Located off the pacific northwest coast, this plate runs from central vancouver island, b. In the last 10 years, several shallow subduction zone earth caused by the large displacement of water near the ocean. The cascadia playbook is the blueprint for preparing for a large scale catastrophic event, but it also guides responses to other emergencies and incidents. Revising an innovative way to study cascadia megaquakes eos. Cascadia is americas own tectonic version of sumatra, where the magnitude 9.
Request pdf continuous chatter of the cascadia subduction zone revealed by machine learning tectonic faults slip in various manners, which range from ordinary earthquakes to slow slip events. Physical model of source region of subduction zone volcanics. Are intermediatedepth earthquakes in subducting slabs linked to metamorphic dehydration reactions. Tectonic evolution and mantle structure of the caribbean. Pdf statistical analyses of great earthquake recurrence. The process of sinking of cold oceanic lithosphere into the mantle, occurring at convergent margins, is called subduction. The oceanic lithosphere entering the cascadia subduction zone in all segments is extremely young, less than 10 ma. Which mountain ranges were caused by the cascadia subduction zone. Because the cascadia subduction zone earthquake will likely be of much longer duration than these two previous events, it has the potential to cause even more damage. Pdf turbidite event historymethods and implications for. The cascadia subduction zone a decade into the 21st century, the world of books, the world of the arts, the world of criticism have all been caught up in violent, unpredictable change. Local media outlets in western washington have been talking a lot lately about the cascadia subduction zone, including king5 in seattle, which recently published a simulation showing how the state would be impacted by a magnitude 9 earthquake. A huge earthquake that happens because of a subduction zone.
When the big one hits the cascadia subduction zone, its gameover for seattle. Thermal models for the cascadia subduction zone hyndman and wang, 1993, 1995 constrained by heat flow measurements showed that the 350c isotherm is offshore beneath the continental slope. Earthquakes on the cascadia subduction zone can be over 9. Subduction zone earthquakes off oregon, washington more. Cascadia subduction zone worse than san andreas fault cnn. Exhumation processes in oceanic and continental subduction. State of oregon office of emergency management cascadia. Of the other six zones around the pacific where young subduction interface in historic time. State of oregon office of emergency management cascadia playbook. Preparing for a cascadia subduction zone earthquake and ensuing tsunami may seem like a daunting task, but each step we take to prepare helps make oregon more resilient.
The cascadia basin is an ideal place to develop a turbidite paleoseismologic method and to record paleoearthquakes because. Nature of the plate contact and subduction zones diversity. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Seismologists predict that about every 300 years, this fault will generate a megathrust earthquake of magnitude 8 or greater. Great earthquakes of variable magnitude at the cascadia subduction zone. Last cascadia megaquake happened 318 years ago friday. We model tsunami runup and inundation along the northern california coast caused by hypothetical earthquakes on the cascadia subduction zone csz.
We present data that indicate the periodicity of slow earthquakes in cascadia and the current onset of such an event. California cascadia subduction zone earthquake and tsunami. The cascadia subduction zone represents the single largest hazard to the people and built environment of oregon. We show significant seismic differences between the flat and normal subduction zones. Cascadia subduction zone csz pacific northwest catastrophic earthquake and tsunami functional exercise. Subduction zone by robert yeats sometime in the future, the pacific northwest, including oregon, washington, vancouver island, and northern california, will experience a devastating earthquake as large as magnitude 9the same magnitude as an earthquake in coastal northeast japan in 2011 in which nearly 16,000 people were killed. Land level change pacific northwest seismic network. This can be as simple as grabbing a bunch of ramen noodles. For this reason, the expected recovery duration for vulnerable buildings in eastern oregon was determined to be 30 days.
Within subduction zone, the depth of decoupling between the mantle wedge and the subducting slab cor responds to the stability depth of serpentine weak. Petrological models marsh 1979, maale and petersen 1981, myers et al. Cascadia subduction zone videos and latest news articles. Cascadia subduction zone wikipedia republished wiki 2.
As a possible analog to the cascadia subduction zone, mazzotti and others 2000 analyze data from a dense gps network in japan and determine that the nankai and japanwest kurile subduction. New cascadia subduction zone earthquake study is worse news. Transportation impacts of a cascadia subduction zone. Cascadia subduction zone csz catastrophic earthquake and. The csz forms the boundary between the pacific and north american tectonic plates and extends from. The black polygon offshore is the modeled fault rupture for this scenario. On april 29, 2014, i presented a talk for data rave, nyc at ebay. As noted by the usgs, recently, it has been discovered that the cascadia subduction zone, like the subduction zone off chile, has a history of producing earthquakes that triggered tsunamis. This collision makes one plate go under the other, producing a leaning area of seismicity known as a wadatibenioff zone, which dives, in some cases, up to 434 mi to the interior of the earth with an inclination of 4060, while the other plates ascent gives rise to mountainous reliefs. In the toe region off muroto, a sedimentary section 1 km thick is accreted to or underthrust below the. U n d e r s t a n d i n g e a r t h q u a k e h a z a r d s i n w a s h i n g t o n s tate modeling a magnitude 9. The cascadia subduction zone shares many characteristics with subduction zones in southern chile, southwestern japan, and colombia, where comparably young. Scientists estimated the magnitude and timing of each quake by examining soil samples at more than 50 undersea sites between washington, oregon and california. Oregons greatest natural threat introduction when, not if, the next great cascadia subduction zone earthquake strikes the pacific northwest, oregon will face the greatest challenge in its history.
This blog covers the talk, and the original slides can be found in my github repo. The findings were published in the september 23 issue of science. Earthquakes on the cascadia subduction zone have struck the northwest offshore for at least 10,000 years. Tectonic plates are those slabs of mantle and crust that, in. The earthquake that will devastate the pacific northwest. Subduction is a geological process that takes place at convergent boundaries of tectonic plates.
The most recent big cascadia earthquake occurred on january 26, 1700, dated by accounts from japan of an orphan tsunami generated by a cascadia earthquake and recorded after the wave crossed the pacific ocean. The recent inversion of gps data by mccaffrey et al. A large part of this change has been unleashed by a continual stream of technological innovations that impact our daily lives and even our personal as well as. Continuous chatter of the cascadia subduction zone revealed. Mexican subduction zone had a maximum depth of about 25 km r. The bend in the margin trend and subducting slab end effects are included. Cascadia ready rrcc exercise phase i week of may 18 th 2015 concept. The impacts of the cascadia subduction zone earthquake on oregon. Add to that seiche, tsunami, and aftershocks and this is the disaster to prepare for. Earthquakes and tsunamis in the cascadia subduction zone.
Transportation impacts of a cascadia subduction zone earthquake. Along the west coast of north america, the cascadia subduction zone stretches more than 1,000 kilometers from vancouver island to cape mendocino, calif. Just north of the san andreas, however, lies another fault line. When the plates move suddenly in an area where they usually stick, an earthquake happens. A catastrophic earthquake and tsunami event along the 800milelong cascadia subduction zone, which lies off the northwest coast of the united states, presents a. Mar 17, 2018 earthquakes on the cascadia subduction zone have struck the northwest offshore for at least 10,000 years. When was the last megathrust earthquake from the cascadia subduction zone.
The cascadia subduction zone csz is a 1,000 km 620 mi long dipping fault that stretches from northern vancouver island to cape mendocino in northern california. As expected, the flat slab region is impacted by colder. Very young oceanic lithosphere 10 million years old is being subducted beneath north america at a rate of approximately 4 centimeters per year. Warmer than 350c and through a transition zone, fault slip is expected to be stable. Feb 11, 2016 the cascadia subduction zone could deliver the worst earthquake in north america. Can a creeping segment of the alaskaaleutian subduction. Most notably, geophysicists in oregon and washington have spent the last 2030 years identifying, mapping and correlating tsunami deposits and earthquaketriggered landslides and turbidites in. The presence of hot, waterrich liquids causes the overlying rock to begin melting. The last major csz earthquake and tsunami occurred in 1700.
Williams and robert mccaffrey, journalgeophysical research letters, year2001, volume28, pages2125. The subduction zone part refers to a region of the planet where one tectonic plate is sliding underneath subducting another. California cascadia subduction zone earthquake and tsunami response plan. D model of the cascadia subduction zone calculates the surface deformation for a locked zone or a rupture zone of variable width along the margin. The csz is different than most subduction zones in that it is locked. Canadian journal of earth sciences canadian science publishing. To investigate these characteristics, we conducted detailed. The parameters have been grouped in tables 15 as follows.
Cascadia subduction zone earthquakes oregon state library. Great earthquakes of variable magnitude at the cascadia. Shallow subduction zone earthquakes and their tsunamigenic. The cascadia subduction zone is capable of generating a devastating earthquake at any time. Recent subduction zone fault earthquakes around the world underscore the similar challenges we will face when. Pdf stress rates in the central cascadia subduction zone. Large subduction earthquakes on the cascadia subduction zone pose a potential seismic hazard. Mar 29, 2002 because subduction zones generate the largest earthquakes, seismic hazard assessment relies on understanding the degree to which slow earthquakes reduce the energy released by infrequent large earthquakes. The impacts of the cascadia subduction zone earthquake on.
The csz has a history of producing large earthquakes and will produce 8. Cascadia subduction zone usgs earthquake hazard program. Using the rv sonne during april and may, 1996, we collected seismic re. The southern end of the zone has historically been more active than the northern. Cascadia ready rrcc exercise phase ii week of february 22 nd 2016. The cascadia subduction zone also referred to as the cascadia fault, or cascadia is a convergent plate boundary that stretches from northern vancouver island in canada to northern california in the united states. Observe an animation of volcanism at a subduction zone. The cascadia subduction zone csz megathrust fault is a 1,000 km long dipping fault that stretches from northern vancouver island to cape mendocino california. Modeling tsunami inundation from a cascadia subduction zone earthquake for long beach and ocean shores, washington a.
Earthquake hazards on the cascadia subduction zone science. Gps strain rates and velocities show that the northwestern. As an oceanic plate descends to hotter depths beneath the overriding plate, it is heated and releases water. An additional day of training could potentially be added. The resulting magma is less dense than the surrounding rock, so it rises up toward the surface. Twodimensional finite element modeling is used to model subduction of an oceanic lithospheric plate beneath continental lithosphere. Childsb, dirk klaeschen a, nina kukowskia, tom parsonsb, david w. Check out these presentations and guides to better understand this hazard and prepare and protect your family, home and business. It runs 700 miles underwater along pacific northwest, from canada to california. The serpentinitetype subduction zones exhume hp to uhp in a 1 to 10 km thick serpentinite subduction channel. The cascadia subduction zone also referred to as the cascadia fault is a convergent plate boundary that stretches from northern vancouver island to northern california. Between earthquakes, when the two converging plates are locked, internal stress stored by the plates slowly deforms the land, pushing it upward and in the direction of motion of the subducting plate inland in cascadia.
You, wonderful volunteers, are invited to play along in this exercise. Using these data and those from the 1995 washington seismic transect luetgert et al. A complete timedependent model for the cascadia subduction zone, including m 8. The noaa center for tsunami research modeled tsunami inundation from a great cascadiasubduction zone earthquake for the coastal communities of long beach and ocean shores. The chart shows all 40 major earthquakes in the cascadia subduction zone that geologists estimate have occurred since 9845 b. In most other subduction zones, tectonic plates slide more freely and therefore have more frequent earthquakes, releasing builtup pressure more often. The cascadia subduction zone off the coast of north america spans from northern california to southern british columbia. This subduction zone can produce earthquakes as large as magnitude 9 and corresponding tsunamis. Subduction zones are confrontation areas of two or more tectonic plates colliding on an ongoing basis. The paper for which the talk and this blog are based is found here. Recent studies show that there is about a 40% chance of a cascadia earthquake occurring in the next 50 years.
The cascadia subduction zone is a fracture in the earths crust that stretches from vancouver island to northern california. Despite various uncertainties in the model and geothermal data, the. Cascadia subduction zone is given in the lower figure. A revised dislocation model of interseismic deformation of. Periodic slow earthquakes from the cascadia subduction zone. Both of these lines of evidence lend support to the model with. Cascadia subduction zone pacific northwest seismic network. The last time the cascadia subduction zone burped up a massive, zone wide earthquake was way back in 1700. Location of coastal sites along the cascadia subduction zone with evidence for great cascadia earthquakes and accompanying tsunamis after atwater and hemphillhaley, 1997, their fig. Cascadia subduction zone earthquake and tsunami youtube. Dec, 2019 the cascadia subduction zone off the coast of north america spans from northern california to southern british columbia.
Elsevier tectonophysics 293 1998 6984 new seismic images of the cascadia subduction zone from cruise so108 orwell ernst r. My collaborators on this project are rob mccaffrey at portland state university and ken creager at the university of washington. Known as the cascadia subduction zone, it runs for seven hundred miles off the coast of the pacific northwest, beginning near cape. Stable subduction zones involve the oceanic lithosphere of one plate sliding beneath the continental or oceanic. As the downgoing subducting plate moves deeper, it transports water into depth where it is heated and released. Hinge line one tectonic plate descends, or subducts, beneath an adjoining plate.
Subduction zone trenches are delineated with black lines, and downgoing caps are labeled with arrows showing the convergence direction. Global bathymetry and topography of the pacific margin illustrates multiple arc. Gps deformation in a region of high crustal seismicity. Sites offigure 2 with long earthquake histories,and with ages more precisethan those from mostsites, are labeled in bold italics. The nankai subduction zone forms an endmember sedimentdominated accretionary prism. Pdf great earthquakes of variable magnitude at the cascadia.
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