Today's Earthquakes in Puget Sound, Washington New tsunami simulation predicts flooding on Olympic Peninsula | Tacoma Puget Sound quake likely in Seattle Fault zone, geologists say - Phys.org [178] Alternately, the OS appears to coincide with a gravitational boundary in the upper crust that has been mapped striking southeast to The Dalles on the Columbia River,[179] where there is a swarm of similarly striking faults. A principal finding is that "[c]rustal seismicity in the southern Puget Sound region appears to be controlled by a key block of Crescent Formation occurring just south of the Seattle fault. The question of where on Puget Sound the line would ultimately end was intentionally left open, and the region's fledgling cities began competing furiously for the good fortune of a major railroad terminus. [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. Rainier is offset because the faults are deep and the conduits do not rise quite vertically.) Fault line puts Seattle at risk of 'The Big One' - UW Magazine Cluster of earthquakes in Puget Sound considered 'normal', earthquake researchers say. 1 - 10 of 77 American Spirit Cruise Reviews. external structure, lines, and riggings; stand deck watches, such as helmsman and lookout underway; stand pier sentry, fire security, anchor, and . This fault produced a large earthquake that left a geologic record of surface offsets about 1100 years ago. Methane Plume Emissions Associated With Puget Sound Faults in the It may also be the original location of the DarringtonDevils Mountain Fault (the dashed line "X" at the top of the following map). Although Washington State's Puget Sound has been shaken every few decades, damage in the region's largest cities, including Seattle, Tacoma and Olympia, has only ever been modest. Yet the former is only the first of at least six more parallel southeast striking faults, which do cross the Salzer Creek Fault. [62] These ridges (part of a broader regional pattern that reflects the roots of the former Calkins Range[63]) are formed of sediments that collected in the Everett basin during the Eocene, and were subsequently folded by northeast-directed compression against the older Cretaceous and Jurassic rock to the east that bound the Puget Lowland. [125] While some coherency is developing, the story is not complete: identified faults do not yet account for much of the region's seismicity. [154] In this view Hood Canal is only a syncline (dip) between the Olympic Mountains and the Puget Lowland, and such faults as have been found there are local and discontinuous, ancillary to the main zone of faulting to the west. A new view is developing that the regional tectonic boundary is not under Hood Canal, but just to the west, involving the Saddle Mountain fault zone (discussed below) and associated faults. [19] These terranes were covered by the basalts of the Crescent Formation (part of Siletzia). The University of Puget Sound's Facilities Services Department is hiring an Electrician responsible for the inspection, installation, modification, maintenance and repair of the electrical systems across Puget Sound's beautiful residential campus community located . [80], In the crowded field of active or potentially active fault zones that have been discovered in the lower Snoqualmie Valley, the Cherry Creek fault zone is particularly notable because east of Duvall[81] it passes through a hotspot of active seismicity, including the 1996 '"`UNIQ--templatestyles-00000057-QINU`"'ML 5.3 Duvall earthquake. Five Puget Sound cities likely to feel strong shaking in a megaquake The last large event was in 1700, but there is a 37 percent chance of an 7.1+ in the next 50 years. [118], Studies of the Seattle Fault west of Bremerton have revealed a complexity of geological structure and faulting. Washington's faults: Where the Earth moves the Seattle area (Links with more information on various hazards can be found at Seattle Fault.). One of these faults, the Sequim Fault Zone (striking east from the town of Sequim), crosses Discovery Bay (and various possible extensions of the Hood Canal Fault) and bounds the Port Ludlow Uplift ("uplift of unknown origin" on the map); it appears to extend to the Southern Whidbey Island Fault. Movement on the southern segment of the DDMFZ that converges with the SCF the Darrington Fault was, as on the SCF itself, right-lateral. Aeromagnetic anomaly maps (USGS OFR 99-514). [123] Other studies have faults extending NW or WNW from the SF towards Dabob Bay;[124] these are now recognized as part of the Dabob Bay fault zone. [39] On the basis of marine seismic reflection surveying in the Strait of Juan de Fuca it has been suggested that the DMF, SPF, and UPF are structurally connected (at least in the segment crossing Whidbey Island). PSE | Technical Resources for Construction - Puget Sound Energy 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. [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. There are some interesting relationships here. Locations of some previously mapped faults have been adjusted on the latest map. Earthquake Fault Maps in Seattle and Washington State This interpretation suggests that the Seattle Uplift acts as a rigid block, and possibly explains the kinematic linkage by which large earthquakes may involve ruptures on multiple faults: the Seattle, Dewatto, and Tacoma faults represent the northern, western, and southern faces of a single block. This is only one of a series of active large crustal faults in the Puget Lowland. In the map above these are represented by the pair of dotted lines at the lower right. [70] Although the intervening section has not been mapped, geologists believe the GFFZ connects with the McMurray FZ to the north, and forms the eastern boundary of the Everett Basin. [198], Does the SHZ extend north? The map also shows potentially active faults from a separate 2014 report (click here to download). A similar line aligns with the termination of the WRZ, SHZ, and Gales Creek Fault Zone (northwest of Portland), with faulting along the upper Nehalem River on the Oregon coast,[211] and a topographical contrast at the coast (between Neahkahnie Mountain and the lower Nehalem River valley) distinct enough to be seen on the seismicity map above (due west of Portland). [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. This may explain why the Seattle and Tacoma faults seem to have ruptured at nearly the same time.[127]. Harold Tobin, . Do you live in a natural-disaster danger zone? Check this Seattle map [51] This is the Dewatto lineament, believed to result from an east-dipping low-angle thrust fault where the western flank of the Seattle Uplift has been pushed into the northwestern corner of the Tacoma Basin. [61], North of Everett is an area of parallel ridges and stream drainages oriented approximately NW-SE, evident even on non-geological maps. [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. slope, need not be high. WASHINGTON: Methane Bubbles Up From Seafloor Near Seattle Conjugate faults are secondary faults that branch off from opposite sides of a strike-slip fault at approximately the same angle. 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. [119] Several studies show that the southernmost strand of the SF, once past Green Mountain, turns southwest, towards the Saddle Mountain and Frigid Creek faults. Click a second point on the map, this will be the right side of the cross-section. King County Emergency Management. 1958 and Geologic Map GM-34 for details.). to the north, past Lummi Island is contrary to the prevailing consensus that the DMF is not offset. [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. Initially it was not specified, and rather vaguely indicated to be west of Restoration Point (i.e., west of Puget Sound). The ultimate driver of the stresses that cause earthquakes are the motions of the tectonic plates: material from the Earth's mantle rises at spreading centers, and moves out as plates of oceanic crust which eventually are subducted under the more buoyant plates of continental crust. Large plumes of methane bubbles have been discovered throughout the waters of Puget Sound prompting questions about the Puget Sound food web, studies of earthquake faults and climate-change research. This structure is shown in the gravitational mapping of 1965, but without comment. Rainier, along the DDMFZ, and under Puget Sound between Olympia and approximately the Southern Whidbey Island Fault. Puget Sound faults - Wikipedia Please follow the steps below: . The Cascadia Fault is 620 miles long off the coast of Washington and British Columbia. A Coast Range Boundary Fault (CRBF, discussed above) was inferred on the basis of differences in the basement rock to the west and east of Puget Sound (the Crescent FormationCascadia core contact), and arbitrarily mapped at various locations including Lake Washington; north of the OWL this is now generally identified, with the Southern Whidbey Island Fault. And since those models for the Seattle Fault were published, there've actually been many more Puget Sound faults discovered. The Doty Fault appears to terminate against, or possibly merge with, the Salzer Creek Fault at Chehalis; the Salzer Creek Fault is traced another seven miles east of Chehalis. [74], Early Eocene igneous units in the area appear to be part of a 49- to 44- Ma magmatic belt that appeared just after the arrival of Siletzia, and possibly associated with that event. Housing: The Puget Sound had the largest increase in population per Ongoing mapping is revealing more faults. [54], It has been suggested that the SWIF might extend past its intersection with the RMFZ (with only peripheral strands turning to join the RMFZ) to cross the Cascades and eventually merge with or cross the OlympicWallowa Lineament;[55] a study of regional features suggests such a pattern. Whether the faulting continues eastward is not yet determined. 48), along the edge of a formation known as the Southern Washington Cascades Conductor. [221] Where it might run south of Seattle is not known; an argument has been made that it runs beneath Seattle[222] but this is still conjectural. PSE | Energize Eastside Improvements Project [138] It arises from the contrast between the denser and more magnetic basalt of the Crescent Formation that has been uplifted to the east, and the glacial sediments that have filled the Dewatto basin to the west. There's a one-in-10 chance that the next . The alternative, that younger faulting in the Rogers Belt has offset the DMF Cheney argued that the MVF had offset the DMF 47km. Seattle Fault Bigger Quake Threat Than Thought | Live Science Bubbles of methane rising from seafloor in Puget Sound - Phys.org King County Emergency News. 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. 4 earthquakes in the past 30 days. The Doty Fault/Chehalis Basin sequence follows the cross-section X-X' shown on the, The long-range mapping plan area and current status of planned mapping can be seen at, For the County's interpretation of the geological hazard and anticipated impacts of a major earthquake, see the, Interstate 5 runs nearly due north from Everett to Mount Vernon, except for a stretch southeast of Conway that parallels one of these low-amplitude folds. American Spirit Cruise Reviews - Cruise Critic A single earthquake in Seattle could cause a catastrophic situation for the northwest corner of the state, a new report from Washington's Department of Natural Resources found. These maps are based on only one Cascadia scenario. Toll Free 1-800-523-5044. Report: Earthquake could produce tsunami waves that would hit Seattle 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. [120] However, the Saddle Mountain fault zone is not quite reciprocally aligned,[121] trending more northerly to where it encounters westeast trending faults (including the Hamma Hamma fault zone) that appear to be a westward extension of the Seattle Fault zone. Arcos' work suggests. Also intersecting at Mount St. Helens is a NE (045) trending line (red) of Pleistocene (about 4 Ma) plug domes and a topographic lineament (followed in part by Highway 12).

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