southern whidbey island fault map

2 0 obj 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. 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. America is going to be punished just like the rest of the world. Johnson and others (1996 #4751) described the structure and stratigraphy of the southern Whidbey Island fault zone. In the month after the main earthquake there were about 60 M7 and M6 earthquakes. The shaking usually lasts less than a minute and doesnt generally cause a tsunami or have many aftershocks. The experts say few are ready. Hey Biden! We do not encourage people to evacuate in vehicles. If they know theres data available that could help them in any way, they want to get it. 1 NE 7th Street Videos: Strong M6.0 earthquake rattles Mindanao in the Philippines, Dramatic earthquake increase in Hawaii! and the Red Cross will be there to care for them. A lock () or https:// means youve safely connected to the .gov website. Theres approximately a 14% chance of another approximately M9 earthquake occurring in the next 50 years. 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 seismic mapping had cost millions of dollars far beyond what most geologists on a government budget could scrape together. Geologists have used the location of these shallow, intermediate, and deep earthquakes to learn about subduction zones throughout the world. The tsunamis can travel far inland and deposit layers of sand and organic material. When this happens, even a very small slope can cause the ground to slide. These faults and earthquakes occur in oceanic crust as it is subducted beneath the continent. Johnson et al. Emergency planners all had a simple message: Its not IF a disaster will happen, its WHEN. Everything points to one thing, Sherrod said, waving his hand across the inland sea. One or possibly two of the unconformities are interpreted as event horizons. View Earthquake Map Faults Interactive fault map and comprehensive geologically based information on known or suspected active faults and folds in the United States. Small fires are the most common hazard after an earthquake. The ground shaking from these earthquakes can last for several minutes. A major southern Whidbey quake, on the other hand, could kill and injure many more, according to Murphy. During the shaking liquefaction occurred, the sand lost its strength, and the car sunk. But it didnt. Do you know what to do if there is an earthquake? Superior Court:(800) 254-2755 He said scientists have known about the southern Whidbey fault for decades. 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. Johnsons curiosity changed the course of his career. Small talk stops. The material becomes so weak that it behaves more like a liquid than a solid. The average time between large earthquakes is about 535 years, but has been as little as 200 years, and more than 1,000 years. The Port of Coupeville will apply for a grant to fund two electric vehicle charging stations. Geologists at the Survey spend time mapping the geology of the state, looking for faults, folds, landslides, and different rock types. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. In the 1990s, scientists producedan animationthat shows inundation, and people wont have much time to run to higher ground. Nearly all earthquakes occur on faults, features in the Earth where rocks move past each other. If a large earthquake happens, be prepared for many more earthquakes. Armentrout, J. J. Miller, C. Finn, C. S. Weaver. It startled Johnson that such massive faults had gone undetected for so long. This fault zone was originally named the Devils Both types of faults can cause ground shaking during an earthquake and may cause permanent deformation of the ground. Most faults in Washington are a mix of a strike-slip fault and a thrust or reverse fault. These cookies will be stored in your browser only with your consent. The strength of ground shaking (called strong motion by seismologists) usually decreases with distance from the earthquake source. These types of faults are common, but usually small. 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. One model suggests it extends to about 30 miles east of Yakima. Large earthquakes are likely to happen in Washington during your lifetime. This means that a large area feels the shaking, but the intensity is less than a similar shallow earthquake. Know what other hazards you might face. The map also shows potentially active faults from a separate 2014 report (click here to download). Deep faults can occur where two tectonic plates collide and one of the plates is forced beneath the other. The southern Whidbey Island fault divides the two. 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. Though it was not directly related to Johnsons work, he asked a friend working for Mobil Oil to pass along the information. The most recent hit roughly 2,700 years ago. . 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. <> Small normal faults are found along the top of folds in eastern Washington in the Saddle Mountain graben. (1996) used seismic-reflection profiles in Puget Sound near Whidbey Island, sea-cliff exposures on Whidbey Island, and sparse borehole data to map and interpret the SWIF as a broad fault zone (6 to 11 km wide) dipping steeply to the northeast. Someone screams. 4 0 obj 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. In the Puget Sound region, it takes a trained eye to recognize rocky outcrops and subtly raised ground as evidence of a fault. This scenario was modeled on the part of the SWIF from Woodinville to just west of Whidbey Island. Strabge sounds very good report thanks a lot. A strike-slip fault occurs when two blocks move past each other. Since their initial discovery, research has shown that the actual number of earthquakes is somewhere between 5 and 10 for each change in magnitude. 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 lock () or https:// means youve safely connected to the .gov website. After large earthquakes there are usually many aftershock earthquakes. This date was confirmed by records in Japan of an orphan tsunami and by many lines of geologic evidence. These maps are created by small planes that use a specific type of laser to measure the elevation of the ground. That place is the Ocosta School. Photo by Steve Palmer. A low-angle fault, which is not conclusively earthquake related, separates a diamicton from the overlying recessional outwash deposit. The last time was 1,000 years ago between 900 and 903 A.D., said Forson. These fault strands follow the valley edges and control the location of the Snoqualmie River along some portions of the valley. The more you know what to expect, the better prepared you will be to help yourself, your family, and others around you. It may not be possible to find water, fuel, or food until services are restored days or even weeks after the event. The last earthquake on the Seattle fault (about AD 950) triggered a landslide and seiche in Lake Washington. An earthquake along the southern Whidbey Island fault reshaped the land some 2,700 years ago. Expect and help to extinguish fires. Do not exit a building during the shaking. Camano Island, WA 98282, Mailing Address southern Whidbey Island fault zone (Class A) No. It might as well have been sitting in a drawer, Johnson said. Consider a magnitude 7.4 quake with Whidbey Island at or near the epicenter. Faults are features in the Earths crust where rock periodically breaks and moves, releasing seismic energy and creating an earthquake. The threat to Puget Sound from a quake along the Cascadia Subduction Zone, off the coast of Washington, Oregon and California, is well documented. The San Andreas in California, for example, left gaping scars in the Earths crust, at the surface. Most are too small to be felt or cause damage. These older faults do not have any evidence for recent activity, but the Earth is always changing. 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. 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. 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. 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. 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. But Forson says you also need to know what to do when the shaking happens. After the shaking stopped the sand regained its strength. Resources on tsunami danger and preparedness in Westport, Grays Harbor County, Long Beach Peninsula, and Coastal evacuation maps. Its certainly not to scare you. A seiche is a large standing wave caused by the resonance of a particular period of wave energy. The buildings in this photo were built on soft materials that liquefied during the 1964 Niigata earthquake in Japan. 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. Watch the video below to learn how you can be ready for the next earthquake. The Seattle fault last ruptured about 1,100 years ago in AD 900950. Many landslide-prone areas of Washington are also located near active faults. Faults can also be grouped based on what part of the crust they occur in. Visit our School Seismic Safety page for more information. Share sensitive information only on official, secure websites. This earthquake caused parts of Restoration Point near on Bainbridge Island to be lifted 35 feet straight up. Scientists dont know. Volcanic eruptions. The western half of Washington state is considered earthquake country, with the potential for very large quakes. By sampling sediment from the marsh to the beach berm, Sherrod and his research partner, Harvey Kelsey, developed a timeline of the oceans climb. Map Releases; Topographic (Topo) Maps; Volcanic Maps; All Maps; Multimedia Gallery. Unlike sound, ground shaking can be amplified or attenuated (made less) depending on the type of material at the Earths surface. This image shows the how the 1700 AD tsunami from the Pacific Northwest crossed the Pacific Ocean. People who look for evidence of past movement on faults are usually called paleoseismologists (from paleo-ancient and seismologist-one who studies earthquakes). This category only includes cookies that ensures basic functionalities and security features of the website. 1 0 obj So the fault remained mostly a mystery until the 1990s. (360) 678-5111 The tsunami becomes taller as the ocean becomes shallow. Both studies suggested that the SWIF This map shows different seismic design categories that correlate with amount of seismic risk. 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. Sherrod remembers his son, age 5 at the time, playing with toy trucks on the mossy banks of the marsh while the scientists worked. This map shows areas of seismic risk from high (red) to low (grayish-green). Like other faults, when enough stress builds up, the megathrust will rupture. You can look at different geological hazard mapson the website of the Department of Natural Resources. Recent geologic mapping by Washington State Department of Natural Resources (DNR) geologists reveals that this major fault zone extends through the Snoqualmie River valley in the vicinity of Carnation, Fall City, and North Bend. Source: United States Geological Survey. A team headed by Joe Dragovich of DNRs Division of Geology and Earth Resources,assisted by geologists from King County, Pacific Northwest Seismic Network, Colorado College, and Washington State University, has been mapping in this area for the past three years. HomePrograms and ServicesGeologyGeologic Hazards. 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. The evidence shows each lake rests on different free-floating jigsaw pieces of planetary crust, separated by the southern Whidbey Island fault. You will not be able to google what to do in an earthquake when it is happening. The South Whidbey Island Fault is also dangerous. The shaking can also cause landslides, surface ruptures, ground cracks, liquefaction, tsunamis, and seiches (standing waves). Radiocarbon dating and other paleoseismic methods have also confirmed this date. 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. An earthquake can be a scary event. A .gov website belongs to an official government organization in the United States. Large and damaging earthquakes are inevitable in Washington, but no one knows exactly when they will happen. The trenches exposed glacial deposits disrupted by faults and liquefaction features. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Maps. % Know what to expect. 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 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. It is a qualitative scale that ranges from IXI (1-11) and measures the amount of damage caused by an event. Southeast Extension of the Southern Whidbey Island Fault By Human Capital March 19, 2019. sw_whidbeyfault_rev122706.pdf (28.68 KB) Drop to your hands and knees. The French Onion trench exposed glaciolacustrine claystones, till, colluvial deposits, and Holocene soils. 572 Last Review Date: 2016-11-29 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. Once in the open, Drop, Cover, and Hold On. Some of these faults are in remote areas. 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. <>/XObject<>/ExtGState<>/Pattern<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Others, like the Seattle fault and southern Whidbey Island fault zone, cross under major cities and pose a significant hazard. Liquefaction has caused significant damage during earthquakes in Washington. 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. The Straight Creek fault in the Cascade Range is an example of this kind of fault and has ~5060 miles of movement across it. Cover your head and neck with your arms to protect against falling debris. 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 buildings sank when ground shaking weakened the underlying sediments. %PDF-1.5 District Court: (800) 946-9765, South Whidbey Island Fault (SWIF) M7.4 Earthquake Scenario. Although we cannot predict exactly when the next earthquake will happen, we can predict the general distribution of earthquake sizes. When an earthquake happens there will not be time to google what you are supposed to do. This is an active fault.. You just need one person to crash or a power line to fall over the road, and the roads are unusable.. Faults often occur at and near the boundary of large tectonic plates because the plates are moving in different directions. Throughout the world shallow earthquakes generally refer to earthquakes that are less than ~45 miles deep. 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 magnitude 7.4 along the southern Whidbey fault would rattle 18 counties in Washington, according to a federal projection . These large underwater slides only occur during very large earthquakes and are one way to learn about earthquakes that happened thousands of years ago. 1 School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada 2 Department of Earth and Environment, Boston University, Boston, Massachusetts 02215, USA 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. In the late 1960s, speculators considered the Puget Sound region a frontier for petroleum exploration. Faults can also occur within a tectonic plate when the plate itself is deforming. Sometimes there may be a layer of volcanic ash or charcoal that has been deformed by the fault. What we know about this fault is that its ruptured may times in the pastit will happen again. Before modern record keeping, Native Americans lived in the Pacific Northwest for thousands of years. And while scientists keep digging for more information and more situational awareness of what we face, the other problem is human. Seattle Fault and Whidbey Faults 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. When a fault with vertical movement ruptures the ocean floor, it lifts up part of the ocean. Buildings could sustain extensive damage. The 2011 Tohoku earthquake in Japan occurred on this type of fault and released enough energy to slightly change the Earths axis of rotation. Lidar maps show the Earths surface without vegetation. Scientists have also dated large underwater landslides and turbidites that travel from the continental edge far out into the ocean basin. Because they can travel great distances, tsunamis generated from earthquakes across the ocean can still cause damage. The best thing you can do is to become prepared. Tsunami waves can travel over 500 miles per hour in the open ocean. Earthquakes. This part of the Japanese coast had not seen this type of seismic rupture in some 800 years, and what failed was that walls built to keep tsunami waves were not high enough. Finding nothing of serious monetary value, the companies abandoned reams of information they had gathered through seismic surveys. 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. And when are documentary film called Cascadia The Big One, Dangerous Inland Earthquake Destroys Homes and Schools near Jakarta, Indonesia, Terrifying video shows olive grove turned into a Gigantic Canyon after Turkeys earthquake split land in huge rifts. The combination of all of these effects is what makes earthquakes such a powerful geologic hazard. They conclude the observed features have a glaciotectonic origin and are not seimotectonic. These faults and earthquakes occur in the continental crust of North America. Radiocarbon ages of macrofossils constrain uplift timing to 2.83.2 ka. A baristas hand hovers over the bean grinder. Jump from 60 to 600 per week in just 5 years in Pahala, Is the Cascadia Subduction Zone about to blow? The coast is now the home of one of the states largest network of warning sirens called All Hazard Alert Broadcast (AHABs). The fault's length depends on whom you ask, Sherrod said. The southern Whidbey Island fault (SWIF) stretches from the vicinity of Victoria, B.C., across Puget Sound as far as the Cascade Range. 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 What are the most dangerous fault lines for Seattle? Stop as quickly as safety permits and stay in the vehicle. Scientists are not sure how far east it goes. 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. Evacuate to higher ground if you are near a large body of water. Power could be out for days. Never use a lighter or match near damaged areas. The April 1949 Tacoma earthquake measured 7.1 on the Richter Scale and caused damage from southern Oregon to British Columbia. 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. 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. A national credit rating service has improved its opinion of WhidbeyHealths financial future. Gower (1980 #6229) showed and named the "southern Whidbey Island fault," and Gower and others (1985 #4725) showed this fault on their seismotectonic map of the Puget Sound region and briefly outlined its geologic relationships. 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). A normal fault occurs when two blocks are pulled away from each other. The Darrington-Devils Mountain fault zone is located in southern Skagit County and northern Snohomish County. 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. Seconds later, its as if Whidbey Island is trapped in a cocktail shaker, lurching back and forth. Charles Richter and Beno Gutenberg discovered that for every magnitude of earthquake, there are about ten times more earthquakes of the next lower magnitude. But the mapping offered geological clues that the newly found fault was indeed capable of future quakes. This new method allows geologists to see through trees and vegetation to find new faults. This is a very good example of a strike-slip fault. Secure .gov websites use HTTPS 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. In 1985, with little concrete evidence of its existence, the pair included the possible fault on a geologic map published by the USGS.