Secondly, did the Loma Prieta earthquake
1989 Loma Prieta earthquake
The 1989 Loma Prieta earthquake occurred in Northern California on October 17 at 5:04 p.m. local time. The shock was centered in The Forest of Nisene Marks State Park approximately 10 mi northeast of Santa Cruz on a section of the San Andreas Fault System and was named for the ne…
Was there a tsunami at Monterey during the 1989 Loma Prieta earthquake?
We investigated the tsunami recorded at Monterey, California, during the 1989 Loma Prieta earthquake (M W =6.9). The first arrival of the tsunami was about 10 min after the origin time of the earthquake.
What caused the Loma Prieta earthquake?
The Loma Prieta earthquake was triggered by the mighty San Andreas Fault, where the massivePacific plate slips northwestward. During the quake, the epicenter slipped up to two meters.
How many people died in the Loma Prieta earthquake?
The Loma Prieta earthquake caused 63 deaths, 3,757 injuries, and about $6 billion in damage. Many casualties occurred as parts of several transportationroutes, including the San Francisco-Oakland Bay Bridgeand a busy freeway, collapsed.
Where can I find media related to the Loma Prieta earthquake?
Wikimedia Commons has media related to Loma Prieta earthquake. The International Seismological Centre has a bibliography and/or authoritative data for this event. "Reflections 20 Years Later in Loma Prieta – Whole Mountain Source Book". "October 17, 1989 Loma Prieta Earthquake – United States Geological Survey".
Did Loma Prieta cause a tsunami?
In a tectonic context similar to the 2010 Haiti earthquake, the 1989, M w 6.9 Loma Prieta earthquake excited tsunamis in the nearby Monterey Bay that required a secondary offshore landslide, assumed to have occurred in shallow waters (Ma et al., 1991) . ...
What were the effects of the 1989 Loma Prieta earthquake?
The Loma Prieta earthquake caused 63 deaths, 3,757 injuries, and about $6 billion in damage. Many casualties occurred as parts of several transportation routes, including the San Francisco-Oakland Bay Bridge and a busy freeway, collapsed. person who participates or competes in sporting events.
Did the 1906 earthquake cause a tsunami?
Even though the magnitude of the 1906 earthquake was large (M 7.8), it generated a tsunami wave only approximately 10 cm in height.
What was the most destructive effect of the Loma Prieta earthquake?
The most severe damage caused by ground shaking occurred in areas near the epicenter or located on poorly consolidated deposits or man-made fill. Ground shaking primarily affected unreinforced masonry structures, toppling chimneys throughout the region and partially to completely collapsing some brick buildings.
What type of earthquake was the Loma Prieta earthquake?
Oblique-slip reverse1989 Loma Prieta earthquakeImage of collapsed Cypress freeway structure in Oakland, CaliforniaSanta Cruz Oakland SalinasEpicenter37.04°N 121.88°WTypeOblique-slip reverseAreas affectedCentral Coast (California) San Francisco Bay Area United States15 more rows
What was the worst earthquake in California?
California's Largest Recorded Earthquakes Since 1800, Ranked by MagnitudeMagnitudeDateLocation7.9Jan. 9, 1857Fort Tejon7.8April 18, 1906San Francisco7.4Mar. 26, 1872Owens Valley7.4Nov. 8, 1980W. of Eureka*12 more rows
Would the San Andreas fault cause a tsunami?
Tsunami Science The San Andreas fault cannot create a big tsunami, as depicted in the movie.
What kind of earthquakes cause tsunamis?
Most tsunamis are generated by earthquakes with magnitudes over 7.0 that occur under or very near the ocean and less than 100 kilometers (62 miles) below Earth's surface (earthquakes deeper than this are unlikely to displace the ocean floor).
What was the biggest tsunami?
1958 Lituya Bay earthquake and megatsunamiTsunami / BiggestLituya Bay, Alaska, July 9, 1958 Its over 1,700-foot wave was the largest ever recorded for a tsunami. It inundated five square miles of land and cleared hundreds of thousands of trees. Remarkably, only two fatalities occurred.
Did the Golden Gate Bridge collapse in 1989?
Loma Prieta Earthquake, October 17, 1989 Although the Golden Gate Bridge suffered no observed damage from the Loma Prieta quake, since the epicenter was located some 60 miles to the south, the earthquake became a catalyst for the extensive seismic retrofit program that the historic structure is undergoing today.
What was the worst earthquake in history?
Great Alaska Earthquake (1964)– 9.2 It lasted approximately 4.5 minutes and is the most powerful recorded earthquake in U.S. history. The earthquake triggered 27-foot (8.2 meters) tsunami which destroyed the village of Chenega, killing 23 of the 68 people who lived there.
Why did the Bay Bridge collapse in 1989?
Silhouette of part of the Bay Bridge connecting San Francisco and Oakland. A section of the Bay Bridge's upper deck collapsed during an earthquake that struck the San Francisco area on October 17, 1989, requiring lengthy repair (see San Francisco earthquake of 1989).
What changed after the Loma Prieta earthquake?
The 1989 Loma Prieta earthquake helped dramatically change San Francisco's Ferry Building and waterfront. After the quake significantly damaged the double decker state highway, city leaders ultimately decided to demolish the freeway and replace it with the tree-lined, wide boulevard that exists today.
What was the worst earthquake in history?
Great Alaska Earthquake (1964)– 9.2 It lasted approximately 4.5 minutes and is the most powerful recorded earthquake in U.S. history. The earthquake triggered 27-foot (8.2 meters) tsunami which destroyed the village of Chenega, killing 23 of the 68 people who lived there.
Why was the Loma Prieta earthquake event important?
San Francisco earthquake of 1989, also called Loma Prieta earthquake, major earthquake that struck the San Francisco Bay Area, California, U.S., on October 17, 1989, and caused 63 deaths, nearly 3,800 injuries, and an estimated $6 billion in property damage.
What is the largest earthquake ever recorded?
magnitude 9.5The largest earthquake ever recorded was a magnitude 9.5 on May 22, 1960 in Chile on a fault that is almost 1,000 miles long…a “megaquake” in its own right.
How many people died in the Loma Prieta earthquake?
63 killed, 3,757 injured. The 1989 Loma Prieta earthquake occurred on California's Central Coast on October 17 at 5:04 p.m. local time. The shock was centered in The Forest of Nisene Marks State Park in Santa Cruz County, approximately 10 mi (16 km) northeast of Santa Cruz on a section of the San Andreas Fault System and was named for ...
Where is Loma Prieta Peak?
Loma Prieta Peak in the Santa Cruz Mountains. See also: California earthquake forecast and Earthquake prediction. Since many forecasts had been presented for the region near Loma Prieta, seismologists were not taken by surprise by the October 1989 event.
What is the most studied fault in California?
The history of earthquake investigations in California has been largely focused on the San Andreas Fault System , due to its strong influence in the state as the boundary between the Pacific Plate and the North American Plate; it is the most studied fault on Earth. Andrew Lawson, a geologist from the University of California, Berkeley, had named the fault after the San Andreas Lake (prior to the occurrence of the 1906 San Francisco earthquake) and later led an investigation into that event. The San Andreas Fault ruptured for a length of 290 mi (470 km) during the 1906 shock, both to the north of San Francisco and to the south in the Santa Cruz Mountains region. Several long term forecasts for a large shock along the San Andreas Fault in that area had been made public prior to 1989 (the event and its aftershocks occurred within a recognized seismic gap) but the earthquake that transpired was not what had been anticipated. The 1989 Loma Prieta event originated on an undiscovered oblique-slip reverse fault that is located adjacent to the San Andreas Fault.
What station was on the air after the earthquake?
About an hour and 40 minutes after the quake, Fox affiliate KTVU resumed broadcasting, with their news anchors, Dennis Richmond and Elaine Corral reporting from the station's parking lot. KCBS-AM ( CBS News Radio) switched immediately to backup power and managed to stay on air despite a subsequent generator failure.
Where did the ML 5.3 earthquake occur?
The ML 5.3 June 1988 and the M L 5.4 August 1989 events also occurred on previously unknown oblique reverse faults and were within 3 mi (4.8 km) of the M6.9 Loma Prieta mainshock epicenter, near the intersection of the San Andreas and Sargent faults. Total displacement for these shocks was relatively small (approximately 4 in (100 mm) of strike-slip and substantially less reverse-slip) and although they occurred on separate faults and well before the mainshock, a group of seismologists considered these to be foreshocks due to their location in space and time relative to the main event. Each event's aftershock sequence and effect on stress drop was closely examined, and their study indicated that the shocks affected the mainshock's rupture process. Following the August 8, 1989 shock, in anticipation of an upcoming large earthquake, staff at the University of California, Santa Cruz deployed four accelerometers in the area, which were positioned at the UCSC campus, two residences in Santa Cruz, and a home in Los Gatos. Unlike other nearby (high gain) seismographs that were overwhelmed (driven off scale) by the large magnitude mainshock, the four accelerometers captured a useful record of the main event and more than half an hour of the early aftershock activity.
What was the worst earthquake in Oakland?
The worst disaster of the earthquake was the collapse of the double-deck Cypress Street Viaduct of Interstate 880 in West Oakland. The failure of a 1.25-mile (2.0 km) section of the viaduct, also known as the "Cypress Structure" and the "Cypress Freeway", killed 42 and injured many more.
What happened in 1989 San Francisco earthquake?
In the 1989 earthquake, the water-saturated unconsolidated mud, sand, and rubble suffered liquefaction, and the earthquake's vertical shock waves rippled the ground more severely. At the intersection of Beach and Divisadero Streets in San Francisco, a natural gas main rupture caused a major structure fire.
Where
- The epicenter was on the San Andreas fault roughly 56 miles south of San Francisco and 10 miles northeast of Santa Cruz, near Mt. Loma Prieta in the Santa Cruz Mountains. The focal depth was 11 miles (typical California earthquake focal depths are 4 to 6 miles). Loma Prleta ruptured the southernmost 30 miles of the break that caused the 1906 San Fr...
How Big
- Magnitude established at 6.9 after consultation with monitoring stations around the world. The Loma Prieta quake was felt as far away as San Diego and western Nevada.
Aftershocks
- A magnitude 5.2 aftershock occurred approximately 2.5 minutes after the main shock. In the week following Loma Prieta, 20 aftershocks magnitude 4.0 or greater and more than 300 of magnitude 2.5 or greater were recorded. Thousands of aftershocks were recorded. The aftershock zone stretched 25 miles, from north of Los Gatos near Highway 17 to south of Watsonville near High…
Damage
- Damage and business interruption estimates reached as high as $10 billion, with direct damage estimated at $6.8 billion. 18,306 houses were damaged and 963 were destroyed. 2,575 businesses were damaged and 147 were destroyed. The most notable damage included the collapse of the elevated Cypress Structure section of Interstate 880 in Oakland, the collapse of …
Warning Signs
- Geologists had forecast a major earthquake in this area based on historical data, especially the lack of a major seismic event along the San Andreas fault since 1906 -- the 8.3 San Francisco earthquake. In the 83 years prior to the 1906 quake, seven damaging earthquakes of magnitude 6.5 or greater occurred. Only two have occurred since the San Francisco earthquake. Several 5.…
The Fault
- The San Andreas Fault is the boundary between the North American plate and the Pacific plate. Land west of the fault has been moving to the northwest relative to land on the east at an average rate of 2 inches per year for millions of year. This motion typically occurs in sudden jumps during large earthquakes. The Pacific plate moved 6.2 feet to the northwest and 4.3 feet upward over t…
Magnitude Defined
- Magnitude is a measure of an earthquake's size, but rather than being a direct measure of the level of ground shaking, it is a measurement of the strength of the seismic sound waves given off by the earthquake. A magnitude 8 earthquake radiates 30 times more energy of a magnitude 7 and 900 times the energy of a magnitude 6. Strong ground shaking for a magnitude 7 quake typi…
What If
- As devastating as Loma Prieta was, a magnitude 7.5 earthquake on the Hayward Fault in the East Bay could do $65 billion in damage.
Overview
The 1989 Loma Prieta earthquake occurred on California's Central Coast on October 17 at 5:04 p.m. local time. The shock was centered in The Forest of Nisene Marks State Park in Santa Cruz County, approximately 10 mi (16 km) northeast of Santa Cruz on a section of the San Andreas Fault System and was named for the nearby Loma Prieta Peak in the Santa Cruz Mountains. With an Mw magnitude …
Background
The history of earthquake investigations in California has been largely focused on the San Andreas Fault system because of its strong influence in the state as the boundary between the Pacific Plate and the North American Plate; it is the most studied fault on Earth. Andrew Lawson, a geologist from the University of California, Berkeley, had named the fault after the San Andreas Lake (prior to th…
Earthquake
The Loma Prieta earthquake was named for Loma Prieta Peak in the Santa Cruz Mountains, which lies just to the east of the mainshock epicenter. The duration of the heaviest shaking in the Santa Cruz Mountains was about 15 seconds, but strong ground motion recordings revealed that the duration of shaking was not uniform throughout the affected area (because of different types and thicknes…
Damage
The earthquake caused severe damage in some very specific locations in the Bay Area, most notably on unstable soil in San Francisco and Oakland. Oakland City Hall was evacuated after the earthquake until a US$80 million (equivalent to US$175 million today) seismic retrofit and hazard abatement work was completed in 1995. Many other communities sustained severe damage throug…
1989 World Series and television coverage of earthquake
The 1989 World Series featured the Oakland Athletics and the San Francisco Giants in the first cross-town World Series since 1956. Game 3 of the series was scheduled to begin at San Francisco's Candlestick Park on October 17 at 5:35 PDT, and American TV network ABC began its pre-game show at 5:00 PDT. When the quake struck at approximately 5:04 PDT, sportscaster Tim McCarver was narrating taped highlights of Game 2, which had been played two days prior acros…
In popular culture
The earthquake is featured in films and television shows:
• The events in the TV sitcom Full House episode "Aftershocks" (December 8, 1989) take place following the Loma Prieta earthquake; it centers on 7-year-old Stephanie Tanner having a hard time telling her father Danny about how she fears another aftershock might happen and kill him (since he is a widowed sin…
See also
• 1906 San Francisco earthquake
• 1992 Landers earthquake
• 1994 Northridge earthquake
• 1999 Hector Mine earthquake
External links
• The International Seismological Centre has a bibliography and/or authoritative data for this event.
• A film clip "Loma Prieta Earthquake, ca. 1989" is available at the Internet Archive
• "October 17, 1989 Loma Prieta Earthquake – United States Geological Survey".