southern whidbey island fault map southern whidbey island fault map

Coupeville, WA 98239, Main Line: 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. Finding and learning about faults requires many different aspects of geology and geophysics. Photo from, Liquefaction can be a big problem. Still think well avoid Gods wrath, its not going to happen regardless of what the multi millionaire TV preachers tell you. These sediments were laid down 20,000 to 60,000 years ago, before the last ice age. In much of Washington, dense vegetation covers the land and makes finding faults very difficult. They didnt recognize the significance of what they found. Then consider that the Seattle Fault is a complex of faults with various branches that run at or just below the surface. Tsunamis are a common result of large earthquakes in Washington. Reverse faults are usually steep and occur in regions of compression. The height difference likely was caused by a 7.5 magnitude earthquake on the fault about 2,700 years ago, Sherrod said. This is sometimes called "The Big One" by news media. In some areas getting up a hill to higher ground will be difficult. Using the stratigraphic column from the Freeport quadrangle map, confirm that you can recognize . Johnsons curiosity changed the course of his career. Once we got it, we were sort of shocked to see these big faults in the Puget lowlands, he said. (360) 678-5111 His team wanted to find the rate of sea level rise along the shore. 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. 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. Sherrod remembers his son, age 5 at the time, playing with toy trucks on the mossy banks of the marsh while the scientists worked. Because they rupture at such great depth, their seismic energy is distributed over a large area. Restoring tap water to some homes could take over a year. Some types of seismic energy (P waves) are similar to sound energy that is released if you break a twig or slide a chair across the floor. When the ground shakes during an earthquake, it moves up and down, acting like additional gravity. This fault zone was originally named the Devils 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. This map is from a 2007 report on the seismic design categories in Washington. The map also shows potentially active faults from a separate 2014 report (click here to download). A strike-slip fault occurs when two blocks move past each other. This is an active fault.. Along the coast residents may have between 20 and 30 minutes to get to higher ground. Nearly all earthquakes occur on faults, features in the Earth where rocks move past each other. This means that the internet, your cell phone, grocery stores, and gas stations may also not work. A special type of shallow fault, called a subduction zone or megathrust, occurs where an oceanic plate moves beneath a continental plate. 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 buildings in this photo were built on soft materials that liquefied during the 1964 Niigata earthquake in Japan. Click the "Seismogenic Features" button in the Map Contents window to display faults and earthquakes. This earthquake caused parts of Restoration Point near on Bainbridge Island to be lifted 35 feet straight up. PO Box 5000 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. The average time between large earthquakes is about 535 years, but has been as little as 200 years, and more than 1,000 years. Customers lift their eyes from phone screens. Its just the way scientists work, he said. 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. 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. Evacuate to higher ground if you are near a large body of water. When the landslide hit the water it may have created a tsunami. View Earthquake Map Faults Interactive fault map and comprehensive geologically based information on known or suspected active faults and folds in the United States. This movement happens because stress builds up as tectonic plates move. (Andy Bronson / The Herald). Hover over a cluster of earthquakes to learn about the different types in the Pacific Northwest. The southern Whidbey Island fault, and several others, were exposed for the first time from a camouflage of forest, ocean and glacial sediment. Many landslide-prone areas of Washington are also located near active faults. There are also many faults that have not been studied enough to know if they are active. It usually also means that there are earthquakes (even small ones) on the fault. Emergency Management Maps - Island County, Washington Earthquake Hazard Maps | Sound Seismic This is a hypothetical scenario created by Mark Murphy of the Snohomish County Department of Emergency Management. 3 0 obj Although both seiches and tsunamis can be large and destructive, they are created differently. Faults can also occur within a tectonic plate when the plate itself is deforming. Tap/click on "gear icon" for options and settings. People who look for evidence of past movement on faults are usually called paleoseismologists (from paleo-ancient and seismologist-one who studies earthquakes). Consider whether earthquake insurance is right for you. Johnson and others (1996 #4751) described the structure and stratigraphy of the southern Whidbey Island fault zone. Liquefaction can be a big problem. 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. The plate that is forced down can have faults within it that still rupture and produce earthquakes. Photo by G.K. Gilbert, from the Steinbrugge Collection of the UC Berkeley Earthquake Engineering Research Center. Source: United States Geological Survey. He said he believes dramatic shifts from that quake also may be visible on the western edge of Camano Island. Theres approximately a 14% chance of another approximately M9 earthquake occurring in the next 50 years. Shallow faults produce earthquakes in the upper 18 miles (30 kilometers) of the Earths crust. Tsunamis and seiches can also be triggered by large slides, both on land and underwater. Graphic from IRIS. Though it was not directly related to Johnsons work, he asked a friend working for Mobil Oil to pass along the information. While the intensity of this seismic event has now decreased, a big earthquake is overdue in the region. #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. Snohomish, King and Island counties would be expected to see the. Johnson and others (1996) have described the southern Whidbey Island fault ( figure 1) as a broad (6 - 11 km) transpressional zone comprising three main splays, within which the local late Quaternary uplift rate is at least 0.6 mm/yr. Depending on the type of fault, the ground can move laterally, vertically, or a combination of both. Geologists do not yet know how often earthquakes happen on this fault. Even when an earthquake happens on a fault that doesnt reach the surface, the ground can still show signs of cracking. Know what other hazards you might face. The fault probably originated during the early Eocene as a dextral strike-slip fault along the eastern side of a continental-margin rift. Notable earthquakes in bold happened in Washington. , * NOTE: Hazard maps for each jurisdiction will only be included if that jurisdiction is at risk to that hazard., Copyright Island County. The French Onion trench exposed glaciolacustrine claystones, till, colluvial deposits, and Holocene soils. A few miles southeast across the white-capped waves of Admiralty Bay, Lake Hancock rises and falls with the tides. District Court: (800) 946-9765, South Whidbey Island Fault (SWIF) M7.4 Earthquake Scenario. Most injuries occur when people inside change rooms or try to leave the building. Some faults reach the surface and can be found by geologists. South Whidbey Island Fault Zone. Sherrod shrugged his shoulders. Many faults have not been studied enough to know if they are active. Stop as quickly as safety permits and stay in the vehicle. They conclude the observed features have a glaciotectonic origin and are not seimotectonic. 3. Aftermath: Infrastructure won't fare well in a big quake Here, were looking at one of the bigger faults in the region, he said. Finding Concealed Active Faults: Extending the Southern Whidbey Island The Seattle fault is a good example of a fault that is mostly reverse. 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. The San Andreas fault in California is a good example of a very active strike-slip fault. 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). Seattle's Faults: Maps That Highlight Our Shaky Ground This map shows different seismic design categories that correlate with amount of seismic risk. The southern Whidbey Island fault divides the two. These aftershocks can last for hours to weeks or months. It is capable of generating severe earthquakes that would impact the entire west coast. Make an emergency response plan for you and your family. Sensitive seismographs located throughout the state, and all over the world, measure this seismic energy. This might include flammable appliances like a water heater, tall items like book cases, or heavy pictures. Drop, Cover, and Hold On whenever you feel shaking. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. Hold on to any sturdy shelter until the shaking stops. Emergency Management Hazard Maps - Island County, Washington 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 1990s, scientists producedan animationthat shows inundation, and people wont have much time to run to higher ground. 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 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). 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 The Survey works to increase public and scientific understanding of fault and earthquake hazards in our state. 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. Both types of faults can cause ground shaking during an earthquake and may cause permanent deformation of the ground. Geologists have used the location of these shallow, intermediate, and deep earthquakes to learn about subduction zones throughout the world. California Department of Conservation. endobj Often this cracking happens because a soft part of the ground liquefies during the shaking. The process of breaking and moving rock releases a large amount of energy that travels through the Earth as seismic waves. The most important thing you can do before the next earthquake is to prepare. . For example, a M7 earthquake releases 32 times more energy than a M6 earthquake, and 1,000 times more than a M5 earthquake. Experts believe a magnitude 9.0 could happen there anytime in the next 200 years or so. Within this rich oral history there are many references to events like earthquakes and tsunamis. Areas like these are also susceptible to liquefaction. Over time, fault movement has created some interesting geologic features. 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. 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. The medic said colleagues were becoming sick and emotionally overwhelmed Both studies suggested that the SWIF The continued movement along faults over millions of years can build mountains, tear a continent apart, and move tectonic plates thousands of miles. Jump from 60 to 600 per week in just 5 years in Pahala, Is the Cascadia Subduction Zone about to blow? Theyre FREE CLICK HERE to subscribe, EAR TO THE GROUND WITH DNR & COMMISSIONER FRANZ, Tree Link helps you answer questions about urbantrees. The Cascadia Subduction Zone (also known as the CSZ) is a 700-mile long fault zone located off the western coastline of British Columbia, Washington, Oregon and northern California. A lock () or https:// means youve safely connected to the .gov website. All Rights Reserved 2021, Site Disclaimer Avoid stopping near or under buildings, trees, overpasses, or utility wires. The Seattle fault last ruptured about 1,100 years ago in AD 900950. PDF Cretaceous-Jurassic accreted terrains - University of Washington Southeast Extension of the Southern Whidbey Island Fault By Human Capital March 19, 2019. sw_whidbeyfault_rev122706.pdf (28.68 KB) 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.