One of the best views of SWIF should be from Grand Avenue Park in Everett. Others, like the Seattle fault and southern Whidbey Island fault zone, cross under major cities and pose a significant hazard. 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. #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. The Darrington-Devils Mountain fault zone is located in southern Skagit County and northern Snohomish County. The buildings in this photo were built on soft materials that liquefied during the 1964 Niigata earthquake in Japan. There are many other active faults in Washington and any of these could produce a large earthquake in the future. Seconds later, its as if Whidbey Island is trapped in a cocktail shaker, lurching back and forth. Larger crustal faults, such as the Seattle fault and southern Whidbey Island fault zone, can produce earthquakes up to magnitude 7.5. An earthquake occurs when rock inside the Earth moves or breaks. Paleoseismologists have found places that record many of these tsunami deposits. California Geological Survey. Earthquakes cause damage by moving and shaking the ground, sometimes for several minutes. Then consider that the Seattle Fault is a complex of faults with various branches that run at or just below the surface. The southern Whidbey fault is unlike more visible faults on the West Coast. Finding and mapping these faults is an important mission of the Washington Geological Survey. This is a very good example of a strike-slip fault. 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. Seismologists estimate that such quakes and tsunami waves occur roughly every 500 years on average on the Cascadia Subduction Zone. 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. Puget Sound Earthquake Faults - Seattle Earthquake Faults In the 1990s, scientists producedan animationthat shows inundation, and people wont have much time to run to higher ground. A lot of people are transplants, Forson said. This new method allows geologists to see through trees and vegetation to find new faults. And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. You saw its potential in the 9.1 magnitude Tohuku earthquake and tsunami that hit northeastern Japan in March 2011. 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. Ground shaking is a hazard near the epicenter of an earthquake and also in areas far from the earthquake where amplification occurs. Were working on pedestrian evacuation maps that show the best routes for pedestrians to take to evacuate, said Forson. 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. 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. So the fault remained mostly a mystery until the 1990s. The Straight Creek fault in the Cascade Range is an example of this kind of fault and has ~5060 miles of movement across it. They havent dug up enough history to estimate. Also check out Ear to the Ground, published by the Department of Natural Resources. The crustal faults the Seattle Fault, the South Whidbey Island Fault, the Tacoma Fault those are less well known, said Forson. An increase of 2 means that ~1,000 times more energy is released. Its certainly not to scare you. Never use a lighter or match near damaged areas. . Once in the open, Drop, Cover, and Hold On. Restoring tap water to some homes could take over a year. Seismic waves travel at hundreds to thousands of miles per hour and quickly reach the surface where they are felt or measured. Depending on the type of fault, the ground can move laterally, vertically, or a combination of both. There must be tsunami deposits of the same age along much of the Oregon and Washington coast in order to qualify as an earthquake. Liquefaction is when wet soil or sediment loses strength because it is being shaken during an earthquake. If everyone tries to use their cell phones, it can overload the system. View Earthquake Map Faults Interactive fault map and comprehensive geologically based information on known or suspected active faults and folds in the United States. The best thing you can do is to become prepared. In the Puget Sound region, it takes a trained eye to recognize rocky outcrops and subtly raised ground as evidence of a fault. 2 0 obj You just need one person to crash or a power line to fall over the road, and the roads are unusable.. You can look at different geological hazard mapson the website of the Department of Natural Resources. Beef Barley and French Onion trenches cross the Little Bear Creek lineament. The map is from a, This car was parked on sand during the 2011 earthquake in Christchurch, New Zealand. Share sensitive information only on official, secure websites. They didnt grow up here, they havent heard this story. The Southern Whidbay Island Fault represents another major earthquake threat for Seattle and its residents. The shaking can damage or destroy buildings and other infrastructure. The most important thing you can do before the next earthquake is to prepare. M 7.4 Scenario Earthquake - Southern Whidbey Island fault-southern 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. Maps. It is not yet possible to predict when a fault will have an earthquake. This earthquake caused parts of Restoration Point near on Bainbridge Island to be lifted 35 feet straight up. Map by And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. Image from the Pacific Geoscience Center of the Natural Resources of Canada. Within minutes, he spotted something groundbreaking. Most of the populated areas of the state have a 4080% chance of having an earthquake in the next 50 years. 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. Other faults are inactive and are left over from much older periods of deformation. ?7) and represents a potential seismic hazard to residents of the Puget Lowland. Still think well avoid Gods wrath, its not going to happen regardless of what the multi millionaire TV preachers tell you. Experts have warned that UK outbreak may be around two weeks behind Italys. Puget Sound faults - Wikipedia 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. Lidar maps show the Earths surface without vegetation. 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. 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 ground shaking from these earthquakes can last for several minutes. Earthquakes can trigger landslides and tsunamis which can happen after the main event. Be prepared and read more on DNR, USGS, King5, Strange Sounds and Steve Quayle. Some people in places like SODO and Harbor Island may have to flee to higher floors in a building. In much of Washington, dense vegetation covers the land and makes finding faults very difficult. Roads, bridges, or ramps may have been damaged by the earthquake. Move away from buildings, streetlights, and utility wires if you can. 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. California Department of Conservation. 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. (360) 678-5111 Additionally, because the continent moves up and over the ocean plate, large amounts of sea water are displaced and cause damaging tsunamis. Once we got it, we were sort of shocked to see these big faults in the Puget lowlands, he 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." The fault, not so much. On Dec. 15th, a small swarm even hit near Bremerton, a few miles away from downtown. An official website of the United States government. For example, the Cascadia subduction zone has had between 15 to 19 earthquakes over the past 10,000 years. 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 Seattle Fault is also likely to create a tsunami that would inundate Harbor Island and much of SODO, Interbay, and the waterfront. Do not exit a building during the shaking. These older faults do not have any evidence for recent activity, but the Earth is always changing. His team wanted to find the rate of sea level rise along the shore. It is mandatory to procure user consent prior to running these cookies on your website. It may not be possible to find water, fuel, or food until services are restored days or even weeks after the event. Tsunami waves can travel over 500 miles per hour in the open ocean. Customers lift their eyes from phone screens. endobj 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. Since their initial discovery, research has shown that the actual number of earthquakes is somewhere between 5 and 10 for each change in magnitude. Quaternary Fault and Fold Database of the United States - USGS He combed through state and federal data to understand the risks, and to help train first responders. Photo from Pacific Northwest Seismic Network Seismo Blog. During the shaking liquefaction occurred, the sand lost its strength, and the car sunk. Because Japan was so well prepared, mostretrofitted buildingsoutside of the tsunami zone survived. PDF Cretaceous-Jurassic accreted terrains - University of Washington Bending of the fault and transpressional deformation began during the late middle Eocene and continues to the present. This means that when the Seattle fault ruptures the south side of the fault moves up relative to the north side. These large underwater slides only occur during very large earthquakes and are one way to learn about earthquakes that happened thousands of years ago. When the ground shakes during an earthquake, it moves up and down, acting like additional gravity. On an inactive fault, the sea would have risen at the same rate at both locations. Fir trees near the failure are tilted and indicate rotation into the lake (to the left of the photo). 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. Save my name, email, and website in this browser for the next time I comment. This can cause landslides to occur where they wouldnt normally happen. An abrupt rise or decline in sea level would reveal if the fault had triggered a quake before. Fault Activity Map of California The friend obliged. Click the "Seismogenic Features" button in the Map Contents window to display faults and earthquakes. Another piece can be seen under the elevated lanes of northbound Interstate 5 in South Seattle not far from the Rainier brewery. Tsunamis triggered by earthquakes usually require at least a M7 event. Standing becomes almost impossible as the jolts turn to rolling waves. Washington has the second highest risk in the U.S. of these large and damaging earthquakes because of its geologic setting. Although both seiches and tsunamis can be large and destructive, they are created differently. Once the shaking has stopped, exit the building if it is safe to do so. 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. Devastating wind storms. Stop as quickly as safety permits and stay in the vehicle. The experts say few are ready. Southeast Extension of the Southern Whidbey Island Fault Prepare to be on your own for at least three days. The Safe America Foundation suggests texting as a way of communication. Plate Tectonics | Pacific Northwest Seismic Network 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. Sherrod says practically every place they. Emergency Management Maps - Island County, Washington Some residents may lose housing temporarily or permanently. The fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. 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. Hundreds could die, with thousands more injured. In Washington, we do not have tsunami walls. The height difference likely was caused by a 7.5 magnitude earthquake on the fault about 2,700 years ago, Sherrod said. Although we cannot predict exactly when the next earthquake will happen, we can predict the general distribution of earthquake sizes. The threat to Puget Sound from a quake along the Cascadia Subduction Zone, off the coast of Washington, Oregon and California, is well documented. On a brilliant November day, Sherrod took in the panorama from the parks bluff. We pray for people of WA and our all north Americans as well. The last time was 1,000 years ago between 900 and 903 A.D., said Forson. There are also many faults that have not been studied enough to know if they are active. Most are too small to be felt or cause damage. 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 fault has at least three almost parallel strands within a 4- to 7-mile-wide band, stretching eastward from Vancouver Island. Finding and learning about faults requires many different aspects of geology and geophysics. Third, the South Whidbey Island Fault running from northwest to southeast of the southern tip of the island. 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 . 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. Earthquake Hazards - Maps | U.S. Geological Survey Seattle Fault Lines. 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. In the area of North Bend, the fault zone is 4 miles wide and consists of a series of parallel faults. Around Puget Sound, it seems everyone knows about The Big One, the potential magnitude 9.0 Cascadia Subduction Zone megaquake some scientists say is due any day. The Flying Squirrel and Mountain Beaver trenches cross the Cottage Lake lineament. Most damage and loss of life in earthquakes is a result of ground shaking. PDF Modeling a Magnitude 7.4 Earthquake on the Southern Whidbey Island PDF Seismic Characterization of the Seattle and Southern Whidbey Island And what were looking at is water.. Share sensitive information only on official, secure websites. Photo by G.K. Gilbert, from the Steinbrugge Collection of the UC Berkeley Earthquake Engineering Research Center. 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?? Scientists are not sure how far east it goes. The 1964 M9.2 Alaska earthquake created a large tsunami from the fault rupture, and many smaller tsunamis from on-land and underwater landslides. Someone screams. A paleoseismologist will look for surface ruptures along faults and may use carbon-14 dating to learn when the rupture happened. Much of the land along the southwestern part of the lake cracked and subsided. In 2017, he began studying the possible aftermath of a major SWIF quake. District Court: (800) 946-9765, South Whidbey Island Fault (SWIF) M7.4 Earthquake Scenario. And experts fear it could be even worse than The Big One.. The Cascadia subduction zone off the Washington and Oregon coast is capable of some of the largest earthquakes in the world. Secure .gov websites use HTTPS But opting out of some of these cookies may affect your browsing experience. Brick chimneys cascade off rooftops. The fault's length depends on whom you ask, Sherrod said. The buildings sank when ground shaking weakened the underlying sediments. The Port of Coupeville will apply for a grant to fund two electric vehicle charging stations. Camano Island, WA 98282, Mailing Address The Moment Magnitude Scale (M) measures the total amount of seismic energy (known as moment to engineers and seismologists) released by an earthquake. Theres approximately a 14% chance of another approximately M9 earthquake occurring in the next 50 years. 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). A major southern Whidbey quake, on the other hand, could kill and injure many more, according to Murphy. Know what other hazards you might face. When a fault with vertical movement ruptures the ocean floor, it lifts up part of the ocean. Tsunamis and seiches are destructive waves which can be triggered by certain types of large earthquakes. Charles Richter and Beno Gutenberg discovered that for every magnitude of earthquake, there are about ten times more earthquakes of the next lower magnitude. The team also found that accumulated movement on the fault has uplifted old Snoqualmie River sediments to their current position on ridges, in some places several hundreds of feet above the modern Snoqualmie valley floor. It might as well have been sitting in a drawer, Johnson said. Experts believe a magnitude 9.0 could happen there anytime in the next 200 years or so. Often this cracking happens because a soft part of the ground liquefies during the shaking. It could also create dangerous currents and hazards to the north including Everett. The Mercalli Intensity scale is another historical way to measure the intensity of an earthquake. 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. The shaking can also cause landslides, surface ruptures, ground cracks, liquefaction, tsunamis, and seiches (standing waves). You will not be able to google what to do in an earthquake when it is happening. 572 Last Review Date: 2016-11-29 In some areas getting up a hill to higher ground will be difficult. Geologic maps show the types and ages of rocks and younger deposits that are found at or near the Earth's surface. Each of the earthquakes listed on the bottom of the screen is capable of significant damage. In effect, the wave energy is trapped by the edges of the body of water. Some events appear to be only 200 years apart, and others are more than 1,000. The process of breaking and moving rock releases a large amount of energy that travels through the Earth as seismic waves. These faults and earthquakes usually occur at great depth (tens to hundreds of miles). Liquefaction can be a big problem. Sheriff:(360) 679-7310, Juror Recordings Check out the liquefaction susceptibility and NEHRP site class maps on the Geologic Hazard Maps page. Excavations across several LiDAR scarps show evidence for multiple post-glacial folding and faulting event on faults with reverse oblique sense of slip. Power could be out for days. Sherrods son has since completed graduate school in applied geosciences. Earthquakes occur nearly every day in Washington. Washington State Earthquake Hazard Map. The northwestern part of the fault zone forms the northeastern limit of the Port Townsend basin (Brocher and others, 2001 #4718). In fact, new faults are found every year during our geologic mapping efforts. One model suggests it extends to about 30 miles east of Yakima. 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. Most of the populated areas of the state have a 4080% chance of having an earthquake in the next 50 years. Along the coast residents may have between 20 and 30 minutes to get to higher ground. USA Earthquake Hazard Map. This kind of landslide is called an earthquake-triggered landslides. In the Pacific Northwest we use the term shallow to talk about faults and earthquakes less than 18 miles deep. By sampling sediment from the marsh to the beach berm, Sherrod and his research partner, Harvey Kelsey, developed a timeline of the oceans climb. When the landslide hit the water it may have created a tsunami. Knowing how often large earthquakes have happened in the past helps us to know how often they might occur in the future. Sherrod remembers his son, age 5 at the time, playing with toy trucks on the mossy banks of the marsh while the scientists worked. For several years, scientists pondered where this important regional fault zone continues southwestward from its mapped location in the Everett area.
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