Tap/click on "gear icon" for options and settings. The southern Whidbey Island fault should be considered capable of generating large earthquakes (Ms ?? The experts say few are ready. For more information about earthquakes, faults, and emergency preparation, consider visiting the following sites: This map shows areas of seismic risk from high (red) to low (grayish-green). The last time was 1,000 years ago between 900 and 903 A.D., said Forson. Map of Puget Sound and Hood Canal in north-central - ResearchGate Kelsey and others (2004 #7651) compared sea-level histories at two salt marshes that straddle a northeast strand of the southern Whidbey Island fault zone: Crockett Marsh (site 572-1) located north of the northeastern fault strand is 8 km north of Hancock Marsh (site 572-2), south of the fault strand. 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. 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. Much of the land along the southwestern part of the lake cracked and subsided. Geologists do not yet know how often earthquakes happen on this fault. Know what to expect. Each of the earthquakes listed on the bottom of the screen is capable of significant damage. The tsunamis can travel far inland and deposit layers of sand and organic material. This kind of landslide is called an earthquake-triggered landslides. DO NOT get in a doorway. Transpressional deformation along the southern Whidbey Island fault is indicated by alongstrike variations in structural style and geometry, positive flower structure, local unconformities, out-of-plane displacements, and juxtaposition of correlative sedimentary units with different histories. The Richter scale was developed in southern California in 1935 and was based on the local ground motion. East of Puget Sound, the SWIF makes landfall between the cities of Seattle and Everett but is concealed . Washington, Seattle, WA 98195 2 U.S. Geological Survey, 345 Middlefield Road, M/S . 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. 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. Southeast Extension of the Southern Whidbey Island Fault Faults can also occur within a tectonic plate when the plate itself is deforming. Some residents may lose housing temporarily or permanently. Finding nothing of serious monetary value, the companies abandoned reams of information they had gathered through seismic surveys. A .gov website belongs to an official government organization in the United States. The Cascadia Subduction Zone (also known as the CSZ) is a 700-mile long fault zone located off the western coastline of British Columbia, Washington, Oregon and northern California. Restoring tap water to some homes could take over a year. This means that the internet, your cell phone, grocery stores, and gas stations may also not work. Since their initial discovery, research has shown that the actual number of earthquakes is somewhere between 5 and 10 for each change in magnitude. (360) 678-5111 Under a scenario played out in a 2019 U.S. Department of Homeland Security study, state-maintained bridges would be severely damaged, leaving them unusable for months or years. In Seattle, the quake damaged buildings, weakened bridges, started fires and opened cracks in the earth. Sherrod remembers his son, age 5 at the time, playing with toy trucks on the mossy banks of the marsh while the scientists worked. You have entered an incorrect email address! Close to shore, this same wave could reach heights of 30100 feet or more. Secure .gov websites use HTTPS 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. Quaternary Fault and Fold Database of the United States - USGS Most faults in Washington are a mix of a strike-slip fault and a thrust or reverse fault. Radiocarbon dating and other paleoseismic methods have also confirmed this date. Because after a region-wide event, it could take that long for help to come from the rest of the country and world. The Cascadia subduction zone last ruptured over 300 years ago on January 26, 1700. 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. So they dont necessarily know the threats they face.. The April 1949 Tacoma earthquake measured 7.1 on the Richter Scale and caused damage from southern Oregon to British Columbia. EVERETT The South Whidbey Island Fault is connected to a system of powerful earthquake fault lines stretching from Victoria, B.C., to Yakima that is capable of unleashing a devastating. M 7.4 Scenario Earthquake - Southern Whidbey Island fault-southern Please visit our Geologic Information Portal and Geologic Hazard Maps page for the most up-to-date listing of all of our hazard maps. The Seattle fault is a good example of a fault that is mostly reverse. Earthquake Hazards - Maps | U.S. Geological Survey There are many other active faults in Washington and any of these could produce a large earthquake in the future. The western half of Washington state is considered earthquake country, with the potential for very large quakes. Fault Activity Map of California. The map is from a 2007 report (click here to download) on seismic design categories in Washington. Resources on tsunami danger and preparedness in Westport, Grays Harbor County, Long Beach Peninsula, and Coastal evacuation maps. Emergency planners all had a simple message: Its not IF a disaster will happen, its WHEN. Puget Sound faults - Wikipedia The friend obliged. Camano Island, WA 98282, Mailing Address In the 1990s, scientists producedan animationthat shows inundation, and people wont have much time to run to higher ground. This photo shows a fence that was offset about 8.5 feet during the 1906 Great San Francisco Earthquake on the San Andreas fault. Bookcases and china cabinets topple, trapping people beneath. Geologists and geophysicists at the Washington Geological Survey map out these areas of amplification to help reduce damage during an earthquake. This category only includes cookies that ensures basic functionalities and security features of the website. Sherrod shrugged his shoulders. endobj Seattle Fault - Wikipedia 121 N East Camano Dr 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. The Seattle Fault is also likely to create a tsunami that would inundate Harbor Island and much of SODO, Interbay, and the waterfront. Discover in this article the most dangerous earthquake zones for Seattle and its area: The Cascadia Subduction Zone, the Seattle Fault and the South Whidbey Island Fault. Facades crumble off buildings along Oak Harbors Pioneer Way, and some of the oldest structures in Langley and Coupeville collapse in a roaring cloud of dust. 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. Buildings could sustain extensive damage. Earthquakes on faults like these may cause tsunamis in the Puget Sound region. In fact, new faults are found every year during our geologic mapping efforts. Whidbey fault quake potentially a bigger 'Big One' Large earthquakes, like those from the Cascadia subduction zone on January 26, 1700, often create tsunamis. Notable earthquakes in bold happened in Washington. Seattle Fault Lines. Washington has few large normal faults because it is mostly in a region of compression. 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. Tsunamis and seiches can also be triggered by large slides, both on land and underwater. Mudslides. Be prepared and read more on DNR, USGS, King5, Strange Sounds and Steve Quayle. USA Earthquake Hazard Map. Faults often occur at and near the boundary of large tectonic plates because the plates are moving in different directions. Disoriented drivers wonder whats wrong with their cars, then realize something much bigger is amiss. By clicking Accept, you consent to the use of ALL the cookies. Sensitive seismographs located throughout the state, and all over the world, measure this seismic energy. Strabge sounds very good report thanks a lot. Videos: Strong M6.0 earthquake rattles Mindanao in the Philippines, Dramatic earthquake increase in Hawaii! For example, it is unlikely that you will be able to use electricity, cell phones, or the internet. Westport currently is the only location with a vertical evacuation structure designed for a tsunami. Know what other hazards you might face. In some areas getting up a hill to higher ground will be difficult. The term active can have different meanings. PDF Modeling a Magnitude 7.4 Earthquake on the Western Section of the 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). 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. Superior Court:(800) 254-2755 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. Earthquakes can be measured in many ways, but the most accepted method is called moment magnitude. Scientists have also dated large underwater landslides and turbidites that travel from the continental edge far out into the ocean basin. 1 NE 7th Street Deformed recessional outwash deposits and Holocene deposits were exposed; three unconformities separated the units. Depending on the type of fault, the ground can move laterally, vertically, or a combination of both. An earthquake along the southern Whidbey Island fault reshaped the land some 2,700 years ago. Customers lift their eyes from phone screens. The buildings sank when ground shaking weakened the underlying sediments. This can cause landslides to occur where they wouldnt normally happen. Unlike sound, ground shaking can be amplified or attenuated (made less) depending on the type of material at the Earths surface. Beef Barley and French Onion trenches cross the Little Bear Creek lineament. In addition, the Survey performs seismic safety evaluations of schools. The last large earthquake on the Cascadia subduction zone was in 1700. Power could be out for days. For the most up-to-date information, please refer to the interactive fault map. Consider a magnitude 7.4 quake with Whidbey Island at or near the epicenter. Landslides can be caused by strong ground shaking during an earthquake. Map by 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 just off the Washington coast is this kind of fault and is one of the largest geologic hazards to our state. PDF The Cottage Lake Aeromagnetic Lineament: a Possible Onshore Extension If everyone tries to use their cell phones, it can overload the system. Its significantly larger than the Seattle Fault, and South Whidbey could hand us a magnitude 7.5 earthquake. The 1964 M9.2 Alaska earthquake created a large tsunami from the fault rupture, and many smaller tsunamis from on-land and underwater landslides. An official website of the United States government. All faults, regardless of size, can be dangerous if they rupture. Before modern record keeping, Native Americans lived in the Pacific Northwest for thousands of years. The affiliate sales will help us to continue the hard work we are putting in this website. The mission of the Washington Geological Survey is to collect, develop, use, distribute, and preserve geologic information to promote the safety, health, and welfare of the citizens, protect the environment, and support the economy of Washington. Consider subscribing to our blog, Washington State Geology News, to receive notifications when new information is published. Like other faults, when enough stress builds up, the megathrust will rupture. What about the localized tsunami risk? The Survey works to increase public and scientific understanding of fault and earthquake hazards in our state. 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. The moment magnitude scale is a type of logarithmic scale, where each increase of 1 means ~32 times more energy is released. You also have the option to opt-out of these cookies. Most are too small to be felt or cause damage. This is a very good example of a strike-slip fault. The Mercalli Intensity scale is another historical way to measure the intensity of an earthquake. Some events appear to be only 200 years apart, and others are more than 1,000. The Moment Magnitude Scale (M) measures the total amount of seismic energy (known as moment to engineers and seismologists) released by an earthquake. The marshy deposits are about a meter higher at Lake Hancock. 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 next earthquake is inevitable, but the variability makes it difficult to know exactly when. 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. In 2017, he began studying the possible aftermath of a major SWIF quake. Though it was not directly related to Johnsons work, he asked a friend working for Mobil Oil to pass along the information. The Eastern Sierra fault along the east side of the Sierra Nevada mountains in California is a good example of an active normal fault. This new method allows geologists to see through trees and vegetation to find new faults. 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. Puget Sound Earthquake Faults - Seattle Earthquake Faults Most faults are considered active if they have evidence for movement (this includes earthquakes) within the past 12,000 years (the Holocene time period). Over time, fault movement has created some interesting geologic features. The bluff, where the cabins now sit, could have jutted up in the most recent Whidbey fault quake, Sherrod said. This movement created a tsunami in Puget Sound and triggered a large landslide into Lake Washington. A damaging earthquake is inevitable on this fault, but we do not know exactly when it will happen. The SWIF was first recognized and mapped at a regional scale by Gower and others (1985) on the basis of gravity and aeromagnetic anomaly maps. It can also make landslides that are much bigger than expected. Johnson, on a whim, acquired the data that would prove its existence beyond a doubt. These faults and earthquakes usually occur at great depth (tens to hundreds of miles). The northwest-trending southern Whidbey Island fault zone occurs along a significant terrane boundary between basement blocks underlain by Eocene marine basalts of the Coast Range province to the southwest and pre-Tertiary metamorphic rocks of the Cascades province to the northeast. Scientists are not sure how far east it goes. @\;L;=}%FC*l $@ 4x: 888O~xrsxx'/*rGRF\gI%~x(G-^-hjjq kx/V ou0hyegy0;ei`Tx&ilZ )TmZ$vb,`bQm|DR5x/ Each year we map additional areas and learn more about existing faults and (or) discover new ones. Maps. Within this rich oral history there are many references to events like earthquakes and tsunamis. 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. 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. Map Releases; Topographic (Topo) Maps; Volcanic Maps; All Maps; Multimedia Gallery. <> PDF Cretaceous-Jurassic accreted terrains - University of Washington 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. Theyre FREE CLICK HERE to subscribe, EAR TO THE GROUND WITH DNR & COMMISSIONER FRANZ, Tree Link helps you answer questions about urbantrees. When this happens, even a very small slope can cause the ground to slide. Devils Mountain Fault -- Online Professional Paper - USGS The Southern Whidbay Island Fault represents another major earthquake threat for Seattle and its residents. The largest active fault that will affect Washington (and the whole Pacific Northwest) is the Cascadia subduction zone. PI22343). These cookies will be stored in your browser only with your consent. We also use third-party cookies that help us analyze and understand how you use this website. Johnson et al. The Survey has developed several types of hazard maps for different types of earthquake- and fault-related hazards: The maps are used by state and local governments to develop and update hazard-mitigation and response plans, and to mark geologically hazardous areas. Liquefaction has caused significant damage during earthquakes in Washington. Shallow faults produce earthquakes in the upper 18 miles (30 kilometers) of the Earths crust. These sediments were laid down 20,000 to 60,000 years ago, before the last ice age. The height difference likely was caused by a 7.5 magnitude earthquake on the fault about 2,700 years ago, Sherrod said. 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." Like a sonogram, the seismic surveys allowed Johnson to see outlines of massive fissures in the earths crust. This is similar to how sound is quieter when you move away from a speaker. 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. The southern Whidbey fault is shallow, running right under Snohomish County as opposed to many miles off shore like the Cascadia fault. Faults can also be grouped based on what part of the crust they occur in. Seconds later, its as if Whidbey Island is trapped in a cocktail shaker, lurching back and forth. The publication Faults and Earthquakes in Washington State is a state-wide compilation of active faults and folds. Many low-lying areas have wet soil or sediment beneath them that could liquefy during earthquakes. Tsunamis are a common result of large earthquakes in Washington. 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. The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks. Photo courtesy of National Center for Tsunami Research, NOAA. That place is the Ocosta School. This map of gravity residuals measured over the puget lowland reveals a pattern of deep, fault bounded basins (cool colors) and uplifts (warm colors). A seiche is a large standing wave caused by the resonance of a particular period of wave energy. Seismic waves travel at hundreds to thousands of miles per hour and quickly reach the surface where they are felt or measured. California Geological Survey. Source: United States Geological Survey. But they didnt document it hardly at all.. 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. A .gov website belongs to an official government organization in the United States. Small fires are the most common hazard after an earthquake. 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. At a downtown coffee shop, the mugs begin to chatter. Ready to retrofit? Even when an earthquake happens on a fault that doesnt reach the surface, the ground can still show signs of cracking. Fir trees near the failure are tilted and indicate rotation into the lake (to the left of the photo). The map is from a, This car was parked on sand during the 2011 earthquake in Christchurch, New Zealand. Tsunamis and seiches are destructive waves which can be triggered by certain types of large earthquakes. Earthquakes can trigger landslides and tsunamis which can happen after the main event. One of these cracks appeared along the pathway around Green Lake. This map shows areas of seismic risk from high (red) to low (grayish-green). It might as well have been sitting in a drawer, Johnson said. View Earthquake Map Faults Interactive fault map and comprehensive geologically based information on known or suspected active faults and folds in the United States. They didnt recognize the significance of what they found. For example, a building on soft soil will experience more shaking than the same building on bedrock. Avoid stopping near or under buildings, trees, overpasses, or utility wires. , * NOTE: Hazard maps for each jurisdiction will only be included if that jurisdiction is at risk to that hazard., Copyright Island County. stream 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). This movement happens because stress builds up as tectonic plates move. Expect and help to extinguish fires. Experts have warned that UK outbreak may be around two weeks behind Italys. Story telling is an important part of the Native tradition and is how their history is passed down to the next generation. The faults length depends on whom you ask, Sherrod said. The moment magnitude scale replaced the Richter scale in the late 1970s. California Department of Conservation. Until much more recently, no one really understood what it could do to a region of over 4 million people. Once a fault is located, it is important to know if it is active. This image shows the how the 1700 AD tsunami from the Pacific Northwest crossed the Pacific Ocean. Oblique convergence and clockwise rotation along the continental margin are the inferred driving forces for ongoing deformation. Later movement on this long-term active fault zone cut the volcano. During the shaking liquefaction occurred, the sand lost its strength, and the car sunk. <>/XObject<>/ExtGState<>/Pattern<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> The average time between large earthquakes is about 535 years, but has been as little as 200 years, and more than 1,000 years. A pair of scientists with the U.S. Geological Survey first theorized that a fissure between two major blocks of the earths crust might run through this slice of Puget Sound. With Medical Martial Law imposed in Washington state. Were working on pedestrian evacuation maps that show the best routes for pedestrians to take to evacuate, said Forson. Check out the liquefaction susceptibility and NEHRP site class maps on the Geologic Hazard Maps page.