A half dozen people reaching for the last can of soup, someone could lose their life over that. The southern Whidbey Island fault zone (SWIF), as previously mapped using borehole data, potential field anomalies, and marine seismic reflection surveys, consists of three subparallel, northwest trending strands extending ~100 km from near Vancouver Island to the northern Puget Lowland. 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. The SWIF has been assessed by the USGS as capable of generating the largest crustal earthquake in Puget Sound. Notable earthquakes in bold happened in Washington. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. An increase of 2 means that ~1,000 times more energy is released. This map shows different seismic design categories that correlate with amount of seismic risk. Earthquakes on shallow faults typically last 20 to 60 seconds and the shaking is localized to the general area of the fault. Large earthquakes are less common but can cause significant damage to the things we count on in everyday life, such as buildings, roads, bridges, dams, and utilities. Contact Us, Whidbey Office Since the last ice age, the southern Whidbey Island fault zone has probably spawned several highly destructive shallow earthquakes. Its a natural curiosity.. The medic said colleagues were becoming sick and emotionally overwhelmed This is an active fault.. This movement created a tsunami in Puget Sound and triggered a large landslide into Lake Washington. You just need one person to crash or a power line to fall over the road, and the roads are unusable.. South Whidbey Island Fault Earthquake Scenario: 7.4 Magnitude Buildings Damaged: 320,776 Fatalities: 90 - 432 Injuries: 2,920 - 7,361 Economic Loss: $15,590,000,000 SeaTac Fault Earthquake Scenario: 7.2 Magnitude Buildings Damaged: 375,954 Fatalities: 16 - 123 Injuries: 1,394 - 3,404 Economic Loss: $13,400,000,000 Tacoma Fault These combination faults are called oblique faults and include the Seattle fault, southern Whidbey Island fault zone, and DarringtonDevils Mountain fault zone. Theres an uneasy hush. South Whidbey Island Fault (SWIF) M7.4 Earthquake Scenario Fire (Vegetation Condition Class) . They didnt grow up here, they havent heard this story. When a fault with vertical movement ruptures the ocean floor, it lifts up part of the ocean. In this photo, visitors to Green Lake Park near Seattle, Washington, have parked their bicycles as they look at the cracks made by the April 1949 earthquake. 552 - Hood Canal fault zone (Class B) 570 - Seattle fault zone 572 - Southern Whidbey Island fault zone 575 - Saddle Mountain faults 581 - Tacoma fault zone. Early mapping of the three subparallel, northwest trending strands of the southern Whidbey Island fault zone was constrained by borehole data, potential field anomalies, marine seismic reflection surveys. Areas like these are also susceptible to liquefaction. Kelsey and others (2004 #7651) suggest that the earthquake resulted in 2.5 m uplift of the salt marsh on the north side of the fault strand relative to the marsh on the south side; no fault scarp has been identified between the marshes. Keaton and Perry (2006 #7653) excavated two trenches on the south end of the Brightwater treatment plant (KP1 site 572-3, and KP2 site 572-4). We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Sheriff:(360) 679-7310, Juror Recordings Restoring tap water to some homes could take over a year. All faults, regardless of size, can be dangerous if they rupture. Customers lift their eyes from phone screens. Large and damaging earthquakes are inevitable in Washington, but no one knows exactly when they will happen. He said he believes dramatic shifts from that quake also may be visible on the western edge of Camano Island. The largest active fault that will affect Washington (and the whole Pacific Northwest) is the Cascadia subduction zone. 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. It startled Johnson that such massive faults had gone undetected for so long. These large underwater slides only occur during very large earthquakes and are one way to learn about earthquakes that happened thousands of years ago. <> People stagger into the streets to avoid an avalanche of debris. Within minutes, he spotted something groundbreaking. The Cascade block to the northeast is floored by diverse assemblages of pre-Tertiary rocks; the Coast Range block to the southwest is floored by lower Eocene marine basaltic rocks of the Crescent Formation. Do not exit a building during the shaking. But Forson says you also need to know what to do when the shaking happens. Like other faults, when enough stress builds up, the megathrust will rupture. (360) 678-5111 Seismologists estimate that such quakes and tsunami waves occur roughly every 500 years on average on the Cascadia Subduction Zone. What we know about this fault is that its ruptured may times in the pastit will happen again. The biggest one is called the South Whidbey Island fault, and it's thought to run from Victoria, B.C., through Woodinville and possibly beyond. These cookies do not store any personal information. The fault probably originated during the early Eocene as a dextral strike-slip fault along the eastern side of a continental-margin rift. Please visit our Geologic Information Portal and Geologic Hazard Maps page for the most up-to-date listing of all of our hazard maps. Photo courtesy of MOHAI (neg. The 1964 M9.2 Alaska earthquake created a large tsunami from the fault rupture, and many smaller tsunamis from on-land and underwater landslides. Both types of faults can cause ground shaking during an earthquake and may cause permanent deformation of the ground. The map is from a, This car was parked on sand during the 2011 earthquake in Christchurch, New Zealand. These include the: Southern Whidbey Island Fault (SWIF) Seattle Fault Devils Mountain Fault Strawberry Point fault Utsalady Point fault USA Earthquake Hazard Map. They conclude the observed features have a glaciotectonic origin and are not seimotectonic. Because they can travel great distances, tsunamis generated from earthquakes across the ocean can still cause damage. During the shaking liquefaction occurred, the sand lost its strength, and the car sunk. Also check out Ear to the Ground, published by the Department of Natural Resources. Geologic maps show the types and ages of rocks and younger deposits that are found at or near the Earth's surface. Geoscientist Brian Sherrod stands near the submerged southern Whidbey Island fault line at the Brightwater Treatment Plant in Woodinville. We do know that it is active and will likely produce a large M67.5 earthquake when it next ruptures. For earthquakes that occurred before seismographs were invented, the Mercalli Intensity scale was used to make maps of damage and determine the size and location of an earthquake. Other faults may lie entirely underground, or could be covered by vegetation and (or) sediment. After the earthquake, many things you count on may not be available. The western half of Washington state is considered earthquake country, with the potential for very large quakes. Kristin D. Morell 1 *, Christine Regalla 2, Lucinda J. Leonard 3, Colin Amos 4, Vic Levson 5. The Westport area is now the first in North America to have acommunity vertical evacuation structure, a building strong enough to resist earthquake and tsunami wave forces and give people a platform above the expected wave heights. By sampling sediment from the marsh to the beach berm, Sherrod and his research partner, Harvey Kelsey, developed a timeline of the oceans climb. Tsunamis and seiches can also be triggered by large slides, both on land and underwater. Official websites use .gov The Survey conducts and publishes geologic mapping to identify and characterize faults throughout the state. With Medical Martial Law imposed in Washington state. Theres approximately a 14% chance of another approximately M9 earthquake occurring in the next 50 years. A .gov website belongs to an official government organization in the United States. Videos: Strong M6.0 earthquake rattles Mindanao in the Philippines, Dramatic earthquake increase in Hawaii! Oblique convergence and clockwise rotation along the continental margin are the inferred driving forces for ongoing deformation. Bending of the fault and transpressional deformation began during the late middle Eocene and continues to the present. His team wanted to find the rate of sea level rise along the shore. 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. Audio; Before and After Images; Images; Slideshows; Stereograms; Videos; Webcams; . In the late 1960s, speculators considered the Puget Sound region a frontier for petroleum exploration. Source: United States Geological Survey. For example, in the open ocean a tsunami may be less than a few feet tall. Experts believe a magnitude 9.0 could happen there anytime in the next 200 years or so. The shaking usually lasts less than a minute and doesnt generally cause a tsunami or have many aftershocks. You can look at different geological hazard mapson the website of the Department of Natural Resources. The southern Whidbey Island fault should be considered capable of generating large earthquakes (Ms ?? A 2014 map shows what we know about the age of faults in Washington. Expect aftershocks. Larger crustal faults, such as the Seattle fault and southern Whidbey Island fault zone, can produce earthquakes up to magnitude 7.5. The Richter scale was developed in southern California in 1935 and was based on the local ground motion. 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. This evidence can come from finding something younger than 12,000 years that has been deformed or moved by the fault. 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. By finding the age of the deformed layer, a paleoseismologist can determine the minimum age of the fault. For example, a M7 earthquake releases 32 times more energy than a M6 earthquake, and 1,000 times more than a M5 earthquake. 3 0 obj The shaking can damage or destroy buildings and other infrastructure. Scientists are not sure how far east it goes. So the fault remained mostly a mystery until the 1990s. Other faults are inactive and are left over from much older periods of deformation. Earthquakes between 45 and 185 miles deep are called intermediate, and earthquakes over 185 miles deep are called deep. Image from the, Aquatic Lands Habitat Restoration Program, South Lake Washington Restoration Project, Scientific and Technical Support to Aquatic Programs, Washington Geologic Survey Publications Catalog, Washington Geologic Survey Photograph Collection, Wetlands of High Conservation Value Map Viewer, Timber Sale Remaining Volume by Purchaser Reports, Spanish - Brocha, Salal y Otros Productos Forestales, Complete: Baker to Bellingham Non-Motorized Recreation Plan, Community Wildfire Resilience and Preparedness, Utility Wildland Fire Prevention Advisory Committee, Blanchard, Reiter, Walker Valley and Nearby Islands, Teanaway Community Forest Advisory Committee, Teanaway Community Forest Advisory Committee Past Meetings, Faults and Earthquakes in Washington State, Pacific Northwest Seismic Network Seismo Blog, https://buildingfailures.files.wordpress.com/2014/02/tiltedbuilding.jpg, Pacific Geoscience Center of the Natural Resources of Canada. DO NOT get in a doorway. Once a fault is located, it is important to know if it is active. For example, it is unlikely that you will be able to use electricity, cell phones, or the internet. Although both seiches and tsunamis can be large and destructive, they are created differently. Then consider that the Seattle Fault is a complex of faults with various branches that run at or just below the surface. All Rights Reserved 2021, Site Disclaimer southern Whidbey Island fault zone (Class A) No. This was a problem because no two locations would agree on the size of the same earthquake. Here, were looking at one of the bigger faults in the region, he said. A normal fault occurs when two blocks are pulled away from each other. Because after a region-wide event, it could take that long for help to come from the rest of the country and world. The Straight Creek fault in the Cascade Range is an example of this kind of fault and has ~5060 miles of movement across it. Its just the way scientists work, he said. Geologists do not yet know how often earthquakes happen on this fault. This map of Puget Sound shows the location of the methane plumes (yellow and white circles) detected along the ship's path (purple). . Using the stratigraphic column from the Freeport quadrangle map, confirm that you can recognize . But the Cascadia Subduction Zone isnt just a fault; its an overlapping joint between tectonic plates, parts of the Earths crust that float on layers of molten rock. The trench did expose faults, but it was not possible to conclusively demonstrate offset of Holocene units. The crustal faults the Seattle Fault, the South Whidbey Island Fault, the Tacoma Fault those are less well known, said Forson. Geologists are constantly trying to better understand the faults in our state. Doorways do not provide protection from falling or flying objects and you may not be able to remain standing. These quakes are capable of magnitudes from 7 to over 9. Get On The List To Receive Your Daily Dose Of Weird News And Amazing Phenomena. Maps. The fault's length depends on whom you ask, Sherrod said. While the intensity of this seismic event has now decreased, a big earthquake is overdue in the region. The northwestern part of the fault zone forms the northeastern limit of the Port Townsend basin (Brocher and others, 2001 #4718). 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. The Geologic Information Portal has a Natural Hazards theme that shows active faults and earthquakes. Additional fault studies by state and federal geologists in the next few years will help determine the frequency and severity of earthquakes along these fault zones. In much of Washington, dense vegetation covers the land and makes finding faults very difficult. Geologists at the Survey spend time mapping the geology of the state, looking for faults, folds, landslides, and different rock types. For some active faults, such as the Seattle fault or Cascadia subduction zone, we can also learn how often large earthquakes have happened in the past. 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." In Seattle, the quake damaged buildings, weakened bridges, started fires and opened cracks in the earth. 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. The buildings in this photo were built on soft materials that liquefied during the 1964 Niigata earthquake in Japan. The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks. 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. The Cascadia subduction zone off the Washington and Oregon coast is capable of some of the largest earthquakes in the world. The more you know what to expect, the better prepared you will be to help yourself, your family, and others around you. Most of the populated areas of the state have a 4080% chance of having an earthquake in the next 50 years. Hold on to any sturdy shelter until the shaking stops. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. The Pacific Tsunami Warning Center is located in Hawaii and is responsible for issuing alerts to all the countries that border the Pacific Ocean. Avoid stopping near or under buildings, trees, overpasses, or utility wires. Visit our School Seismic Safety page for more information. Scientists have also dated large underwater landslides and turbidites that travel from the continental edge far out into the ocean basin. Finding faults and knowing how often they rupture is one of the most important tasks to keep society safe from these hazards. PO Box 5000 A damaging earthquake is inevitable on this fault, but we do not know exactly when it will happen. 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?? Official websites use .gov Theres a must-see documentary film called Cascadia The Big One that exposes whats currently going on in this region of the Cascade volcanoes and the Pacific NorthWest. Johnson and others . For example, a building on soft soil will experience more shaking than the same building on bedrock. In fact, new faults are found every year during our geologic mapping efforts. Johnson, on a whim, acquired the data that would prove its existence beyond a doubt. This map of gravity residuals measured over the puget lowland reveals a pattern of deep, fault bounded basins (cool colors) and uplifts (warm colors). Even if the earthquake is too small to be felt by people, seismographs can detect it. The April 1949 Tacoma earthquake measured 7.1 on the Richter Scale and caused damage from southern Oregon to British Columbia. If the epicenter is Everett, the SWIF could cause. Even places that are far from active faults are still at risk during a large Cascadia subduction zone earthquake. This is sometimes called "The Big One" by news media. 121 N East Camano Dr In the early 2000s, USGS scientists including Brian Sherrod set out to further Johnsons work and better understand the slumbering fissure. 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. STAY THERE until the shaking stops. Also, very large earthquakes were difficult to measure accurately. Make an emergency response plan for you and your family. Mudslides. However, we can learn which faults are active and which are inactive. One of the best views of SWIF should be from Grand Avenue Park in Everett. America is going to be punished just like the rest of the world. The French Onion trench exposed glaciolacustrine claystones, till, colluvial deposits, and Holocene soils. By Julia-Grace Sanders The Everett Herald May 14, 2021 2:40 pm, Luella Meaux: November 21, 1929 January 21, 2023, Claudia Anderson: October 1, 1939 January 31, 2023, Chieko Yamane Miller: July 26, 1936 February 16, 2023, Guarding the flock: Chicken farms rely on specialized dogs, Flying colors: Irish artist finds success on Whidbey. Liquefaction has caused significant damage during earthquakes in Washington. At the time, Johnson worked in southwest Washington, searching for natural gas and oil deposits. Power could be out for days. 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). If folding on the Little Bear Creek lineament resulted in one or two of unconformities, the poorly constrained timing of the earthquakes is younger than 12,000 yr BP and older than about 2,850 cal yr BP. Tsunami waves can travel over 500 miles per hour in the open ocean. An abrupt rise or decline in sea level would reveal if the fault had triggered a quake before. Prepare to be on your own for at least three days. The tsunami becomes taller as the ocean becomes shallow. The most important thing you can do before the next earthquake is to prepare. Sherrods son has since completed graduate school in applied geosciences. On Dec. 15th, a small swarm even hit near Bremerton, a few miles away from downtown. Seconds later, its as if Whidbey Island is trapped in a cocktail shaker, lurching back and forth. Coupeville, WA 98239, Main Line: Black lines show the South Whidbey Island Fault Zone, the Seattle Fault Zone and the Tacoma Fault Zone. Not all faults are active. 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 2011 Tohoku earthquake in Japan occurred on this type of fault and released enough energy to slightly change the Earths axis of rotation. Because they rupture at such great depth, their seismic energy is distributed over a large area. The map also shows potentially active faults from a separate 2014 report (click here to download). Photo by Steve Palmer. These fault strands follow the valley edges and control the location of the Snoqualmie River along some portions of the valley. It can also make landslides that are much bigger than expected. 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. The Flying Squirrel and Mountain Beaver trenches cross the Cottage Lake lineament. This might include flammable appliances like a water heater, tall items like book cases, or heavy pictures. Faults can be grouped based on their relative movement into three types. When earthquakes occur on faults that reach the Earths surface, the ground may rupture. You have entered an incorrect email address! An official website of the United States government. @\;L;=}%FC*l $@ 4x: 888O~xrsxx'/*rGRF\gI%~x(G-^-hjjq kx/V ou0hyegy0;ei`Tx&ilZ )TmZ$vb,`bQm|DR5x/ This website uses cookies to improve your experience while you navigate through the website. Know what to expect. A major southern Whidbey quake, on the other hand, could kill and injure many more, according to Murphy. There must be tsunami deposits of the same age along much of the Oregon and Washington coast in order to qualify as an earthquake. A community meeting about a shelter at the Harbor Inn may have yielded more questions than answers. The Darrington-Devils Mountain fault zone is located in southern Skagit County and northern Snohomish County. Although we know much about active faults and earthquakes, there is much more to learn. In places where there is little vegetation, different rock types and faults can be found with relative ease. The Eastern Sierra fault along the east side of the Sierra Nevada mountains in California is a good example of an active normal fault. PI22343). Share sensitive information only on official, secure websites. Often this cracking happens because a soft part of the ground liquefies during the shaking. But it didnt. The fault's length depends on whom you ask, Sherrod said. The buildings in this photo were built on soft materials that liquefied during the 1964 Niigata earthquake in Japan. Earthquakes, tornadoes, hurricanes, pandemics, too many people think it cant happen to them and they still think that they can still make a quick run to Walmart to pick up enough to last for 2-3 days and then the govt. This map shows areas of seismic risk from high (red) to low (grayish-green). Unlike sound, ground shaking can be amplified or attenuated (made less) depending on the type of material at the Earths surface. Oil companies descended in search of riches. It usually also means that there are earthquakes (even small ones) on the fault. Sometimes there may be a layer of volcanic ash or charcoal that has been deformed by the fault. This date was confirmed by records in Japan of an orphan tsunami and by many lines of geologic evidence. Some faults reach the surface and can be found by geologists. The 1949 earthquake near Tacoma triggered a landslide near the Tacoma Narrows that caused a local tsunami. We also use third-party cookies that help us analyze and understand how you use this website. One model suggests it extends to about 30 miles east of Yakima. In addition, the Survey performs seismic safety evaluations of schools. Most are too small to be felt or cause damage. Large earthquakes, like those from the Cascadia subduction zone on January 26, 1700, often create tsunamis. Deep faults can occur where two tectonic plates collide and one of the plates is forced beneath the other. Scientists are not sure how far east it goes. HOLOCENE FAULT SCARPS AND SHALLOW MAGNETIC ANOMALIES ALONG THE SOUTHERN WHIDBEY ISLAND FAULT ZONE NEAR WOODINVILLE, WASHINGTON By Brian L. Sherrod1, Richard J. Blakely2, Craig Weaver1, Harvey Kelsey3, Elizabeth Barnett1, and Ray Wells4 1 U.S. Geological Survey, Dept.