Coal Creek is a creek in Bellevue , Washington , United States, on Seattle 's Eastside . It is named for the coal mining industry prominent in the area in the 19th century. There is a popular trail which parallels the creek, allowing views of defunct coal mining equipment and even some bits of coal sitting on the ground in spots.
26-460: The source of Coal Creek is 1,400 feet (425 m) above sea level on Cougar Mountain . It flows approximately 7 miles (11 km) to the northwest, emptying into Lake Washington at Newport Shores. The surveyors Philip H. Lewis and Edwin Richardson first discovered coal along the creek in 1863. This coal was better located for transport to Seattle than the mines further east at Squak Mountain , and in
52-859: A regional system of faults . First suspected from mapping of gravitational anomalies in 1965 and an uplifted marine terrace at Restoration Point (foreground in picture above), the Seattle Fault's existence and likely hazard were definitively established by a set of five reports published in Science in 1992. These reports looked at the timing of abrupt uplift and subsidence around Restoration Point and Alki Point (distant right side of picture), tsunami deposits on Puget Sound, turbidity in lake paleosediments, rock avalanches, and multiple landslides around Lake Washington, and determined that all these happened about 1,100 years ago (between 923 and 924 CE , and most likely due to an earthquake of magnitude 7 or greater on
78-516: A 4 to 7 km (2.5 to 4.3 miles) wide zone of complex faulting, with three or more main south-dipping thrust faults . Most of the faulting is "blind" (not reaching the surface), and generally difficult to locate because of heavy vegetation or development. Three principal strands have been identified, their location determined by high-resolution seismic reflection and aeromagnetic surveys. The northernmost strand lies nearly along Interstate 90 and then under Lake Sammamish . The central section of
104-518: A northwest axis and created the Newcastle Anticline . The anticline exposed earlier ( Eocene to Oligocene ) sedimentary and volcanic rocks that, due to erosion, now form the surface of Cougar Mountain. The northern edge of Cougar Mountain is distinct due to the Seattle Fault , which runs along I-90. The Seattle Fault caused a large earthquake approximately 1100 years ago. Cougar Mountain
130-609: A rare exception can be seen at Mee Kwa Mooks Park south of Alki Point . This is the site of the West Seattle Fault ; the prominent rise there is due to uplift on the north side of the fault. The Seattle Fault (and the related Tacoma Fault) is not the only source of earthquake hazard in the Puget Lowland. Other faults in the near surface continental crust, such as the South Whidbey Island Fault (near Everett), and
156-629: Is a stub . You can help Misplaced Pages by expanding it . This article related to a river in the state of Washington is a stub . You can help Misplaced Pages by expanding it . Cougar Mountain Cougar Mountain is a peak in the Issaquah Alps in King County, Washington . It is part of the highlands in the Eastside suburbs of Seattle , and at 1,614 feet (492 m) it is the lowest and westernmost of
182-521: Is about the time that the strike-slip movement on the north-striking Straight Creek Fault to the east ceased, due to the intrusions of plutons . It appears that when the Straight Creek Fault became stuck the north–south compressive force that it had accommodated by strike-slip motion was transferred to the crust of the Puget Lowland, which subsequently folded and faulted, and the various blocks jammed over one another. Other scarps associated with
208-435: Is believed to be the only instance in the past 7,000 years of the type that causes a regional uplift. The other type is more localized and shallower (and therefore more damaging); at least four such events are believed to have occurred in the past 3,000 years on the west end of the fault. (The history of the central and eastern segments is not known.) Calculations based on fault length and paleoseismological studies show that
234-670: Is concern that such an earthquake on the Seattle Fault would devastate unreinforced masonry (URM) buildings , of which the City of Seattle is estimated to have around a thousand, concentrated in Capitol Hill , Pioneer Square , and the International District . Other recent work indicates that the Seattle Fault can generate two types of earthquakes; both pose "considerable hazard" to the Seattle metropolitan region. The A.D. 900–930 earthquake
260-755: Is part of the Eastern Puget Uplands level IV ecoregion, as defined by the EPA . This ecoregion is a transition between the ecology of the Puget Sound and the forests of the Cascades . The ecology of Cougar Mountain is thus more similar to the Sammamish Plateau than the rest of the Issaquah Alps. Cougar Mountain contains species and habitats that were once common closer to Puget Sound. Extensive logging has rendered
286-628: Is the structural boundary where 50–60 million years old (early Tertiary ) basalt of the Crescent Formation on the south has been uplifted – the Seattle Uplift – and is tipping into the Seattle Basin, where the Tertiary bedrock is buried under at least 7 km (4.3 miles) of relatively softer, lighter sedimentary strata of the younger Blakeley and Blakely Harbor formations. This has resulted in
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#1733093828644312-400: The U.S. state of Washington ) in the vicinity of Interstate Highway 90 . The Seattle Fault was first recognized as a significant seismic hazard in 1992, when a set of reports showed that about 1,100 years ago it was the scene of a major earthquake of about magnitude 7 – an event that entered Native American oral traditions. Extensive research has since shown the Seattle Fault to be part of
338-466: The 1870s the mining of this coal led to the founding of Newcastle, Washington . In 1983, the Office of Surface Mining Reclamation and Enforcement reclaimed entries to the mine, and by 1984 fenced off 16 "extremely hazardous" openings, contracting work to permanently seal them by 1986. In 1987, King County and the City of Bellevue produced a hydrological model and subsequent watershed management plan for
364-704: The Alps. About two-thirds of Cougar Mountain has experienced residential development, and is home to many neighborhood communities such as Lakemont . The forested heart of the hill was officially preserved by King County in June 1983 as Cougar Mountain Regional Wildland Park . Cougar Mountain is home to the Cougar Mountain Zoo . Cougar Mountain was formed in the Miocene when tectonic forces folded western Washington along
390-422: The Seattle Fault can generate a very damaging magnitude 7.0 earthquake. In addition to extensive damage to unreinforced structures and structures built on fill (such as much of Seattle's Pioneer Square area, the industrial area, and the waterfront), computer modeling has shown that such earthquakes could cause a tsunami of about 2 m (6 feet 7 inches) high on Elliott Bay . The modeling shows that such
416-526: The Seattle Fault. Although the 923-924 CE earthquake was over a thousand years ago, local traditional stories have preserved an association of a powerful supernatural spirit – a'yahos, noted for shaking, rushes of water, and landsliding – with five locales along the trace of the Seattle Fault, including a "spirit boulder" called Psai-Yah-hus near the Fauntleroy ferry dock in West Seattle. The Seattle Fault
442-469: The Seattle Uplift as a sheet of rock that is being forced up a ramp. Subsequent work suggests that the structure of the Seattle Fault may vary from east to west, with both models being applicable in different sections. A later model has part of the north-thrusting sheet forming a wedge between the sedimentary formations of the Seattle Basin and the underlying bedrock. The Seattle Fault is believed to date from about 40 million years ago (late Eocene ). This
468-542: The Seattle fault have been identified by LIDAR -based mapping; trenching has generally shown the faulting to be more complex than was first realized. Many of the details of the Seattle Fault, including recurrence rate, remain to be resolved. A study of sediments in Lake Washington found evidence of seven large (M > 7) earthquakes in the last 3,500 years. Surface scarps due to faulting are rarely observed in this area (due to topography, vegetation, and urbanization);
494-585: The Seattle–Tacoma area, whereas a magnitude 9 subduction event would damage only around 87 bridges in all of Western Washington. The same study also found that with failure of just six bridges (the minimum damage for a Benioff M 6.5 event) there could be at least $ 3 billion lost in business revenue alone. Subsequent retrofitting by the Washington Department of Transportation and the City of Seattle would likely reduce damage to key bridges. But there
520-489: The creek. The earlier mining activity included mine tailings dumped along the stream bank, creating steep slopes which would collapse and create landslides, contributed to "extensive sedimentation problems" in Coal Creek. Additionally, it was found that 10% of base flows were from mine tunnels. As of sampling in 2007, concentrations of arsenic , nickel , and Bis(2-ethylhexyl) phthalate were still higher concentrations than
546-552: The ecosystem less diverse than its original state. The top of Cougar Mountain features views of Seattle , Mercer Island , Lake Washington and the Olympic Mountains . Cougar Mountain is home to some of Seattle area radio station's transmitters. These include: Seattle Fault The Seattle Fault is a zone of multiple shallow east–west thrust faults that cross the Puget Sound Lowland and through Seattle (in
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#1733093828644572-497: The fault zone – where it crosses the apparent location of the Olympic–Wallowa Lineament – shows marked variation in the location of the strands and of the underlying structure, but the nature and significance of this is not understood. The fault extends for approximately 70 km (43 miles) from near Fall City on the east, where it appears to be terminated by the South Whidbey Island Fault , to Hood Canal on
598-402: The magnitude 9 1700 Cascadia earthquake , where the entire Cascadia subduction zone , from Cape Mendocino to Vancouver Island , slips. But the Seattle and Tacoma faults are probably the most serious earthquake threat to the populous Seattle–Tacoma area. A 2002 study of bridge vulnerability estimated that a magnitude 7 earthquake on the Seattle Fault would damage approximately 80 bridges in
624-791: The sediment cleanup objectives set forth in the watershed management plan. As part of the Bellevue city watershed management plan , Coal Creek salmon escapement is monitored annually. Populations of adult coho salmon stock were re-introduced into the creek in 2014, 2019, and 2021 from the Issaquah hatchery, as well as " 9,000 - 13,800 zero age coho into Coal Creek from 1994 - 1997 ". Other species of fish observed include sockeye salmon , chinook salmon , steelhead , and trout . 47°32′16″N 122°07′44″W / 47.537717°N 122.129002°W / 47.537717; -122.129002 This King County, Washington state location article
650-568: The west (not shown on the map). However, boundaries defining the western termination zone is currently unclear (see Puget Sound faults#Question of western termination ). It is the northern edge of the Seattle Uplift, of which the Tacoma Fault is the southern edge. One model has the Seattle and Tacoma faults converging at depth to form a wedge, which is being popped up by approximately north–south oriented compression that ultimately derives from plate tectonics. Another model (see diagram) interprets
676-499: The yet to be studied Olympia Fault (near Olympia), though historically quiescent, are suspected of generating earthquakes of around magnitude 7. Others, such as the 2001 Nisqually earthquake , originate about 50 to 60 km (31 to 37 miles) below Puget Sound in the Benioff zone of the subducting Juan de Fuca plate ; being so deep their energy is dissipated. And there are the infrequent but very powerful great subduction events, such as
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