southern whidbey island fault map southern whidbey island fault map

These and other problems led to the search for a scale that was based on the physical processes that happen during an earthquake. Brick chimneys cascade off rooftops. Do you know what to do if there is an earthquake? Deep faults can occur where two tectonic plates collide and one of the plates is forced beneath the other. 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 This uplift creates a very broad wave called a tsunami. These differences are related to the overall pattern of stress in the crust, what types of rocks the crust is made from, and how many faults there are. Latest earthquakes map and list (past 24 hours, M2.5+) from the ANSS (Advanced National Seismic System). Small talk stops. Seattle Fault Lines. Many landslide-prone areas of Washington are also located near active faults. If they know theres data available that could help them in any way, they want to get it. @\;L;=}%FC*l $@ 4x: 888O~xrsxx'/*rGRF\gI%~x(G-^-hjjq kx/V ou0hyegy0;ei`Tx&ilZ )TmZ$vb,`bQm|DR5x/ Learning earthquake faults around where we live is a first good way to prepare the next devastating earthquake. And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. The Cascadia subduction zone last ruptured over 300 years ago on January 26, 1700. Ready to retrofit? Earthquakes occur nearly every day in Washington. These include the: Southern Whidbey Island Fault (SWIF) Seattle Fault Devils Mountain Fault Strawberry Point fault Utsalady Point fault Much of the Southern Whidbey Island fault zone (SWIF), which runs in a north-westward direction from Woodinville to near Port Townsend, Washington, remains mostly . Earthquakes occur nearly every day in Washington. In fact, until the 1980s, no one knew SWIF existed. Consider subscribing to our blog, Washington State Geology News, to receive notifications when new information is published. The last time was 1,000 years ago between 900 and 903 A.D., said Forson. As an example, parts of Seattle and certain areas of downtown Olympia are built on softer ground that will amplify ground shaking during an earthquake. They didnt recognize the significance of what they found. The southern Whidbey Island fault, and several others, were exposed for the first time from a camouflage of forest, ocean and glacial sediment. But scientists theorize that the area has suffered only four . Close to shore, this same wave could reach heights of 30100 feet or more. Floods. Source: United States Geological Survey. Do not exit a building during the shaking. Photo courtesy of National Center for Tsunami Research, NOAA. The spectacular falls flow over the remains of a newly discovered 20-million-year-old volcano, apparently formed atop the main part of the fault zone as magma rose upward along weak fault planes. In the month after the main earthquake there were about 60 M7 and M6 earthquakes. SWIF ranges from 12 miles underground at its deepest to right at sea level in a few scattered spots, like Cama Beach, Holmes Harbor and Woodinville, according to Sherrods research. DO NOT get in a doorway. A team headed by Joe Dragovich of DNRs Division of Geology and Earth Resources,assisted by geologists from King County, Pacific Northwest Seismic Network, Colorado College, and Washington State University, has been mapping in this area for the past three years. Each of these aftershocks would be a significant earthquake if it happened on its own. They havent dug up enough history to estimate. This kind of grouping gives us information about how common earthquakes might be and how large an area may be affected. Even if the earthquake is too small to be felt by people, seismographs can detect it. The southern Whidbey Island fault divides the two. We work closely with the Washington Emergency Management Division, the Washington Seismic Safety Committee, and the Federal Emergency Management Agency to ensure that the best-available science is used in the development of hazard mitigation plans. Most faults are considered active if they have evidence for movement (this includes earthquakes) within the past 12,000 years (the Holocene time period). Although we know much about active faults and earthquakes, there is much more to learn. Faults often occur at and near the boundary of large tectonic plates because the plates are moving in different directions. View Earthquake Map Faults Interactive fault map and comprehensive geologically based information on known or suspected active faults and folds in the United States. One model suggests it extends to about 30 miles east of Yakima. Hey Biden! For example, in the open ocean a tsunami may be less than a few feet tall. Most are too small to be felt or cause damage. Map Releases; Topographic (Topo) Maps; Volcanic Maps; All Maps; Multimedia Gallery. Not all faults are active. A community meeting about a shelter at the Harbor Inn may have yielded more questions than answers. . 572 Last Review Date: 2016-11-29 What we know about this fault is that its ruptured may times in the pastit will happen again. Wagner and Wiley (1983 #6230) and Wagner and Tomson (1987 #6249) mapped and briefly discussed offshore parts of this fault zone and also used the name "southern Whidbey Island fault." Trenches by Sherrod and others, 2008 #7652) are less than 1 km south of KP1 and KP2 and Sherrod and others (2008 #7652) conclude that deformation in the area is due to surface-rupturing earthquakes. Landslides can be caused by strong ground shaking during an earthquake. Evidence for Quaternary movement on the southern Whidbey Island fault includes (1) offset and disrupted upper Quaternary strata imaged on seismic-reflection profiles; (2) borehole data that suggests as much as 420 m of structural relief on the Tertiary-Quaternary boundary in the fault zone; (3) several meters of displacement along exposed faults in upper Quaternary sediments; (4) late Quaternary folds with limb dips of as much as ???9?? Armentrout, J. J. Miller, C. Finn, C. S. Weaver. 4 0 obj Washington has dozens of active faults and fault zones. Another piece can be seen under the elevated lanes of northbound Interstate 5 in South Seattle not far from the Rainier brewery. Tsunamis triggered by earthquakes usually require at least a M7 event. During the shaking liquefaction occurred, the sand lost its strength, and the car sunk. The fault zone is up to 57 km, correlates with gravity and magnetic anomalies (Finn and others, 1991 #4753; Blakely and others, 1999 #4747), and has been interpreted as a complex zone of transpressional deformation (Johnson and others, 1996 #4751). District Court: (800) 946-9765, South Whidbey Island Fault (SWIF) M7.4 Earthquake Scenario. Theres approximately a 14% chance of another approximately M9 earthquake occurring in the next 50 years. It is not yet possible to predict when a fault will have an earthquake. Kristin D. Morell 1 *, Christine Regalla 2, Lucinda J. Leonard 3, Colin Amos 4, Vic Levson 5. The coast is now the home of one of the states largest network of warning sirens called All Hazard Alert Broadcast (AHABs). We pray for people of WA and our all north Americans as well. This photo shows a fence that was offset about 8.5 feet during the 1906 Great San Francisco Earthquake on the San Andreas fault. southern Whidbey Island fault zone (Class A) No. The Eastern Sierra fault along the east side of the Sierra Nevada mountains in California is a good example of an active normal fault. Walsh said that Whidbey Island through the years has been subjected to a number of small quakes, roughly 2 or 3 on the Richter scale. Additionally, because the continent moves up and over the ocean plate, large amounts of sea water are displaced and cause damaging tsunamis. Its significantly larger than the Seattle Fault, and South Whidbey could hand us a magnitude 7.5 earthquake. The term active can have different meanings. When this happens, even a very small slope can cause the ground to slide. A damaging earthquake is inevitable on this fault, but we do not know exactly when it will happen. For example, it is unlikely that you will be able to use electricity, cell phones, or the internet. Tsunamis are a common result of large earthquakes in Washington. For each increase in earthquake magnitude, there are about 10 times fewer earthquakes. The South Whidbey Island Fault is also dangerous. This map of Puget Sound shows the location of the methane plumes (yellow and white circles) detected along the ship's path (purple). One or possibly two of the unconformities are interpreted as event horizons. View of the Sunset Lake liquefaction failure about three weeks after the earthquake. During site visits in 2005, Sherrods team found evidence of four SWIF earthquakes in the past 30,000 years. Many faults have not been studied enough to know if they are active. Liquefaction has caused significant damage during earthquakes in Washington. Each year we map additional areas and learn more about existing faults and (or) discover new ones. Sheriff:(360) 679-7310, Juror Recordings Most damage and loss of life in earthquakes is a result of ground shaking. This movement happens because stress builds up as tectonic plates move. Experts believe a magnitude 9.0 could happen there anytime in the next 200 years or so. Most of the populated areas of the state have a 4080% chance of having an earthquake in the next 50 years. Secure .gov websites use HTTPS The 1949 earthquake near Tacoma triggered a landslide near the Tacoma Narrows that caused a local tsunami. The last large earthquake on the Cascadia subduction zone was in 1700. PO Box 5000 This map is from a 2007 report on the seismic design categories in Washington. <> A lot of people are transplants, Forson said. Photo from, Liquefaction can be a big problem. Expect aftershocks. Drop, Cover, and Hold On whenever you feel shaking. In much of Washington, dense vegetation covers the land and makes finding faults very difficult. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. These older faults do not have any evidence for recent activity, but the Earth is always changing. (1999 . Large earthquakes, like those from the Cascadia subduction zone on January 26, 1700, often create tsunamis. Hold on to any sturdy shelter until the shaking stops. Learn how your comment data is processed. You just need one person to crash or a power line to fall over the road, and the roads are unusable.. Were working on pedestrian evacuation maps that show the best routes for pedestrians to take to evacuate, said Forson. High-resolution LiDAR topographic maps have since revealed several potential faults scarps, and subsequent studies provide more detailed information about the fault zone's past. Tap/click on "gear icon" for options and settings. The map is from a 2007 report (click here to download) on seismic design categories in Washington. It can also make landslides that are much bigger than expected. Within minutes, he spotted something groundbreaking. This part of the Japanese coast had not seen this type of seismic rupture in some 800 years, and what failed was that walls built to keep tsunami waves were not high enough. The strength of ground shaking (called strong motion by seismologists) usually decreases with distance from the earthquake source. % Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. East of Puget Sound, the SWIF makes landfall between the cities of Seattle and Everett but is concealed . In Washington, the risk from earthquake-induced landslides is large. Johnson et al. In addition, the Survey performs seismic safety evaluations of schools. Each type has different kinds of earthquakes. 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. There are many other active faults in Washington and any of these could produce a large earthquake in the future. Photo courtesy of MOHAI (neg. Hundreds could die, with thousands more injured. In 2017, he began studying the possible aftermath of a major SWIF quake. A special type of shallow fault, called a subduction zone or megathrust, occurs where an oceanic plate moves beneath a continental plate. By clicking Accept, you consent to the use of ALL the cookies. Westport currently is the only location with a vertical evacuation structure designed for a tsunami. Please visit our Geologic Information Portal and Geologic Hazard Maps page for the most up-to-date listing of all of our hazard maps. Story telling is an important part of the Native tradition and is how their history is passed down to the next generation. 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. Geologists do not yet know how often earthquakes happen on this fault. Earthquakes between 45 and 185 miles deep are called intermediate, and earthquakes over 185 miles deep are called deep. And when are documentary film called Cascadia The Big One, Dangerous Inland Earthquake Destroys Homes and Schools near Jakarta, Indonesia, Terrifying video shows olive grove turned into a Gigantic Canyon after Turkeys earthquake split land in huge rifts. The 1964 M9.2 Alaska earthquake created a large tsunami from the fault rupture, and many smaller tsunamis from on-land and underwater landslides. If the epicenter is Everett, the SWIF could cause. 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. You also have the option to opt-out of these cookies. Never use a lighter or match near damaged areas. This fault will have an earthquake in the future, but we cannot predict exactly when. The Pacific Tsunami Warning Center is located in Hawaii and is responsible for issuing alerts to all the countries that border the Pacific Ocean. These faults and earthquakes occur in oceanic crust as it is subducted beneath the continent. Scientists have been trying to understand how often earthquakes happen for over 100 years. It may not be possible to find water, fuel, or food until services are restored days or even weeks after the event. The evidence shows each lake rests on different free-floating jigsaw pieces of planetary crust, separated by the southern Whidbey Island fault. Photo by G.K. Gilbert, from the Steinbrugge Collection of the UC Berkeley Earthquake Engineering Research Center. There are also tsunami evacuation signs on the highways. A lock () or https:// means youve safely connected to the .gov website. The Straight Creek fault in the Cascade Range is an example of this kind of fault and has ~5060 miles of movement across it. The moment magnitude scale is a type of logarithmic scale, where each increase of 1 means ~32 times more energy is released. Superior Court:(800) 254-2755 The friend obliged. This northwest-trending fault zone extends more than 65 km across Possession Sound, southern Whidbey Island, Admiralty Inlet into the eastern Strait of Juan de Fuca. In the area of North Bend, the fault zone is 4 miles wide and consists of a series of parallel faults. Using the stratigraphic column from the Freeport quadrangle map, confirm that you can recognize . The Survey works to increase public and scientific understanding of fault and earthquake hazards in our state. In some areas getting up a hill to higher ground will be difficult. The fault's length depends on whom you ask, Sherrod said. The largest active fault that will affect Washington (and the whole Pacific Northwest) is the Cascadia subduction zone. Visit our School Seismic Safety page for more information. Bending of the fault and transpressional deformation began during the late middle Eocene and continues to the present. Necessary cookies are absolutely essential for the website to function properly. 121 N East Camano Dr The Seattle fault last ruptured about 1,100 years ago in AD 900950. endobj The southern Whidbey Island fault (SWIF) stretches from the vicinity of Victoria, B.C., across Puget Sound as far as the Cascade Range. 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. The most important thing you can do before the next earthquake is to prepare. Also check out Ear to the Ground, published by the Department of Natural Resources. Sensitive seismographs located throughout the state, and all over the world, measure this seismic energy. The southern Whidbey Island fault zone (SWIF) is a mostly concealed, northwest-trending structure extending across southern Whidbey Island toward Vancouver Island (Figures 1 and 2). However, we can learn which faults are active and which are inactive. Before modern record keeping, Native Americans lived in the Pacific Northwest for thousands of years. The map also shows potentially active faults from a separate 2014 report (click here to download). 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). The most recent hit roughly 2,700 years ago. Sherrods son has since completed graduate school in applied geosciences. At the Washington Geological Survey, active means that a fault has evidence for movement within the Holocene time period (since about 12,000 years ago). After large earthquakes there are usually many aftershock earthquakes. Ground shaking is a hazard near the epicenter of an earthquake and also in areas far from the earthquake where amplification occurs. A drill rig left of the blockade is collecting data about the failure. Strait of Juan de Fuca Fault Map The Puget Sound faults under the highly populated Seattle and Puget Sound region of Washington state form a regional network of interrelated seismologic geologic faults. It will happen; we dont know when.. It is capable of generating severe earthquakes that would impact the entire west coast. He said scientists have known about the southern Whidbey fault for decades. Third, the South Whidbey Island Fault running from northwest to southeast of the southern tip of the island. Some people in places like SODO and Harbor Island may have to flee to higher floors in a building. North Anatolian Fault is currently locked, accumulating stresses which could be suddenly released anytime now like the Hayward Fault in California, Videos: New destructive M7.5 earthquake hits Turkey a few hours after largest quake in 100 years kills 1300. When earthquakes occur on faults that reach the Earths surface, the ground may rupture. Part 2 will be full Martial Law and mandatory vaccines? The trench did expose faults, but it was not possible to conclusively demonstrate offset of Holocene units. A half dozen people reaching for the last can of soup, someone could lose their life over that. 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. Many low-lying areas have wet soil or sediment beneath them that could liquefy during earthquakes. Because they can travel great distances, tsunamis generated from earthquakes across the ocean can still cause damage. 1 School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada 2 Department of Earth and Environment, Boston University, Boston, Massachusetts 02215, USA Areas like these are also susceptible to liquefaction. We do not encourage people to evacuate in vehicles. Identify and secure items in your home or work that could cause damage. Know what other hazards you might face. 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. At a downtown coffee shop, the mugs begin to chatter. Liquefaction is when wet soil or sediment loses strength because it is being shaken during an earthquake. This diagram shows the many types of active faults and the general location of past earthquakes in Washington. Consider a magnitude 7.4 quake with Whidbey Island at or near the epicenter. Map by And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. " A lot of people are transplants, " Forson said. Stay inside until the shaking stops and it is safe to go outside. Even places that are far from active faults are still at risk during a large Cascadia subduction zone earthquake. Once a fault is located, it is important to know if it is active. For example, a building on soft soil will experience more shaking than the same building on bedrock.