what type of plate boundary caused the 1964 alaska earthquake what type of plate boundary caused the 1964 alaska earthquake

Do earthquakes occur at divergent plate boundaries? Only time will tell if new building codes are strong enough to withstand the next massive Alaskan earthquake. The 1964 Alaska earthquake resulted from rupture along the thrust fault boundary bet- ween the downgoing Pacific Plate and the overriding North American Plate, causing widespread shaking and tectonic defor- mation. Notice what happens as you move your left hand away and slide your right hand toward you. Tectonic plates move very slowly relative to each other, typically a few centimetres per year, but this still causes a huge amount of deformation at the plate boundaries, which in turn results in earthquakes. The only stronger trembling ever recorded was a magnitude-9.5 monster that shook Chile in May 1960. UA is committed to providing accessible websites. Thursday NightLife (21+): 6 10 pm. No Alaskan who survived would ever forget this day. The movements of the plates help shape the geological features of our planet. Earth definitely moved with a start during the 1964 quake. According to the United States Geological Survey, The 1964 earthquake was giant because of the large area of the fault that slipped during the earthquake and the large amount of slip, or relative motion, between opposite sides of the earthquake fault.. And it moved parts of the Alaskan coast 15 meters (50 feet) toward the sea. Downtown Anchorage had the most property damage mainly due to immense landslides, one of which dropped the business district nine feet. Through very complete mapping of vertical deformation and faulting and the application of tectonics, he was first to propose in 1965 that the source of the 1964 Alaska earthquake was a low-angle thrust fault. But Plafker saw it first, there in Alaska. UAF is an AA/EO employer and educational institution and prohibits illegal discrimination against any individual: If you have difficulty accessing the information on this website due to a disability, please contact the web administrator by email at uaf-aec@alaska.edu or by phone at 907-474-7320. The seismographs recorded these aftershocks as well. They were lifted out of the ocean as part of the accretionary wedge of an ancient subduction zone. A reverse fault, like the Cascadia subduction zone off the coast of Oregon and Northern California (north of Mendocino California), has relatively deep earthquakeslike the 1964 Alaska earthquake and the 2004 The town of Valdez was originally built on sand and gravel. There are three types of plate boundaries: spreading zones, transform faults, and subduction zones. Convergent (Colliding): This occurs when plates move towards each other and collide. Originating off the coast of southern Chile on May 22, 1960, the temblor caused substantial damage and loss of life both in that country andas a result of the tsunamis that it generatedin distant Pacific coastal areas. These maps, by Randall W. Jibson and John A. Michael, depict seismic landslide hazards in Anchorage and are an important tool for planning, zoning, and emergency-response preparation. As the plates grind together, they get stuck and pressure builds up. As the mid-ocean ridge separating the Farallon and Pacific Plates entered the subduction zone, the Farallon Plate separated into the Juan de Fuca and Cocos Plates. The earthquake hit at 3:11 pm approximately 100 miles (160 km) off the coast of Chile . The San Andreas Fault is just one of several faults that accommodate the transform motion between the Pacific and North American plates. Subduction of the Farallon Plate beneath the entire West Coast created a line of volcanoes from Alaska to Central America. Seismicity of the United States, 1568-1989 (Revised), The Transverse Ranges north and east of Los Angeles are so named because they trend in an east-west direction, contrary to the northwest-southeast orientation typical of other ranges along the San Andreas transform plate boundary. Movement in narrow zones along plate boundaries causes most earthquakes. The San Andreas Fault and Queen Charlotte Fault are transform plate boundaries developing where the Pacific Plate moves northward past the North American Plate. The damage was caused entirely by the shifting of ground along the fracture, USGS concluded. The Earthquake Trail at Point Reyes weaves back and forth across the fault line. Add some life to your inbox.Subscribe to our NightLife newsletter. NCEI is the global data and information service for tsunamis. Such movement on the faults is generally a response to long-term deformation and the buildup of stress. USGS published the results of investigations of the Alaska earthquake of March 27, 1964 in a series of six Professional Papers. Plafker spent most of the summer in Alaska researching and documenting the earthquake. Magnitude type: M l 2; Event type: earthquake; Tectonic Setting of Southern Alaska . Transform plate boundaries produce enormous and deadly earthquakes. UA is committed to providing accessible websites. . S. Ornes. . And it has forever changed what scientists understand about the constant remodeling of Earths surface. When a fault actually slips, the motion is both sudden and exaggerated. This USGS Fact Sheet by Thomas M. Brocher, et al. The transform plate boundary between the Pacific and North American Plates in western California formed fairly recently. Most seismic activity occurs at three types of plate boundariesdivergent, convergent, and transform. What kind of plate boundary causes mountains to form? These tectonic plates move gradually, bumping and grinding against each other. Thousands of strong aftershocks continued for weeks after the earthquake, some measuring greater than magnitude 6.2. When the earthquake struck, seismic waves caused soil liquefaction and a portion of the delta slumped into Port Valdez, taking much of the ports resources, living and otherwise, with it. First posted September 10, 2012 Revised August 8, 2013, For additional information: This is known as subduction. Evidence for progressive coastal submergence in the deformed region for several centuries preceding the earthquake, in combin1ation with transverse horizontal shortening indicated by the retriangulation data, suggests pre-earthquake strain directed at a gentle angle downward beneath the arc. Historically, the Alaska subduction zone is known for its large earthquakes, where the Pacific and North American plates scrape against each other violently as one slides suddenly over the other in the subduction zone. As the two tectonic plates converge, friction between them causes coupling of the plates on locked patches of the fault (yellow line, part A). Tomales Bay. April 30May 2, 2014 in Anchorage, Alaska. Anchorage house pulled apart as the ground on which it had been anchored opened up, creating a fissure (or graben). Monday Saturday: 9:30 am 5 pm Shallow earthquakes, less than 20 km deep, are associated with _____. The lithosphere is relatively rigid and is broken into slowly moving tectonic plates. the earthquake and tsunami caused the deaths of over . Was the 1964 Alaska earthquake was the first time earthquakes were linked to plate tectonics? California Academy of Sciences. Strong, destructive earthquakes can accompany a rapid, several-meter uplift of bedrock along subduction zones. 1). The plate boundary is a broad zone of deformation with a width of about 60 miles (100 kilometers). Feb. 13, 2013. United States Government Printing Office, Washington: 1993. Afterwards, geologists realized subduction zonesareas where two tectonic plates (huge slabs of rock made of the earths crust and upper mantle) meet and one bends under the otherplayed a major role in creating the immense Alaskan quake. http://earthquake.usgs.gov/. Summary of the earthquakes cause and effects from the Alaska Earthquake Information Center. Beginning about 30 million years ago, so much of the Farallon Plate was consumed by subduction that the Pacific and North American plates were in contact, forming the San Andreas transform plate boundary in western California. Another form of convergent boundary is a collision where two continental plates meet head-on. Some had been up to 24 inches (61 centimeters) in diameter and as much as 101 feet (30.8 meters) above sea level. The motion on the north is not pure transform; there is some convergence that contributes to uplift of the topography. Plafker had confirmed that the earthquake occurred in a subduction zone. Parks near the coast, including Point Reyes National Seashore, Golden Gate National Recreation Area, and Pinnacles National Park, contain volcanic and plutonic rocks that were plucked from the edge of the North American Plate and transported tens to hundreds of miles northwestward as part of the Pacific Plate. USGS.The 1964 Tsunami Strikes Valdez. April 30, 202323:15:06 AKDT (May 1, 202307:15:06 UTC)62.0155N148.8858W Depth 13.6 miles (22 km), This event has not been reviewed by a seismologist, 2156 Koyukuk Drive, PO Box 757320, Fairbanks, AK 99775. Lucky for this team, 70 new seismographs (SIZE moh grafs) had recently been installed all over the world. plate convergenceplate convergence: where the Pacific Plate is being overridden by the North American Plate, it descends, or subducts, into the Earths mantle along the Aleutian Trench. Much to the dismay of some earthquake experts, luxury homes were rebuilt on areas most likely to experience earthquake damage, including on top of the ruins in Turnagain Heights. For western California, each slipping card face would be a fault surface. The 1964 M9.2 Great Alaska Earthquake, which is still the second largest earthquake ever recorded worldwide, began under Prince William Sound. W.R. Hansen/USGS, 1964 Alaska quake files. Eventually the weakest card face (the San Andreas Fault) dominates within the broad transform plate boundary. The Great Alaskan Earthquake was a magnitude-9.2 event. IRIS video directed by Robert F. Butler explaining the science behind the earthquake. Since neither plate is stronger than the other, they crumple and are pushed up. But 50 years ago, that now infamous Alaska quake shook steadily and terrifyingly for almost five solid minutes. A transform plate boundary developed where the Pacific Plate was in contact with the North American Plate and the volcanism ceased in central California. Alaska's continental shelf and North American plate rose over 9 meters during the earthquake. Scientists next had to fit this finding to their understanding of plate tectonics. The average movement of the Pacific Plate past the North American Plate in California is about 2 inches (5 centimeters) per year. In fact, megathrust events are the largest type of earthquake on the planet, notes Peter Haeussler. National Park Service lands contain not only active examples of all types of plate boundaries and hotspots, but also rock layers and landscapes that reveal plate-tectonic activity that occurred in the distant past. One was figuring out why some parts of Alaska had risen as much as 11.5 meters (38 feet), while the ground at other sites had dropped, or subsided. fault (in geology) A fracture along which there is movement of part of Earths lithosphere. (For example, the 2011 magnitude-9.0 earthquake off the eastern coast of Japan that unleashed a huge tsunami also was a megathrust earthquake.) That is where the plates push into, against or away from each other. National Park Service sites in the San Francisco Bay Area reveal a sheared-up, ancient subduction zone landscape developed along the San Andreas Fault. Plafker, G., 1969, Tectonics of the March 27, 1964 Alaska earthquake: U.S. Geological Survey Professional Paper 543I, 74 p., 2 sheets, scales 1:2,000,000 and 1:500,000, https://pubs.usgs.gov/pp/0543i/. Along much of the boundary, the bulk of the motion occurs along the San Andreas Fault. This was the Big One. Is earthquake a result of plate tectonics? Download the official NPS app before your next visit, Plate Tectonics and Our National ParksSite Index, Plate TectonicsThe Unifying Theory of Geology, Tectonic Settings of NPS SitesMaster List. If one plate is trying to move past the other, they will be locked until sufficient stress builds up to cause the plates to slip relative to each other. Georges interpretation of this as a subduction zone was a real key, says Gary Fuis. S. Perkins. They have been transported about 300 miles (500 kilometers) in a north-northwestward direction along the transform plate boundary. The March 27, 1964, earthquake was accomp anied by crustal deformation-including warping, horizontal distortion, and faulting-over probably more than 110,000 square miles of land and sea bottom in south-central Alaska. In Valdez, the ground beneath the harbor slumped and nearly swallowed a ship docked there. Earths big breakup. Science News for Students. Landslide and slumping effects in the Turnagain Heights area, Anchorage, Alaska, caused by the March 28, 1964, earthquake. As bad as the tremors were, the worst was yet to come. The earthquake lasted approximately 4.5 minutes and is the most powerful recorded earthquake in U.S. history. The Sierra Nevada are the eroded remnants of the volcanic arc developed when the Farallon Plate subducted beneath the continent. Magnitude type: M l 2; Event type: earthquake; Tectonic Setting of Southern Alaska . S. Ornes. The earthquake triggered a swell of devastating tsunamis, landslides and submarine. Alaskas long southern coastline marks where the Pacific Plate, moving north, dives beneath the North American Plate. Movement on the megathrust was accompanied by subsidiary reverse faulting, and perhaps wrench faulting, within the upper plate. By recording the size, direction and arrival times of the different seismic waves from a quake, seismographs help pinpoint its size and epicenter. Experiment: Are fingerprint patterns inherited? In Mexico, a combinatiion of divergent and transform plate boundary motion is opening the Gulf of California, causing the Baja Peninsula to separate from the rest of Mexico. They washed away everything in their immediate path buildings, docks and people. The 1964 quake woke up the dormant Hanning Bay fault on Montague Island in Alaskas Prince William Sound. Earthquakes at divergent plate boundaries occur as new crust is created and other crust is pushed apart. The 1964 earthquake was the first time people understood that there were places called subduction zones that produce these really enormous earthquakes. The theory of plate tectonics is a relatively new scientific concept. Such boundaries are called transform plate boundaries because they connect other plate boundaries in various combinations, transforming the site of plate motion. The map shows the epicenter of the 1964 Alaska Earthquake (red star), caused when the Pacific Plate lurched northward underneath the North American Plate. Includes extensive archival footage of the earthquake and aftermath. About 200 million years ago, a large tectonic plate (called the Farallon Plate) started to subduct beneath the western edge of North America. The data helped engineers develop earthquake-resistant structures to limit future casualties and property damage. tsunami One or many long, high sea waves caused by an earthquake, submarine landslide or other disturbance. It caused extensive damage to the city, including fires that lasted for several days, and killed an estimated 3,000 people. President Lyndon Johnson declared the entire state of Alaska a major disaster area a day after the earthquake. The 1964 Great Alaska Quake caused several downtown areas of Anchorage to collapse. But its interesting to note that this region is so heavily populated because of the same tectonic forces that sometimes shake it up with such violent consequences during earthquakes. The new magma (molten rock) rises and may erupt violently to form volcanoes, often building arcs of islands along the convergent boundary. But if you see something that doesn't look right, click here to contact us! Parks in western California contain blocks of crust that have moved great distances north-northwestward along the San Andreas Fault. uplift A upward shift in some section of Earths surface due to tectonic activity along a fault. During the earthquake, its estimated the fault slipped between 30 to 60 feet, an immense shift. Earths crust The outermost layer of Earth. Scientists also confirmed that earthquake-related tsunamis arent always localized and can happen thousands of miles from the epicenter. Molten rock from the mantle erupts along the opening, forming new crust. Railroad tracks warped. Shallow earthquakes and little volcanism occur where one plate slides laterally past another. An expanded version (11 min) is also available: 1964 Quake: The Alaska Earthquake Still, the fact that it reached those areas at all is testament to the enormity of the quake. These unleashed more tsunamis. The aftermath of the Great Alaska Earthquake and Tsunami led to the creation of the NOAANational Tsunami Warning Centerin Palmer, Alaska. Animations explain the magnitude (Just how big is 9.2? This 3-panel image shows a simplified representation of a tsunami-generating earthquake cycle on the Alaska-Aleutian Megathrust. Typically, a convergent plate boundarysuch as the one between the Indian Plate and the Eurasian Plateforms towering mountain ranges, like the Himalaya, as Earths crust is crumpled and pushed upward. This sudden displacement of the ocean floor, along with earthquake-induced landslides, generated massive local tsunamis that resulted in 70 percent of the fatalities in southern Alaska. Most earthquakes occur at the boundaries where the plates meet. HS-ESS2-1, HS-ESS2-2, HS-PS4-1, MS-ESS2-1, MS-ESS2-2, MS-ESS2-3, MS-PS4-1, MS-PS4-2. Along convergent boundaries, neighboring plates either collide head-on or a denser ocean plate dives beneath a lighter continental plate. Produced by Creative Arts Studio in 1964 for the USGS. The route is dotted by some serious volcanoes and wracked by violent earthquakes. Success! Seismically triggered landslides are one of the greatest geologic hazards in Anchorage. After wreaking havoc on southeastern Alaskan coastal towns that had already endured local tsunamis, the tectonic tsunami made its way to British Columbia where it ravaged small villages along the coastline near Vancouver. The 1964 M9.2 Great Alaska Earthquake, which is still the second largest earthquake ever recorded worldwide, began under Prince William Sound. Warping resulted in permanent tilt of larger lake basins and temporary reductions in discharge of some major rivers. The rocks pulled down under the continent begin to melt. So this was the first earthquake to be recorded around the world. In the days and weeks that followed, dozens of smaller earthquakes continued to rattle Alaska. Natasha Ruppert at the Alaska Earthquake Center in Fairbanks is another seismologist. The reason: This quake opened a new era in geology. The broad zone of shearing at a transform plate boundary includes masses of rock displaced tens to hundreds of miles, shallow earthquakes, and a landscape consisting of long ridges separated by narrow valleys. As convergent plates collide, the overriding or top plate gets slowly pushed up. UAF is an AA/EO employer and educational institution and prohibits illegal discrimination against any individual: If you have difficulty accessing the information on this website due to a disability, please contact the web administrator by email at uaf-aec@alaska.edu or by phone at 907-474-7320. SSAs 2014 Annual Meeting will provide a stimulating exchange of research on a wide range of topics with colleagues from all over the world. Uplift that averages 6 feet over broad areas occurred mainly along the coast of the Gulf of Alaska, on the adjacent Continental Shelf, and probably on the continental slope. The 1964 Alaska Earthquake and Tsunami lecture by George Plafker, USGS Geologist Emeritus. The Ring of Fire also marks the edge of the Pacific Plate. Policies and Notices, U.S. Department of the Interior | Produced under a Cooperative Agreement for earth science education between the National Park Service's Geologic Resources Division and the American Geosciences Institute. The earthquake rupture started approximately 25 km beneath the surface, with its epicenter about 6 miles (10 km) east of the mouth of College Fiord, 56 miles (90 km) west of Valdez and 75 miles (120 km) east of Anchorage. Copalis River, Washington Trees along the Washington coast were killed by salt-water invasion when the land suddenly dropped during the last great Cascadia Subduction Zone earthquake . The collision of tectonic plates can result in earthquakes, volcanoes, the formation of mountains, and other geological events. 1719 N Street, N.W., Washington, D.C. 20036, People and animals sometimes team up to hunt for food, Pokmon evolution looks more like metamorphosis, These beetles drink water using their butts. The Aleutian Trench (or Aleutian Trough) is an oceanic trench along a convergent plate boundary which runs along the southern coastline of Alaska and the Aleutian islands.The trench extends for 3,400 kilometres (2,100 mi) from a triple junction in the west with the Ulakhan Fault and the northern end of the Kuril-Kamchatka Trench, to a junction with the northern end of the Queen Charlotte . Look at your fingernails and watch them grow. An animation that describes earthquakes along the Aleutian subduction zone, one of the most seismically active in the world, and the Queen Charlotte Transform Fault. The U.S. Army Corps of Engineers spent about $110 million dollars repairing infrastructure, rebuilding communities, and clearing debris. Most seismic activity occurs at three types of plate boundariesdivergent, convergent, and transform. Most earthquakes rattle the ground for just seconds. Photo courtesy of Robert J. Lillie. FOIA The 1964 earthquake was a defining moment in a territory that had just achieved statehood. At an ocean-ocean convergent boundary, one of the plates (oceanic crust and lithospheric mantle) is pushed, or subducted, under the other (Figure 4.6. ), rupture processes, elastic rebound, and resulting tsunami. These instruments detect and record earthquakes. U.S. Geological Survey Contact Information, Menlo Park, Calif. Two types of tsunami were produced as a result of this massive quake. National Park Service Sites (shown in red) Both plates are capped by oceanic crust. The San Andreas Fault is one of the best examples of lateral plate motion. Today, almost 60 years since the Great Alaska Earthquake, the Tsunami Warning Centers issue tsunami warnings in minutes, not hours, after a major earthquake occurs. Question: What type of tectonic plate boundary exists along the edge of the North American plate near the coast of Northern California, Oregon, and Washington? The San Andreas Transform Plate Boundary developed within the past 40 million years as a large portion of the Farallon Plate was subducted and the Pacific Plate made contact with the North American Plate in the California region. Although the school was destroyed, the nearby water tower was undamaged. Where tectonic plates slip horizontally past one another, lithosphere is neither created nor destroyed. Produced under a Cooperative Agreement for earth science education between the National Park Service's Geologic Resources Division and the American Geosciences Institute. The 1964 M9.2 Great Alaska Earthquake, which is still the second largest earthquake ever recorded worldwide, began under Prince William Sound. to A.D. 2022, U.S. Drought: Weekly Report for April 25, 2023, U.S. Drought: Weekly Report for April 18, 2023, U.S. Drought: Weekly Report for April 11, 2023. Comparable horizontal movements are presumed to have affected those parts of the major zones of uplift and subsidence for which retriangulation data are unavailable.