The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks. Do not exit a building during the shaking. 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 The 1949 earthquake near Tacoma triggered a landslide near the Tacoma Narrows that caused a local tsunami. Johnson and others (1996 #4751) described the structure and stratigraphy of the southern Whidbey Island fault zone. 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. DO NOT get in a doorway. Both studies suggested that the SWIF Both types of faults can cause ground shaking during an earthquake and may cause permanent deformation of the ground. But they didnt document it hardly at all.. It might as well have been sitting in a drawer, Johnson said. x\[s8~OU)! The Geologic Information Portal has a Natural Hazards theme that shows active faults and earthquakes. In general, larger faults make larger earthquakes. Photo from, This image shows the how the 1700 AD tsunami from the Pacific Northwest crossed the Pacific Ocean. The southern Whidbey fault is shallow, running right under Snohomish County as opposed to many miles off shore like the Cascadia fault. This fault zone was originally named the Devils Scientists are not sure how far east it goes. 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. The DNR team found that the Seattle fault is intercepted by the southern Whidbey Island fault zone in the vicinity of Fall City. Be prepared and read more on DNR, USGS, King5, Strange Sounds and Steve Quayle. Geologists have used the location of these shallow, intermediate, and deep earthquakes to learn about subduction zones throughout the world. 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. So the fault remained mostly a mystery until the 1990s. An earthquake occurs when rock inside the Earth moves or breaks. %
However, we can learn which faults are active and which are inactive. Radiocarbon ages of macrofossils constrain uplift timing to 2.83.2 ka. You also have the option to opt-out of these cookies. Beef Barley and French Onion trenches cross the Little Bear Creek lineament. 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. Story telling is an important part of the Native tradition and is how their history is passed down to the next generation. This is similar to how sound is quieter when you move away from a speaker. This map of gravity residuals measured over the puget lowland reveals a pattern of deep, fault bounded basins (cool colors) and uplifts (warm colors). 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. Since the last ice age, the southern Whidbey Island fault zone has probably spawned several highly destructive shallow earthquakes. With Medical Martial Law imposed in Washington state. South Whidbey Island Fault (SWIF) M7.4 Earthquake Scenario Fire (Vegetation Condition Class) . The most recent hit roughly 2,700 years ago. They conclude the observed features have a glaciotectonic origin and are not seimotectonic. Johnson and others . Superior Court:(800) 254-2755
Move away from buildings, streetlights, and utility wires if you can. A .gov website belongs to an official government organization in the United States. Sherrods son has since completed graduate school in applied geosciences. Earthquakes occur nearly every day in Washington. 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. Its a natural curiosity.. It will happen; we dont know when.. Camano Island, WA 98282, Mailing Address
Each of these aftershocks would be a significant earthquake if it happened on its own. Finding faults and knowing how often they rupture is one of the most important tasks to keep society safe from these hazards. 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. Every year Western. A national credit rating service has improved its opinion of WhidbeyHealths financial future. Earthquakes cause damage by moving and shaking the ground, sometimes for several minutes. The Port of Coupeville will apply for a grant to fund two electric vehicle charging stations. 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. These fault strands follow the valley edges and control the location of the Snoqualmie River along some portions of the valley. Kristin D. Morell 1 *, Christine Regalla 2, Lucinda J. Leonard 3, Colin Amos 4, Vic Levson 5. 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. 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?? 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. On a brilliant November day, Sherrod took in the panorama from the parks bluff. Graphic from IRIS. Scientists are not sure how far east it goes. In Washington, the risk from earthquake-induced landslides is large. In the late 1960s, speculators considered the Puget Sound region a frontier for petroleum exploration. Sometimes Geologists can use the offset land surface to understand how much the fault moved during the earthquake. When earthquakes occur on faults that reach the Earths surface, the ground may rupture. There are many other active faults in Washington and any of these could produce a large earthquake in the future. southern Whidbey Island fault zone (Class A) No. 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. 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. 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. This diagram shows the many types of active faults and the general location of past earthquakes in Washington. Black lines are trace projections of the South Whidbey Island Fault, Seattle Fault Zone, and Tacoma Fault Zone faults and the N-S Hood Canal and Puget Sound faults of S. Y. Johnson et al. Westport currently is the only location with a vertical evacuation structure designed for a tsunami. Then consider that the Seattle Fault is a complex of faults with various branches that run at or just below the surface. ?7) and represents a potential seismic hazard to residents of the Puget Lowland. Even when the location of a fault is known, there is much additional work to determine how hazardous it may be. The material becomes so weak that it behaves more like a liquid than a solid. This fault produces some of the largest and most damaging earthquakes in the world (M9). Stop as quickly as safety permits and stay in the vehicle. 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. Finding and learning about faults requires many different aspects of geology and geophysics. Johnson et al. Though it was not directly related to Johnsons work, he asked a friend working for Mobil Oil to pass along the information. Geologists and geophysicists at the Washington Geological Survey map out these areas of amplification to help reduce damage during an earthquake. What makes these faults mega is that the amount of energy released is hundreds to thousands of times more than almost any other type of fault. And what were looking at is water.. Because Japan was so well prepared, mostretrofitted buildingsoutside of the tsunami zone survived. Using the stratigraphic column from the Freeport quadrangle map, confirm that you can recognize . We use the term deep to talk about faults and earthquakes deeper than about 18 miles. Moving inland, the Seattle Fault is capable of a magnitude 7. Sherrod and others, 2008 #7652) report results from four trenches located near Crystal Lake: Flying Squirrel trench (572-5), Mountain Beaver trench (572-6), Beef Barley trench (572-7), and French Onion trench (572-8). The Seattle Fault is a zone of multiple shallow east-west thrust faults that cross the Puget Sound Lowland and through Seattle (in the U.S. state of Washington) in the vicinity of Interstate Highway 90.The Seattle Fault was first recognized as a significant seismic hazard in 1992, when a set of reports showed that about 1,100 years ago it was the scene of a major earthquake of about . 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. This northwest-trending fault comprises a broad (as wide as 6-11 km), steep, northeast-dipping zone that includes several splays with inferred strike-slip, reverse, and thrust displacement. This means that when the Seattle fault ruptures the south side of the fault moves up relative to the north side. 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. (Andy Bronson / The Herald). Fault Activity Map of California. The last large earthquake on the Cascadia subduction zone was in 1700. This evidence can come from finding something younger than 12,000 years that has been deformed or moved by the fault. 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). Volcanic eruptions. The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks. An increase of 2 means that ~1,000 times more energy is released. Do you know what to do if there is an earthquake? The southern Whidbey Island fault divides the two. This movement created a tsunami in Puget Sound and triggered a large landslide into Lake Washington. Other faults are inactive and are left over from much older periods of deformation. 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. And experts fear it could be even worse than The Big One.. Source: United States Geological Survey. Like other faults, when enough stress builds up, the megathrust will rupture. The Survey works to increase public and scientific understanding of fault and earthquake hazards in our state. /L\Axc4Q/w4Ks^#,
sRITgZf>,e}iI5,F_ADGc?f e@L. South Whidbey Island Fault Zone. America is going to be punished just like the rest of the world. For each increase in earthquake magnitude, there are about 10 times fewer earthquakes. Brick chimneys cascade off rooftops. After a large earthquake it is common to have other large earthquakes for hours, days, and even weeks. In the early 2000s, USGS scientists including Brian Sherrod set out to further Johnsons work and better understand the slumbering fissure. 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. 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. And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. The Seattle fault last ruptured about 1,100 years ago in AD 900950. Large earthquakes are likely to happen in Washington during your lifetime. " A lot of people are transplants, " Forson said. 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. Disoriented drivers wonder whats wrong with their cars, then realize something much bigger is amiss. 121 N East Camano Dr
Geologists do not yet know how often earthquakes happen on this fault. <>
Although we cannot predict exactly when the next earthquake will happen, we can predict the general distribution of earthquake sizes.