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Explorer Ridge
The Explorer Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located about west of Vancouver Island, British Columbia, Canada. It lies at the northern extremity of the Pacific spreading axis. To its east is the Explorer plate, which together with the Juan de Fuca plate and the Gorda plate to its south, is what remains of the once-vast Farallon plate which has been largely subducted under the North American plate. The Explorer Ridge consists of one major segment, the Southern Explorer Ridge, and several smaller segments. It runs northward from the Sovanco fracture zone to the Queen Charlotte triple junction, a point where it meets the Queen Charlotte Fault and the northern Cascadia subduction zone. Geology This divergent boundary first formed about 5–7 million years ago when the northern end of the Juan de Fuca plate broke off along the Nootka Fault to form the Explorer plate. This apparently had some important ramifications for regional geologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explorer Ridge Map
Exploration is the process of exploring, an activity which has some expectation of discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organisms capable of directed locomotion and the ability to learn, and has been described in, amongst others, social insects foraging behaviour, where feedback from returning individuals affects the activity of other members of the group. Types Geographical Geographical exploration, sometimes considered the default meaning for the more general term exploration, is the practice of discovering lands and regions of the planet Earth remote or relatively inaccessible from the origin of the explorer. The surface of the Earth not covered by water has been relatively comprehensively explored, as access is generally relatively straightforward, but underwater and subterranean areas are far less known, and even at the surface, much is still to be discovered in detail in the more remote and inaccessib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascadia Subduction Zone
The Cascadia subduction zone is a convergent plate boundary, about off the Pacific coast of North America, that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30 m (100 ft) high. The Oregon Department of Emergency Management estimates shaking would last 5–7 minutes along the coast, with strength and intensity decreasing further from the epicenter. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating in Canada at about Vancouver Island in British Columbia. The Explorer, Juan de Fuca, and Gorda plates are some of the remnants of the vast ancient Farallon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rift Valley
A rift valley is a linear shaped lowland between several highlands or mountain ranges produced by the action of a geologic rift. Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear depression may subsequently be further deepened by the forces of erosion. More generally the valley is likely to be filled with sedimentary deposits derived from the rift flanks and the surrounding areas. In many cases rift lakes are formed. One of the best known examples of this process is the East African Rift. On Earth, rifts can occur at all elevations, from the sea floor to plateaus and mountain ranges in continental crust or in oceanic crust. They are often associated with a number of adjoining subsidiary or co-extensive valleys, which are typically considered part of the principal rift valley geologically. Earth's rift valleys The most extensive rift valley is located along the crest of the mid-ocean ridge system and is the result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismology
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes (or generally, quakes) and the generation and propagation of elastic waves through planetary bodies. It also includes studies of the environmental effects of earthquakes such as tsunamis; other seismic sources such as volcanoes, plate tectonics, glaciers, rivers, oceanic microseisms, and the atmosphere; and artificial processes such as explosions. Paleoseismology is a related field that uses geology to infer information regarding past earthquakes. A recording of Earth's motion as a function of time, created by a seismograph is called a seismogram. A seismologist is a scientist who works in basic or applied seismology. History Scholarly interest in earthquakes can be traced back to antiquity. Early speculations on the natural causes of earthquakes were included in the writings of Thales of Miletu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the northernmost, westernmost, and easternmost (the Aleutian Islands cross the 180th meridian into the eastern hemisphere) state in the United States. It borders the Canadian territory of Yukon and the province of British Columbia to the east. It shares a western maritime border, in the Bering Strait, with Russia's Chukotka Autonomous Okrug. The Chukchi and Beaufort Seas of the Arctic Ocean lie to the north, and the Pacific Ocean lies to the south. Technically, it is a semi-exclave of the U.S., and is the largest exclave in the world. Alaska is the largest U.S. state by area, comprising more total area than the following three largest states of Texas, California, and Montana combined, and is the seventh-largest subnational division i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transform Fault
A transform fault or transform boundary, is a fault (geology), fault along a plate boundary where the motion (physics), motion is predominantly Horizontal plane, horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subduction, subduction zone. A transform fault is a special case of a ''strike-slip fault'' that also forms a plate boundary. Most such faults are found in oceanic crust, where they accommodate the lateral offset between segments of Divergent boundary, divergent boundaries, forming a zigzag pattern. This results from oblique seafloor spreading where the direction of motion is not perpendicular to the trend of the overall divergent boundary. A smaller number of such faults are found on land, although these are generally better-known, such as the San Andreas Fault and North Anatolian Fault. Nomenclature Transform boundaries are also known as conservative plate boundaries because they involve no addit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ranges
The Pacific Ranges are the southernmost subdivision of the Coast Mountains portion of the Pacific Cordillera. Located entirely within British Columbia, British Columbia, Canada, they run northwest from the lower stretches of the Fraser River to Bella Coola, British Columbia, Bella Coola and Burke Channel, north of which are the Kitimat Ranges. The Coast Mountains lie between the Interior Plateau and the British Columbia Coast, Coast of British Columbia. The Pacific Ranges include four of the five major coastal icecaps in the southern Coast Mountains. These are the largest temperate-latitude icecaps in the world and fuel a number of very major rivers (by volume, not length). One of these contains Mount Waddington, the highest summit entirely within British Columbia. Also within this region is Hunlen Falls, among the highest in Canada, located in Tweedsmuir South Provincial Park. Other than logging and various hydroelectric developments, and a large ski resort at Whistler, Briti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macdonald%20Mid-Ocean%20Ridge%20Tectonics.pdf Volcanoes can also form where there is str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Crust
Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumulates. The crust lies above the rigid uppermost layer of the mantle. The crust and the rigid upper mantle layer together constitute oceanic lithosphere. Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium. It is thinner than continental crust, or sial, generally less than 10 kilometers thick; however, it is denser, having a mean density of about 3.0 grams per cubic centimeter as opposed to continental crust which has a density of about 2.7 grams per cubic centimeter. The crust uppermost is the result of the cooling of magma derived from mantle material below the plate. The magma is injected into the spreading center, which consists mainly of a partly solidified crystal mush derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olympic Mountains
The Olympic Mountains are a mountain range on the Olympic Peninsula of the Pacific Northwest of the United States. The mountains, part of the Pacific Coast Ranges, are not especially high – Mount Olympus (Washington), Mount Olympus is the highest summit at ; however, the eastern slopes rise precipitously out of Puget Sound from sea level, and the western slopes are separated from the Pacific Ocean by the low-lying wide Pacific Ocean coastal plain. These densely forested western slopes are the wettest place in the 48 contiguous states. Most of the mountains are protected within the bounds of Olympic National Park and adjoining segments of Olympic National Forest. The mountains are located in western Washington (state), Washington in the United States, spread out across four counties: Clallam County, Washington, Clallam, Grays Harbor County, Washington, Grays Harbor, Jefferson County, Washington, Jefferson and Mason County, Washington, Mason. Physiographically, they are a sectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascade Range
The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington (state), Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as many of those in the North Cascades, and the notable volcanoes known as the High Cascades. The small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The highest peak in the range is Mount Rainier in Washington at . part of the Pacific Ocean's Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the eruptions in the contiguous United States over the last 200 years have been from the Cascade Volcanoes. The two most recent were Lassen Peak from 1914 to 1921 and a 1980 eruption of Mount St. Helens, major eruption of Mount St. Helens in 1980. Minor eruptions of Mount St. Helens have also occurred since, most recently from 2004 to 2008. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
