southern whidbey island fault map
A .gov website belongs to an official government organization in the United States. Despite its location well offshore, a Cascadia quake would likely kill at least 10,000 and injure more than 30,000 in Washington, Murphy found. And what were looking at is water.. Johnson and others (1996 #4751) described multiple sub-parallel strands and referred to the overall structure as the "southern Whidbey Island fault zone," and this name is also used herein for this zone of faults that crosses the southern part of Whidbey Island. The South Whidbey Island Fault is also dangerous. Also check out Ear to the Ground, published by the Department of Natural Resources. The southern Whidbey Island fault: An active structure in the Puget But opting out of some of these cookies may affect your browsing experience. Someone screams. Stay inside until the shaking stops and it is safe to go outside. Subtle scarps and topographic lineaments on Pleistocene surfaces are visible on high-resolution LiDAR topography at a number of locations (Sherrod and others, 2008 #7652); the northeast-side-up scarps exhibit 15 m of vertical relief, late glacial and post-glacial sediments (Sherrod and others, 2008 #7652). Oil companies descended in search of riches. The key, Sherrods group would discover, was buried on Whidbey Island under layers of mud, peat moss and decaying marsh grass in the murky tidal waters at Crockett Lake, alongside the Coupeville ferry dock. Official websites use .gov The fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. The team also found that accumulated movement on the fault has uplifted old Snoqualmie River sediments to their current position on ridges, in some places several hundreds of feet above the modern Snoqualmie valley floor. . You will not be able to google what to do in an earthquake when it is happening. Reverse faults are usually steep and occur in regions of compression. People are already fighting over toilet paper, just imagine what will it be like when they go shopping for food and the shelves are almost empty. This means that a large area feels the shaking, but the intensity is less than a similar shallow earthquake. We do not encourage people to evacuate in vehicles. A thrust fault is a special kind of reverse fault that has a shallow dip. The team determined that the Rattlesnake Mountain fault zone, originally mapped by DNR geologist Tim Walsh in the 1980s, is likely the southern continuation of the southern Whidbey Island fault, extending this fault zone from the Strait of Juan de Fuca to Rattlesnake Mountain near North Bend. This image shows the how the 1700 AD tsunami from the Pacific Northwest crossed the Pacific Ocean. The Port of Coupeville will apply for a grant to fund two electric vehicle charging stations. This earthquake caused parts of Restoration Point near on Bainbridge Island to be lifted 35 feet straight up. Not all faults are active. Another big one is expected, and it could be devastating. Fir trees near the failure are tilted and indicate rotation into the lake (to the left of the photo). The years have gone by. Why you should be prepared: 3 big earthquake threats in PNW In much of Washington, dense vegetation covers the land and makes finding faults very difficult. Its significantly larger than the Seattle Fault, and South Whidbey could hand us a magnitude 7.5 earthquake. The fault zone, known to geologists as SWIF, cuts through Puget Sound in a diagonal line roughly from Port Townsend to the southern tip of Whidbey Island, then to Mukilteo, Bothell, North Bend and possibly farther east below the Cascades. As of January 12, 2017, the USGS maintains a limited number of metadata fields that characterize the Quaternary faults and folds of the United States. The plate that is forced down can have faults within it that still rupture and produce earthquakes. In Washington, we do not have tsunami walls. The Cascadia subduction zone just off the Washington coast is this kind of fault and is one of the largest geologic hazards to our state. Sherrod shrugged his shoulders. Bubbles of methane rising from seafloor in Puget Sound <>/XObject<>/ExtGState<>/Pattern<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Whidbey fault quake potentially a bigger 'Big One' At the time, Johnson worked in southwest Washington, searching for natural gas and oil deposits. Earthquakes and Faults | WA - DNR - Washington State Department of This video from the 2011 Tohoku subduction zone earthquake shows the earthquakes before, during, and after the main M8.7 event on March 11 (at 1:50 in the video). Charles Richter and Beno Gutenberg discovered that for every magnitude of earthquake, there are about ten times more earthquakes of the next lower magnitude. Deep faults can occur where two tectonic plates collide and one of the plates is forced beneath the other. . Electricity, water, natural gas, and phones may not work. Even when an earthquake happens on a fault that doesnt reach the surface, the ground can still show signs of cracking. When the ground shakes during an earthquake, it moves up and down, acting like additional gravity. This evidence can come from finding something younger than 12,000 years that has been deformed or moved by the fault. Jump from 60 to 600 per week in just 5 years in Pahala, Is the Cascadia Subduction Zone about to blow? The South Whidbey Island Fault and Darrington Devil's Mountain Fault bound the Everett Basin. It startled Johnson that such massive faults had gone undetected for so long. Kristin D. Morell 1 *, Christine Regalla 2, Lucinda J. Leonard 3, Colin Amos 4, Vic Levson 5. This photo shows a fence that was offset about 8.5 feet during the 1906 Great San Francisco Earthquake on the San Andreas fault. It might as well have been sitting in a drawer, Johnson said. Thats why were pushing for a lot of vertical evacuation structures to be built hotels or schools, because its not an easy problem to solve, he said. Most are too small to be felt or cause damage. Black squares are urban sewer outfalls, which don't match the bubble plumes' locations. If they know theres data available that could help them in any way, they want to get it. stream Large and damaging earthquakes are inevitable in Washington, but no one knows exactly when they will happen. Stay away from glass, windows, outside doors and walls, and anything that could fall down. People who look for evidence of past movement on faults are usually called paleoseismologists (from paleo-ancient and seismologist-one who studies earthquakes). Read more below to learn about how and where earthquakes occur, what to do before, during, and after an earthquake, and what scientists are doing to learn more about them. (1999 . Because they can travel great distances, tsunamis generated from earthquakes across the ocean can still cause damage. Whidbey fault quake potentially a bigger 'Big One' Quake fault under Whidbey linked to potential mainland dangers Faults are features in the Earths crust where rock periodically breaks and moves, releasing seismic energy and creating an earthquake. M 7.4 Scenario Earthquake - Southern Whidbey Island fault-southern These include (from north to south, see map) the: Devils Mountain Fault Strawberry Point and Utsalady Point faults Southern Whidbey Island Fault (SWIF) Rogers Belt (Mount Vernon Fault/Granite Falls Fault Zone) Cherry Creek Fault Zone Rattlesnake Mountain Fault Zone Seattle Fault Tacoma Fault Saddle Mountain Faults PI22343). The crustal faults the Seattle Fault, the South Whidbey Island Fault, the Tacoma Fault those are less well known, said Forson. Clicking on the map will download the publication. Photo courtesy of MOHAI (neg. These older faults do not have any evidence for recent activity, but the Earth is always changing. And experts fear it could be even worse than The Big One.. For example, the DNR team found evidence that the rocks creating Snoqualmie Falls are much younger than previously thought. A national credit rating service has improved its opinion of WhidbeyHealths financial future. A drill rig left of the blockade is collecting data about the failure. Then the world rattles up and down. Another piece can be seen under the elevated lanes of northbound Interstate 5 in South Seattle not far from the Rainier brewery. Theres approximately a 14% chance of another approximately M9 earthquake occurring in the next 50 years. Within this rich oral history there are many references to events like earthquakes and tsunamis. The age of the earthquake is learned by dating the organic material in these tsunami deposits. Photo from, This image shows the how the 1700 AD tsunami from the Pacific Northwest crossed the Pacific Ocean. We use the term deep to talk about faults and earthquakes deeper than about 18 miles. This new method allows geologists to see through trees and vegetation to find new faults. Southeast Extension of the Southern Whidbey Island Fault, Washington: Implications for Earthquake Hazards, 12201 Sunrise Valley Drive Reston, VA 20192, Region 2: South Atlantic-Gulf (Includes Puerto Rico and the U.S. Virgin Islands), Region 12: Pacific Islands (American Samoa, Hawaii, Guam, Commonwealth of the Northern Mariana Islands). Over time, fault movement has created some interesting geologic features. This means that a tsunami made by an earthquake on the Cascadia subduction zone will start to impact the Washington coast in less than 15 minutes. Tsunamis and seiches can also be triggered by large slides, both on land and underwater. A small quake was registered in the Coupeville area just this summer. The seismic mapping had cost millions of dollars far beyond what most geologists on a government budget could scrape together. Hover over a cluster of earthquakes to learn about the different types in the Pacific Northwest. In the early 2000s, USGS scientists including Brian Sherrod set out to further Johnsons work and better understand the slumbering fissure. Hold on to any sturdy shelter until the shaking stops. The fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. Stories from tribes near Seattle have also helped us to learn that the last earthquake on the Seattle fault was about AD 900950. (1996) used seismic-reflection profiles in Puget Sound near Whidbey Island, sea-cliff exposures on Whidbey Island, and sparse borehole data to map and interpret the SWIF as a broad fault zone (6 to 11 km wide) dipping steeply to the northeast. The SWIF has been assessed by the USGS as capable of generating the largest crustal earthquake in Puget Sound. Mapping along the Snoqualmie River valley also helped answer the important question of where the Seattle fault lies east of its last mapped position near Issaquah. Official websites use .gov Coupeville, WA 98239, Camano Office In the month after the main earthquake there were about 60 M7 and M6 earthquakes. All faults, regardless of size, can be dangerous if they rupture. By finding the age of the deformed layer, a paleoseismologist can determine the minimum age of the fault. 1. Buried danger: A slumbering geologic fault beneath us The Seattle fault is a good example of a fault that is mostly reverse. Earthquakes occur nearly every day in Washington. This means that the internet, your cell phone, grocery stores, and gas stations may also not work. endobj The Darrington-Devils Mountain fault zone is located in southern Skagit County and northern Snohomish County. Stratigraphy in the Flying Squirrel trench showed gentle warping of late glacial and post-glacial sediments; no faults were exposed. Earthquakes. During site visits in 2005, Sherrods team found evidence of four SWIF earthquakes in the past 30,000 years. In the Pacific Northwest we use the term shallow to talk about faults and earthquakes less than 18 miles deep. That may not sound like much more than the magnitude 6.8 quake of 2001 based on the numbers, but that the Nisqually quake occurred some 30 miles underground. Share sensitive information only on official, secure websites. Washington State Earthquake Hazard Map. Geologic maps of 7.5-minute topographic quadrangles covering parts of the Seattle fault and southern Whidbey Island fault zone are available on the DNR website as: Sign-up for DNR enewsletters. Many faults have not been studied enough to know if they are active. America is going to be punished just like the rest of the world. This is a very good example of a strike-slip fault. 1 0 obj The San Andreas fault in California is a good example of a very active strike-slip fault. Learning earthquake faults around where we live is a first good way to prepare the next devastating earthquake. 3. Aftermath: Infrastructure won't fare well in a big quake Close to shore, this same wave could reach heights of 30100 feet or more. A lock () or https:// means youve safely connected to the .gov website. Cover your head and neck with your arms to protect against falling debris. Washington, Seattle, WA 98195 2 U.S. Geological Survey, 345 Middlefield Road, M/S . Although both seiches and tsunamis can be large and destructive, they are created differently. Gower (1980 #6229) showed and named the "southern Whidbey Island fault," and Gower and others (1985 #4725) showed this fault on their seismotectonic map of the Puget Sound region and briefly outlined its geologic relationships. Radiocarbon ages of macrofossils constrain uplift timing to 2.83.2 ka. Liquefaction is when wet soil or sediment loses strength because it is being shaken during an earthquake. Hundreds could die, with thousands more injured. The shaking usually lasts less than a minute and doesnt generally cause a tsunami or have many aftershocks. This map shows different seismic design categories that correlate with amount of seismic risk. Once we got it, we were sort of shocked to see these big faults in the Puget lowlands, he said. Puget Sound Earthquake Faults - Seattle Earthquake Faults The last time was 1,000 years ago between 900 and 903 A.D., said Forson. Whats up with the 50 US nuclear bombs stored at the Incirlik Air Base in Turkey, right on the same fault line California hasnt seen a catastrophic earthquake recently. The Seattle fault last ruptured about 1,100 years ago in AD 900950. Scientists are not sure how far east it goes. Scientists have used the stories from tribes along the entire Pacific Northwest coast to learn that the last large earthquake on the Cascadia subduction zone was about AD 1700. Landslides can be caused by strong ground shaking during an earthquake. A lot of people are transplants, Forson said. 4 0 obj Sheriff:(360) 679-7310, Juror Recordings This was a problem because no two locations would agree on the size of the same earthquake. Ready to retrofit? Scientists are not sure how far east it goes. When a fault with vertical movement ruptures the ocean floor, it lifts up part of the ocean. Quaternary Rupture of a Crustal Fault beneath Victoria, British Necessary cookies are absolutely essential for the website to function properly. This fault produces some of the largest and most damaging earthquakes in the world (M9). PDF Holocene Fault Scarps and Shallow Magnetic Anomalies Along the Southern The moment magnitude scale replaced the Richter scale in the late 1970s. The map also shows potentially active faults from a separate 2014 report (click here to download). Swarm of hundreds of small earthquakes rattle Vancouver Island. Finding Concealed Active Faults: Extending the Southern Whidbey Island It devastated the coast of the Pacific Northwest and sent an orphan tsunami to Japan. Secure .gov websites use HTTPS Third, the South Whidbey Island Fault running from northwest to southeast of the southern tip of the island. Snohomish, King and Island counties would be expected to see the. Superior Court:(800) 254-2755 Both studies suggested that the SWIF These cookies do not store any personal information. % On an inactive fault, the sea would have risen at the same rate at both locations. This kind of landslide is called an earthquake-triggered landslides. This is sometimes called "The Big One" by news media. The 1964 M9.2 Alaska earthquake created a large tsunami from the fault rupture, and many smaller tsunamis from on-land and underwater landslides. Since the last ice age, the southern Whidbey Island fault zone has probably spawned several highly destructive shallow earthquakes. Small talk stops. They didnt grow up here, they havent heard this story. These aftershocks can last for hours to weeks or months. The average time between large earthquakes is about 535 years, but has been as little as 200 years, and more than 1,000 years. At the Brightwater treatment plant in Woodinville and at Crystal Lake in Maltby, the government researchers found telltale slopes of offset ground, known as scarps, indicative of a long-ago quake. Radiocarbon dating and other paleoseismic methods have also confirmed this date. This might include flammable appliances like a water heater, tall items like book cases, or heavy pictures. Along the water at Cama Beach State Park, cabins on a bluff overlook Saratoga Passage, facing the general direction of Lake Hancock on Whidbey Island. What about the localized tsunami risk? Photo by G.K. Gilbert, from the Steinbrugge Collection of the UC Berkeley Earthquake Engineering Research Center. When earthquakes occur on faults that reach the Earths surface, the ground may rupture. Tsunamis and seiches are destructive waves which can be triggered by certain types of large earthquakes. Small fires are the most common hazard after an earthquake. This car was parked on sand during the 2011 earthquake in Christchurch, New Zealand. Fault Activity Map of California Theyre FREE CLICK HERE to subscribe, EAR TO THE GROUND WITH DNR & COMMISSIONER FRANZ, Tree Link helps you answer questions about urbantrees. The best thing you can do is to become prepared. The Flying Squirrel and Mountain Beaver trenches cross the Cottage Lake lineament. This website uses cookies to improve your experience while you navigate through the website. The southern Whidbey Island fault (SWIF) stretches from the vicinity of Victoria, B.C., across Puget Sound as far as the Cascade Range. Sherrod says practically every place they. An official website of the United States government. Were working on pedestrian evacuation maps that show the best routes for pedestrians to take to evacuate, said Forson. (360) 678-5111 An earthquake can be a scary event. There are also many faults that have not been studied enough to know if they are active. This fundamental tool for earth scientists, maps show map units, faults and folds, cross sections, and other regional or local features, depending on map scale. A baristas hand hovers over the bean grinder. Geologists have used the location of these shallow, intermediate, and deep earthquakes to learn about subduction zones throughout the world. This can cause landslides to occur where they wouldnt normally happen. The trenches exposed glacial deposits disrupted by faults and liquefaction features. Photo from, Liquefaction can be a big problem. Washington has the second highest risk in the U.S. of these large and damaging earthquakes because of its geologic setting. It usually also means that there are earthquakes (even small ones) on the fault. Sherrods son has since completed graduate school in applied geosciences. The 2011 Tohoku earthquake in Japan occurred on this type of fault and released enough energy to slightly change the Earths axis of rotation. While the intensity of this seismic event has now decreased, a big earthquake is overdue in the region. The tsunamis can travel far inland and deposit layers of sand and organic material. The fault probably originated during the early Eocene as a dextral strike-slip fault along the eastern side of a continental-margin rift. Floods. In general, larger faults make larger earthquakes. Image from the Pacific Geoscience Center of the Natural Resources of Canada. This averages to ~660 to 525 years between events, but there is a lot of variation. Liquefaction has caused significant damage during earthquakes in Washington. Later movement on this long-term active fault zone cut the volcano. Photo courtesy of National Center for Tsunami Research, NOAA. Once in the open, Drop, Cover, and Hold On. Brick chimneys cascade off rooftops. Sometimes Geologists can use the offset land surface to understand how much the fault moved during the earthquake. Its a natural curiosity.. from Whidbey Island to Vancouver Island (Figure 1). Unlike sound, ground shaking can be amplified or attenuated (made less) depending on the type of material at the Earths surface. View Earthquake Map Faults Interactive fault map and comprehensive geologically based information on known or suspected active faults and folds in the United States. The Mercalli Intensity scale is another historical way to measure the intensity of an earthquake. For several years, scientists pondered where this important regional fault zone continues southwestward from its mapped location in the Everett area. The map is from a 2007 report (click here to download) on seismic design categories in Washington. South Whidbey fault has potential for major quake Johnson, on a whim, acquired the data that would prove its existence beyond a doubt. Notice the Seattle Fault Zone bounding the Seattle Basin to the south. PDF Cretaceous-Jurassic accreted terrains - University of Washington Unlike The Big One, scientists who have studied the southern Whidbey fault have far less understanding of when the next sudden shift might hit. The map is from a 2007 report (click here to download) on seismic design categories in Washington. For each increase in earthquake magnitude, there are about 10 times fewer earthquakes. The fault, not so much. These quakes are capable of magnitudes from 7 to over 9. Tap/click on "gear icon" for options and settings. The moment magnitude scale is a type of logarithmic scale, where each increase of 1 means ~32 times more energy is released. /L\Axc4Q/w4Ks^#, sRITgZf>,e}iI5,F_ADGc?f e@L. Across the northern portion of Bainbridge Island, light radar or lidar images taken from airplanes clearly show the Seattle Fault running right on the surface. Large earthquakes, like those from the Cascadia subduction zone on January 26, 1700, often create tsunamis. For example, it is unlikely that you will be able to use electricity, cell phones, or the internet. For example, if there is one M7 earthquakes in an area every 1,000 years, then there will be about 10 M6 earthquakes, 100 M5 earthquakes, and 1,000 M4 earthquakes during the same 1,000 years. These and other problems led to the search for a scale that was based on the physical processes that happen during an earthquake. A reverse fault occurs when two blocks are pushed together and one moves up and over the other. So I think it is worth your time to learn more about the biggest seismic riskss and major fault lines criss-crossing this part of the Pacific Northwest, namely: Now lets visit the 3 most dangerous earthquake faults for Seattle one by one: The Cascadia Subduction Zone is a giant fault running from Cape Mendocino, Calif. past Oregon and Washington and doesnt end until its north of Vancouver Island in Canada. Puget Sound faults - Wikipedia Bookcases and china cabinets topple, trapping people beneath. Southeast Extension of the Southern Whidbey Island Fault By Human Capital March 19, 2019. sw_whidbeyfault_rev122706.pdf (28.68 KB) At a downtown coffee shop, the mugs begin to chatter. We also use third-party cookies that help us analyze and understand how you use this website. The Survey works to increase public and scientific understanding of fault and earthquake hazards in our state. The Cascadia subduction zone along the Washington and Oregon coast is one of the biggest hazards to our state and is a good examples of this kind of fault. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. Faults can also be grouped based on what part of the crust they occur in. The Survey is working with the Office of the Superintendent of Public Instruction (OSPI) and Reid Middleton, an engineering firm, to perform seismic safety assessments of 220 school buildings across the state. Nearly all earthquakes occur on faults, features in the Earth where rocks move past each other. Many landslide-prone areas of Washington are also located near active faults. The process of breaking and moving rock releases a large amount of energy that travels through the Earth as seismic waves. If a large earthquake happens, be prepared for many more earthquakes. Seattle Fault Lines. California Geological Survey. Each type has different kinds of earthquakes. Once the shaking has stopped, exit the building if it is safe to do so. The continued movement along faults over millions of years can build mountains, tear a continent apart, and move tectonic plates thousands of miles. 12201 Sunrise Valley Drive Reston, VA 20192, Region 2: South Atlantic-Gulf (Includes Puerto Rico and the U.S. Virgin Islands), Region 12: Pacific Islands (American Samoa, Hawaii, Guam, Commonwealth of the Northern Mariana Islands), The southern Whidbey Island fault: An active structure in the Puget Lowland, Washington, S. Y. Johnson, C. J. Potter, J.M. Drop to your hands and knees. Seattle Fault and Whidbey Faults HAZARD MAPS As part of the Hazard Mitigation Planning process, mapping of the hazards that have the potential to affect the jurisdiction is performed using geographic information systems (GIS) software. Using the stratigraphic column from the Freeport quadrangle map, confirm that you can recognize . Each year we map additional areas and learn more about existing faults and (or) discover new ones.