In response to the magnitude 6.7 and 7.9 events, the Alaska Earthquake Information Center (AEIC) staff installed a network of temporary instruments for the aftershock monitoring. The Nenana Mountain and Denali Fault earthquakes generated a vigorous aftershock sequence. It began with thrusting on the previously unrecognized Susitna Glacier fault⦠The largest inland earthquake in North America in almost 150 years struck Alaska on November 3, 2002. Many active faults in Alaska are capable of generating large tsunamis that threaten coastal communities ⦠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. The largest inland earthquake in North America in almost 150 years struck Alaska on November 3, 2002. If weâre talking sheer magnitude, the largest recorded earthquake on North American soil hit Alaska on November 3, 2002. The fault's rate of displacement varies from 1 mm to 35 mm per year. Alaskaâs Denali Fault was on the move, jostling the state with a magnitude 7.9 earthquake. Evidence of the 1685 earthquake was only discovered in the past 20 years. 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. (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. 40Ar/39Ar data from the Richardson mining district, Big Delta Quadrangle, Alaska - RDF 2020-11 They already know huge earthquakes happen on the fault. Yellowstone National Park
had the most energetic swarm of triggered earthquakes. On November 3, 2002 a devastating earthquake rattled Alaska. It illuminates earthquake mechanics and hazards of large strike-slip faults. Imaging The M7.9 Denali Fault Earthquake 2002 Rupture At The Delta River Using SASW, LIDAR, and RADAR 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. 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. The majority of
landslides clustered in a narrow band extending about 8 to 12 miles on either
side of the rupture. 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. 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. Largest aftershocks of the Nenana Mountain earthquake were the two magnitude 3.8 events. The Great M7.9 Denali Fault, Alaska earthquake of Nov 3, 2002: Geotechnical Engineering Reconnissance Report - A Slide Presentation. It started with thrust (upward) motion on a previously unknown fault, now called the Susitna Glacier Fault. Instrumental recordings
of ground motion near earthquakes like the Denali Fault quake are critical for
improving engineering design, but such quakes do not occur often. The second largest instrumentally recorded earthquake in the world occurred along the eastern Aleutian subduction zone, the Mw9.2 Great Alaskan earthquake of 1964. During the 10 days following
the Denali Fault earthquake, geologists from the USGS and Alaska Division of
Geological and Geophysical Surveys, as well as several universities, mapped
and measured the earthquake rupture on the ground and using aircraft. One facility that was badly damaged by the earthquake was the runway at Northway
Airport, 40 miles from the eastern part of the November 3, 2002, fault rupture. Violent, prolonged shaking
from the quake triggered thousands of landslides, especially on the steep slopes
of the Alaska Range. 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. 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. Areas that experienced liquefaction during the
earthquake include much of the Tanana River Valley north and east of the rupture
and other locations near smaller rivers. 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. Seiches were seen as far away as Lake Pontchartrain in Louisiana. In the left foreground, the Nenana River marks the eastern boundary of Denali National Park. Like the Denali Fault quake, the Nenana Mountain shock caused only limited damage
because of its remote location. 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. 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 ⦠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. Its epicenter was located on the Denali fault 22 km east of the M 7.9 event epicenter. 2). In 2002, the Denali Fault in central Alaska ruptured catastrophically, unleashing a magnitude-7.9 earthquake. Like most earthquakes of its size, it was complex, consisting of several subevents. 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. 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 magnitude of completeness mc of the aftershock catalog varies along the rupture zone. The November 2002 earthquake had a magnitude of 7.9 and caused a surface rupture 325 km (~200 miles) long, mostly on the central Denali Fault (see red line on map below). Mountainsides gave way, burying the valleys and glaciers
below in deposits of rock and ice as much as 15 feet thick. Although
comparable in size and type to the quake that devastated San Francisco in 1906,
the Denali Fault earthquake caused no deaths and little damage to structures
because it struck a sparsely populated region of south-central Alaska. AEIC receives data from more than 370 seismic stations, integrating
all seismic networks in Alaska. The Denali Fault event was felt as far as Washington and caused seiches in pools and lakes as far as Texas and Louisiana. Following the Denali Fault earthquake, the analyst processing load increased from an average of 40 events per day in September to an average of over 400 events per day in November. Four month of data remain unprocessed at this time (January-April, 2003). The aftershock zone terminates !10 km west of The first locatable triggered earthquake was a magnitude 2.6 shock about 12.5 miles east of Salt Lake City. 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. But there's still a lot scientists don't know about it. It started on the previously unrecognized Susitna Glacier Thrust fault, a splay fault south of the McKinley strand of the Denali fault system (DFS). Like some other large earthquakes, the Denali Fault quake triggered small shocks
as far as 2,000 miles away, mainly in volcanic areas. No oil spilled, and pipeline operations resumed after ⦠This event was followed by numerous aftershocks that defined a 45-km-long zone along the Denali fault. The Denali
Fault quake is similar to three earthquakes that ruptured the San Andreas Fault
in the past few centuries. 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. 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 This success is a major achievement in U.S. efforts to reduce earthquake
losses. 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. 2004; Doser 2004). Deborah and Hess rise to about 12,000 feet (3650 m) just north of the epicenters and the bend in the Denali fault. [[{"type":"media","view_mode":"media_large","fid":"155","attributes":{"alt":"","class":"media-image","height":"369","typeof":"foaf:Image","width":"480"}}]], white line - mapped rupture |Â 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. 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. 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. UAF is an AA/EO employer and educational institution and prohibits illegal discrimination against any individual. 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 Denali fault earthquake sequence be-gan with the moment magnitude (M W) 6.7 Nenana Mountain earthquake on 23 Octo-ber 2002 (Fig. This presents a
rare opportunity to catch a major earthquake in the act. Called the Denali Fault earthquake,
this shock was the strongest ever recorded in the interior of Alaska. The focus of our investigation was to characterize the spatial extent and amplitude of ground failures and fault ⦠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. The data from the dense network should give seismologists a better idea of the Denali Faultâs character. Alaskaâs Denali Fault was on the move, jostling the state with a magnitude 7.9 earthquake. 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 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. It occurred a little before 3:30 p.m. The epicenter of the November 3 earthquake was approximately 42 miles (68 km) east of the highway. Geotechnical Observations of the November 3, 2002 M7.9 Denali Fault Earthquake. Due to Alyeskaâs earthquake protection, the Denali Fault earthquake did not compromise the integrity of the pipeline. This event caused significant damage to the transportation systems in central Alaska. 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 November 3, 2002, magnitude (M) 7.9 Denali Fault earthquake was the strongest ever recorded in the interior of Alaska. Following
the Denali Fault earthquake, adjacent fault segments have been stressed, increasing
the likelihood of additional earthquakes on those segments. 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. Here a video about the 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Fr⦠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. 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. 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, the 1906 earthquake near San Francisco killed at least 700
people (the actual death toll was probably 3 to 4 times greater). 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. The M 7.9 Denali Fault event was preceded by the magnitude 6.7 Nenana Mountain event on October 23, 2002. 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. 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. 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. Multiple land slides and rock avalanches occurred in the Alaska Range with the largest slide on the Black Rapids Glacier. The earthquake began about 80 km (50 miles) east of the Denali Visitor Center, and ruptured eastward along the Denali Fault, ⦠The M7.9 was the largest earthquake to occur in the interior of the state in recorded history. 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 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. 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 ⦠Bedrock geologic map of the eastern Denali Highway area, Mount Hayes, Healy, and Talkeetna Mountains quadrangles, Alaska - RI 2020-7 New release! However, full ANSS
instrumentation on either end of the 2002 rupture is critical if this goal is
to be achieved. 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. 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 ⦠The diffuse zone of seismicity between Cook Inlet and the Denali Fault may mark a deformation zone between the Bering microplate to the ⦠7.9 magnitude earthquake hits! It ruptured three different faults ending with a total rupture length of ~330 km. 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. A magnitude 4.4 foreshock preceded the Denali Fault mainshock by 3.5 hours. 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
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