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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 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 legend. Extensive research has since shown the Seattle Fault to be part of a regional system of faults. Notable earthquake 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 pict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seattle
Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest region of North America. The Seattle metropolitan area's population is 4.02 million, making it the 15th-largest in the United States. Its growth rate of 21.1% between 2010 and 2020 makes it one of the nation's fastest-growing large cities. Seattle is situated on an isthmus between Puget Sound (an inlet of the Pacific Ocean) and Lake Washington. It is the northernmost major city in the United States, located about south of the Canadian border. A major gateway for trade with East Asia, Seattle is the fourth-largest port in North America in terms of container handling . The Seattle area was inhabited by Native Americans for at least 4,000 years before the first permanent European settlers. Arthur A. Denny and his group of travelers, subsequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fauntleroy, Seattle
Fauntleroy is a neighborhood in the southwest corner of Seattle, Washington. Part of West Seattle and situated on Puget Sound's Fauntleroy Cove (into which Fauntleroy Creek flows from its source in Fauntleroy Park), it faces Vashon Island, Blake Island, and the Kitsap Peninsula to the west. On sunny days, many locations in the neighborhood offer views of the Olympic Mountains, which are about to the west. The neighborhood adjoins Lincoln Park to the north, Fauntlee Hills to the east, and Arbor Heights to the south. Within Fauntleroy is an area known as Endolyne (the "end of the line" of the Fauntleroy Park streetcar route in the early 1900s). Fauntleroy is home to an eponymous Washington State Ferries terminal, providing service to Vashon Island and Southworth. Fauntleroy Way runs into the West Seattle Bridge, which runs across the Duwamish Waterway ( Duwamish River). History The neighborhood, creek, and park all take their name from the cove, itself named by one Lt. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluton
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained (phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Intrusions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Straight Creek Fault
__NOTOC__ The Straight Creek Fault (SCF) is the principal north-south strike-slip fault in the state of Washington, with a minimum of 90 kilometers (54 miles) of right-lateral offset, and a major geological structure in the North Cascade mountains, where it separates the pre-Cenozoic igneous and metamorphic rocks of the North Cascades on the east from the younger accreted terranes on the west. The SCF can be traced from its junction with the Olympic–Wallowa Lineament (OWL) near the town of Easton northward into British Columbia, where it joins the Fraser River Fault system; the combined system (over 570 km 40 mileslong) is known as the Fraser—Straight Creek Fault system (FSCF). No trace of the SCF has been found south of the OWL. Some geologists believe it does continue south, with all traces covered by more recent volcanic deposits. Others have speculated that it simply ends, or turns and aligns with the OWL, or has been offset elsewhere. (See discussion at Ol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tacoma Fault
The Tacoma Fault, just north of the city of Tacoma, Washington, is an active east–west striking north dipping reverse fault with approximately 35 miles (56 km) of identified surface rupture. It is believed capable of generating earthquakes of at least magnitude , and there is evidence of such a quake approximately 1,000 years ago, possibly the same earthquake documented on the Seattle Fault 24 miles (38 km) to the north. Geology The Tacoma Fault – actually a zone of connected faults – was first suspected from gravitational surveying in the 1960s, subsequently confirmed by seismic reflection and other geophysical data, and traced by detailed Lidar mapping; trenching and other paleoseismological studies have documented late Holocene uplift. It extends west to the small town of Allyn (near the tip of Hood Canal), terminating at the same north-striking geophysical anomaly (tentatively named the Tahuya Fault) that terminates the Seattle Fault to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hood Canal
Hood Canal is a fjord forming the western lobe, and one of the four main basins,Features Of Puget Sound Region: Oceanography And Physical Processes Chapter 3 of th King County Department of Natural Resources, Seattle, Washington, 2001. of in the US state of Washington. It is one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fall City, Washington
Fall City is an unincorporated community and census-designated place (CDP) in King County, Washington, United States, east of Seattle. The community lies along the Snoqualmie River and Raging River. The population was 1,993 at the 2010 census. History The first settlements in the area were two forts built in 1856 during the Puget Sound War to protect future settlers against possible uprisings by the native population. Fort Patterson, a few miles downstream, and Fort Tilton, a few miles upstream, were built with the help of Indians led by Chief Patkanim, and both were abandoned within two years after interactions with the local tribes remained peaceful. A historical marker can be found north of Fall City on the Fish Hatchery Road where Fort Tilton once stood. A trading post was established near the present-day location of the Last Frontier Saloon in 1869 and became a hub of the local economy. Fall City was known at the time as "The Landing", as shallow water and rapids upstr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Sammamish
Lake Sammamish is a freshwater lake east of Seattle in King County, Washington, United States. The lake is long and wide, with a maximum depth of and a surface area of . It lies east of Lake Washington and west of the Sammamish Plateau, and stretches from Issaquah in the south to Redmond in the north. At Issaquah it is fed by Issaquah Creek, and at Redmond it drains to Lake Washington via the Sammamish River, named after the native people who once lived along its entire length. The Lake Sammamish watershed stretches from Redmond through Bellevue, and Issaquah to Preston and Hobart, and consists of numerous creeks which flow into the lake. Issaquah Creek is the largest tributary, furnishing over 70% of the lake's inflow. Development The area surrounding Lake Sammamish has been, in recent times, the most rapidly growing suburban district in the Greater Seattle Metropolitan Area. During the late 1990s and early 2000s, the cities of Redmond, Snoqualmie, Fall City, Issaquah ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeromagnetic Survey
An aeromagnetic survey is a common type of geophysical survey carried out using a magnetometer aboard or towed behind an aircraft. The principle is similar to a magnetic survey carried out with a hand-held magnetometer, but allows much larger areas of the Earth's surface to be covered quickly for regional reconnaissance. The aircraft typically flies in a grid-like pattern with height and line spacing determining the resolution of the data (and cost of the survey per unit area). Method As the aircraft flies, the magnetometer measures and records the total intensity of the magnetic field at the sensor, which is a combination of the desired magnetic field generated in the Earth as well as tiny variations due to the temporal effects of the constantly varying solar wind and the magnetic field of the survey aircraft. By subtracting the solar, regional, and aircraft effects, the resulting aeromagnetic map shows the spatial distribution and relative abundance of magnetic minerals (mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection Seismology
Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves. The method requires a controlled seismic source of energy, such as dynamite or Tovex blast, a specialized air gun or a seismic vibrator. Reflection seismology is similar to sonar and echolocation. This article is about surface seismic surveys; for vertical seismic profiles, see VSP. History Reflections and refractions of seismic waves at geologic interfaces within the Earth were first observed on recordings of earthquake-generated seismic waves. The basic model of the Earth's deep interior is based on observations of earthquake-generated seismic waves transmitted through the Earth's interior (e.g., Mohorovičić, 1910). The use of human-generated seismic waves to map in detail the geology of the upper few kilometers of the Earth's crust followed shortly thereafter and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial planet, rocky planet or natural satellite, moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of volcanism on Venus, Venus, which cover ~80% of the surface, are basaltic; the lunar mare, lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
