Part 2 will be full Martial Law and mandatory vaccines? A drill rig left of the blockade is collecting data about the failure. What are the most dangerous fault lines for Seattle? California Geological Survey. and the Red Cross will be there to care for them. This was a problem because no two locations would agree on the size of the same earthquake. The Geologic Information Portal has a Natural Hazards theme that shows active faults and earthquakes. Restoring tap water to some homes could take over a year. 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. The Cascadia subduction zone last ruptured over 300 years ago on January 26, 1700. His team wanted to find the rate of sea level rise along the shore. People who look for evidence of past movement on faults are usually called paleoseismologists (from paleo-ancient and seismologist-one who studies earthquakes). But they didnt document it hardly at all.. Why is Strange Sounds focusing so much on disaster preps? In this sense, the shaking of the ground is the sound of rocks breaking and moving deep within the Earth. M 7.4 Scenario Earthquake - Southern Whidbey Island fault-southern Overview Interactive Map Regional Information Impact ShakeMap Technical Origin Download Event KML Earthquakes Hazards Data & Products Learn Monitoring Research M 7.4 Scenario Earthquake - Southern Whidbey Island fault-southern 2017-05-12 20:14:09 (UTC) 48.036N 122.452W 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. , * NOTE: Hazard maps for each jurisdiction will only be included if that jurisdiction is at risk to that hazard., Copyright Island County. Third, the South Whidbey Island Fault running from northwest to southeast of the southern tip of the island. We just dont know when.. The trenches exposed glacial deposits disrupted by faults and liquefaction features. Each peak of the Olympics stuck out with picturesque clarity in the distance. The last time was 1,000 years ago between 900 and 903 A.D., said Forson. 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. For several years, scientists pondered where this important regional fault zone continues southwestward from its mapped location in the Everett area. For example, the Cascadia subduction zone has had between 15 to 19 earthquakes over the past 10,000 years. 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. For example, a M7 earthquake releases 32 times more energy than a M6 earthquake, and 1,000 times more than a M5 earthquake. Sometimes Geologists can use the offset land surface to understand how much the fault moved during the earthquake. There are many other active faults in Washington and any of these could produce a large earthquake in the future. Share sensitive information only on official, secure websites. Resources on tsunami danger and preparedness in Westport, Grays Harbor County, Long Beach Peninsula, and Coastal evacuation maps. Tsunamis are a common result of large earthquakes in Washington. This fault zone was originally named the Devils If everyone tries to use their cell phones, it can overload the system. The fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. 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. Coupeville, WA 98239, Main Line: #4747 Blakely, R.J., Wells, R.E., and Weaver, C.S., 1999, Puget Sound aeromagnetic maps and data: U.S. Geological Survey Open-File Report 99-514. Maps. The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks. Be prepared and read more on DNR, USGS, King5, Strange Sounds and Steve Quayle. STAY THERE until the shaking stops. 121 N East Camano Dr We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Most are too small to be felt or cause damage. The Survey conducts and publishes geologic mapping to identify and characterize faults throughout the state. 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. This means that a large area feels the shaking, but the intensity is less than a similar shallow earthquake. 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. Because Japan was so well prepared, mostretrofitted buildingsoutside of the tsunami zone survived. . Hey Biden! Swarm of hundreds of small earthquakes rattle Vancouver Island. DO NOT get in a doorway. Most faults in Washington are a mix of a strike-slip fault and a thrust or reverse fault. The Straight Creek fault in the Cascade Range is an example of this kind of fault and has ~5060 miles of movement across it. Seattle Fault Lines. This kind of grouping gives us information about how common earthquakes might be and how large an area may be affected. Kristin D. Morell 1 *, Christine Regalla 2, Lucinda J. Leonard 3, Colin Amos 4, Vic Levson 5. For example, a building on soft soil will experience more shaking than the same building on bedrock. Like a sonogram, the seismic surveys allowed Johnson to see outlines of massive fissures in the earths crust. During the shaking liquefaction occurred, the sand lost its strength, and the car sunk. Geologists have used the location of these shallow, intermediate, and deep earthquakes to learn about subduction zones throughout the world. Until much more recently, no one really understood what it could do to a region of over 4 million people. We do not encourage people to evacuate in vehicles. You saw its potential in the 9.1 magnitude Tohuku earthquake and tsunami that hit northeastern Japan in March 2011. Knowing how often large earthquakes have happened in the past helps us to know how often they might occur in the future. 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). 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. At the time, Johnson worked in southwest Washington, searching for natural gas and oil deposits. Landslides can be caused by strong ground shaking during an earthquake. 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. Faults can also be grouped based on what part of the crust they occur in. 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. This means that when the Seattle fault ruptures the south side of the fault moves up relative to the north side. 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. The affiliate sales will help us to continue the hard work we are putting in this website. The threat to Puget Sound from a quake along the Cascadia Subduction Zone, off the coast of Washington, Oregon and California, is well documented. Other faults are inactive and are left over from much older periods of deformation. The South Whidbey Island Fault and Darrington Devil's Mountain Fault bound the Everett Basin. The years have gone by. Snohomish, King and Island counties would be expected to see the. It is not yet possible to predict when a fault will have an earthquake. These cookies do not store any personal information. 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 They knew something was there, said Sam Johnson, a retired USGS geologist who would follow up on their work. 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. The combination of all of these effects is what makes earthquakes such a powerful geologic hazard. This photo shows a fence that was offset about 8.5 feet during the 1906 Great San Francisco Earthquake on the San Andreas fault. The Moment Magnitude Scale (M) measures the total amount of seismic energy (known as moment to engineers and seismologists) released by an earthquake. 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. It usually also means that there are earthquakes (even small ones) on the fault. Unlike sound, ground shaking can be amplified or attenuated (made less) depending on the type of material at the Earths surface. When an earthquake happens there will not be time to google what you are supposed to do. 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). Others, like the Seattle fault and southern Whidbey Island fault zone, cross under major cities and pose a significant hazard. The shaking usually lasts less than a minute and doesnt generally cause a tsunami or have many aftershocks. The fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. Shallow faults produce earthquakes in the upper 18 miles (30 kilometers) of the Earths crust. The trench did expose faults, but it was not possible to conclusively demonstrate offset of Holocene units. The buildings in this photo were built on soft materials that liquefied during the 1964 Niigata earthquake in Japan. 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. Secure .gov websites use HTTPS Photo from, Liquefaction can be a big problem. Scientists are not sure how far east it goes. 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. The Port of Coupeville will apply for a grant to fund two electric vehicle charging stations. Move away from buildings, streetlights, and utility wires if you can. Map Releases; Topographic (Topo) Maps; Volcanic Maps; All Maps; Multimedia Gallery. Camano Island, WA 98282, Mailing Address East of Puget Sound, the SWIF makes landfall between the cities of Seattle and Everett but is concealed . View Earthquake Map Faults Interactive fault map and comprehensive geologically based information on known or suspected active faults and folds in the United States. Below you will find links to view and download hazard maps created for each jurisdiction included in the current mitigation planning process. Never use a lighter or match near damaged areas. Washington has dozens of active faults and fault zones. In the Puget Sound region, it takes a trained eye to recognize rocky outcrops and subtly raised ground as evidence of a fault. endobj What about the localized tsunami risk? Its a natural curiosity.. Earthquakes cause damage by moving and shaking the ground, sometimes for several minutes. The faults length depends on whom you ask, Sherrod said. We pray for people of WA and our all north Americans as well. 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 southern Whidbey Island fault, and several others, were exposed for the first time from a camouflage of forest, ocean and glacial sediment. <>/XObject<>/ExtGState<>/Pattern<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> 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. But it didnt. These include the: Southern Whidbey Island Fault (SWIF) Seattle Fault Devils Mountain Fault Strawberry Point fault Utsalady Point fault 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. An official website of the United States government. It devastated the coast of the Pacific Northwest and sent an orphan tsunami to Japan. Power could be out for days. Other types of seismic energy (S waves) also travel through the earth, but they move with a side-to-side (shearing) motion. Stratigraphy in the Flying Squirrel trench showed gentle warping of late glacial and post-glacial sediments; no faults were exposed. After the shaking stopped the sand regained its strength. A normal fault occurs when two blocks are pulled away from each other. These combination faults are called oblique faults and include the Seattle fault, southern Whidbey Island fault zone, and DarringtonDevils Mountain fault zone. Many landslide-prone areas of Washington are also located near active faults. Many faults have not been studied enough to know if they are active. Superior Court:(800) 254-2755 This earthquake caused parts of Restoration Point near on Bainbridge Island to be lifted 35 feet straight up. Its certainly not to scare you. At a downtown coffee shop, the mugs begin to chatter. For each increase in earthquake magnitude, there are about 10 times fewer earthquakes. Devastating wind storms. The plate that is forced down can have faults within it that still rupture and produce earthquakes. This new method allows geologists to see through trees and vegetation to find new faults. 4 0 obj 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. They didnt grow up here, they havent heard this story. 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). Earthquakes can be measured in many ways, but the most accepted method is called moment magnitude. 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. Most of the populated areas of the state have a 4080% chance of having an earthquake in the next 50 years. These fault strands follow the valley edges and control the location of the Snoqualmie River along some portions of the valley. 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). Stay inside until the shaking stops and it is safe to go outside. A lot of people are transplants, Forson said. The Eastern Sierra fault along the east side of the Sierra Nevada mountains in California is a good example of an active normal fault. The term active can have different meanings. 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. Westport currently is the only location with a vertical evacuation structure designed for a tsunami. Buildings could sustain extensive damage. Seismologists estimate that such quakes and tsunami waves occur roughly every 500 years on average on the Cascadia Subduction Zone. A small quake was registered in the Coupeville area just this summer. Each year we map additional areas and learn more about existing faults and (or) discover new ones. The map is from a 2007 report (click here to download) on seismic design categories in Washington. (1999 . Scientists dont know. Official websites use .gov This movement created a tsunami in Puget Sound and triggered a large landslide into Lake Washington. If a large earthquake happens, be prepared for many more earthquakes. The SWIF has been assessed by the USGS as capable of generating the largest crustal earthquake in Puget Sound. <>>> One model suggests it extends to about 30 miles east of Yakima. He said he believes dramatic shifts from that quake also may be visible on the western edge of Camano Island. 3 0 obj But the mapping offered geological clues that the newly found fault was indeed capable of future quakes. Roads, bridges, or ramps may have been damaged by the earthquake. from Whidbey Island to Vancouver Island (Figure 1). Once the shaking has stopped, exit the building if it is safe to do so. This map shows different seismic design categories that correlate with amount of seismic risk. Charles Richter and Beno Gutenberg discovered that for every magnitude of earthquake, there are about ten times more earthquakes of the next lower magnitude. Hundreds could die, with thousands more injured. When a fault with vertical movement ruptures the ocean floor, it lifts up part of the ocean. All faults, regardless of size, can be dangerous if they rupture. Its significantly larger than the Seattle Fault, and South Whidbey could hand us a magnitude 7.5 earthquake. It may not be possible to find water, fuel, or food until services are restored days or even weeks after the event. 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. Emergency planners all had a simple message: Its not IF a disaster will happen, its WHEN. The Darrington-Devils Mountain fault zone is located in southern Skagit County and northern Snohomish County. The marshy deposits are about a meter higher at Lake Hancock. Some parts of major cities (including Seattle, Tacoma, and Olympia) have been built on land that was reclaimed from soft and wet tidal ocean areas. But Forson says you also need to know what to do when the shaking happens. Photo from Pacific Northwest Seismic Network Seismo Blog. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. The study of seismic waves is called seismology and has allowed scientists to learn much about the internal structure of the Earth. 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. The below map shows that Seattle and its surroundings is constantly being rattled by small earthquakes and tremors. PO Box 5000 Within this rich oral history there are many references to events like earthquakes and tsunamis. The tsunamis can travel far inland and deposit layers of sand and organic material. Many low-lying areas have wet soil or sediment beneath them that could liquefy during earthquakes. And what were looking at is water.. When this happens, even a very small slope can cause the ground to slide. Southeast Extension of the Southern Whidbey Island Fault By Human Capital March 19, 2019. sw_whidbeyfault_rev122706.pdf (28.68 KB) ?7) and represents a potential seismic hazard to residents of the Puget Lowland. Larger crustal faults, such as the Seattle fault and southern Whidbey Island fault zone, can produce earthquakes up to magnitude 7.5. Floods. The largest active fault that will affect Washington (and the whole Pacific Northwest) is the Cascadia subduction zone. In much of Washington, dense vegetation covers the land and makes finding faults very difficult. 2 0 obj Finding faults and knowing how often they rupture is one of the most important tasks to keep society safe from these hazards. The buildings in this photo were built on soft materials that liquefied during the 1964 Niigata earthquake in Japan. The southern Whidbey fault is shallow, running right under Snohomish County as opposed to many miles off shore like the Cascadia fault. The Richter scale was developed in southern California in 1935 and was based on the local ground motion. Coupeville, WA 98239, Camano Office Lidar maps show the Earths surface without vegetation. It is a qualitative scale that ranges from IXI (1-11) and measures the amount of damage caused by an event. This map of gravity residuals measured over the puget lowland reveals a pattern of deep, fault bounded basins (cool colors) and uplifts (warm colors). 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. Sherrod says practically every place they. This category only includes cookies that ensures basic functionalities and security features of the website. Geologists at the Survey spend time mapping the geology of the state, looking for faults, folds, landslides, and different rock types. Liquefaction has caused significant damage during earthquakes in Washington. Depending on the type of fault, the ground can move laterally, vertically, or a combination of both. 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. Each of the earthquakes listed on the bottom of the screen is capable of significant damage. There must be tsunami deposits of the same age along much of the Oregon and Washington coast in order to qualify as an earthquake. Close to shore, this same wave could reach heights of 30100 feet or more. Unlike The Big One, scientists who have studied the southern Whidbey fault have far less understanding of when the next sudden shift might hit.