southern whidbey island fault map

In some areas getting up a hill to higher ground will be difficult. 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. This evidence can come from finding something younger than 12,000 years that has been deformed or moved by the fault. This map is from a 2007 report on the seismic design categories in Washington. Photo courtesy of National Center for Tsunami Research, NOAA. The trench did expose faults, but it was not possible to conclusively demonstrate offset of Holocene units. These cookies will be stored in your browser only with your consent. When the ground shakes during an earthquake, it moves up and down, acting like additional gravity. Because they rupture at such great depth, their seismic energy is distributed over a large area. 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). 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. Brick chimneys cascade off rooftops. Please visit our Geologic Information Portal and Geologic Hazard Maps page for the most up-to-date listing of all of our hazard maps. Much of the land along the southwestern part of the lake cracked and subsided. The largest active fault that will affect Washington (and the whole Pacific Northwest) is the Cascadia subduction zone. 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. By sampling sediment from the marsh to the beach berm, Sherrod and his research partner, Harvey Kelsey, developed a timeline of the oceans climb. 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. A drill rig left of the blockade is collecting data about the failure. Earthquakes occur nearly every day in Washington. Because they can travel great distances, tsunamis generated from earthquakes across the ocean can still cause damage. 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. An earthquake occurs when rock inside the Earth moves or breaks. Tsunamis and seiches can also be triggered by large slides, both on land and underwater. The more you know what to expect, the better prepared you will be to help yourself, your family, and others around you. They knew something was there, said Sam Johnson, a retired USGS geologist who would follow up on their work. Photo from, This image shows the how the 1700 AD tsunami from the Pacific Northwest crossed the Pacific Ocean. Along the water at Cama Beach State Park, cabins on a bluff overlook Saratoga Passage, facing the general direction of Lake Hancock on Whidbey Island. 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. Below you will find links to view and download hazard maps created for each jurisdiction included in the current mitigation planning process. The DNR team found that the Seattle fault is intercepted by the southern Whidbey Island fault zone in the vicinity of Fall City. In Washington, the risk from earthquake-induced landslides is large. This car was parked on sand during the 2011 earthquake in Christchurch, New Zealand. For earthquakes that occurred before seismographs were invented, the Mercalli Intensity scale was used to make maps of damage and determine the size and location of an earthquake. 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. Washington, Seattle, WA 98195 2 U.S. Geological Survey, 345 Middlefield Road, M/S . Earthquakes on shallow faults typically last 20 to 60 seconds and the shaking is localized to the general area of the fault. 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. Faulting produced warping at the site of greater than 2 m. Radiocarbon ages provide a maximum age for the folding event of 12,09011,670 cal yr BP. The crustal faults the Seattle Fault, the South Whidbey Island Fault, the Tacoma Fault those are less well known, said Forson. 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. As of January 12, 2017, the USGS maintains a limited number of metadata fields that characterize the Quaternary faults and folds of the United States. Many landslide-prone areas of Washington are also located near active faults. Until much more recently, no one really understood what it could do to a region of over 4 million people. 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 . Washington has few large normal faults because it is mostly in a region of compression. 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. The buildings sank when ground shaking weakened the underlying sediments. Cover your head and neck with your arms to protect against falling debris. Sherrods son has since completed graduate school in applied geosciences. Move away from buildings, streetlights, and utility wires if you can. The moment magnitude scale replaced the Richter scale in the late 1970s. Black lines show the South Whidbey Island Fault Zone, the Seattle Fault Zone and the Tacoma Fault Zone. The fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. Even places that are far from active faults are still at risk during a large Cascadia subduction zone earthquake. 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). 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. 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. Experts have warned that UK outbreak may be around two weeks behind Italys. A lock () or https:// means youve safely connected to the .gov website. Often this cracking happens because a soft part of the ground liquefies during the shaking. The fault, not so much. Story telling is an important part of the Native tradition and is how their history is passed down to the next generation. This fault will have an earthquake in the future, but we cannot predict exactly when. Additionally, because the continent moves up and over the ocean plate, large amounts of sea water are displaced and cause damaging tsunamis. Many low-lying areas have wet soil or sediment beneath them that could liquefy during earthquakes. 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. Swarm of hundreds of small earthquakes rattle Vancouver Island. The southern Whidbey Island fault should be considered capable of generating large earthquakes (Ms ?? The age of the earthquake is learned by dating the organic material in these tsunami deposits. The Flying Squirrel and Mountain Beaver trenches cross the Cottage Lake lineament. Do you know what to do if there is an earthquake? The last major earthquake was over 300 years ago. 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. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. Sherrod remembers his son, age 5 at the time, playing with toy trucks on the mossy banks of the marsh while the scientists worked. Some faults reach the surface and can be found by geologists. It forms the northern boundary of the Everett basin and lies along a series of high-amplitude aeromagnetic anomalies that extend from the Cascade Mountains to Vancouver Island, B.C. Sheriff:(360) 679-7310, Juror Recordings In fact, new faults are found every year during our geologic mapping efforts. The process of breaking and moving rock releases a large amount of energy that travels through the Earth as seismic waves. There must be tsunami deposits of the same age along much of the Oregon and Washington coast in order to qualify as an earthquake. Part 2 will be full Martial Law and mandatory vaccines? Much of the Southern Whidbey Island fault zone (SWIF), which runs in a north-westward direction from Woodinville to near Port Townsend, Washington, remains mostly . The Geologic Information Portal has a Natural Hazards theme that shows active faults and earthquakes. Learning earthquake faults around where we live is a first good way to prepare the next devastating earthquake. California Department of Conservation. 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. This map of Puget Sound shows the location of the methane plumes (yellow and white circles) detected along the ship's path (purple). Trenches by Sherrod and others, 2008 #7652) are less than 1 km south of KP1 and KP2 and Sherrod and others (2008 #7652) conclude that deformation in the area is due to surface-rupturing earthquakes. <> A baristas hand hovers over the bean grinder. The medic said colleagues were becoming sick and emotionally overwhelmed And experts fear it could be even worse than The Big One.. Map by And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. Never use a lighter or match near damaged areas. For example, a building on soft soil will experience more shaking than the same building on bedrock. 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. Stratigraphy in the Flying Squirrel trench showed gentle warping of late glacial and post-glacial sediments; no faults were exposed. The Port of Coupeville will apply for a grant to fund two electric vehicle charging stations. . Hold on to any sturdy shelter until the shaking stops. Photo courtesy of MOHAI (neg. Know what other hazards you might face. It is a qualitative scale that ranges from IXI (1-11) and measures the amount of damage caused by an event. These sediments were laid down 20,000 to 60,000 years ago, before the last ice age. The Seattle Fault is also likely to create a tsunami that would inundate Harbor Island and much of SODO, Interbay, and the waterfront. 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. Southeast Extension of the Southern Whidbey Island Fault By Human Capital March 19, 2019. sw_whidbeyfault_rev122706.pdf (28.68 KB) It is capable of generating severe earthquakes that would impact the entire west coast. 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. You can look at different geological hazard mapson the website of the Department of Natural Resources. The map is from a, This car was parked on sand during the 2011 earthquake in Christchurch, New Zealand. endobj #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. 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, it is unlikely that you will be able to use electricity, cell phones, or the internet. , * NOTE: Hazard maps for each jurisdiction will only be included if that jurisdiction is at risk to that hazard., Copyright Island County. The Seattle fault is a good example of a fault that is mostly reverse. Kelsey and others (2004 #7651) suggest that the earthquake resulted in 2.5 m uplift of the salt marsh on the north side of the fault strand relative to the marsh on the south side; no fault scarp has been identified between the marshes. This means that the internet, your cell phone, grocery stores, and gas stations may also not work. A lock () or https:// means youve safely connected to the .gov website. A .gov website belongs to an official government organization in the United States. Expect and help to extinguish fires. Hover over a cluster of earthquakes to learn about the different types in the Pacific Northwest. This is similar to how sound is quieter when you move away from a speaker. Higher risk areas are in orange and lower risk areas are in green. When this happens, even a very small slope can cause the ground to slide. 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). Theyre FREE CLICK HERE to subscribe, EAR TO THE GROUND WITH DNR & COMMISSIONER FRANZ, Tree Link helps you answer questions about urbantrees. Expect aftershocks. 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. A reverse fault occurs when two blocks are pushed together and one moves up and over the other. Geologists have used the location of these shallow, intermediate, and deep earthquakes to learn about subduction zones throughout the world. But Forson says you also need to know what to do when the shaking happens. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. PO Box 5000 Coupeville, WA 98239, Camano Office For some active faults, such as the Seattle fault or Cascadia subduction zone, we can also learn how often large earthquakes have happened in the past. But they didnt document it hardly at all.. Since their initial discovery, research has shown that the actual number of earthquakes is somewhere between 5 and 10 for each change in magnitude. Proceed cautiously once the earthquake has stopped. These faults and earthquakes occur in oceanic crust as it is subducted beneath the continent. Hundreds could die, with thousands more injured. 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. It will happen; we dont know when.. In addition, the Survey performs seismic safety evaluations of schools. The southern Whidbey fault is unlike more visible faults on the West Coast. Buildings could sustain extensive damage. Some residents may lose housing temporarily or permanently. The southern Whidbey Island fault, and several others, were exposed for the first time from a camouflage of forest, ocean and glacial sediment. The friend obliged. Faults can also occur within a tectonic plate when the plate itself is deforming. Click the "Seismogenic Features" button in the Map Contents window to display faults and earthquakes. Videos: Strong M6.0 earthquake rattles Mindanao in the Philippines, Dramatic earthquake increase in Hawaii! The shaking can damage or destroy buildings and other infrastructure. This category only includes cookies that ensures basic functionalities and security features of the website. Johnson and others . For example, a M7 earthquake releases 32 times more energy than a M6 earthquake, and 1,000 times more than a M5 earthquake. Share sensitive information only on official, secure websites. The western half of Washington state is considered earthquake country, with the potential for very large quakes. 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). Close to shore, this same wave could reach heights of 30100 feet or more. <>/XObject<>/ExtGState<>/Pattern<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> ?7) and represents a potential seismic hazard to residents of the Puget Lowland. The video is also available in Spanish and there is a fun activity/coloring book that can be found here. The French Onion trench exposed glaciolacustrine claystones, till, colluvial deposits, and Holocene soils. . 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 plate that is forced down can have faults within it that still rupture and produce earthquakes. Nearly all earthquakes occur on faults, features in the Earth where rocks move past each other. 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. And what were looking at is water.. In Washington, we do not have tsunami walls. Oil companies descended in search of riches. A damaging earthquake is inevitable on this fault, but we do not know exactly when it will happen. Prepare to be on your own for at least three days. 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). These quakes are capable of magnitudes from 7 to over 9. In the early 2000s, USGS scientists including Brian Sherrod set out to further Johnsons work and better understand the slumbering fissure. Graphic from IRIS. The 1949 earthquake near Tacoma triggered a landslide near the Tacoma Narrows that caused a local tsunami. In fact, until the 1980s, no one knew SWIF existed. The shaking can also cause landslides, surface ruptures, ground cracks, liquefaction, tsunamis, and seiches (standing waves). What are the most dangerous fault lines for Seattle? All Rights Reserved 2021, Site Disclaimer Washington has the second highest risk in the U.S. of these large and damaging earthquakes because of its geologic setting. A paleoseismologist will look for surface ruptures along faults and may use carbon-14 dating to learn when the rupture happened. Charles Richter and Beno Gutenberg discovered that for every magnitude of earthquake, there are about ten times more earthquakes of the next lower magnitude. Snohomish, King and Island counties would be expected to see the. Geologic maps show the types and ages of rocks and younger deposits that are found at or near the Earth's surface. At the time, Johnson worked in southwest Washington, searching for natural gas and oil deposits. A 2014 map shows what we know about the age of faults in Washington. Also check out Ear to the Ground, published by the Department of Natural Resources. Earthquakes can be measured in many ways, but the most accepted method is called moment magnitude. Restoring tap water to some homes could take over a year. By finding the age of the deformed layer, a paleoseismologist can determine the minimum age of the fault. The affiliate sales will help us to continue the hard work we are putting in this website. This is called liquefaction and is discussed in the next section. Like other faults, when enough stress builds up, the megathrust will rupture. Seismic waves travel at hundreds to thousands of miles per hour and quickly reach the surface where they are felt or measured. HomePrograms and ServicesGeologyGeologic Hazards. Washington has dozens of active faults and fault zones. Fault Activity Map of California. 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). 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. These and other problems led to the search for a scale that was based on the physical processes that happen during an earthquake. Dishes jitter off tables, shattering on the floor. Here, were looking at one of the bigger faults in the region, he said. A .gov website belongs to an official government organization in the United States. View of the Sunset Lake liquefaction failure about three weeks after the earthquake. A thrust fault is a special kind of reverse fault that has a shallow dip. The moment magnitude scale is a type of logarithmic scale, where each increase of 1 means ~32 times more energy is released. In the area of North Bend, the fault zone is 4 miles wide and consists of a series of parallel faults. Theres an uneasy hush. This fault produces some of the largest and most damaging earthquakes in the world (M9). Faults are features in the Earths crust where rock periodically breaks and moves, releasing seismic energy and creating an earthquake. 572 Last Review Date: 2016-11-29 Because they need large earthquakes that move the ocean floor, tsunamis are most commonly made by subduction zone faults like those found off the coasts of the Pacific Northwest, Japan, and Chile.