Bookcases and china cabinets topple, trapping people beneath. Strabge sounds very good report thanks a lot. Stay away from glass, windows, outside doors and walls, and anything that could fall down. Learn how your comment data is processed. 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. 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 Surface Geology | WA - DNR Buildings could sustain extensive damage. After large earthquakes there are usually many aftershock earthquakes. Although we know much about active faults and earthquakes, there is much more to learn. Westport currently is the only location with a vertical evacuation structure designed for a tsunami. 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. But they didnt document it hardly at all.. They didnt recognize the significance of what they found. The shaking can damage or destroy buildings and other infrastructure. Stay inside until the shaking stops and it is safe to go outside. In the early 2000s, USGS scientists including Brian Sherrod set out to further Johnsons work and better understand the slumbering fissure. Southeast Extension of the Southern Whidbey Island Fault It devastated the coast of the Pacific Northwest and sent an orphan tsunami to Japan. The height difference likely was caused by a 7.5 magnitude earthquake on the fault about 2,700 years ago, Sherrod said. The faults length depends on whom you ask, Sherrod said. A special type of shallow fault, called a subduction zone or megathrust, occurs where an oceanic plate moves beneath a continental plate. Since the last ice age, the southern Whidbey Island fault zone has probably spawned several highly destructive shallow earthquakes. Southern Whidbey Island Fault Zone Mapped through Snoqualmie Valley The San Andreas in California, for example, left gaping scars in the Earths crust, at the surface. HomePrograms and ServicesGeologyGeologic Hazards. Areas like these are also susceptible to liquefaction. A baristas hand hovers over the bean grinder. Photo from, Liquefaction can be a big problem. The last major earthquake was over 300 years ago. It startled Johnson that such massive faults had gone undetected for so long. This map of gravity residuals measured over the puget lowland reveals a pattern of deep, fault bounded basins (cool colors) and uplifts (warm colors). A magnitude 7.4 along the southern Whidbey fault would rattle 18 counties in Washington, according to a federal projection . Some people in places like SODO and Harbor Island may have to flee to higher floors in a building. In the 1990s, scientists producedan animationthat shows inundation, and people wont have much time to run to higher ground. Radiocarbon ages of macrofossils constrain uplift timing to 2.83.2 ka. In the Puget Sound region, it takes a trained eye to recognize rocky outcrops and subtly raised ground as evidence of a fault. Whats up with the 50 US nuclear bombs stored at the Incirlik Air Base in Turkey, right on the same fault line California hasnt seen a catastrophic earthquake recently. This kind of landslide is called an earthquake-triggered landslides. Each peak of the Olympics stuck out with picturesque clarity in the distance. The fault, not so much. If everyone tries to use their cell phones, it can overload the system. A reverse fault occurs when two blocks are pushed together and one moves up and over the other. 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. Hold on to any sturdy shelter until the shaking stops. Source: United States Geological Survey. DO NOT get in a doorway. South Whidbey Island Fault Earthquake Scenario: 7.4 Magnitude Buildings Damaged: 320,776 Fatalities: 90 - 432 Injuries: 2,920 - 7,361 Economic Loss: $15,590,000,000 SeaTac Fault Earthquake Scenario: 7.2 Magnitude Buildings Damaged: 375,954 Fatalities: 16 - 123 Injuries: 1,394 - 3,404 Economic Loss: $13,400,000,000 Tacoma Fault Deformed recessional outwash deposits and Holocene deposits were exposed; three unconformities separated the units. Photo from, This image shows the how the 1700 AD tsunami from the Pacific Northwest crossed the Pacific Ocean. Expect aftershocks. The moment magnitude scale is a type of logarithmic scale, where each increase of 1 means ~32 times more energy is released. These cookies will be stored in your browser only with your consent. Were working on pedestrian evacuation maps that show the best routes for pedestrians to take to evacuate, said Forson. You will not be able to google what to do in an earthquake when it is happening. In the area of North Bend, the fault zone is 4 miles wide and consists of a series of parallel faults. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. This evidence can come from finding something younger than 12,000 years that has been deformed or moved by the fault. Each of the earthquakes listed on the bottom of the screen is capable of significant damage. What about the localized tsunami risk? 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. During site visits in 2005, Sherrods team found evidence of four SWIF earthquakes in the past 30,000 years. This can cause landslides to occur where they wouldnt normally happen. Earthquake Hazard Maps | Sound Seismic Beef Barley and French Onion trenches cross the Little Bear Creek lineament. 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 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. By finding the age of the deformed layer, a paleoseismologist can determine the minimum age of the fault. On an inactive fault, the sea would have risen at the same rate at both locations. x\[s8~OU)! %PDF-1.5 Finding and learning about faults requires many different aspects of geology and geophysics. 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. Aftershocks can be nearly as large as the main earthquake and can cause significant additional damage. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. Visit our School Seismic Safety page for more information. Johnson and others (1996 #4751) described multiple sub-parallel strands and referred to the overall structure as the "southern Whidbey Island fault zone," and this name is also used herein for this zone of faults that crosses the southern part of Whidbey Island. Do you know what to do if there is an earthquake? Johnsons curiosity changed the course of his career. When an earthquake happens there will not be time to google what you are supposed to do. stream This is a very good example of a strike-slip fault. Drop, Cover, and Hold On whenever you feel shaking. A thrust fault is a special kind of reverse fault that has a shallow dip. Fir trees near the failure are tilted and indicate rotation into the lake (to the left of the photo). Check out the liquefaction susceptibility and NEHRP site class maps on the Geologic Hazard Maps page. Clicking on the map will download the publication. Although both seiches and tsunamis can be large and destructive, they are created differently. endobj Official websites use .gov 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. The map is from a 2007 report (click here to download) on seismic design categories in Washington. America is going to be punished just like the rest of the world. Earthquake Fault Maps in Seattle and Washington State We use the term deep to talk about faults and earthquakes deeper than about 18 miles. Fault Activity Map of California The last large earthquake on the Cascadia subduction zone was in 1700. 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. Its significantly larger than the Seattle Fault, and South Whidbey could hand us a magnitude 7.5 earthquake. These cookies do not store any personal information. Scientists have also dated large underwater landslides and turbidites that travel from the continental edge far out into the ocean basin. 572 Last Review Date: 2016-11-29 Early mapping of the three subparallel, northwest trending strands of the southern Whidbey Island fault zone was constrained by borehole data, potential field anomalies, marine seismic reflection surveys. Quaternary Fault and Fold Database of the United States - USGS Quaternary Rupture of a Crustal Fault beneath Victoria, British Stratigraphy in the Flying Squirrel trench showed gentle warping of late glacial and post-glacial sediments; no faults were exposed. An earthquake can be a scary event. 1 NE 7th Street Customers lift their eyes from phone screens. <>>> By sampling sediment from the marsh to the beach berm, Sherrod and his research partner, Harvey Kelsey, developed a timeline of the oceans climb. 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. Seattle Fault - Wikipedia Charles Richter and Beno Gutenberg discovered that for every magnitude of earthquake, there are about ten times more earthquakes of the next lower magnitude. This website uses cookies to improve your experience while you navigate through the website. Within minutes, he spotted something groundbreaking. One of these cracks appeared along the pathway around Green Lake. 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). Doctor reveals the horrors Italian medics are facing in overwhelmed hospitals where dying patients are being left untreated as experts warn UK and US are just two weeks behind Italy and the public are not SCARED enough, An intensive care doctor in northern Italy has described the scale of the crisis We do know that it is active and will likely produce a large M67.5 earthquake when it next ruptures. One model suggests it extends to about 30 miles east of Yakima. But scientists theorize that the area has suffered only four . Seconds later, its as if Whidbey Island is trapped in a cocktail shaker, lurching back and forth. And what were looking at is water.. It is capable of generating severe earthquakes that would impact the entire west coast. It could also create dangerous currents and hazards to the north including Everett. 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. The fault probably originated during the early Eocene as a dextral strike-slip fault along the eastern side of a continental-margin rift. PDF Modeling a Magnitude 7.4 Earthquake on the Western Section of the This is a hypothetical scenario created by Mark Murphy of the Snohomish County Department of Emergency Management. Geologists have used the location of these shallow, intermediate, and deep earthquakes to learn about subduction zones throughout the world. By clicking Accept, you consent to the use of ALL the cookies. Earthquakes between 45 and 185 miles deep are called intermediate, and earthquakes over 185 miles deep are called deep. Landslides can be caused by strong ground shaking during an earthquake. 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. There are also many faults that have not been studied enough to know if they are active. Sherrods son has since completed graduate school in applied geosciences. The Cascadia subduction zone last ruptured over 300 years ago on January 26, 1700. A .gov website belongs to an official government organization in the United States. An earthquake occurs when rock inside the Earth moves or breaks. On Dec. 15th, a small swarm even hit near Bremerton, a few miles away from downtown. If you are already planning your Christmas gifts, please buy with us on Amazon. Sherrod says practically every place they. A low-angle fault, which is not conclusively earthquake related, separates a diamicton from the overlying recessional outwash deposit. Story telling is an important part of the Native tradition and is how their history is passed down to the next generation. These aftershocks can last for hours to weeks or months. These types of faults are common, but usually small. The age of the earthquake is learned by dating the organic material in these tsunami deposits. Washington State Earthquake Hazard Map. A half dozen people reaching for the last can of soup, someone could lose their life over that. . of Earth and Space Sciences, Box 351310, Univ. Moving inland, the Seattle Fault is capable of a magnitude 7. And experts fear it could be even worse than The Big One.. The northwestern part of the fault zone forms the northeastern limit of the Port Townsend basin (Brocher and others, 2001 #4718). Washington has few large normal faults because it is mostly in a region of compression. In fact, new faults are found every year during our geologic mapping efforts. There are many other active faults in Washington and any of these could produce a large earthquake in the future. 1. Buried danger: A slumbering geologic fault beneath us Experts believe a magnitude 9.0 could happen there anytime in the next 200 years or so. PDF The Cottage Lake Aeromagnetic Lineament: a Possible Onshore Extension
southern whidbey island fault map