In central and southern California, for example, the volcanoes have largely eroded away and massive areas of granite from the cooled magma chambers form portions of the Sierra Nevada Mountains, including Yosemite National Park. URL: https://pubs.usgs.gov/pp/0543i/ The earthquake lasted approximately 4.5 minutes and is the most powerful recorded earthquake in U.S. history. This post is part of Exploring Earthquakes, a rich collection of resources co-presented by the California Academy of Sciences and KQED. Other parks in the region, namely Pinnacles, Channel Islands and Joshua Tree national parks, Cabrillo National Monument and Santa Monica Mountains National Recreation Area, reveal evidence of the shearing, rotation, and uplift that occurs within the broad zone of deformation between the two plates. Plate boundaries are found at the edge of the lithospheric plates and are of three types, convergent, divergent and conservative. Geological surveys taken immediately afterward showed parts of the Alaskan coast sank up to eight feet, other parts rose up to 38 feet and much of the coast moved 50 feet towards the ocean. By definition, intraplate earthquakes do not occur near plate boundaries, but along faults in the normally stable interior of plates. Learn about the great leaps in research over the past 50 years. uplift A upward shift in some section of Earths surface due to tectonic activity along a fault. HISTORY.com works with a wide range of writers and editors to create accurate and informative content. Perhaps nowhere on Earth is such a landscape more dramatically displayed than along the San Andreas Fault in western California. Some start and then stop, only to start again much later. There are three types of plate boundaries: spreading zones, transform faults, and subduction zones. Photo courtesy of the National Parks Conservation Association. 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 . It effortlessly toppled telephone poles, buckled railroad tracks, split roads in half, uprooted buildings, cars and docks and tore homes apart. Find History on Facebook (Opens in a new window), Find History on Twitter (Opens in a new window), Find History on YouTube (Opens in a new window), Find History on Instagram (Opens in a new window), Find History on TikTok (Opens in a new window), Education Images/Universal Images Group/Getty Images, Department of Homeland Security & Emergency Management, https://www.history.com/topics/natural-disasters-and-environment/1964-alaska-earthquake. M 9.2 - 1964 Prince William Sound Earthquake, Alaska - USGS Farther to the south, the Pacific Plate slides past the North American Plate. The earthquake hit at 3:11 pm approximately 100 miles (160 km) off the coast of Chile . Is earthquake a result of plate tectonics? 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. ), rupture processes, elastic rebound, and resulting tsunami. Plate boundaries. April 27, 2012. In the Caribbean Sea, the U. S. Virgin Islands lie along a transform plate boundary where the small Caribbean Plate moves eastward past the oceanic part of the North American Plate. On This Day: Great Alaska Earthquake and Tsunami, Aftershocks from the quake continued for three weeks, Transoceanic tsunami waves swept across the Pacific and reached as far away as Hawaii and Japan, The earthquake and ensuing tsunamis caused about $311 million in damages in 1964(about$2.3 billiontoday), Tsunami Warning Centers issue tsunami warnings in minutes, not hours, after a major earthquake occurs, National Tsunami Hazard Mitigation Program, Tsunami Forecast Model Animation: 1964 Alaska Earthquake, NCEI Great Alaska Earthquake Image Database, VIDEO: NCEI Ask a Scientist with Nic Arcos: Tsunamis. The San Andreas Fault is the transform plate boundary where a thin sliver of western California, as part of the Pacific Plate, slides north-northwestward past the rest of North America. Photo by Robert J. Lillie. You push and push. Which type of boundaries can produce earthquakes at which produces the largest earthquakes? To the north and northwest of the zone of uplift, subsidence forms a broad asymmetrical downwarp centered over the Kodiak-Kenai-Chugach Mountains that averages 2 feet and attains a measured maximum of 7 feet along the southwest coast of the Kenai Peninsula. Together, these destructive waves swept Alaskas coastline with devastating speed and power. These forces also create a sheared-up landscape that includes spectacularly beautiful coastlines and economically important harbors. Explains how Yakutat terrane accretion drives mountain building and crustal fault earthquakes like the 2002 M7.9 Denali Earthquake. S. Ornes. Glennallen M1.9 | Alaska Earthquake Center Page Last Modified: Thursday, December 01, 2016, 04:21:41 PM, Download the latest version of Adobe Reader, free of charge. Most earthquakes occur at the boundaries where the plates meet. Nows a great time to start window-shopping at the. They have been transported about 300 miles (500 kilometers) in a north-northwestward direction along the transform plate boundary. Since neither plate is stronger than the other, they crumple and are pushed up. Animations explain the magnitude (Just how big is 9.2? Then, as Alaskas shaking ceased, things got worse much worse. From Montague Island, the faults and related belt of maximum uplift may extend southwestward on the Continental Shelf to the vicinity of the Kodiak group of islands. Read personal accounts of the earthquake and submit your own story. The site is secure. March 27, 1964, was a quiet day in Alaska. Its a bit like a rug wrinkling. By recording the size, direction and arrival times of the different seismic waves from a quake, seismographs help pinpoint its size and epicenter. A documentary chronicling the first 72 hours after the 1964 Alaska Earthquake and the response to the disaster by the United States Office of Civil Defense, U.S. Military, and local, state, and federal officials. In Anchorage, roads buckled and sank. This can lead to the formation of huge, high mountain ranges such as the Himalayas. Scientists are still working out many details of plate tectonics. Hear a first-person account of the event, watch an animation that illustrates the subduction of the Pacific plate under the North American plate, and observe how Valdez was affected. The quake that shook up geology - Science News Explores N&SP = National and State Parks Thousands of earthquakes over millions of years have built this landscape not only along the major fault linethe San Andreas Faultbut also on other faults within the broad zone of shearing between the Pacific and North American plates. 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. An offset fence line reveals the 16 feet (5 meters) of lateral ground breakage that occured as the San Andreas Fault suddenly let loose during the 1906 San Francisco Earthquake. Where plates crash together, one dives (subducts) beneath the other, causing volcanoes (red triangles) to erupt on the overriding plate and earthquakes (black stars) at a variety of depths. July 6, 2011. Coastal forests plunged below sea level and were destroyed by salt water. It was so large that it caused the entire Earth to ring like a bell, observes seismologist Tom Brocher and his colleagues from the U.S. Geological Survey (USGS) in a recent publication. Active volcanoes of the Lesser Antilles Island Arc form as the North American Plate subducts beneath the Caribbean Plate. 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. Produced under a Cooperative Agreement for earth science education between the National Park Service's Geologic Resources Division and the American Geosciences Institute. 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. Imagine that your left hand is the undeformed Pacific Plate, your right hand the intact North American Plate. The valleys are commonly due to erosion along individual fault lines. Letters in ovals are abbreviations for NPS sites listed above. That doesnt seem like much, but over time it adds up. S. Ornes. , Divergent boundaries where two plates are moving apart. U.S. Geological Survey This megathrust fault has been the source of many large earthquakes including the 1964 Alaskan earthquake that registered a magnitude 9.2 and remains the second largest earthquake in . Four minutes may not seem like a long time, but when it comes to earthquakes, its an eternity, and tremors during the Great Alaska Earthquake of 1964 lasted at least four minutes. Earth definitely moved with a start during the 1964 quake. Earthquake history, photos, videos, and more from the Alaska Division of Homeland Security & Emergency Management. NS = National Seashore in that one quake, it was the first time that you could actually see plate motion in action. Earthquakes and tsunamis can happen along any coastline, at any time of the year, but Alaska is particularly prone to them because it sits on the convergence of two tectonic platesthe Pacific Plate and the North American Plate. This subduction zone landscape was later plucked from the edge of the North American Plate and transported nearly 200 miles northwestward along the San Andreas Fault. Cabrillo National Monument south of San Diego also lies within the broad zone of deformation between the two plates. Modified from Parks and Plates: The Geology of our National Parks, Monuments and Seashores, by Robert J. Lillie, New York, W. W. Norton and Company, 298 pp., 2005, www.amazon.com/dp/0134905172. Earthquakes - General Interest Publication - USGS Convergent (Colliding): This occurs when plates move towards each other and collide. Photo courtesy of Robert J. Lillie. Eventually the weakest card face (the San Andreas Fault) dominates within the broad transform plate boundary. 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.. The motion on the north is not pure transform; there is some convergence that contributes to uplift of the topography. Download the latest version of Adobe Reader, free of charge. Where do earthquakes happen besides plate boundaries? USGS concluded that the earthquake did not shake down much of the snowpack. 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 San Andreas Fault is one of the best examples of lateral plate motion. And they are powerful. These tectonic plates move gradually, bumping and grinding against each other. Sometimes the valleys are partially filled with water, as at Point Reyes National Seashore, where Tomales Bay and Olema Valley follow the main trace of the San Andreas Fault. Californias sheared-up landscape and earthquake hazards reflect the movement of the Pacific Plate past the edge of North America along a transform plate boundary that extends from the Mexican border to north of San Francisco. 1964 Alaska Earthquake - History It caused extensive damage to the city, including fires that lasted for several days, and killed an estimated 3,000 people. And it moved parts of the Alaskan coast 15 meters (50 feet) toward the sea. plate tectonicsThe study of massive moving pieces that make up Earths outer layer, which is called the lithosphere, and the processes that cause those rock masses to rise from inside Earth, travel along its surface and sink back down. Uplift and subsidence relative to sea level caused profound modifications in shoreline morphology with attendant catastrophic effects on the nearshore biota and costly damage to coasta1 installations. Society for Science & the Public 20002023. Houses pulled apart. Plate Boundaries: Divergent, Convergent, and Transform Map showing plate boundaries that were active during the 1964 Great Quake. This is called subduction. You'll be happy you did. Some had been up to 24 inches (61 centimeters) in diameter and as much as 101 feet (30.8 meters) above sea level. Maximum indicated uplift in the Alaska and Aleutian Ranges to the north of the zone of subsidence was l feet. This is because the plates slide past each other without moving up or down. The San Andreas Fault is just one of many active earthquake faults in a broad zone of shearing along the transform plate boundary in the San Francisco Bay Area. Transform boundaries - where plates slide passed each other. Which of the following measures an earthquake's intensity based on the observed effects on people and structures? Ground subsidence due to the earthquake created a huge, deep ditch (a graben) that ran through the yard and under this house in Anchorage. 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. To view this site, enable JavaScript by changing your browser options and try again. Scientists are still working out many details of plate tectonics. Richter scale Modified Mercalli scale the Centigrade scale the moment magnitude scale. Hes a research geologist with USGS and its Alaska coordinator of earthquake hazards research. The granite rocks in the foreground are similar to those found in Yosemite National Park in the Sierra Nevada Mountains. They recalled seeing asphalt roads rise and fall like waves and the ground opening and closing before them, water shooting up through the ensuing cracks. An expanded version (11 min) is also available: 1964 Quake: The Alaska Earthquake Subduction zones usually have a deep trench along the top. Menlo Park, CA 94025 The video features USGS geologist George Plafker who, in the 1960s, correctly interpreted the quake as a subduction zone event. subduction zone A large fault where one tectonic plate sinks beneath another as they collide. By midnight, 131 people were dead. Convergent Plate BoundariesSubduction Zones - National Park Service 1964 Alaskan Tsunami. The April 1933 M6.9 earthquake, which caused considerable damage in Anchorage, appears to have occurred on such . 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. But this was no ordinary tremor. M9.2 Alaska Earthquake and Tsunami of March 27, 1964 - USGS The Alaska earthquake was a subduction zone (megathrust) earthquake, caused by an oceanic plate sinking under a continental plate. The 1964 M9.2 Great Alaska Earthquake, which is still the second largest earthquake ever recorded worldwide, began under Prince William Sound. What causes earthquakes? - British Geological Survey These plates constantly move. Seismicity of the United States, 1568-1989 (Revised), Earthquakes occur along fault lines, cracks in Earths crust where tectonic plates meet. Most seismic activity occurs at three types of plate boundariesdivergent, convergent, and transform. July 26, 2013. Like modern subduction zones, the region had an accretionary wedge (Coast Range), a forearc basin (Great Valley), and a volcanic arc (Sierra Nevada). 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 Sierra Nevada are the eroded remnants of the volcanic arc developed when the Farallon Plate subducted beneath the continent. Popular Geology - Earthquakes & Tsunamis</ | Alaska Division of The Virgin Islands are in a broad zone where the landscape is being sheared up as the Carribean Plate slides eastward past the oceanic part of the North American Plate. The town of Valdez was originally built on sand and gravel. This type of knowledge helps us better design and site infrastructure, and develop disaster preparedness plans so that our families and communities are less at risk when earthquakes do strike. Summary of the earthquakes cause and effects from the Alaska Earthquake Information Center. It was the largest U.S. earthquake ever recorded, and a turning point in earth science. Tsunamis trek traced in the sky. Science News for Students. 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/. 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. Lucky for this team, 70 new seismographs (SIZE moh grafs) had recently been installed all over the world.