southern whidbey island fault map

The experts say few are ready. This was a problem because no two locations would agree on the size of the same earthquake. A lock () or https:// means youve safely connected to the .gov website. The combination of all of these effects is what makes earthquakes such a powerful geologic hazard. Both studies suggested that the SWIF Stratigraphy and diatom assemblages of the marsh cores suggest Crockett Marsh underwent a 12 m of abrupt uplift relative to sea level at a time that relative sea level remained the same at Hancock Marsh. The most important thing you can do before the next earthquake is to prepare. The southeastern and central parts of the southern Whidbey Island fault zone form the southwest margin of the Everett basin and northeast boundary of the Seattle basin. Most damage and loss of life in earthquakes is a result of ground shaking. Roads, bridges, or ramps may have been damaged by the earthquake. These fault strands follow the valley edges and control the location of the Snoqualmie River along some portions of the valley. 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. It is capable of generating severe earthquakes that would impact the entire west coast. The buildings sank when ground shaking weakened the underlying sediments. Strabge sounds very good report thanks a lot. This date was confirmed by records in Japan of an orphan tsunami and by many lines of geologic evidence. Both of these things can cause equal or greater damage than the actual earthquake. Its certainly not to scare you. The process of breaking and moving rock releases a large amount of energy that travels through the Earth as seismic waves. Official websites use .gov Most faults in Washington are a mix of a strike-slip fault and a thrust or reverse fault. These large underwater slides only occur during very large earthquakes and are one way to learn about earthquakes that happened thousands of years ago. These cookies will be stored in your browser only with your consent. southern Whidbey Island fault zone (Class A) No. Many universities and other organizations (such as Cascadia Region Earthquake Working Group and the Pacific Northwest Seismic Network) also work to understand active faults in Washington. Another big one is expected, and it could be devastating. Contact Us, Whidbey Office Earthquakes on shallow faults typically last 20 to 60 seconds and the shaking is localized to the general area of the fault. The best thing you can do is to become prepared. Once the shaking has stopped, exit the building if it is safe to do so. Disoriented drivers wonder whats wrong with their cars, then realize something much bigger is amiss. 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. Image from the Pacific Geoscience Center of the Natural Resources of Canada. A baristas hand hovers over the bean grinder. Expect and help to extinguish fires. The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks. Both types of faults can cause ground shaking during an earthquake and may cause permanent deformation of the ground. These cookies do not store any personal information. 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. But Forson says you also need to know what to do when the shaking happens. 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. Still think well avoid Gods wrath, its not going to happen regardless of what the multi millionaire TV preachers tell you. PO Box 5000 In places where there is little vegetation, different rock types and faults can be found with relative ease. Even if the earthquake is too small to be felt by people, seismographs can detect it. For example, it is unlikely that you will be able to use electricity, cell phones, or the internet. This fault produces some of the largest and most damaging earthquakes in the world (M9). #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. These sediments were laid down 20,000 to 60,000 years ago, before the last ice age. Photo from https://buildingfailures.files.wordpress.com/2014/02/tiltedbuilding.jpg. 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. Thats why were pushing for a lot of vertical evacuation structures to be built hotels or schools, because its not an easy problem to solve, he said. The map is from a 2007 report (click here to download) on seismic design categories in Washington. Additionally, because the continent moves up and over the ocean plate, large amounts of sea water are displaced and cause damaging tsunamis. After a large earthquake it is common to have other large earthquakes for hours, days, and even weeks. 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. from Whidbey Island to Vancouver Island (Figure 1). There are many other active faults in Washington and any of these could produce a large earthquake in the future. 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). The Flying Squirrel and Mountain Beaver trenches cross the Cottage Lake lineament. Later movement on this long-term active fault zone cut the volcano. Tsunamis triggered by earthquakes usually require at least a M7 event. Stratigraphy in the Flying Squirrel trench showed gentle warping of late glacial and post-glacial sediments; no faults were exposed. Why is Strange Sounds focusing so much on disaster preps? California Department of Conservation. A damaging earthquake is inevitable on this fault, but we do not know exactly when it will happen. They didnt recognize the significance of what they found. They didnt grow up here, they havent heard this story. The shaking can damage or destroy buildings and other infrastructure. 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. Clicking on the map will download the publication. By finding the age of the deformed layer, a paleoseismologist can determine the minimum age of the fault. Faults can also occur within a tectonic plate when the plate itself is deforming. Even when an earthquake happens on a fault that doesnt reach the surface, the ground can still show signs of cracking. You can look at different geological hazard mapson the website of the Department of Natural Resources. The San Andreas in California, for example, left gaping scars in the Earths crust, at the surface. Third, the South Whidbey Island Fault running from northwest to southeast of the southern tip of the island. Earthquakes occur nearly every day in Washington. Scientists are not sure how far east it goes. The Pacific Tsunami Warning Center is located in Hawaii and is responsible for issuing alerts to all the countries that border the Pacific Ocean. When earthquakes occur on faults that reach the Earths surface, the ground may rupture. Power could be out for days. You have entered an incorrect email address! And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. Also, very large earthquakes were difficult to measure accurately. Cover your head and neck with your arms to protect against falling debris. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. These faults and earthquakes usually occur at great depth (tens to hundreds of miles). 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. 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. 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. In the Puget Sound region, it takes a trained eye to recognize rocky outcrops and subtly raised ground as evidence of a fault. Share sensitive information only on official, secure websites. 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. 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 . Map by And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. This diagram shows the many types of active faults and the general location of past earthquakes in 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. We do not encourage people to evacuate in vehicles. In fact, until the 1980s, no one knew SWIF existed. Once we got it, we were sort of shocked to see these big faults in the Puget lowlands, he said. This map shows different seismic design categories that correlate with amount of seismic risk. Identify and secure items in your home or work that could cause damage. Theres a reason the lands around the Pacific Ocean are called the Ring of Fire. The earthquakes, tsunamis, and the proximity of volcanos are all part of the same system. Sherrod shrugged his shoulders. Snohomish, King and Island counties would be expected to see the. One of the best views of SWIF should be from Grand Avenue Park in Everett. The SWIF has been assessed by the USGS as capable of generating the largest crustal earthquake in Puget Sound. Fault Activity Map of California. This earthquake is along the southern Whidbey Island fault, a less-known, less-studied subterranean boundary. These older faults do not have any evidence for recent activity, but the Earth is always changing. And experts fear it could be even worse than The Big One.. stream Unlike sound, ground shaking can be amplified or attenuated (made less) depending on the type of material at the Earths surface. Each peak of the Olympics stuck out with picturesque clarity in the distance. 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. The continued movement along faults over millions of years can build mountains, tear a continent apart, and move tectonic plates thousands of miles. Lidar maps show the Earths surface without vegetation. ; (5) large-scale liquefaction features in upper Quaternary sediments within the fault zone; and (6) minor historical seismicity. Also issued a warning for the UK that the Italian chaos could come to Britain document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. Maps. The Survey works to increase public and scientific understanding of fault and earthquake hazards in our state. Part 2 will be full Martial Law and mandatory vaccines? 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. After the shaking stopped the sand regained its strength. This evidence can come from finding something younger than 12,000 years that has been deformed or moved by the fault. Like other faults, when enough stress builds up, the megathrust will rupture. Because after a region-wide event, it could take that long for help to come from the rest of the country and world. 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). A special type of shallow fault, called a subduction zone or megathrust, occurs where an oceanic plate moves beneath a continental plate. We also use third-party cookies that help us analyze and understand how you use this website. <> One or possibly two of the unconformities are interpreted as event horizons. Geologic maps show the types and ages of rocks and younger deposits that are found at or near the Earth's surface. Then the world rattles up and down. Customers lift their eyes from phone screens. Know what other hazards you might face. 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. Before modern record keeping, Native Americans lived in the Pacific Northwest for thousands of years. Tsunami waves can travel over 500 miles per hour in the open ocean. Shallow faults produce earthquakes in the upper 18 miles (30 kilometers) of the Earths crust. Other types of seismic energy (S waves) also travel through the earth, but they move with a side-to-side (shearing) motion. The Richter scale was developed in southern California in 1935 and was based on the local ground motion. The Port of Coupeville will apply for a grant to fund two electric vehicle charging stations. Each year we map additional areas and learn more about existing faults and (or) discover new ones. Like a sonogram, the seismic surveys allowed Johnson to see outlines of massive fissures in the earths crust. We use the term deep to talk about faults and earthquakes deeper than about 18 miles. Small normal faults are found along the top of folds in eastern Washington in the Saddle Mountain graben. In general, larger faults make larger earthquakes. Know what to expect. % The years have gone by. But quiet period wont last, Strongest earthquake in 40 years rattle residents of Buffalo, NY, Is Istanbul next? Hover over a cluster of earthquakes to learn about the different types in the Pacific Northwest. Black squares are urban sewer outfalls, which don't match the bubble plumes' locations. The plate that is forced down can have faults within it that still rupture and produce earthquakes. This is sometimes called "The Big One" by news media. Faults can also be grouped based on what part of the crust they occur in. 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. The shaking usually lasts less than a minute and doesnt generally cause a tsunami or have many aftershocks. In the Pacific Northwest we use the term shallow to talk about faults and earthquakes less than 18 miles deep. Photo from Pacific Northwest Seismic Network Seismo Blog. 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. This uplift creates a very broad wave called a tsunami. endobj Experts have warned that UK outbreak may be around two weeks behind Italys. The largest active fault that will affect Washington (and the whole Pacific Northwest) is the Cascadia subduction zone. The term active can have different meanings. Watch the video below to learn how you can be ready for the next earthquake. Photo from, Liquefaction can be a big problem. Dishes jitter off tables, shattering on the floor. The tsunamis can travel far inland and deposit layers of sand and organic material. Hundreds could die, with thousands more injured. You also have the option to opt-out of these cookies. 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. Most of the populated areas of the state have a 4080% chance of having an earthquake in the next 50 years. Kristin D. Morell 1 *, Christine Regalla 2, Lucinda J. Leonard 3, Colin Amos 4, Vic Levson 5. 1 0 obj While the intensity of this seismic event has now decreased, a big earthquake is overdue in the region. Audio; Before and After Images; Images; Slideshows; Stereograms; Videos; Webcams; . They knew something was there, said Sam Johnson, a retired USGS geologist who would follow up on their work. On an inactive fault, the sea would have risen at the same rate at both locations. Within this rich oral history there are many references to events like earthquakes and tsunamis. That place is the Ocosta School. This car was parked on sand during the 2011 earthquake in Christchurch, New Zealand. Reverse faults are usually steep and occur in regions of compression. Then consider that the Seattle Fault is a complex of faults with various branches that run at or just below the surface. In 2017, he began studying the possible aftermath of a major SWIF quake. Mapping along the Snoqualmie River valley also helped answer the important question of where the Seattle fault lies east of its last mapped position near Issaquah. These maps are created by small planes that use a specific type of laser to measure the elevation of the ground. The ground shaking from these earthquakes can last for several minutes. 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. A national credit rating service has improved its opinion of WhidbeyHealths financial future. 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. 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. You will not be able to google what to do in an earthquake when it is happening. Large earthquakes, like those from the Cascadia subduction zone on January 26, 1700, often create tsunamis. Many faults have not been studied enough to know if they are active. This might include flammable appliances like a water heater, tall items like book cases, or heavy pictures. Many landslide-prone areas of Washington are also located near active faults. Liquefaction can be a big problem. 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). Notice the Seattle Fault Zone bounding the Seattle Basin to the south. 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. <>/XObject<>/ExtGState<>/Pattern<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> In fact, new faults are found every year during our geologic mapping efforts. The average time between large earthquakes is about 535 years, but has been as little as 200 years, and more than 1,000 years. Using the stratigraphic column from the Freeport quadrangle map, confirm that you can recognize . Large and damaging earthquakes are inevitable in Washington, but no one knows exactly when they will happen. Its a natural curiosity.. The fault's length depends on whom you ask, Sherrod said. Drop, Cover, and Hold On whenever you feel shaking. For the most up-to-date information, please refer to the interactive fault map. However, seismic tomography studies (Brocher and others, 2001 #4718) reveal that only the northwestern end of the fault zone in the southeastern Strait of Juan de Fuca is associated with a strong velocity contrast. These types of faults are common, but usually small. endobj Sherrod remembers his son, age 5 at the time, playing with toy trucks on the mossy banks of the marsh while the scientists worked. There are also tsunami evacuation signs on the highways. Each of these aftershocks would be a significant earthquake if it happened on its own. Do you live or work near an area that could have liquefaction? South Whidbey Island Fault Zone. An abrupt rise or decline in sea level would reveal if the fault had triggered a quake before. 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). Faults are features in the Earths crust where rock periodically breaks and moves, releasing seismic energy and creating an earthquake. He said scientists have known about the southern Whidbey fault for decades. 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. DO NOT get in a doorway. The last time was 1,000 years ago between 900 and 903 A.D., said Forson. Bookcases and china cabinets topple, trapping people beneath. Share sensitive information only on official, secure websites. One model suggests it extends to about 30 miles east of Yakima. 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. Everything points to one thing, Sherrod said, waving his hand across the inland sea. For example, a building on soft soil will experience more shaking than the same building on bedrock. Stay away from glass, windows, outside doors and walls, and anything that could fall down. HomePrograms and ServicesGeologyGeologic Hazards. Once a fault is located, it is important to know if it is active. The Darrington-Devils Mountain fault zone is located in southern Skagit County and northern Snohomish County. It may not be possible to find water, fuel, or food until services are restored days or even weeks after the event. Make an emergency response plan for you and your family. If the epicenter is Everett, the SWIF could cause. Scientists dont know. Tsunamis and seiches can also be triggered by large slides, both on land and underwater. The seismic mapping had cost millions of dollars far beyond what most geologists on a government budget could scrape together. Move away from buildings, streetlights, and utility wires if you can. Johnson and others (1996 #4751) described the structure and stratigraphy of the southern Whidbey Island fault zone. It is mandatory to procure user consent prior to running these cookies on your website. Not all faults are active. The material becomes so weak that it behaves more like a liquid than a solid. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. PI22343). Do you know what to do if there is an earthquake? . They havent dug up enough history to estimate. The map also shows potentially active faults from a separate 2014 report (click here to download). Earthquakes occur nearly every day in Washington. 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. The fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. What scientists dont know is its timing interval. 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. A small quake was registered in the Coupeville area just this summer. 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 For example, in the open ocean a tsunami may be less than a few feet tall. A .gov website belongs to an official government organization in the United States. Oil companies descended in search of riches. Swarm of hundreds of small earthquakes rattle Vancouver Island. 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. 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 coast is now the home of one of the states largest network of warning sirens called All Hazard Alert Broadcast (AHABs). The DNR team found that the Seattle fault is intercepted by the southern Whidbey Island fault zone in the vicinity of Fall City. That could spell trouble not only for its namesake island but for south and north King County and further west. America is going to pay for sitting back doing nothing while almost 70 million babies were slaughtered and their body parts sold to the highest bidder for the last 43 years. Save my name, email, and website in this browser for the next time I comment. Here, were looking at one of the bigger faults in the region, he said. This kind of grouping gives us information about how common earthquakes might be and how large an area may be affected. The fault's length depends on whom you ask, Sherrod said. Southeast Extension of the Southern Whidbey Island Fault By Human Capital March 19, 2019. sw_whidbeyfault_rev122706.pdf (28.68 KB) @\;L;=}%FC*l $@ 4x: 888O~xrsxx'/*rGRF\gI%~x(G-^-hjjq kx/V ou0hyegy0;ei`Tx&ilZ )TmZ$vb,`bQm|DR5x/ Check out the liquefaction susceptibility and NEHRP site class maps on the Geologic Hazard Maps page. The last large earthquake on the Cascadia subduction zone was in 1700. Coupeville, WA 98239, Main Line: In some areas getting up a hill to higher ground will be difficult. The southern Whidbey Island fault: An active structure in the Puget Lowland Washington, Geological Society of America Bulletin 1996;108;334-354. 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 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. What we know about this fault is that its ruptured may times in the pastit will happen again. And being ready means being able to support yourself, your loved ones, your neighborhood for 2 weeks.