Boulder Weekly is an alternative newsweekly that publishes every Thursday in Boulder, Colorado . The paper is a member of the Association of Alternative Newsweeklies (AAN) and is owned and published by Stewart Sallo.
120-574: After the Loma Prieta earthquake in 1989, Sallo left Santa Cruz, Calif., where he had ownership of two publications — Summer Santa Cruz and Student Guide . By 1992, he had set his sights on Boulder, Colorado. He moved to Boulder in 1993, and the first edition of Boulder Weekly hit the stands on Aug. 19 of that year. In the years since, Boulder Weekly has garnered numerous state journalism awards for opinion, news, features, and entertainment writing. Between 1996 and 2000, Boulder Planet operated as
240-606: A competing publication to the Weekly. The continued publication of the Weekly despite the competition has been a source of satisfaction for Sallo. The paper is currently the only independent newspaper published in Boulder. Initially, Sallo saw the paper as a business opportunity in a city lacking a weekly newspaper. However, an article by Joel Dyer in 1994 reshaped Sallo's view on the newspaper's potential impact ("Deadly ground: Beech Aircraft toxins poison open space," Sept. 14, 1994). As
360-459: A crack down the front of the building. Many homes were dislodged if they were not bolted to their foundations. There were structural failures of twin bridges across Struve Slough near Watsonville. In Moss Landing, the liquefaction destroyed the causeway that carried the Moss Beach access road across a tidewater basin, damaged the approach and abutment of the bridge linking Moss Landing spit to
480-566: A crucial link to rescue workers. Widespread search operations were organized to find possible victims inside the remains of fallen structures. As many as six teams of dogs and their handlers were at work identifying the large number of damaged buildings that held no victims. The quake claimed one life in Watsonville : a driver who collided with panicked horses after they escaped their collapsed corral. In other Santa Cruz and Monterey county locations such as Boulder Creek and Moss Landing ,
600-476: A large slide and one person was killed by a rockfall along the coast. Other areas with certain soil conditions were susceptible to site amplification due to the effects of liquefaction , especially near the shore of San Francisco Bay (where its effects were severe in the Marina District ) and to the west of the epicenter near rivers and other bodies of water. Minor lateral spreading was also seen along
720-560: A link between the water level in Lake Cahuilla (now the Salton Sea ) and seismic activity along the southern San Andreas Fault. The study suggests that major earthquakes along this section of the fault coincided with high water levels in the lake. The hydrological load caused by high water levels can more than double the stress on the southern San Andreas Fault, which is likely sufficient for triggering earthquakes. This may explain
840-563: A magnitude 7.8 earthquake along the southern San Andreas Fault could cause about 1,800 deaths and $ 213 billion in damage. This scenario hypothesizes the potential effects of a 7.0 magnitude earthquake on the San Andreas Fault in the San Francisco Bay Area. It aims to estimate the impacts on urban infrastructures along with the rebuilding efforts to both the landscape and economy. This study combines not only
960-476: A number of structures were damaged, with some knocked off of their foundations. Many residents slept outside their homes out of concern for further damage from aftershocks, of which there were 51 with magnitudes greater than 3.0 in the following 24 hours, and 16 more the second day. The earthquake damaged several historic buildings in the Old Town district of Salinas , and some were later demolished. Damage to
1080-587: A possible driver for the deformation of the Basin and Range , separation of the Baja California peninsula , and rotation of the Transverse Range . The main southern section of the San Andreas Fault proper has only existed for about 5 million years. The first known incarnation of the southern part of the fault was Clemens Well-Fenner- San Francisquito fault zone around 22–13 Ma. This system added
1200-498: A result, Boulder Weekly' s editorial direction shifted toward a more aggressive, alternative approach to news. Dyer later became editor of Boulder Weekly , eventually leaving the paper to write books and publish his own newsweekly, the Fort Collins Weekly , from 2002 to 2007. Succeeding Dyer, Greg Campbell maintained the investigative editorial direction, publishing articles such as "Eternal flame: Think you've paid at
1320-668: A section of the double-deck Nimitz Freeway in Oakland was the site of the largest number of casualties for the event, but the collapse of human-made structures and other related accidents contributed to casualties occurring in San Francisco, Los Gatos , and Santa Cruz. The history of earthquake investigations in California has been largely focused on the San Andreas Fault system because of its strong influence in
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#17327808586921440-453: A substantial increase in noise was measured in the frequency range 0.01–10 Hz. The measurement instrument was a single-axis search-coil magnetometer that was being used for low frequency research. Precursor increases of noise apparently started a few days before the earthquake, with noise in the range 0.01–0.5 Hz rising to exceptionally high levels about three hours before the earthquake. The Fraser-Smith et al. report remains one of
1560-466: A thing. McCarver: I guess Dave Parker ... Michaels: Well, heh, I don't know if we're on the air or not, and I'm not sure I care at this particular moment but we are. Well, folks, that's the greatest open in the history of television! Bar none! McCarver: Opened with a bang! San Andreas Fault The San Andreas Fault is a continental right-lateral strike-slip transform fault that extends roughly 1,200 kilometers (750 mi) through
1680-499: Is a combined effort from experts in the physical sciences, social sciences, and engineering both in the public and private sectors- ranging from urban planners to economists/business professionals. Not only does this study aim to estimate the impacts of the event, but aims to estimate the years of rebuilding and funding needed to recover communities from a potential disaster such as the HayWired Scenario. The first volume of
1800-468: Is located adjacent to the San Andreas Fault. Since many forecasts had been presented for the region near Loma Prieta, seismologists were not taken by surprise by the October 1989 event. Between 1910 and 1989 there were 20 widely varying forecasts that were announced, with some that were highly specific, covering multiple aspects of an event, while others were less complete and vague. With a M6.5 event on
1920-614: Is not clear. Several hypotheses have been offered and research is ongoing. One hypothesis – which gained interest following the Landers earthquake in 1992 – suggests the plate boundary may be shifting eastward away from the San Andreas towards Walker Lane. Assuming the plate boundary does not change as hypothesized, projected motion indicates that the landmass west of the San Andreas Fault, including Los Angeles, will eventually slide past San Francisco, then continue northwestward toward
2040-494: Is not seen in the Santa Cruz Mountains. Three scenarios were presented that might explain this disparity. The first is that the geometry of the San Andreas Fault goes through a transition every several thousand years. Secondly, slip type could vary from event to event. And lastly, the 1989 event did not occur on the San Andreas Fault. While the effects of a four-year drought limited the potential of landslides ,
2160-566: Is the approximate location of the epicenter of the 1906 San Francisco earthquake . The fault returns onshore at Bolinas Lagoon just north of Stinson Beach in Marin County . It returns underwater through the linear trough of Tomales Bay which separates the Point Reyes Peninsula from the mainland, runs just east of Bodega Head through Bodega Bay and back underwater, returning onshore at Fort Ross . (In this region around
2280-420: The 1994 Northridge earthquake ) occurs about once every 6.7 years statewide. The same report also estimated there is a 7% probability that an earthquake of magnitude 8.0 or greater will occur in the next 30 years somewhere along the San Andreas Fault. A different USGS study in 2008 tried to assess the physical, social and economic consequences of a major earthquake in southern California. That study predicted that
2400-681: The Aleutian Trench , over a period of perhaps twenty million years. The San Andreas began to form in the mid- Cenozoic about 30 Mya (million years ago). At this time, a spreading center between the Pacific plate and the Farallon plate (which is now mostly subducted, with remnants including the Juan de Fuca plate , Rivera plate , Cocos plate , and the Nazca plate ) was beginning to reach
2520-791: The Loma Prieta earthquake occurred at the Central Coast of California. 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 M w magnitude of 6.9 and a maximum Modified Mercalli intensity of IX ( Violent ),
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#17327808586922640-548: The Salinas River rail bridge and subsequent repairs led to reduced traffic on the Monterey Branch Line , which contributed to the discontinuance of freight rail services in western Monterey County. The San Francisco–Oakland Bay Bridge suffered severe damage, as a 76-by-50-foot (23 m × 15 m) section of the upper deck on the eastern cantilever side fell onto the deck below. The quake caused
2760-587: The Salton Sea . Here, the plate motion is being reorganized from right-lateral to divergent . In this region (known as the Salton Trough ), the plate boundary has been rifting and pulling apart, creating a new mid-ocean ridge that is an extension of the Gulf of California . Sediment deposited by the Colorado River is preventing the trough from being filled in with sea water from the gulf. The fault
2880-573: The San Francisco Bay Area several significant "sister faults" run more-or-less parallel, and each of these can create significantly destructive earthquakes.) From Fort Ross, the northern segment continues overland, forming in part a linear valley through which the Gualala River flows. It goes back offshore at Point Arena . After that, it runs underwater along the coast until it nears Cape Mendocino , where it begins to bend to
3000-473: The San Gabriel Fault as a primary focus of movement between 10–5 Ma. Currently, it is believed that the modern San Andreas will eventually transfer its motion toward a fault within the eastern California shear zone . This complicated evolution, especially along the southern segment, is mostly caused by either the "Big Bend" and/or a difference in the motion vector between the plates and the trend of
3120-699: The San Gabriel Mountains . These mountains are a result of movement along the San Andreas Fault and are commonly called the Transverse Range. In Palmdale , a portion of the fault is easily examined at a roadcut for the Antelope Valley Freeway . The fault continues northwest alongside the Elizabeth Lake Road to the town of Elizabeth Lake . As it passes the towns of Gorman , Tejon Pass and Frazier Park ,
3240-584: The Santa Cruz Mountains (the location of the Loma Prieta earthquake in 1989). Studies of the relative motions of the Pacific and North American plates have shown that only about 75 percent of the motion can be accounted for in the movements of the San Andreas and its various branch faults. The rest of the motion has been found in an area east of the Sierra Nevada mountains called the Walker Lane or Eastern California Shear Zone. The reason for this
3360-526: The State office of Emergency Services issued (for the first time in Bay Area history) short term advisories for a possible large earthquake, which meant there was "a slightly increased likelihood of an M6.5 event on the Santa Cruz Mountains segment of the San Andreas fault". The advisories following the two Lake Elsman events were issued in part because of the statements made by WGCEP and because they were two of
3480-524: The Transbay Tube between the date of the earthquake and December 3 that same year. 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. Built in
3600-526: The U.S. Geological Survey (USGS) have made variable predictions as to the risk of future seismic events. The ability to predict major earthquakes with sufficient precision to warrant increased precautions has remained elusive. The U.S. Geological Survey's most recent forecast, known as UCERF3 (Uniform California Earthquake Rupture Forecast 3), released in November 2013, estimated that an earthquake of magnitude 6.7 M or greater (i.e. equal to or greater than
3720-463: 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
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3840-587: The California economy within the first 6 months post-recovery from the event through estimates of "utility outages, property damages, and supply chain disruptions resulting in an estimated $ 44 billion of gross state product (GSP) losses, or translated at 4% of the California economy"(Wein et al.). This study also projects the recovery of jobs lost in highly impacted areas, such as Alameda County, could take up to 10 years to fully recover job losses and possible economic recession. Trajectories for economic recovery are improved by reconstruction but also delayed with impacts to
3960-647: The Cypress Street Viaduct in Oakland) the intensity of the shaking was more severe and lasted longer. The strong motion records also allowed for the causative fault to be determined – the rupture was related to the San Andreas Fault System. While a Mercalli Intensity of VIII ( Severe ) covered a large swath of territory relatively close to the epicenter (including the cities of Los Gatos, Santa Cruz, and Watsonville ) farther to
4080-527: The East Bay, and near the shore of Monterey Bay , where a non-destructive tsunami was also observed. Because it happened during a national live broadcast of the 1989 World Series , the annual championship series of Major League Baseball , taking place between Bay Area teams San Francisco Giants and the Oakland Athletics , it is sometimes referred to as the "World Series earthquake" , with
4200-516: The Emergency Broadcast System to the public after the quake because the engineering department at KNBR experienced major technical malfunctions and difficulties. The malfunctions during the aftermath of the earthquake caused confusion as to whether an earthquake would cause the Emergency Broadcast System to activate. KNBR began using an emergency generator, hooking up the signal from a command center right after their nearby studio
4320-661: The HayWired Scenario study was released in 2017, with consistent continuations and contributions by engineers. This continuation was published in the second volume, Engineering Implications, in 2018. As of the 2021 Fact sheet update, there are several estimates on damages ranging from the approximate people affected at home, work, effects of lifeline infrastructures such as telecommunications, and more. This group of scientists have worked together to create estimates of how hazards such as liquefaction, landslides, and fire ignition will impact access to utilities, transportation, and general emergency services. This study goes into detail about
4440-424: The Oakland side of the bridge to shift 7 in (18 cm) to the east, and caused the bolts of one section to shear off, sending the 250-short-ton (230 t; 500,000 lb; 226,800 kg) section of roadbed crashing down like a trapdoor. Traffic on both decks came to a halt, blocked by the section of the roadbed. Police began unsnarling the traffic jam, telling drivers to turn their cars around and drive back
4560-463: The San Andreas fault has reached a sufficient stress level for an earthquake of magnitude greater than 7.0 on the moment magnitude scale to occur. This study also found that the risk of a large earthquake may be increasing more rapidly than scientists had previously believed. Moreover, the risk is currently concentrated on the southern section of the fault, i.e. the region around Los Angeles, because strong earthquakes have occurred relatively recently on
4680-575: The San Juan Bautista segment, or an M7 event on the San Francisco Peninsula segment, United States Geological Survey (USGS) seismologist Allan Lindh's 1983 forecasted rupture length of 25 miles (40 km) (starting near Pajaro Gap, and continuing to the northwest) for the San Juan Bautista segment nearly matched the actual rupture length of the 1989 event. An updated forecast was presented in 1988, at which time Lindh took
4800-585: The Santa Cruz Historic Building Survey. The four oldest were built in 1894, the five oldest withstood the 1906 San Francisco earthquake. Immediately, a number of civilians began to free victims from the rubble of Ford's Department Store and the Santa Cruz Coffee Roasting Company – both buildings had collapsed inward on customers and employees alike. Two police officers crawled through voids in
4920-469: 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 thicknesses of soil ). At sites with rocky terrain, the duration was shorter and the shaking was much less intense, and at locations with unconsolidated soil (like the Marina District in San Francisco or
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5040-661: The Santa Cruz Mountains, pieces of concrete fell from a parking structure at the Sunnyvale Town Center , a two-level shopping mall in Santa Clara County. More moderate damage resulted from the August 8, 1989, shock (intensity VII, Very strong ) when chimneys were toppled in Cupertino , Los Gatos, and Redwood Estates . Other damage included cracked walls and foundations and broken underground pipes. At
5160-572: The U.S. state of California . It forms part of the tectonic boundary between the Pacific plate and the North American plate . Traditionally, for scientific purposes, the fault has been classified into three main segments (northern, central, and southern), each with different characteristics and a different degree of earthquake risk. The average slip rate along the entire fault ranges from 20 to 35 mm (0.79 to 1.38 in) per year. In
5280-586: The United States. In 2003, Pamela White took on the role of editor, becoming the first woman to do so. With a notable background in journalism, White emphasized human-rights reporting, with a focus on prison issues, women's rights, and American Indian issues. She came to the Weekly after serving as editor of Colorado Daily , where she and her staff won the 2000 Roy W. Howard Award for Public Service (National Journalism Awards) and several other national awards for investigative journalism. Joel Dyer returned to
5400-677: The Weekly as editor in November 2011. He was last listed on the masthead as editor-at-large in the April 6, 2023 issue Shay Castle was appointed the new (and current) editor on October 30, 2023. Recently, the paper employed 18 full-time staff members in addition to numerous freelance writers and circulation drivers. It publishes opinion, news, an outdoor recreation section, a food section, and an arts and entertainment section, as well as several special editions, notably The Best of Boulder County, tri-annual Boulderganic, Summer Scene, Student Guide, and VOTE, its annual election guide. Regular contributors to
5520-578: The abnormally long period of time since the last major earthquake in the region since the lake has dried up. The San Andreas Fault System has been the subject of a flood of studies. In particular, scientific research performed during the last 23 years has given rise to about 3,400 publications. A study published in 2006 in the journal Nature by Yuri Fialko, an associate professor at the Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics at Scripps Institution of Oceanography , found that
5640-425: The affected area, many people had left work early or were staying late to participate in after work group viewings and parties. As a consequence the normally crowded freeways contained unusually light traffic. If traffic had been normal for a Tuesday rush hour , injuries and deaths would certainly have been higher. The initial media reports failed to take into account the game's effect on traffic and initially estimated
5760-630: The cable cars. Amtrak intercity rail service into Oakland from the California Zephyr continued, but the Coast Starlight was temporarily suspended north of Salinas because of damage to the Southern Pacific 's Coast Line . The earthquake changed the Bay Area's automobile transportation landscape. Not only did the quake force seismic retrofitting of all Bay Area bridges, it caused enough damage that some parts of
5880-1194: The central ( 1857 ) and northern ( 1906 ) segments of the fault, while the southern section has not seen any similar rupture for at least 300 years. According to this study, a major earthquake on that southern section of the San Andreas fault would result in major damage to the Palm Springs – Indio metropolitan area and other cities in San Bernardino , Riverside and Imperial counties in California, and Mexicali Municipality in Baja California . It would be strongly felt (and potentially cause significant damage) throughout much of Southern California , including densely populated areas of Los Angeles County , Ventura County , Orange County , San Diego County , Ensenada Municipality and Tijuana Municipality , Baja California, San Luis Rio Colorado in Sonora and Yuma, Arizona . Older buildings would be especially prone to damage or collapse, as would buildings built on unconsolidated gravel or in coastal areas where water tables are high (and thus subject to soil liquefaction ). Of
6000-403: The championship games of the year being referred to as the "Earthquake Series". Rush-hour traffic on the Bay Area freeways was much lighter than normal because the game, being played at Candlestick Park in San Francisco, was about to begin, and this may have prevented a larger loss of life, as several of the Bay Area's major transportation structures suffered catastrophic failures. The collapse of
6120-681: The collapse of buildings along the Pacific Garden Mall in Santa Cruz, and five people were killed in the collapse of a brick wall on Bluxome Street in San Francisco. When the earthquake hit, the third game of the 1989 World Series baseball championship was about to begin. Because of the unusual circumstance that both of the World Series teams (the San Francisco Giants and Oakland Athletics ) were based in
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#17327808586926240-636: The collapse of the Cypress Street Viaduct on the Nimitz Freeway ( Interstate 880 ), where the upper level of a double-deck portion of the freeway collapsed, crushing the cars on the lower level, and causing crashes on the upper level. One 50-foot (15 m) section of the San Francisco–Oakland Bay Bridge also collapsed, leading to a single fatality, Anamafi Moala, a 23-year-old woman. Three people were killed in
6360-523: The construction industry. A 2008 paper, studying past earthquakes along the Pacific coastal zone, found a correlation in time between seismic events on the northern San Andreas Fault and the southern part of the Cascadia subduction zone (which stretches from Vancouver Island to Northern California). Scientists believe quakes on the Cascadia subduction zone may have triggered most of the major quakes on
6480-434: The damage. That same day, survivor Buck Helm was freed from the wreckage, having spent 90 hours trapped in his car. Dubbed "Lucky Buck" by the local radio, Helm lived for another 29 days on life support , but then died of respiratory failure at the age of 58. Although the freeway reopened in stages between 1997 and 1999, it was not fully rebuilt until 2001 so that it would comply with safety and reinforcement standards. In
6600-468: The death toll at 300, a number that was corrected to 63 in the days after the earthquake. After the earthquake occurred, a group led by Antony C. Fraser-Smith of Stanford University reported that the event was preceded by disturbances in background magnetic field noise as measured by a sensor placed in Corralitos , about 4.5 miles (7 km) from the epicenter. From October 5, they reported that
6720-444: The debris, found one victim alive and another dead inside the coffee house. Santa Cruz beach lifeguards assisted in moving the victims. Police dogs were brought in to help locate other victims. A woman was found dead inside Ford's. The civilians who were helpful initially, were soon viewed by police and fire officials as a hindrance to operations, with frantic coworkers and friends of a coffee house employee thought to be trapped under
6840-490: The earthquake struck at approximately 5:04 PDT, sportscaster Tim McCarver was narrating taped highlights of Game 2, which had been played two days prior across the Bay Bridge in Oakland. Television viewers saw the video signal begin to break up, heard McCarver repeat a sentence as the shaking distracted him, and heard McCarver's colleague Al Michaels exclaim, "I'll tell you what, we're having an earth – ." At that moment,
6960-629: The earthquake. In Santa Cruz , close to the epicenter, 40 buildings collapsed, killing six people. At the Santa Cruz Beach Boardwalk, the Plunge Building was significantly damaged. Liquefaction also caused damage in the Watsonville area. For example, sand volcanoes formed in a field near Pajaro as well as in a strawberry field. The Ford's department store in Watsonville experienced significant damage, including
7080-665: The eastern side of the fault. The effect is expressed as the Coast Ranges. The northwest movement of the Pacific plate is also creating significant compressional forces which are especially pronounced where the North American plate has forced the San Andreas to jog westward. This has led to the formation of the Transverse Ranges in Southern California, and to a lesser but still significant extent,
7200-681: The edge of the freeway. Nearby residents and factory workers came to the rescue, climbing onto the wreckage with ladders and forklifts and pulling trapped people out of their cars from under a four-foot gap in some sections. 60 members of Oakland's Public Works Agency left the nearby city yard and joined rescue efforts. Employees from Pacific Pipe drove heavy lift equipment to the scene and started using it to raise sections of fallen freeway enough to allow further rescue. Local workers continued their volunteer operation nonstop until October 21, 1989, when they were forced to pause as U.S. President George H. W. Bush and California Governor George Deukmejian viewed
7320-399: The epicenter resulted from liquefaction of soil used to create waterfront land. Other effects included sand volcanoes , landslides and ground ruptures. Some 12,000 homes and 2,600 businesses were damaged. The Federal Emergency Management Agency (FEMA) turned people who were homeless prior to the earthquake away from homeless shelters and provided shelter for those with homes prior to
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#17327808586927440-515: The fault and its surrounding branches. The fault was first identified in Northern California by UC Berkeley geology professor Andrew Lawson in 1895 and named by him after the surrounding San Andreas valley. Eleven years later, Lawson discovered that the San Andreas Fault stretched southward into southern California after reviewing the effects of the 1906 San Francisco earthquake . Large-scale (hundreds of miles) lateral movement along
7560-428: The fault begins to bend northward, forming the "Big Bend". This restraining bend is thought to be where the fault locks up in Southern California , with an earthquake-recurrence interval of roughly 140–160 years. Northwest of Frazier Park, the fault runs through the Carrizo Plain , a long, treeless plain where much of the fault is plainly visible. The Elkhorn Scarp defines the fault trace along much of its length within
7680-465: The fault from 2004 to 2007. The aim was to collect core samples and make direct geophysical and geochemical observations to better understand fault behavior at depth. The northern segment of the fault runs from Hollister , through the Santa Cruz Mountains , epicenter of the 1989 Loma Prieta earthquake , then up the San Francisco Peninsula , where it was first identified by Professor Lawson in 1895, then offshore at Daly City near Mussel Rock . This
7800-452: The fault he previously discovered. He concluded that the fault must have been the origin of the earthquake. This line ran through San Andreas Lake , a sag pond . The lake was created from an extensional step over in the fault, which created a natural depression where water could settle. A common misconception is that Lawson named the fault after this lake. However, according to some of his reports from 1895 and 1908, he actually named it after
7920-575: The fault was first proposed in a 1953 paper by geologists Mason Hill and Thomas Dibblee . This idea, which was considered radical at the time, has since been vindicated by modern plate tectonics . Seismologists discovered that the San Andreas Fault near Parkfield in central California consistently produces a magnitude 6.0 earthquake approximately once every 22 years. Following recorded seismic events in 1857, 1881, 1901, 1922, 1934, and 1966, scientists predicted that another earthquake should occur in Parkfield in 1993. It eventually occurred in 2004 . Due to
8040-400: The four deaths, one family lost their infant son who choked on dust while trapped for an hour inside their collapsed apartment. The Marina district was built on a landfill made of a mixture of sand, dirt, rubble, waste, and other materials containing a high percentage of groundwater . Some of the fill was rubble dumped into San Francisco Bay after the 1906 San Francisco earthquake, but most
8160-474: The frequency of predictable activity, Parkfield has become one of the most important areas in the world for large earthquake research. In 2004, work began just north of Parkfield on the San Andreas Fault Observatory at Depth (SAFOD). The goal of SAFOD is to drill a hole nearly 3 kilometres (1.9 mi) into the Earth's crust and into the San Andreas Fault. An array of sensors will be installed to record earthquakes that happen near this area. A 2023 study found
8280-433: The geological impacts/effects of the event, but also the societal impacts such as property damage, economic rebuilding, and aims at estimating damages if cities increased risk-reduction. It was developed for preparedness geared towards Bay Area residents and as a warning with an attempt to encourage local policy makers to create infrastructure and protections that would further risk reduction and resilience-building. This study
8400-438: 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 . The San Francisco Fire Department selected civilians to help run fire hoses from a distance because the nearby hydrant system failed. Since the bay was only two blocks from the burning buildings, water from the bay was pumped by the fireboat Phoenix , to engines on
8520-399: 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. The June 27, 1988, shock occurred with a maximum intensity of VI ( Strong ). Its effects included broken windows in Los Gatos, and other light damage in Holy City , where increased flow was observed at a water well . Farther away from
8640-507: The late 1950s and opened to traffic in 1957 (as SR 17), the Cypress Street Viaduct, a stretch of Interstate 880, was a double-deck freeway section made of nonductile reinforced concrete that was constructed above and astride Cypress Street in Oakland. Roughly half of the land the Cypress Viaduct was built on was filled marshland and the other half somewhat more stable alluvium . Because of new highway structure design guidelines –
8760-415: 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
8880-413: The mainland and cracked the paved road on Paul's Island. In the Old Town historical district of the city of Salinas, unreinforced masonry buildings were partially destroyed. Following the quake, an estimated 1.4 million people experienced power losses that were mainly due to damaged electrical substations . Many San Francisco radio and television stations were temporarily knocked off the air. KGO-TV ,
9000-547: The meantime, traffic was detoured through nearby Interstate 980 , causing increased congestion. Instead of rebuilding Interstate 880 over the same ground, Caltrans rerouted the freeway farther west around the outskirts of West Oakland to provide better access to the Port of Oakland and the San Francisco–Oakland Bay Bridge, and to meet community desires to keep the freeway from cutting through residential areas (at
9120-449: The most expensive natural disasters in U.S. history at the time. Private donations poured into aid relief efforts and on October 26, President George H. W. Bush signed a $ 1.1 billion ($ 2.7 billion today) earthquake relief package for California. Four people died in San Francisco's Marina District, four buildings were destroyed by fire, and seven buildings collapsed. Another 63 damaged structures were judged too dangerous to live in. Among
9240-480: The most frequently cited claims of a specific earthquake precursor; more recent studies have cast doubt on the connection, attributing the Corralitos signals to either unrelated magnetic disturbance or, even more simply, to sensor-system malfunction. 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
9360-400: The next morning. Large cracks in Oakland's runway and taxiway reduced the usable length to two-thirds normal, and damage to the dike required quick remediation to avoid flooding the runway with water from the bay. Oakland Airport repair costs were assessed at $ 30 million (equivalent to $ 77 million today). San Francisco Municipal Railway (Muni) lost all power to electric transit systems when
9480-491: The next several hours, some of it picked up and broadcast nationally over their respective networks, as well as on CNN , in a manner anticipating later major catastrophes such as the 1994 Los Angeles earthquake and the 9/11 terror attacks ). Power was restored to most of San Francisco by midnight, and all but 12,000 customers had their power restored within two days. The quake caused an estimated $ 6 billion (equivalent to $ 15 billion today) in property damage, becoming one of
9600-601: The north into the San Francisco Bay Area , both on the San Francisco Peninsula and across the bay in Oakland . No surface faulting occurred, though many other ground failures and landslides were present, especially in the Summit area of the Santa Cruz Mountains. Liquefaction was also a significant issue, especially in the heavily damaged Marina District of San Francisco , but its effects were also seen in
9720-486: The north, portions of San Francisco were assessed at intensity IX ( Violent ). At more than 44 miles (70 km) distant, the San Francisco Bay Area recorded peak horizontal accelerations that were as high as 0.26 g , and close to the epicenter they peaked at more than 0.6 g . In a general way, the location of aftershocks of the event delineated the extent of the faulting, which (according to seismologist Bruce Bolt ) extended about 24 miles (40 km) in length. Because
9840-561: The north, the fault terminates offshore near Eureka, California , at the Mendocino triple junction , where three tectonic plates meet. The Cascadia subduction zone intersects the San Andreas fault at the Mendocino triple junction. It has been hypothesized that a major earthquake along the Cascadia subduction zone could trigger a rupture along the San Andreas Fault. In the south, the fault terminates near Bombay Beach, California , in
9960-523: The occurrence of an event at the location that was forecast by the WGCEP in 1988 was coincidental. The contrasting characteristics of the 1906 and 1989 events were examined by seismologists Hiroo Kanamori and Kenji Satake . 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
10080-547: The office of the Los Gatos City Manager, a window that was cracked had also been broken in the earlier shock. Also in Los Gatos, one man died when he fell or jumped through a window and impacted the ground five stories below. 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
10200-402: The open gap in time; the 1980 Mercury Zephyr plunged over the edge and smashed onto the collapsed roadbed. The driver, Anamafi Moala, died, and the passenger, her brother, was seriously injured. Caltrans removed and replaced the collapsed section, and re-opened the bridge on November 18. To assist with transportation during Bay Bridge repairs, Bay Area Rapid Transit ran 24-hour service in
10320-552: The opportunity to assign a new name to the San Juan Bautista segment – the Loma Prieta segment. In early 1988, the Working Group for California Earthquake Probabilities (WGCEP) made several statements regarding their forecasts for the 225 mi (360 km) northern San Andreas Fault segment, the 56 mi (90 km) San Francisco Peninsula segment, and a 18.8–22 mi (30–35 km) portion of that segment which
10440-859: The paper include populist author and columnist Jim Hightower , astrologer Rob Brezsny author Ben Corbett, former Boulder mayor Paul Danish, and music critic David Kirby. Among the Boulder Weekly's awards, in April 2023 it won seven awards in the Society of Professional Journalists ' Top of the Rockies competition including two first prizes. In April 2018, it won 27 awards in the 2017 Society of Professional Journalists ' competition, including 10 first prizes. 39°59′02″N 105°14′52″W / 39.983791°N 105.247757°W / 39.983791; -105.247757 1989 Loma Prieta earthquake On October 17, 1989, at 5:04 p.m. local time,
10560-609: The plain. The southern segment, which stretches from Parkfield in Monterey County all the way to the Salton Sea , is capable of an 8.1-magnitude earthquake. At its closest, this fault passes about 35 miles (56 km) to the northeast of Los Angeles. Such a large earthquake on this southern segment would kill thousands of people in Los Angeles, San Bernardino, Riverside, and surrounding areas, and cause hundreds of billions of dollars in damage. The Pacific plate , to
10680-655: The pump? Try paying with your life. Boulder Weekly visits Nigeria," April 19, 2001, which exposed the suffering of a Nigerian village at the hands of an Italian gas company. Campbell is the author of Blood Diamonds: Tracing the Deadly Path of the World's Most Precious Stones. Wayne Laugesen , following his tenure at Soldier of Fortune magazine, served as Boulder Weekly's editor. He is best known for his award-winning opinion column "Wayne's Word," and his byline has appeared in national magazines and nearly every major newspaper in
10800-501: The quake hit, but otherwise suffered little damage and no injuries to operators or riders. Cable cars and electric trains and buses were stalled in place – half of Muni's transport capability was lost for 12 hours. Muni relied on diesel buses to continue abbreviated service until electric power was restored later that night, and electric units could be inspected and readied for service on the morning of October 18. After 78 hours, 96 percent of Muni services were back in operation, including
10920-498: The region's freeway system had to be demolished. Damage to the region's transportation system was estimated at $ 1.8 billion (equivalent to $ 4.4 billion today). 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 television network ABC began its pre-game show at 5:00 PDT . When
11040-466: The requirement of ductile construction elements – instituted following the 1971 San Fernando earthquake , a limited degree of earthquake reinforcement was retrofitted to the Cypress Viaduct in 1977. The added elements were longitudinal restraints at transverse expansion joints in the box girder spans, but no studies were made of possible failure modes specific to the Cypress Viaduct. Caltrans has since received widespread backlash for not thoroughly studying
11160-438: The rubble continuing their efforts in the dark. Police arrested those who refused to stop searching. This became a political issue in the following days. The body of a young woman coffee worker was found under a collapsed wall late the next day. During the first few days following the quake, electric power to most Santa Cruz County subscribers was out, and some areas had no water. Limited phone service remained online, providing
11280-414: The rupture took place bilaterally, the duration of strong shaking was about half of what it would have been had it ruptured in one direction only. The duration of a typical M6.9 shock with a comparable rupture length would have been about twice as long. Gregory Beroza , a seismologist with Stanford University , made several distinctions regarding the 1906 and 1989 events. Near Loma Prieta, the 1906 rupture
11400-556: The shock was responsible for 63 deaths and 3,757 injuries. The Loma Prieta segment of the San Andreas Fault System had been relatively inactive since the 1906 San Francisco earthquake (to the degree that it was designated a seismic gap ) until two moderate foreshocks occurred in June 1988 and again in August 1989. Damage was heavy in Santa Cruz County and less so to the south in Monterey County , but effects extended well to
11520-589: 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
11640-473: The shore, and from there sprayed on the fire. The apartment structures that collapsed were older buildings that included ground-floor garages, which engineers refer to as a soft story building . 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
11760-447: The shores of San Francisco Bay and to the south near Monterey Bay. Other ground effects included downslope movement, slumps , and ground cracks. Fifty-seven of the deaths were directly caused by the earthquake; six further fatalities were ruled to have been caused indirectly. In addition, there were 3,757 injuries as a result of the earthquake, 400 of which were serious. The highest number of deaths, 42, occurred in Oakland because of
11880-533: The signal from Candlestick Park was lost. The network put up a green ABC Sports "World Series" technical difficulties telop graphic while it scrambled to repair the video feed (the broadcast cameras and mics were powered by the local power supply), but audio from the stadium was restored after thirteen seconds via a telephone link: Al Michaels: Well, heh, I don't know if we're on the air... We are in commercial, I guess. Jim Palmer : Yes, yes, we hear you. Tim McCarver: I guess... Michaels: I don't hear
12000-526: The specific populations to be hardest impacted by a potential earthquake of a 7.0 magnitude, specifically in the San Francisco Bay Area. This includes intensified hardships for those with low-income, racially and culturally-diverse populations, and people with literacy hardships that would significantly "increase their risk of displacement and add to recovery challenges" (Wein et al.). In addition to societal and landscape impacts, this study looks at potential business interruptions. This portion estimates impacts to
12120-508: 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
12240-409: 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. KNBR-AM (the designated station for the Bay Area's Emergency Broadcast System at the time) failed to communicate a catastrophe with the activation and instructions of
12360-602: The steep terrain near the epicenter was prone to movement, and up to 4,000 landslides may have occurred during the event. The majority of landslides occurred to the southwest of the epicenter, especially along road cuts in the Santa Cruz Mountains and in the Summit Road area, but also along the bluffs of the Pacific Coast, and as far north as the Marin Peninsula. Highway 17 was blocked for several weeks by
12480-432: The structure. When the earthquake hit, the shaking was amplified on the former marshland, and soil liquefaction occurred. When the earthquake struck, the freeway buckled and twisted before the support columns failed and the upper deck fell on the lower deck. Forty-two people were crushed to death in their cars. Cars on the upper deck were tossed around violently, some of them flipped sideways, and some were left dangling at
12600-412: The study, Fialko stated: All these data suggest that the fault is ready for the next big earthquake but exactly when the triggering will happen and when the earthquake will occur we cannot tell. It could be tomorrow or it could be 10 years or more from now. Nevertheless, in the 18 years since that publication there has not been a substantial quake in the Los Angeles area, and two major reports issued by
12720-500: The subduction zone off the western coast of North America. As the relative motion between the Pacific and North American plates was different from the relative motion between the Farallon and North American plates, the spreading ridge began to be "subducted", creating a new relative motion and a new style of deformation along the plate boundaries. These geological features are what are chiefly seen along San Andreas Fault. It also includes
12840-533: The surrounding San Andreas Valley. Following the 1906 San Francisco earthquake, Lawson also concluded that the fault extended all the way into Southern California . In 1953, geologist Thomas Dibblee concluded that hundreds of miles of lateral movement could occur along the fault. A National Science Foundation funded project called the San Andreas Fault Observatory at Depth (SAFOD) near Parkfield, California , involved drilling through
12960-455: The three largest shocks to occur along the 1906 earthquake's rupture zone since 1914. The M L 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
13080-535: The time the original viaduct was constructed, West Oakland was predominantly occupied by African- and Hispanic-Americans). Street-level Mandela Parkway now occupies the previous roadbed of the Cypress structure. Immediately after the earthquake, Bay Area airports were closed so officials could conduct a visual inspection and damage assessment procedures. San Jose International Airport , Oakland International Airport and San Francisco International Airport all opened
13200-404: The way they had come. Eastbound drivers stuck on the lower deck between the collapse and Yerba Buena Island were routed up to the upper deck and westward back to San Francisco. A miscommunication made by emergency workers at Yerba Buena Island routed some drivers the wrong way; they were directed to the upper deck where they drove eastward toward the collapse site. One of these drivers did not see
13320-420: The west of the fault, is moving in a northwest direction while the North American plate to the east is moving toward the southwest, but relatively southeast under the influence of plate tectonics . The rate of slippage averages about 33 to 37 millimeters (1.3 to 1.5 in) a year across California. The southwestward motion of the North American plate towards the Pacific is creating compressional forces along
13440-423: The west, terminating at the Mendocino triple junction . The central segment of the San Andreas Fault runs in a northwestern direction from Parkfield to Hollister . While the southern section of the fault and the parts through Parkfield experience earthquakes, the rest of the central section of the fault exhibits a phenomenon called aseismic creep , where the fault slips continuously without causing earthquakes. It
13560-473: Was evacuated after the earthquake until a US$ 80 million (equivalent to US$ 197 million today) seismic retrofit and hazard abatement work was completed in 1995. Many other communities sustained severe damage throughout the region located in Alameda , San Mateo , Santa Clara , San Benito , Santa Cruz and Monterey counties. Major property damage in San Francisco's Marina District 60 mi (97 km) from
13680-425: Was first identified in 1895 by Professor Andrew Lawson of UC Berkeley . In the wake of the 1906 San Francisco earthquake , Lawson was tasked with deciphering the origin of the earthquake. He began by surveying and mapping offsets (such as fences or roads that had been sliced in half) along surface ruptures. When the location of these offsets were plotted on a map, he noted that they made a near perfect line on top of
13800-528: Was formed by a transform boundary. The southern segment (also known as the Mojave segment) begins near Bombay Beach, California . Box Canyon, near the Salton Sea , contains upturned strata associated with that section of the fault. The fault then runs along the southern base of the San Bernardino Mountains , crosses through Cajon Pass and continues northwest along the northern base of
13920-404: Was more shallow, had more strike-slip, and occurred on a fault that was near vertical. The 1989 event's oblique-slip rupture was at 10 km and below on a fault plane that dipped 70° to the southwest. Because much of the slip in 1989 occurred at depth and the rupture propagated up dip, Beroza proposed that the overlying San Andreas Fault actually inhibited further rupture and also maintains that
14040-668: Was referred to as the southern Santa Cruz Mountains segment. The thirty year probability for one or more M7 earthquakes in the study area was given as 50%, but because of a lack of information and low confidence, a 30% probability was assigned to the Southern Santa Cruz Mountains segment. Two moderate shocks, referred to as the Lake Elsman earthquakes by the USGS, occurred in the Santa Cruz Mountains region in June 1988 and again in August 1989. Following each event,
14160-429: 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 because of when and where they occurred relative to the main event. Each event's aftershock sequence and effect on stress drop was closely examined, and their study indicated that
14280-471: Was sand and debris laid down in preparation for the 1915 Panama-Pacific International Exposition , a celebration of San Francisco's ability to rebound after its catastrophe in 1906. After the Exposition, apartment buildings were erected on the landfill. In the 1989 earthquake, the water-saturated unconsolidated mud, sand, and rubble suffered liquefaction , and the earthquake's vertical shock waves rippled
14400-456: Was severely shaken during the quake, when most of the KNBR staff were at Candlestick for the World Series. The Mayor of San Francisco, Art Agnos , later came on the air and provided an update on the earthquake. (All four network-affiliated TV stations (KRON, KGO, KTVU and CBS affiliate KPIX ) would recover enough to broadcast continuous breaking news coverage of the aftermath of the quake for
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