swarm, in July and early August of 1978, Santa Barbara residents complained of an unusually large amount of oil and tar on local beaches. Another common occurrence for the Santa Barbara area, the oil from these natural seeps was considered only a minor nuisance.

Then, on August 13, 1978, on a sunny Sunday afternoon, the earth shifted abruptly underneath the channel. The earthquake started just to the southwest of the city of Santa Barbara, about 9 kilometers (5.5 miles) underneath the Santa Barbara Channel. The earthquake ruptured to the northwest, focusing its energy toward Goleta, the most intense ground motion occurring between Turnpike Road and Winchester Canyon Road, an area that includes the University of California, Santa Barbara.

A strong-motion seismograph on the UCSB campus recorded an acceleration of 0.45 times that of gravity. Another seismograph, located at the top of North Hall, recorded an acceleration of 0.94 times that of gravity. One-third of the books at the UCSB library--some 400,000 volumes--were thrown to the floor. Elsewhere in Goleta, store goods were thrown to the ground, windows of businesses and residences were shattered, the Santa Barbara airport terminal was left leaning, dozens of mobile homes were thrown from their supports, and a landslide blocked San Marcos Pass. Ten minutes after the earthquake a freight train heading through Goleta derailed at a kink in the tracks.

65 people were treated for injuries at local hospitals. No deaths occurred, but had classes been in session at UCSB, it is almost certain that many more serious injuries would have resulted.

Back

This page was last updated August 9, 2009.