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Mendocino Fault
The Mendocino Fracture Zone is a fracture zone and transform boundary over 4000 km (2500 miles) long, starting off the coast of Cape Mendocino in far northern California. It runs westward from a triple junction with the San Andreas Fault and the Cascadia subduction zone to the southern end of the Gorda Ridge. It continues on west of its junction with the Gorda Ridge, as an inactive remnant section which extends for several hundred miles. Technically, a fracture zone is not a transform fault, but in the case of the Mendocino, the term has been loosely applied to the active fault segment east of the Gorda Ridge as well as to the true fracture zone segment west of it. Many seismologists refer to the active segment as the Mendocino Fault or Mendocino fault zone. The fault section demarcates the boundary between the northwestward-moving Pacific Plate and the eastward-moving Gorda Plate. The Gorda Plate is subducting beneath the North American Plate just offshore of Cape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascade Volcanic Arc
The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over . The arc formed due to subduction along the Cascadia subduction zone. Although taking its name from the Cascade Range, this term is a geologic grouping rather than a geographic one, and the Cascade Volcanoes extend north into the Coast Mountains, past the Fraser River which is the northward limit of the Cascade Range proper. Some of the major cities along the length of the arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10 million. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc. Because the population of the Pacific Northwest is rapidly increasing, the Cascade volcanoes are some of the most dangerous, due to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crescent City, California
Crescent City ( Tolowa: ''Taa-’at-dvn''; Yurok: ''Kohpey''; Wiyot: ''Daluwagh'') is the only incorporated city in Del Norte County, California; it is also the county seat. Named for the crescent-shaped stretch of sandy beach south of the city, Crescent City had a total population of 6,673 in the 2020 census, down from 7,643 in the 2010 census. The population includes inmates at Pelican Bay State Prison, also within the city limits, and the former census-designated place Crescent City North annexed to the city. The city is also the site of the Redwood National Park headquarters, as well as the historic Battery Point Light. Due to the richness of the local Pacific Ocean waters and the related catch, and ease of access, Crescent City Harbor serves as home port for numerous commercial fishing vessels. The city is on the Pacific coast in the upper northwestern part of California, about south of the Oregon border. Crescent City's offshore geography makes it unusually susceptib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture Zones
Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displacement develops perpendicular to the surface, it is called a normal tensile crack or simply a crack; if a displacement develops tangentially, it is called a shear crack, slip band or dislocation. Brittle fractures occur with no apparent deformation before fracture. Ductile fractures occur after visible deformation. Fracture strength, or breaking strength, is the stress when a specimen fails or fractures. The detailed understanding of how a fracture occurs and develops in materials is the object of fracture mechanics. Strength Fracture strength, also known as breaking strength, is the stress at which a specimen fails via fracture. This is usually determined for a given specimen by a tensile test, which charts the stress–strain cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fracture Zones
Fracture zones are common features in the geology of oceanic basins. Globally most fault zones are located on divergent plate boundaries on oceanic crust. This means that they are located around mid-ocean ridges and trend perpendicular to them. The term fracture zone is used almost exclusively for features on oceanic crust; similar structures on continental crust are instead termed transform or strike slip faults, a denomination active fracture zones also can have. Some fracture zones have been created by mid-ocean ridge segments that have been subducted and may not longer exist. Pacific Ocean Most fracture zones in the Pacific Ocean originate from large mid-ocean ridges (also called "rises") such as the East Pacific Rise, Chile Rise and Juan de Fuca Ridge. The plates that host the fractures are Nazca, Pacific, Antarctic, Juan de Fuca and Cocos among others. Fracture zones being subducted under Southern and Central America are generally southwest-northeast oriented reflecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blanco Fracture Zone
The Blanco Fracture Zone or Blanco Transform Fault Zone (BTFZ) is a right lateral transform fault zone, which runs northwest off the coast of Oregon in the Pacific Northwest of the United States, extending from the Gorda Ridge in the south to the Juan de Fuca Ridge in the north. Morphology The Blanco Transform Fault Zone is an approximately 350 km long zone that varies in width between 20 and 75 km. The Blanco Fracture Zone starts about 150 km off Cape Blanco, and extends northwest to about 500 km off of Newport. It consists of a series of deep basins interrupted by transform faults. The western part of the fracture zone, from the Cascadia Depression to the Juan de Fuca Ridge, moves at 1.4 cm/a; the eastern segment, from the Cascadia Depression to the Gorda Ridge moves at 3.9 cm/a. The whole zone averages a slip rate of 2.0 cm/a. Through it, Cascadia Channel passes. Eastern segment The principal feature of the eastern portion of the z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Rock Desert
__NOTOC__ The Black Rock Desert is a semi-arid region (in the Great Basin shrub steppe eco-region) of lava beds and playa, or alkali flats, situated in the Black Rock Desert–High Rock Canyon Emigrant Trails National Conservation Area, a silt playa north of Reno, Nevada that encompasses more than of land and contains more than of historic trails. It is in the northern Nevada section of the Great Basin with a lakebed that is a dry remnant of Pleistocene Lake Lahontan. The Great Basin, named for the geography in which water is unable to flow out and remains in the basin, is a rugged land serrated by hundreds of mountain ranges, dried by wind and sun, with spectacular skies and scenic landscapes. The average annual precipitation ''(years 1971-2000)'' at Gerlach, Nevada (extreme south-west of the desert) is . The region is notable for its paleogeologic features, as an area of 19th-century Emigrant Trails to California, as a venue for rocketry, and as an alternative to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California. It is noted for both its arid climate and the basin and range topography that varies from the North American low point at Badwater Basin in Death Valley to the highest point of the contiguous United States, less than away at the summit of Mount Whitney. The region spans several physiographic divisions, biomes, ecoregions, and deserts. Definition The term "Great Basin" is applied to hydrographic, biological, floristic, physiographic, topographic, and ethnographic geographic areas. The name was originally coined by John C. Frémont, who, based on information gleaned from Joseph R. Walker as well as his own travels, recognized the hydrographic nature of the landform as "having no connection to the ocean". The hydrographic definition is the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia Plateau
The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Columbia River. Geology During late Miocene and early Pliocene times, a flood basalt engulfed about of the Pacific Northwest, forming a large igneous province. Over a period of perhaps 10 to 15 million years, lava flow after lava flow poured out, ultimately accumulating to a thickness of more than 6,000 feet (1.8 km). As the molten rock came to the surface, the Earth's crust gradually sank into the space left by the rising lava. The Columbia River Basalt Group consists of seven formations: The Steens Basalt, Imnaha Basalt, Grande Ronde Basalt, Picture Gorge Basalt, Prineville Basalt, Wanapum Basalt, and Saddle Mountains Basalt. Many of these formations are subdivided into formal and informal members and flows. The subsidence of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modoc Plateau
__NOTOC__ The Modoc Plateau lies in the northeast corner of California as well as parts of Oregon and Nevada. Nearly of the Modoc National Forest are on the plateau between the Medicine Lake Highlands in the west and the Warner Mountains in the east. Its landform is volcanic table land ranging from 4,000 to 6,000 feet above sea level, cut by many north–south faults. "Occasioned lakes, marshes, and sluggishly flowing streams meander across the plateau."‘’California Geologic Provinces,’’ Note 36, page 2 It is a thick accumulation of and [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honey Lake Fault
The Honey Lake Fault Zone is a right lateral-moving (dextral) geologic fault extending through northwestern Nevada and northeastern California. It is considered an integral part of the Walker Lane. A zone of disturbed landforms reveals the fault's presence on the surface. The geological evidence shows at least four surface-faulting earthquakes have occurred in the late Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ... era. References Additional reading * Dextral Displacement on the Honey Lake Fault Zone, Northern Walker LanUSGS Database Seismic faults of California Seismic faults of Nevada {{US-geology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walker Lane
The Walker Lane is a geologic trough roughly aligned with the California/Nevada border southward to where Death Valley intersects the Garlock Fault, a major left lateral, or sinistral, strike-slip fault. The north-northwest end of the Walker Lane is between Pyramid Lake in Nevada and California's Lassen Peak where the Honey Lake Fault Zone, the Warm Springs Valley Fault, and the Pyramid Lake Fault Zone meet the transverse tectonic zone forming the southern boundary of the Modoc Plateau and Columbia Plateau provinces. The Walker Lane takes up 15 to 25 percent of the boundary motion between the Pacific Plate and the North American Plate, the other 75 percent being taken up by the San Andreas Fault system to the west. The Walker Lane may represent an incipient major transform fault zone which could replace the San Andreas as the plate boundary in the future. The Walker Lane deformation belt also accommodates nearly 12 mm/yr of dextral shear between the Sierra Nevada– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Lassen
Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, Cornwall, England * Mounts, Indiana, a community in Gibson County, Indiana, United States People * Mount (surname) * William L. Mounts (1862–1929), American lawyer and politician Computing and software * Mount (computing), the process of making a file system accessible * Mount (Unix), the utility in Unix-like operating systems which mounts file systems Displays and equipment * Mount, a fixed point for attaching equipment, such as a hardpoint on an airframe * Mounting board, in picture framing * Mount, a hanging scroll for mounting paintings * Mount, to display an item on a heavy backing such as foamcore, e.g.: ** To pin a biological specimen, on a heavy backing in a stretched stable position for ease of dissection or display ** To pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
