"We. Crustal Faults | Pacific Northwest Seismic Network On the east, the Devils Mountain Fault connects with the south striking Darrington Fault (not shown) which runs to the OWL, and the Southern Whidbey Island Fault extends via the Rattlesnake Mountain Fault Zone (dashed line) to the OWL. But it does not appear that there have been studies of the deeper structure of these faults, or whether there has been any recent activity. Folding and faulting has exposed these basalts in some places (black areas in diagram); the intervening basins have been filled by various sedimentary formations, some of which have been subsequently uplifted. 1 - 10 of 77 American Spirit Cruise Reviews. These maps are based on only one Cascadia scenario. Study of surface deformation suggests possible unmapped faults near Federal Way, running between Sumner and Steilacoom, and south of Renton.[223]. [67] However, subsequent mapping shows that the Woods Creek Fault (WCF), a four-mile wide strip of oblique-slip and strike-slip faults just to the west and passing directly under Sultan, appears to be the more significant fault, and better aligned with Mount Vernon. The Frigid Creek fault seems more directly aligned with this southwestward extension of the Seattle Fault, but such a connection seems to be as yet unremarked by geologists. The answer is still unresolved. The first item on your list though is the fault of builders and nobody else. Conjugate faults are secondary faults that branch off from opposite sides of a strike-slip fault at approximately the same angle. 182-3]", "Western limits of the Seattle fault zone and its interaction with the Olympic Peninsula, Washington", "Seismic reflection imaging across the eastern portions of the Tacoma fault zone", "The western extension of the Seattle fault: new insights from seismic reflection data", "Seismic Characterization of the Seattle and Southern Whidbey Island Fault Zones in the Snoqualmie River Valley, Washington", "Fault number 552, Hood Canal fault zone", "Radiocarbon Ages of Probable Coseismic Features from the Olympic Peninsula and Lake Sammamish, Washington", "Geologic map of the Summit Lake 7.5-minute quadrangle, Thurston and Mason Counties, Washington", "The Olympia structure; ramp or discontinuity? [130] This is likely not coincidental, as it appears that the Tacoma and Seattle faults converge at depth (see diagram above) in a way that northsouth compression tends to force the Seattle Uplift up, resulting in dip-slip movement on both fault zones. [79] It is deemed a "major active or potentially active" structure. At the edge of this older rock is the Rogers Belt, a geologically interesting zone running from the area of Sultan (due east of Everett) to Mount Vernon (just north of the bend in the Devils Mountain Fault). Arcos' work suggests. E.g., mapping along the Rattlesnake Mountain Fault Zone has revealed a complex network of active or potentially active faults across (and likely beyond) the lower Snoqualmie Valley, including the Cherry Creek Fault Zone, scene of the 1996 M 5.3 Duvall earthquake. The Woods Lake Fault, running past Lake Chaplain, corresponds closest to the mapped position of the southern end of Cheney's Mount Vernon Fault. Seismic tomography studies show a change in seismic velocities across the northern end of the SWIF, suggesting that this is also part of the Coast RangeCascade contact. This may explain why the Seattle and Tacoma faults seem to have ruptured at nearly the same time.[127]. [102] Or the Crescent margin may simply (and quietly) just run south-southeast under Seattle to the WRZ. 5) Select plot type. (A) Map of the Seattle fault zone (SFZ) in the central Puget Sound The Devils Mountain Fault (DMF) runs about 125km (75 miles) from the town of Darrington in the Cascade foothills due west to the northern tip of Whidbey Island, and on towards Victoria, British Columbia, where the DMF is believed to join the Leech River fault system at the southern end of Vancouver Island. Not until 2001 was it identified as a fault zone,[12] and only in 2004 did trenching reveal Holocene activity. While the great subduction events release much energy (around magnitude 9), that energy is spread over a large area, and largely centered near the coast. These lineaments have been associated with possible zones of faulting in the crust and subducting plate.[212]. (1997) a slab of rock mainly basalts of the Crescent Formation about 20km thick is being pushed up a "master ramp" of deeper material; this forms the Seattle Uplift. They estimate the fault is within a few miles of the surface and was active as recently as 1,000 to 1,100 years ago. Locations of some previously mapped faults have been adjusted on the latest map. A Puget Sound Fault running down the center of Puget Sound (and Vashon Island) was once proposed,[220] but seems to have not been accepted by the geological community. [83], The CCFZ appears to be related to the parallel Tokul Creek fault zone to the south; both appear to be conjugate faults[84] to the northwest-trending SWIF. Fault Lines In America: 9 Things (2023) You Need To Know - Gokce Capital [198], Does the SHZ extend north? Nurse Information Line at VA Puget Sound health care, 800-329-8387 x4. A magnitude 7.1 earthquake in the Tacoma Fault Zone A plausible scenario for the southern Puget Sound region, Washington May 18, 2010 Citation Information. [190] These faults also cross the Saint Helens Zone (SHZ), a deep, north-northwest trending zone of seismicity that appears to be the contact between different crustal blocks. If, as this model suggests, the various faults are interconnected within the thrust sheet, there is a possibility that one earthquake could trigger others. These features suggest that the southern Puget Lowland is influenced by the deep crust and even the subducting Juan de Fuca plate, but the details and implications are not yet known. [100], However, gravity and other data suggest that near the southern tip of Whidbey Island the Crescent Formation contact may turn away from the SWIF, and may even be reentrant under north Seattle,[101] forming the northwestern side of the Seattle Basin, and possibly connecting with the recently reported "Bremerton trend" of faulting running from the southern end of Hood Canal, through Sinclair Inlet (Bremerton), and across Puget Sound. OLYMPIA, Wash. - A 9. Black lines show the South Whidbey Island Fault Zone, the Seattle Fault Zone and the Tacoma Fault Zone. https://en.wikipedia.org/w/index.php?title=Puget_Sound_faults&oldid=1132982136, Creative Commons Attribution-ShareAlike License 3.0, A great subduction earthquake, such as the. 1 earthquake in the past 7 days. [73] The presence of detritus from the Idaho Batholith[72] indicates a former location closer to southern Idaho. Yet the former is only the first of at least six more parallel southeast striking faults, which do cross the Salzer Creek Fault. TTY Relay 711. [42] Marine seismic reflection surveys show it striking northwest across the eastern end of the Strait of Juan de Fuca. Subsidence dated to between AD 1445 and 1655 has been reported in Mud Bay (just west of Olympia). Contact Us | VA Puget Sound Health Care | Veterans Affairs One study compared the relative elevation of two marshes on opposite sides of Whidbey Island, and determined that approximately 3,000 years ago an earthquake of M 6.57.0 caused 1 to 2 meters of uplift. There are some interesting relationships here. New tsunami maps show how water could reach Seattle, Everett, Tacoma (See, There is a preliminary report of aeromagnetic and gravity mapping placing the eastern edge of the Siletz terrane under Lake Washington. This fault seems to be associated with the Kingston arch anticline, and part of the uplift and basin pattern, but shortened because of the geometry of the SWIF. There is a general pattern where most of these faults partition a series of basins and uplifts, each about 20km wide. The northern end of the Crescent Formation (aka Metchosin Formation) has been identified as the eastwest trending Leech River Fault on the southern tip of Vancouver Island. The history and capabilities of the Frigid Creek Fault are not known. Bubbles of methane rising from seafloor in Puget Sound - Phys.org Offsets in the eastwest oriented Monroe Fault (south side of the Skykomish River), earthquake focal mechanisms, and kinematic indications show that the CCFZ is a left-lateral strike-slip fault, possibly with some oblique motion (up on the eastern side). [92] This is where the SWIF encounters the edge of the Western and Eastern Melange Belts (remnants of a mid-Cretaceous subduction zone[93]); the RMFZ is where the Seattle Uplift is being forced against the Western Melange belt[94], To the north the Melange Belt is manifested as the Rogers Belt, a zone of low-amplitude folding stretching from Monroe to Mount Vernon; the apparent western edge of this zone is on-strike with the RMFZ. This follows the front of the Rosedale monocline, a gently southwest-tilting formation that forms the bluffs on which Tacoma is built. [91] The relationship between these two fault zones is not entirely clear. Rainier, along the DDMFZ, and under Puget Sound between Olympia and approximately the Southern Whidbey Island Fault. Where it intersects the northwest-trending Johnsons Swamp fault zone, easternmost member of the RMFZ. Bubbles of methane rising from seafloor in Puget Sound The Doty fault particularly seems to have gained prominence with geologists since it was associated with an aeromagnetic anomaly,[184] and a report in 2000 credited it capable of a magnitude 6.7 to 7.2 earthquake. Even before Washington became a state in 1889, Puget Sound beaches had been exploited as log dumps, farmed for shellfish, occupied as homesites and enjoyed for recreation. [6] The first definite indications of most of these faults came from gravitational mapping in 1965,[7] and their likely existence noted on mapping in 1980 and 1985. The Puget Sound faults under the heavily populated Puget Sound region (Puget Lowland) of Washington state form a regional complex of interrelated seismogenic (earthquake-causing) geologic faults. [170] Gower, Yount & Crosson (1985), labelling it "structure L", mapped it from Shelton (near the Olympic foothills) southeast to Olympia (pretty nearly right under the state Legislature), directly under the town of Rainier, to a point due east of the Doty Fault, and apparently marking the northeastern limit of a band of southeast striking faults in the Centralia-Chehalis area. King County Emergency Management. [125] While some coherency is developing, the story is not complete: identified faults do not yet account for much of the region's seismicity. [71], These faults cut through the Western Mlange Belt (WMB; blue area in map), exposed from North Bend (on Interstate 90) to Mount Vernon. The lowest exposed strata of Tiger Mountain, the mid-Eocene marine sediments of the Raging River formation, may be correlative with the SWCC. Another model (of Stanley, Villaseor & Benz 1999, USGS Open-File Report 990311) not so much in competition with the first as complementing it used seismic and other data to create a 3-D tectonic model of the whole crust; this was then analyzed using finite element methods to determine regional geodynamic characteristics. 2-5 Cruises Age 60s. (Links with more information on various hazards can be found at Seattle Fault.). Housing: The Puget Sound had the largest increase in population per Review for American Constellation to U.S.A. chatuga. [61], North of Everett is an area of parallel ridges and stream drainages oriented approximately NW-SE, evident even on non-geological maps. Publication Year: 2010: Title: A magnitude 7.1 earthquake in the Tacoma Fault Zone A plausible scenario for the southern Puget Sound region, Washington: DOI: 10.3133/fs20103023: Authors: A parallel line ("B") about 15 miles (25 kilometers) to the west corresponds to the western limit of a zone of seismicity stretching from the WRZ to southwest of Portland. If so, this would be a major fault system (over 185km long), connecting the Puget Lowland with the Yakima Fold Belt on the other side of the Cascades, with possible implications for both the OlympicWallowa Lineament (which it parallels) and geological structure south of the OWL. Gonzalez: That Seattle Fault tsunami has been modeled by others. ecc.kc@kingcounty.gov. Although the largely unstudied White River Fault (WRF) appears to lie just outside the Puget Lowland, it may actually connect under the Muckleshoot Basin to the East Passage Zone and the Tacoma Fault (map). The last major earthquake on the Seattle Fault occurred around 1,100 years ago, shifting the landscape in Puget Sound. [43] Just south of Victoria, British Columbia it intersects the west-striking Devils Mountain Fault (reviewed above), and either merges with it,[44] or crosses (and possibly truncates) it to connect with the Leech River Fault. Other faults to the south and southeast the Frigid Creek Fault and (to the west) Canyon River Fault suggest an extended zone of faulting at least 45km long. Puget Sound Energy transmission line project Energize Eastside. Modeling a Magnitude 7.2 Earthquake on the Seattle Fault Zone in [38] These earthquakes probably caused tsunamis, and several nearby locations have evidence of tsunamis not correlated with other known quakes. Tacoma, WA. When the applied stresses become overpowering, the rocks at the fault rupture. At Darrington it is seen to connect with the Darrington Fault, which runs nearly south 110km to converge with the Straight Creek Fault (SCF), and then to turn near Easton to align with the OlympicWallowa Lineament; together these are known as the DarringtonDevils Mountain Fault Zone (DDMFZ). ), and headed for the definitely active Saint Helens Zone; this appears to be a large-scale structure. The EPZ is active, being the locale of the 1995 M 5 Point Robinson earthquake.[136]. It is uncertain how these faults relate to the structure, and whether they are deep-seated faults, or fractures due to bending of the shallow crust. Plot Type: X-Section Depth Cumulative # Mag-Time. $30 to $33 Hourly. The Seattle Fault is a zone of complex thrust and reverse faults between lines E and F on the map up to 7km wide and over 70km long that delineates the north edge of the Seattle Uplift. In the angle between these is located the minor Lincoln Creek uplift, the Doty Hills, and, further west, an impressive chunk of Crescent basalt. Methane Plume Emissions Associated With Puget Sound Faults in the Cascadia Forearc. Display Faults. Accommodation of strain (displacement) between the Seattle Fault and the Saddle Mountain deformation zone is likely distributed across the more pliable sediments of the Dewatto Basin; this, and the greater depth to the Crescent Formation, may account for the subdued expression of the Seattle Fault west of Green Mountain. [88] (See the adjacent map. Discovery of faults has been greatly facilitated with the development of LIDAR, a technique that can generally penetrate forest canopy and vegetation to image the actual ground surface with an unprecedented accuracy of approximately one foot (30cm). The magnitude-4.0 earthquake that rattled people awake across the Puget Sound region last Wednesday probably struck on the western edge of the Seattle Fault, according to geologists. The Pacific Northwest Seismic Network (PNSN) reported at least three earthquakes within the past few days. Those Hollywood depictions of a. Saint Helens and Mt. [216], An Everett Fault, running east-northeast along the bluffs between Mukilteo and Everett that is, east of the SWIF and at the southern edge of the Everett Basin has been claimed, but this does not appear to have been corroborated.[217]. [160] The Canyon River Fault is a major fault in itself, associated with a 40km long lineament and distinct late Holocene scarps of up to 3 meters.[161]. Devils Mountain Fault Zone, Northern Puget Sound, Washington [11] Marine seismic reflection surveys on Puget Sound where it cuts across the various faults have provided cross-sectional views of the structure of some of these faults, and an intense, wide-area combined on-shore/off-shore study in 1998 (Seismic Hazards Investigation in Puget Sound, or SHIPS)[12] resulted in a three-dimensional model of much of the subsurface geometry. American Seattle Cruise Reviews - Cruise Critic [200], Mount St. Helens and Mount Rainier are located where their associated fault zones make a bend (see map, above).[201](Mt. It is believed capable of generating earthquakes of at least magnitude 7, and there is evidence of such a quake approximately 1,000 years ago, possibly the same earthquake documented on the Seattle Fault 24 miles (38km) to the north. Geochemistry, Geophysics, Geosystems , 2021; 23 (1) DOI: 10.1029/2021GC010211 Cite This Page : [122] This trend extends further north where the Pleasant Harbor lineament appears to terminate other westward extensions of the SFZ. Most people in the United States know just one fault line by name: the San Andreas, which runs nearly the length of California and is perpetually rumored to be on the verge of unleashing "the. A different mountain and fault zone of the same name are located near Pasco; see QFFDB Fault #565), The southern end of Rattlesnake Mountain is truncated at the OlympicWallowa Lineament (OWL), and the faults turn easterly to merge with the OWL. [75], The strongly expressed topographical lineaments at the north end of the Rogers Belt pose a perplexing problem, as they show no definite offset where they are bisected by the left-lateral oblique-slip Devils Mountain Fault. 4) Drag square on line to include events to plot. (Not included in QFFDB. The Doty fault has been mapped from the north side of the Chehalis airport due west to the old logging town of Doty (due north of Pe Ell), paralleled most of that distance by its twin, the Salzer Creek Fault, about half a mile to the north. This map of Puget Sound shows the location of the methane plumes (yellow and white circles) detected along the ship's path (purple). [90], The RMFZ continues NNW past Fall City and Carnation, where strands of the RMFZ have been mapped making a gentle turn of 15 to 20 west to meet the Southern Whidbey Island Fault zone (SWIF, discussed above); the RMFZ is therefore considered to be an extension of the SWIF. A Seattle Fault quake could be as large as M7.5,160 but less than M7.0 is more probable. Bubbles of methane rising from seafloor in Puget Sound [132], Scarps associated with Holocene uplift of the Tacoma fault have been traced westward to Prickett Lake (southwest of Belfair, see map). The Seattle Fault is the most studied of the regional faults, which has led to several models of its structure, which may also be relevant to other faults. The discovery was an alarm bell for engineers and emergency planners. See Snavely et al. [44] The significance of this whether the edge of the Crescent Formation (and implicitly of the Siletz terrane) turns southward (discussed below), or the metamorphic basement is supplanted here by other volcanic rock is not known. Geologic Hazard Maps | WA - DNR Over 7,000 people are dead after a magnitude 7.8 earthquake shook southern Turkey, near the Turkish-Syrian border. Let's make your home safer [21] The OWL appears to be a deep-seated structure over which the shallower crust of the Puget Lowland is being pushed, but this remains speculative. [162] Trench studies indicate major earthquakes (in the range of M 6. to 7.8) on the Saddle Mountain faults [163] at nearly the same time (give or take a century) as the great quake on the Seattle Fault about 1100 years ago (900930 AD). The Puget Sound faults under the highly populated Seattle and Puget Sound region of Washington state form a regional network of interrelated seismologic geologic faults.