Violent, prolonged shaking from the quake triggered thousands of landslides, especially on the steep slopes of the Alaska Range. In the distance, the rugged peaks of Mts. Gedney, Larry, and Estes, Steve, 1982, A Recent earthquake on the Denali Fault in the southeast Alaska Range, in Alaska Division of Geological & Geophysical Surveys, Short Notes on Alaskan Geology - 1981: Alaska Division of Geological & Geophysical Surveys Geologic Report 73J, p. 51-54. They also located major landslides caused by the quake. The pattern of landsliding may help to better estimate levels of shaking along the length of the fault, especially because of the sparsity of seismic instruments in this rugged mountainous region. Additional instruments were deployed after the Denali Fault quake, and as of December 2002, a total of 26 temporary seismic stations were gathering data on the quake's aftershocks. The Denali Fault quake is similar to three earthquakes that ruptured the San Andreas Fault in the past few centuries. The epicenter of the November 3 earthquake was approximately 42 miles (68 km) east of the highway. A rupture there caused a magnitude 7.9 earthquake on November 3, 2002, tearing a 200-mile line across the face of Alaska, through soil and glacial ice. 40Ar/39Ar data from the Richardson mining district, Big Delta Quadrangle, Alaska - RDF 2020-11 There were reports of triggered seismicity in volcanic and geothermal centers in Washington and California and regional seismicity in Utah.Â, 2156 Koyukuk Drive, PO Box 757320, Fairbanks, AK 99775. The focus of our investigation was to characterize the spatial extent and amplitude of ground failures and fault … The Trans-Alaska Pipeline suffered some damage, but no oil spills occurred. A magnitude 4.4 foreshock preceded the Denali Fault mainshock by 3.5 hours. The largest aftershock (M 5.8) occurred 20 minutes after the main shock and was located 95 km east of the mainshock's epicenter (~10 km east of the Richardson highway crossing). However, full ANSS instrumentation on either end of the 2002 rupture is critical if this goal is to be achieved. Should such a quake occur today, San Bernardino, Los Angeles, and other populations centers in southern California could suffer heavy damage and loss of life. 2). The locations of the Nenana Mountain and Denali Fault earthquakes and their aftershocks were determined by the Alaska Earthquake Information Center (AEIC) at the University of Alaska Fairbanks. The Great M7.9 Denali Fault, Alaska earthquake of Nov 3, 2002: Geotechnical Engineering Reconnissance Report - A Slide Presentation. No oil spilled, and pipeline operations resumed after … They already know huge earthquakes happen on the fault. While the fault rupture lasted for approximately 100 sec from its initiation to the arrest, its distal effects were felt for many days. They identified the previously unknown Susitna Glacier Fault in the area where the quake began and showed that the rest of the rupture exactly followed an older rupture that geologists had documented in the 1970's. 2004; Doser 2004). The largest on-land earthquake in North America in almost 150 years occurred along the Denali fault in 2002 and was a powerful reminder of the … Following the Mw 7.9 earthquake on the Denali and Totschunda faults on 3 November 2002, we conducted a reconnaissance of the region to investigate geotechnical and surface rupture features of the event. UAF is an AA/EO employer and educational institution and prohibits illegal discrimination against any individual. The quake was the largest on the Denali Fault since at least 1912 and among the strongest earthquakes recorded in North America in the last 100 years. The majority of landslides clustered in a narrow band extending about 8 to 12 miles on either side of the rupture. It was the largest inland earthquake to hit North … Its epicenter was located on the Denali fault 22 km east of the M 7.9 event epicenter. Yellowstone National Park had the most energetic swarm of triggered earthquakes. These include the magnitude 7.8 San Francisco earthquake in 1906, the magnitude 7.9 Fort Tejon earthquake in 1857 north of Los Angeles, and a quake that struck east of what is now Los Angeles in about 1685. The M 7.9 Denali Fault event was preceded by the magnitude 6.7 Nenana Mountain event on October 23, 2002. The second largest instrumentally recorded earthquake in the world occurred along the eastern Aleutian subduction zone, the Mw9.2 Great Alaskan earthquake of 1964. The November 3, 2002, magnitude (M) 7.9 Denali Fault earthquake was the strongest ever recorded in the interior of Alaska. The Denali Fault event was felt as far as Washington and caused seiches in pools and lakes as far as Texas and Louisiana. The Parks Highway, which connects Anchorage and Fairbanks, lies immediately east of the river north of the fault, but diverges from the river to the south. The largest inland earthquake in North America in almost 150 years struck Alaska on November 3, 2002. It started on the previously unrecognized Susitna Glacier Thrust fault, a splay fault south of the McKinley strand of the Denali fault system (DFS). Because the 2002 Denali Fault earthquake occurred on a "strike-slip" fault, like the San Andreas Fault, it offers a realistic example of effects likely to accompany the next major earthquake in California. Rupture Directivity of the 3 November 2002 Denali Fault Earthquake Determined from Surface Waves Bulletin of the Seismological Society of America Radiated Energy and the Rupture Process of the Denali Fault Earthquake Sequence of 2002 from Broadband Teleseismic Body Waves In 2002, the Denali Fault in central Alaska ruptured catastrophically, unleashing a magnitude-7.9 earthquake. The estimated magnitude of this earthquake ranges from the body wave magnitude mb of 7.0 to the moment magnitude MW of 7.9 to the surface wave magnitude MS of 8.5. The data from the dense network should give seismologists a better idea of the Denali Fault’s character. Four month of data remain unprocessed at this time (January-April, 2003). Mountainsides gave way, burying the valleys and glaciers below in deposits of rock and ice as much as 15 feet thick. This powerful shock may have been triggered by a magnitude 6.7 temblor, the Nenana Mountain earthquake, that occurred nearby on the same fault 10 days earlier. The MW (moment magnitude) 7.9 Denali fault earthquake on 3 November 2002 was associated with 340 kilometers of surface rupture and was the largest strike-slip earthquake in North America in almost 150 years. Shortly after midday on November 3, 2002, a magnitude 7.9 earthquake ruptured the Denali Fault in the rugged Alaska Range, about 90 miles south of Fairbanks. These effects were the result of a phenomenon called "liquefaction," in which strong, prolonged earthquake shaking transforms loose, water-saturated sediments into a liquid slurry. The Denali fault earthquake sequence be-gan with the moment magnitude (M W) 6.7 Nenana Mountain earthquake on 23 Octo-ber 2002 (Fig. Geotechnical Observations of the November 3, 2002 M7.9 Denali Fault Earthquake. The Denali Fault is a Strike-Slip Fault Line Aftershocks of over M 5.0 are being felt near the epicenter of the original quake. The aftershock zone terminates !10 km west of Many active faults in Alaska are capable of generating large tsunamis that threaten coastal communities … Like some other large earthquakes, the Denali Fault quake triggered small shocks as far as 2,000 miles away, mainly in volcanic areas. The Nenana Mountain and Denali Fault earthquakes generated a vigorous aftershock sequence. Alaska’s Denali Fault was on the move, jostling the state with a magnitude 7.9 earthquake. Looking west along Denali fault photo: Wesley K. Wallace 2002: Mw = 7.9 Rupture length = 330 km Maximum RL offset = 8.8 m Denali Fault 2002 Denali Quake Caused huge landslide from an unnamed 7,000-foot-high peak in the Alaska Range, less than 10 miles west of the Trans- Alaska Oil Pipeline Was triggered by the 2002 Denali Fault earthquake. The Castle Mountain Fault, which passes 25 miles north of Anchorage, exhibits geological evidence of Holocene offsets and generated the M5.6 1984 Sutton earthquake. While on average for October-December data mc is 1.4, it is as low as 1.1 at the western end of the rupture and as high as 2.2 at the eastern end. This event caused significant damage to the transportation systems in central Alaska. [[{"type":"media","view_mode":"media_large","fid":"155","attributes":{"alt":"","class":"media-image","height":"369","typeof":"foaf:Image","width":"480"}}]], white line - mapped rupture | red lines - fault traces | dashed black line - Trans-Alaska Pipeline | black lines - roads | blue lines - major rivers, This high-altitude view shows the approximate locations of the earthquake epicenters. The temporary network was dismantled in June, 2003. It started with thrust (upward) motion on a previously unknown fault, now called the Susitna Glacier Fault. This success is a major achievement in U.S. efforts to reduce earthquake losses. 7.9 magnitude earthquake hits! The AEIC located over 1,000 aftershocks of the M 6.7 event prior to the M 7.9 mainshock and over 35,000 aftershocks through the end of 2004. Bedrock geologic map of the eastern Denali Highway area, Mount Hayes, Healy, and Talkeetna Mountains quadrangles, Alaska - RI 2020-7 New release! It occurred a little before 3:30 p.m. The earthquake began about 80 km (50 miles) east of the Denali Visitor Center, and ruptured eastward along the Denali Fault, … The principal rupture was a 210-kilometer-long section of the Denali fault, with horizontal shifts of up to nearly 9 meters (26 feet). Following the Denali Fault earthquake, adjacent fault segments have been stressed, increasing the likelihood of additional earthquakes on those segments. This places the rupture in the same class as those that produced the San Andreas fault's two historical great earthquakes in 1906 and 1857. (Photo and interpretation by Wesley K. Wallace, Geophysical Institute, University of Alaska Fairbanks), Of the population centers, the hardest hit were the villages of Mentasta and Northway, located at the eastern end of the rupture zone. The M7.9 was the largest earthquake to occur in the interior of the state in recorded history. USGS studies of the Denali Fault earthquake are part of the National Earthquake Hazard Reduction Program's ongoing efforts to safeguard lives and property from the future quakes that are certain to strike in Alaska, California, and elsewhere in the United States. The Denali Fault earthquake ruptured the Earth's surface for 209 miles, crossing beneath the vital Trans-Alaska Oil Pipeline, which carries 17% of the U.S. domestic oil supply. A few of these stations are part of the new Advanced National Seismic System (ANSS) being deployed by the USGS and cooperators. The November 3, 2002, M w 7.9 Denali Fault earthquake produced about 340 km of surface rupture along the Susitna Glacier Thrust Fault and the right-lateral, strike-slip Denali and Totschunda Faults. Evidence of the 1685 earthquake was only discovered in the past 20 years. The onslaught of the data has created processing delays. It illuminates earthquake mechanics and hazards of large strike-slip faults. The view is eastward along the main strand of the Denali fault, which is marked here by a prominent linear valley along the southern edge of the Alaska Range. The 1857 California and 2002 Alaska earthquakes struck far from major cities, causing little or no loss of life. The magnitude of completeness mc of the aftershock catalog varies along the rupture zone. It started on the previously unrecognized Susitna Glacier Thrust fault, a splay fault south of the McKinley strand of the Denali fault system (DFS). The runway was rendered unusable by lateral spreading, accompanied by sand boils. The first locatable triggered earthquake was a magnitude 2.6 shock about 12.5 miles east of Salt Lake City. But there's still a lot scientists don't know about it. Many geologists who study evidence of ancient earthquakes in deposits and landforms along the southernmost San Andreas Fault, where the 1685 earthquake occurred, have concluded that a major quake on this segment of the fault is likely to happen again in the near future. It ruptured three different faults ending with a total rupture length of ~330 km. In 2002, the Denali Fault ruptured in a sequence of earthquakes that commenced with the October 23 M6.7 Nenana Mountain right-lateral strike-slip earthquake and culminated with the November 3, M7.9 Denali earthquake which started as a thrust earthquake along a then unrecognized fault and continued with a larger right … In contrast, the 1994 Northridge, California, earthquake, which had the same magnitude, caused 67 deaths and $40 billion in damage when it struck the densely populated Los Angeles region. Starting on the Susitna Glacier Thrust Fault, the rupture raced along the Denali Fault System and continued 220 kilometers until it reached the Totschunda Fault, rattling 70 more kilometers. When the Denali Fault earthquake struck a few days later, these stations helped to provide crucial data. Like most earthquakes of its size, it was complex, consisting of several subevents. The 2002 M7.9 Denali fault earthquake resulted in 340 km of ruptures along three separate faults, causing widespread liquefaction in the fluvial deposits of the alpine valleys of the Alaska Range and eastern lowlands of the Tanana River. Our research team examines major fault systems in Alaska capable of generating large earthquakes, including the Alaska-Aleutian subduction zone, the Denali Fault system, and the Queen Charlotte-Fairweather Fault system. The largest inland earthquake in North America in almost 150 years struck Alaska on November 3, 2002. Although slightly damaged by movement on the fault and by intense shaking, the pipeline did not break in the quake, averting a major economic and environmental disaster. Compiled By Gary S. Fuis and Lisa A. Wald, Edited by James W. Hendley II and Peter H. Stauffer Graphic design by Susan Mayfield, Sara Boore, Eleanor Omdahl, and J. Luke Blair; Web layout by Carolyn Donlin, COOPERATING ORGANIZATIONS Alaska Division of Geological and Geophysical Surveys Alaska Earthquake Information Center, Geophysical Institute, University of Alaska Fairbanks Alaska Volcano Observatory Alyeska Pipeline Service Company California Institute of Technology Central Washington University Humboldt State University University of California Berkeley West Coast and Alaska Tsunami Warning Center, For more information contact: Earthquake Information Hotline (650) 329-4085 U.S. Geological Survey, Mail Stop 977 345 Middlefield Road, Menlo Park, CA 94025 Visit the USGS Earthquake Hazards Program website to learn more, PDF version of this fact sheet (2.2 MB) REDUCING EARTHQUAKE LOSSES THROUGHOUT THE UNITED STATES, For questions about the content of this report, contact Gary Fuis, Download the current version of Acrobat Reader for free, | Help | PDF help | Geopubs main page | Fact Sheets |, | Department of the Interior | Privacy Statement | Disclaimer | Accessibility | URL of this page: https://pubs.usgs.gov/fs/2003/fs014-03/ Maintained by: Michael Diggles Created: February 5, 2003 Last modified: May 17, 2005 (mfd), the pipeline did not break in the quake, the 2002 Denali Fault earthquake occurred on a "strike-slip" fault, Denali Fault quake is similar to three earthquakes that ruptured the San Andreas Fault in the past few centuries, USGS Earthquake Hazards Program website. However, the 1906 earthquake near San Francisco killed at least 700 people (the actual death toll was probably 3 to 4 times greater). Then the rupture transferred onto the main strand of the DFS and continued as a right-lateral strike-slip event for ~220 km until it reached the Totschunda fault near 143W longitude. The fault's rate of displacement varies from 1 mm to 35 mm per year. Seiches were seen as far away as Lake Pontchartrain in Louisiana. earthquake is believed to have ruptured at least part of the same segment of the Denali Fault in 1912 (Carver et al. If we’re talking sheer magnitude, the largest recorded earthquake on North American soil hit Alaska on November 3, 2002. Alaska's network of faults is a result of tectonic activity; the Pacific Plate is actively subducting (sliding under) the North American Plate, and the Denali Fault is located on the boundary between the two plates. In the left foreground, the Nenana River marks the eastern boundary of Denali National Park. In the 12 days following the Denali fault earthquake, the mean rate of earthquakes above magnitude 1.5 in the Wasatch Front area increased to almost triple the mean rate for the previous three … Following the Denali Fault earthquake, Lake Union in Seattle experienced an earthquake-induced seiche, or water sloshing, which knocked many houseboats off their moorings and caused minor damage. The survival of the Trans-Alaska Oil Pipeline in the 2002 Denali Fault earthquake demonstrates the value of combining careful geologic studies of earthquake hazards and creative engineering in designing and protecting such important structures and lifelines. Between 1912 and 2002 the level of recorded seismicity on this section of the Denali Fault was very low with the majority of earthquakes M >4.5 occurring on thrust faults to the north or south … Imaging The M7.9 Denali Fault Earthquake 2002 Rupture At The Delta River Using SASW, LIDAR, and RADAR Additional delays have been caused by the necessity of reviewing the earthquake locations a second time when the data from the temporary Denali network were brought back from the field and merged with the bulk of AEIC data. After the Nenana Mountain earthquake, AEIC installed several temporary seismographs, including some ANSS instruments. The earthquake began at 1:12 p.m. Alaska local time, and was centered approximately 135 kilometers (84 miles) south of Fairbanks and 283 kilometers (176 miles) north of Anchorage. • The 2002 Denali Fault earthquake – United States Geological Survey It began with thrusting on the previously unrecognized Susitna Glacier fault… It ruptured three different faults ending with a total rupture length of ~330 km. The epicenters (point on the earth surface where the quakes originate) of each of these large earthquakes was about 50 km (30 miles) east of the park, on the Denali fault. Here a video about the 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Fr… By studying earthquakes like the 2002 Denali Fault earthquake, scientists and engineers gain the knowledge necessary to reduce the vulnerability of buildings and other structures to damage in these inevitable and terrifying events. Unprocessed at this time ( January-April, 2003 ) the runway was rendered by! 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