What was the magnitude of the 89 earthquake?
magnitude 6.9On October 17, 1989, a magnitude 6.9 earthquake hit the San Francisco Bay Area, killing 67 people and causing more than $5 billion in damages. Despite the fact that the disaster was one of the most powerful and destructive quakes ever to hit a populated area of the United States, the death toll was relatively small.
What was the magnitude of the 1989 Loma Prieta earthquake and how long did the shaking last?
Its epicentre was in the Forest of Nisene Marks State Park, near Loma Prieta peak in the Santa Cruz mountains, northeast of Santa Cruz and approximately 60 miles (100 km) south of San Francisco. It struck just after 5:00 pm local time and lasted approximately 15 seconds, with a moment magnitude of 6.9.
How strong was the Loma Prieta earthquake 1989?
magnitude 6.9On October 17, 1989, at 5:04:15 p.m. (PDT), a magnitude 6.9 earthquake severely shook the San Francisco and Monterey Bay regions. The epicenter was located near Loma Prieta peak in the Santa Cruz Mountains, approximately 14 km (9 mi) northeast of Santa Cruz and 96 km (60 mi) south-southeast of San Francisco.
What type of earthquake was Loma Prieta?
1989 Loma Prieta earthquakeImage of collapsed Cypress freeway structure in Oakland, CaliforniaSanta Cruz Oakland SalinasDepth19 km (12 mi)Epicenter37.04°N 121.88°WTypeOblique-slip reverse15 more rows
What's the strongest 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 far can a 7.0 earthquake be felt?
But a 7.0 quake can cause damage 100-150 miles away. The distance shrinks very rapidly as the magnitude drops. But can an earthquake far away affect the tectonics (earthquake potential) in another area?
What's 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
What was the biggest earthquake in California?
In 1994, a 6.7 earthquake hit near Northridge, Calif. Its peak G-force acceleration was the highest ever recorded with modern instrumentation in a North American city. In 1989, a 6.9 earthquake hit Loma Prieta, Calif. It felled Bay Area freeway interchanges, interrupted a World Series and caused $10 billion in damage.
How long did the 1989 earthquake last?
Caused by a slip along the San Andreas Fault, the quake lasted 10–15 seconds and measured 6.9 on the moment magnitude scale, or 6.9 on the open-ended Richter Scale. The quake killed 63 people throughout northern California, injured 3,757 and left some 3,000-12,000 people homeless.
Is a 5.2 earthquake strong?
Moderate: 5 - 5.9 Getty Images A moderate earthquake registers between 5 and 5.9 on the Richter scale and causes slight damage to buildings and other structures. There are about 500 of these around the globe every year.
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 magnitude earthquake can you feel?
The magnitude, location, and depth of an earthquake, and overlying soil conditions determine how widely and strongly any particular event can be felt. Typically, people report feeling earthquakes larger than about magnitude 3.0.
How long did the 1989 earthquake last?
Caused by a slip along the San Andreas Fault, the quake lasted 10–15 seconds and measured 6.9 on the moment magnitude scale, or 6.9 on the open-ended Richter Scale. The quake killed 63 people throughout northern California, injured 3,757 and left some 3,000-12,000 people homeless.
How long does an earthquake last?
about 10 to 30 secondsHow long do earthquakes last? Generally, only seconds. Strong ground shaking during a moderate to large earthquake typically lasts about 10 to 30 seconds. Readjustments in the earth cause more earthquakes (aftershocks) that can occur intermittently for weeks or months.
How many seconds did the shaking from the earthquake in San Francisco last?
Violent shocks punctuated the strong shaking which lasted some 45 to 60 seconds. The earthquake was felt from southern Oregon to south of Los Angeles and inland as far as central Nevada.
What was the magnitude of the October 1989 Loma Prieta EQ approximate the length of fault rupture from the map?
The 1989 Loma Prieta earthquake had a moment magnitude of 6.9.
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.
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 ...
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.
How many people lost power in the San Francisco earthquake?
An estimated 1.4 million people lost power following the quake, mainly due to damaged electrical substations. Many San Francisco radio and television stations were temporarily knocked off the air. KGO-TV, the local ABC station in San Francisco, was off the air for about 15 minutes, while KRON-TV (at the time the region's NBC affiliate) was off the air for about half an hour, and KGO-AM ( ABC News Radio) was off the air for about 40 minutes. 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. KCBS later won a Peabody Award for their news coverage, as did KGO-TV.
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 significance of vertical displacement in 1989?
The significant amount of vertical displacement in 1989 was a key aspect to consider because a long-term sequence of 1989-type events (with an 80–100-year recurrence interval) normally result in regions with high topographic relief , which is not seen in the Santa Cruz Mountains.
How many buildings were destroyed in the 1906 San Francisco earthquake?
In Santa Cruz, the Pacific Garden Mall was severely damaged, with falling debris killing three people, half of the six earthquake deaths in Santa Cruz and Monterey Counties. Some 31 buildings were damaged enough to warrant demolition, seven of which had been listed in the Santa Cruz Historic Building Survey. The four oldest were built in 1894, the five oldest withstood the 1906 San Francisco earthquake.
What was the magnitude of the Loma Prieta earthquake?
The 6.9 magnitude Loma Prieta earthquake, which occurred 25 years ago on Oct. 17, ended decades of seismic tranquility in the region and was a wakeup call to the region to prepare for even more devastating shocks in the future.
Where is the epicenter of Loma Prieta?
Today, the marker is the only indication that this tranquil redwood forest, located about 10 miles from Santa Cruz, ...
What campus was the aftermath of Loma Prieta?
The Stanford campus and Bay Area in the aftermath of Loma Prieta.
What happened in 1989?
At the close of a busy workday in the fall of 1989, a fault line buried miles beneath the quiet heart of a redwood forest near Santa Cruz ruptured, generating devastating seismic waves that sped across the Bay Area. The 6.9 magnitude Loma Prieta earthquake, which occurred 25 years ago on Oct.
What did the Loma Prieta earthquake teach us?
Listen to what the Loma Prieta earthquake of 1989 taught about seismology, early warning system, earthquake preparedness and the role of the Berkeley seismology lab. A discussion of the lessons learned from the Loma Prieta (San Francisco–Oakland) earthquake of 1989. Displayed by permission of The Regents of the University of California.
Where was the 1989 World Series earthquake?
Remarkably, the earthquake struck just before the start of the third game of the 1989 World Series, which was to be played in San Francisco’s Candlestick Park between the two Bay Area baseball teams, the San Francisco Giants and the Oakland Athletics. The disaster’s occurrence during a major live television broadcast meant that news ...
How many people died in the 1989 earthquake?
The quake struck with a moment magnitude of 6.9 on October 17, just before the start of the third game of the World Series, which was being held at San Francisco's Candlestick Park. Sixty-three people died, and nearly 3,800 were injured.
What happened to Santa Cruz in 1989?
Damaged buildings in Santa Cruz, California, following the San Francisco-Oakland earthquake of 1989. C.E. Meyer/U.S. Geological Survey. The earthquake significantly damaged the transportation system of the Bay Area. The collapse of the Cypress Street Viaduct (Nimitz Freeway) caused most of the earthquake-related deaths.
What was the hardest hit area in San Francisco?
San Francisco’s Marina district was particularly hard hit because it had been built on filled land (comprising loose, sandy soil), and the unreinforced masonry buildings in Santa Cruz (many of which were 50 to 100 years old) failed completely. San Francisco-Oakland earthquake of 1989.
When was the San Francisco earthquake?
( A Britannica Publishing Partner) See all videos for this article. 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, ...
How long has it been since the Loma Prieta earthquake?
SAN FRANCISCO (KGO) -- It has been 30 years since the Loma Prieta earthquake. The shaking devastated towns, collapsed bridges and highways, and changed thousands of lives in an instant. In the days that followed, the stories of survival spread.
What happened 89 hours after the earthquake?
"The memories are as fresh as the day it happened," said Whipple, as he choked back tears. The Caltrans worker found a survivor, Buck Helms, trapped in a car crushed to a height of about 3 feet.
Overview
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".