Another, Wrangell-St. Elias National Park, is a vast region that extends across the accretionary wedge and volcanic arc, and is built of accreted terranes. Along this fault, the Pacific plate is moving northwestward relative to the North American plate at an approximate rate of 16.4 feet per 100 years (5 cm/year). Error message | View complete answer on https://www.britannica.com Are the Nazca Plate and South American plates divergent plates? Is the Nazca plate convergent or divergent? The three West Coast states are especially meaningful because they have geologic features that, when the quarters are stacked, represent the surface and subsurface of the chain of volcanoes that has been developing over the past 200 million years. Layers of pillow basalt exposed at NPS sites in the Coastal Ranges are evidence that lava flows that formed in the Pacific Ocean were later scraped off the subducting plate and lifted upward as part of the accretionary wedge. Transcribed image text: Question 1 (1 point) Saved Unclick all the other layers you've been using, and then click next to "plate boundary model" layer. The southern boundary is a mid-oceanic ridge, the Galapagos Rise. For example, the Queen Charlotte Fault connects the north end of the Juan de Fuca Ridge, starting at the north end of Vancouver Island, to the Aleutian subduction zone. The Cocos plate was created about 23 million years ago when a larger plate broke into two pieces. Garibaldi to Lassen Peak, coincides with the north-to-south extent of the subducting plate boundary. CC BY. Mazama, erupted and collapsed 7,700 years ago, forming the large cavity (caldera) that now holds Crater Lake. The Pacific Plate is almost entirely oceanic, but it does include the part of California west of the San Andreas Fault. The Cocos Plate is a tectonic plate beneath the Pacific Ocean off the west coast of Central America. Near their boundary, the plates can lock together for centuries, then suddenly let go as a giant earthquake. Rainier National Park. The San Andreas Fault and Queen Charlotte Fault are transform plate boundaries developing where the Pacific Plate moves northward past the North American Plate. The rising water melts rock in its path, forming a volcanic arc on the overrriding plate. Plates move as rigid bodies, so it may seem surprising that the North American Plate can be moving at different rates in different places. As they were caught in the vise between the converging Juan de Fuca and North American plates, some of the layers were so contorted that they are now in vertical orientations along the coast. It runs along the west coast of Mexico and western Caribbean countries. Where is a divergent plate boundary located? Mazama, violently erupted 7,700 years ago. What type of plate boundaies are found between the Cocos, Nazca, and Pacific plates? Taiwan area is the collision boundary between the Philippine Sea plate and the Eurasia plate, which has complex interaction, attracting much attention[3033]. Hood in Oregon, Mt. This plate includes the islands that make up the Philipines and north to include parts of southern Japan. A by-product of the metamorphism is the release of hot fluids, especially water. Farther east, the continent began to rift apart in the Basin and Range Province. Examples of ocean-continent convergent boundaries are subduction of the Nazca Plate under South America (which has created the Andes Range) and subduction of the Juan de Fuca Plate under North America (creating the mountains Garibaldi, Baker, St. Elias National Park St. Helens in 1980. . The 1,200-kilometer-long San Andreas fault zone is part of the boundary between the Pacific and North American plates, and thus is known as a transform fault. This highly active convergent plate boundary extends along both sides the Philippine Islands, from Luzon in the north to the Celebes Islands in the south. Puget Sound and the Willamette Valley are areas near sea level between the coastal and volcanic mountain ranges. The two parallel mountain ranges influence many of the physical and cultural aspects of the Pacific Northwest. Later, most of the settlers coming on the Oregon Trail continued past central Oregon and Washington to the lush farmland of the Willamette Valley and Puget Sound, the low-lying region between the two rising mountain ranges. That the Atlantic Ocean rift may have occurred in approximately the same place during two separate events several hundred million years apart is probably no coincidence. Parks in the Cascadia Subduction Zone dramatically display the two distinct mountain ranges the Coast Range just above where the Juan de Fuca Plate begins to subduct, and the volcanic Cascade Range farther inland, where the top of the plate is deeper. Start with the major plates, and then work on the smaller ones. Five park sites in southern Alaska showcase landscapes formed by the subduction of the northward-moving Pacific Plate beneath North America. The Coast Range and Cascades are the two parallel mountain ranges that form the Cascadia Subduction Zone in the Pacific Northwest. The Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. Roughly 3.2 million square kilometers (1.2 million square miles) in area, the Caribbean. As explained above, most transform faults connect segments of mid-ocean ridges and are thus ocean-ocean plate boundaries (Figure \(\PageIndex{11}\)). These mega-earthquakes occur every 200 to 600 years or so, and the last one was in the year 1700. The Cascadia Subduction Zone, extending from northern California through western Oregon and Washington to southern British Columbia, is a type of convergent plate boundary. Subduction of the Farallon Plate beneath the entire West Coast created a line of volcanoes from Alaska to Central America. Mt. This plate is moving northwest towards the Australia, Filipino, and Eurasia plates. Igneous, sedimentary, and metamorphic rocks are all found in abundance. The ocean area along southern Asia up to the India plate is also a part of the Australia plate. Modified from Beauty from the Beast: Plate Tectonics and the Landscapes of the Pacific Northwest, by Robert J. Lillie, Wells Creek Publishers, 92 pp., 2015, www.amazon.com/dp/1512211893. As the mid-ocean ridge separating the Farallon and Pacific Plates entered the subduction zone, the Farallon Plate separated into the Juan de Fuca and Cocos Plates. And at times, lower-silica components of their magma chambers erupt, producing basalt lava flows as well as cinders and volcanic bombs. Redoubt, an active volcano in Lake Clark National Park, illustrates how a volcano can pose an unexpected hazard in our modern age and why monitoring volcanic activity is so important (see photo below). The initial magma formed as mantle rock melts beneath a subduction zone has low silica (basalt) composition. Like Mt. A mid-oceanic ridge, a divergent tectonic plate boundary located along the floor of the Pacific Ocean. A glance at a map of the western United States might suggest that the Sierra Nevada are a southward continuation of the Cascade Volcanoes. Some geological processes act so slowly that we may think of the Earth as rock-solid and unmoving. Credit: Photo Courtesy of Robert J. Lillie. The grinding action also produces devastating earthquakes, including some that result in giant tsunami waves. The Cocos Ridge (CR), which formed when the Cocos Plate drifted over the Galapagos Hotspot (Walther, 2003) , is a bathymetric high reaching about 2 km above the surrounding seafloor and stretching about 2000 km long and 200-300 km wide across the Cocos Plate . This plate makes up most of the Pacific Ocean. These quarters featured iconic images that have special meaning to each state. Cocos and Rivera Plates Maximilian Goetz. Credit: Photo courtesy of Robert J. Lillie. As a result of this collision, the oceanic Cocos plate is subducted below the Caribbean along the Mesoamerican trench plate at speeds ranging from 2 in. More recent studies of continental matchups and the magnetic ages of ocean-floor rocks have enabled us to reconstruct the history of the break-up of Pangea. Sea lions resting on layers of pillow basalt that formed beneath the ocean and were uplifted as part of the accretionary wedge. The resulting magmas can therefore have a variety of compositions, ranging from the original (low-silica) basalt, to (intermediate-silica) andesite, all the way up to (high-silica) rhyolite. National Park Service sites in the Coastal Ranges of Washington, Oregon and northern California contain rugged mountains of rocks that were manufactured in the ocean, then scraped off the plate and lifted out of the sea. The Sierra Nevada are a remnant of volcanoes that extended southward when the ancient Farallon Plate dove beneath the edge of North America. Jennifer Natoli was a seasonal ranger at Redwood National and State Parks in California. This plate is bound by the North-American and Caribbean Plates to the north-east, the small Rivera Plate to the north-west, the Pacific Plate to the west, Mount Rainier. It was preceded by Pannotia (600 to 540 Ma), by Rodinia (1,100 to 750 Ma), and by others before that. Antarctic plate, Pacfic plate, Eurasia plate, India Plate, Africa plate. Granite rocks found in national parks in the Sierra Nevada are the cooled and eroded remnants of magma chambers that fed ancient subduction zone volcanoes in California. The physical landscape was an important component of the practical and spiritual aspects of Native Americans lives. But the incident highlighted the importance of monitoring volcanic activity and making the information immediately available to the airline industry and other segments of the public. The major plates are Eurasia, Pacific, India, Australia, North America, South America, Africa, and Antarctic. The fact that the plates include both crustal material and lithospheric mantle material makes it possible for a single plate to be made up of both oceanic and continental crust. This plate is moving north east towards the Arabia and Eurasia plates. Download the official NPS app before your next visit, Accretionary WedgeCoast Ranges [3 parks], Accretionary WedgeSouthern Alaska [1park]. Once youve named most of the plates, draw arrows to show the general plate motions. It runs from the tip of South America eastwards to form a barrier between the Antarctic plate and the South America plate. Lake Clark National Park and Preserve contains an active composite volcano with a profile and recent history reminiscent of Mt. Asterisk - Location of the January 12, 2010 earthquake. Cocos Tectonic Plate When a series of mantle plumes exists beneath a large continent, the resulting rifts may align and lead to the formation of a rift valley (such as the present-day Great Rift Valley in eastern Africa). This subduction-subduction-transform (SST) triple junction is referred to hereafter as the NACC triple junction. Find the boundary between the North American and Cocos plates. The northern boundary of the Cocos Plate is the Middle America Trench. In central and southern California the ancient volcanoes have largely eroded away. Cocos Plate; Type: Minor: Approximate area: 2,900,000 km 2: Movement 1: north-east: Speed 1: 67 mm/year: . In her version of the Oreo cookie demonstration, the creamy filling is the layers of sediment and basalt on the ocean floor. Most of the sedimentary rocks formed from layers of sand and mud deposited in the ocean. To the north it borders the North American Plate, which encompasses the entire north of the continent. This plate is moving directly east towards the South America plate. This plate is in the Pacific Ocean between the Pacific plate and the South America plate. Redoubt, on the eastern side of the park, had four explosive eruptions that resulted in large volumes of ash and mudflows. This plate moves north and slightly west towards the Caribbean plate and the North America plate. Is the Nazca Plate a convergent boundary? The Pacific Plate is moving to the northwest at a speed of between 7 and 11 centimeters (cm) or ~3-4 inches a year. The Cocos plate is found on the west side of Mexico. Increased temperature and pressure at that depth cause the rocks to metamorphose and dehydrate (sweat). Figure \(\PageIndex{4}\): Steven Earle. Off the Pacific coast, the Cocos plate is subducted beneath both the North American and Caribbean plates, which are separated by a sinistral transcurrent boundary. This plate is small. Massive areas of granite from the cooled magma chambers that fed the volcanoes form portions of the Sierra Nevada Mountains, including Yosemite National Park. A mature island arc develops into a chain of relatively large islands (such as Japan or Indonesia) as more and more volcanic material is extruded and sedimentary rocks accumulate around the islands. It separates the Pacific Plate to the west from (north to south) the North American Plate, the Rivera Plate, the Cocos Plate, the Nazca Plate, and the Antarctic Plate. The buoyancy of the mantle plume material creates a dome within the crust, causing it to fracture in a radial pattern, with three arms spaced at approximately 120 (Figure \(\PageIndex{5}\)). It is subducting under (that is, being forced under) the South American plate. Wrangell (left) and Mt. The resulting magma ascends through the crust, producing a mountain chain with many volcanoes. St. Helens. Vents and fractures (also called fissures ) in these mid-ocean ridges allow magma and gases to escape into the ocean. What type of boundary is the San Andreas Fault? As discussed in the context of subduction-related volcanism in Chapter 4, the significant volume of water within the subducting material is released as the subducting crust is heated. When the plates suddenly let go, a massive earthquake will shake the entire Pacific Northwest, a series of tsunami waves will pound the Coast, and landslides will make it difficult to reach some of those in need. Now suppose the subduction processes that form the volcanoes were to stop, shutting off the magma supply that feeds the volcanoes. What type of boundary is the Cocos Plate? Rainier were to suddenly and violently eruptso much that its magma chamber empties and the volcanic peak collapses in on itself. And very large parks in the Southern Alaska Subduction Zone display magnificent mountains, rock layers and active volcanoes that tell the story ongoing plate convergence along the North Pacific Coast. The distribution and depths of earthquakes in the Caribbean and Central America area are shown in Figure 11.2.3. Rainier in Mt. What type of plate boundary is the Cocos Plate? The North American Plate, for example, rotates counter-clockwise; the Eurasian Plate rotates clockwise. During the same period, the Atlantic Ocean began to open up between northern Africa and North America, and India broke away from Antarctica. The major plates are Eurasia, Pacific, India, Australia, North America, South America, Africa, and Antarctic. Sediment that has accumulated on the continental slope is thrust up into an accretionary wedge, and compression leads to thrusting within the continental plate (Figure \(\PageIndex{7}\)). Shasta in California, and other Cascade Volcanoes. With continued uplift and erosion, most of the volcanic material would erode. The Cascadia Subduction Zone and Southern Alaska are the sites of ongoing subduction as the Pacific and Juan de Fuca plates slide beneath the North American Plate. Contents1 What boundary [] This plate includes the northeastern part of the Atlantic ocean, all of Europe, all of Russia (except its most eastern part), and down through southeast Asia, including China and Indonesia. Find the boundary between the North American and Cocos plates. Divergent boundaries are spreading boundaries, where new oceanic crust is created to fill in the space as the plates move apart. A transform plate boundary developed where the Pacific Plate was in contact with the North American Plate and the volcanism ceased in central California. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate broke into two pieces, which also created the Nazca Plate. o The boundary is found far from the North American Plate in the Pacific Ocean The boundary appears to be situated on a mid-ocean ridge ( ) The boundary is found close to the North American Plate. By 80 Ma, Africa had separated from South America, most of Europe had separated from North America, and India had separated from Antarctica. This affects not only plant and animal communities, but also human habitation and land use. Final answer. For example the Juan de Fuca Plate is actually three separate plates (Gorda, Juan de Fuca, and Explorer) that all move in the same general direction but at slightly different rates. Off the Pacific coast, the Cocos plate is subducted beneath both the North American and Caribbean plates, which are separated by a sinistral transcurrent boundary. Magma from the mantle pushing up to fill the voids left by divergence of the two plates, Magma cooling more slowly in the lower part of the new crust and forming gabbro bodies, Figure \(\PageIndex{1}\): Plates tect2 en by the. Without warning the plane flew right through the eruption cloud at 25,000 feet (7,500 meters) altitude. Individual earthquakes can offset or lift the land a fraction of an inch or a few inches (centimeters) at a time. The eruption of Mt. In doing so the magma is enriched in silica, because high-silica minerals commonly are the first ones to melt. Magmas high in silica are thick and pasty. The largest (locked zone earthquakes) occur where the Juan de Fuca and North American plates are stuck together, as they have been for the past three centuries. More than 40 volcanoes have erupted in Alaska since Russians first arrived in the mid 1700s a great many of the volcanoes are in areas that are now National Park Service sites. This plate makes up all of Antarctica and much of the surrounding ocean. The magma, which is lighter than the surrounding mantle material, rises through the mantle and the overlying oceanic crust to the ocean floor where it creates a chain of volcanic islands known as an island arc. A map of the ocean floor reveals a deep underwater trench (dark blue line) running along the southern coast of Mexico, defining the boundary between two tectonic plates. If spreading along the mid-Atlantic ridge continues to be slower than spreading within the Pacific Ocean, the Atlantic Ocean will start to close up, and eventually (in a 100 million years or more) North and South America will collide with Europe and Africa. Some parks in the Sierra Nevada Mountains reveal igneous magma chamber rocks that represent the eroded remnants of an ancient subduction zone, when volcanoes similar to those found in the modern Cascade Mountains extended southward all the way through California. The Philippine Sea plate is tectonically unusual in that almost all the boundaries are convergent. Many National Park Service sites are found in active and ancient subduction zones. New Guinea and the northern parts of New Zealand are part of the Australia plate. To see the timing of these processes for yourself, go to time lapse of Continental Movements. Plates move as rigid bodies, so it may seem surprising that the North American Plate can be moving at different rates in different places. Incipient rifting has begun along the Great Rift Valley of eastern Africa, extending from Ethiopia and Djibouti on the Gulf of Aden (Red Sea) all the way south to Malawi. Based on Keary and Vine, 1996, Global Tectonics (2ed), Blackwell Science Ltd., Oxford. rare Examine the interactive globe. This contortion attests to the great forces that squeezed and lifted the layers from the sea. Katmai National Park (Click on arrows and slide left and right to see labels.). The triangular zone of partial melting near the ridge crest is approximately 60 km thick and the proportion of magma is about 10% of the rock volume, thus producing crust that is about 6 km thick. There are also numerous small plates (e.g., Juan de Fuca, Cocos, Nazca, Scotia, Philippine, Caribbean), and many very small plates or sub-plates. Ancient magma chamber rocks can be exposed if subduction stops and the volcanoes erode away. When caught between the converging Juan de Fuca and North American plates, the pillows and other ocean layers can be lifted upward to more than a mile above sea level. The low region between the two parallel mountain ranges is the, 150 miles inland, the top of the subducting plate reaches depths where its hot enough to generate fluids, forming volcanoes in the. Plate borders the North American Plate, the South American Plate, the Nazca Plate and the Cocos Plate. This page titled 10.4: Plate, Plate Motions, and Plate Boundary Processes is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Steven Earle (BCCampus) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request. The explanation is that plates move in a rotational manner. Rocks in Yosemite, Kings Canyon, Sequoia, and Joshua Tree national parks contain exumed magma chamber rock that formed beneath the ancient volcanoes. Similarly the South American Plate extends across the western part of the southern Atlantic Ocean, while the European and African plates each include part of the eastern Atlantic Ocean. National Park Service sites are shown in red. Two parallel mountain ranges have been forming as a result of the Juan de Fuca Plate subducting beneath the edge of North America. An ancient volcano, Mt. The spectacular pillow lavas seen on the road up Hurricane Ridge indicate that lava formed on the sea floor and was later uplifted. Point Reyes National Seashore and Golden Gate National Recreation Area are the only two NPS sites that are right on the San Andreas Fault. They are part of the volcanic arc that extends northeastward from the Aleutian Islands, across the Alaska Peninsula and Aniakchak National Monument, Katmai and Lake Clark national parks, and then bends eastward to Wrangell-St. Elias National Park. Detailed Description Map of the North American - Caribbean tectonic plate boundary. Multiple complex plate boundaries contribute lots of earthquake and volcanic activity in the region. The caldera has partially filled with water an approximately half-scale version of the better-known Crater Lake in Oregon. . At an ocean-continent convergent boundary, the oceanic plate is pushed under the continental plate in the same manner as at an ocean-ocean boundary. The Philippine Sea Plate has an area of approximately 3400 square kilometers. Transform faults do not just connect divergent boundaries. This plate is moving north east towards the Caribbean and North America plates. Without referring to the plate map in Figure \(\PageIndex{1}\), or any other resources, write in the names of as many of the plates as you can. At transform boundaries lithosphere is neither created nor destroyed. USGS photo. Is the Philippine plate convergent or divergent? Much of the stable plate is under water and is called the Caribbean ocean . Photo courtesy of Robert J. Lillie. Most divergent boundaries are located at the oceanic ridges (although some are on land), and the crustal material created at a spreading boundary is always oceanic in character; in other words, it is mafic igneous rock (e.g., basalt or gabbro, rich in ferromagnesian minerals). St. Helens in 1980. Left image The plates are made up of crust and the lithospheric part of the mantle (Figure \(\PageIndex{2}\)), and even though they are moving all the time, and in different directions, there is never a significant amount of space between them. Hydrothermal features on the flanks of Lassen Peak include numerous hot springs, mudpots and fumaroles that suggest there is still hot magma beneath the mountain. The Cocos Plate is a small, oceanic plate just to the west of Central America. There is tremendous deformation of the pre-existing continental rocks, and creation of mountains from that rock, from any sediments that had accumulated along the shores (i.e., within geosynclines) of both continental masses, and commonly also from some ocean crust and upper mantle material. Now you should see color coded lines that are the plate boundaries, and the names of Earth's major plates. It is bordered by the Caribbean, North American, Pacific, and Nazca tectonic plates. Listing total number of features into an ArcGIS Online feature pop-up, Convergent boundaries: where two plates are colliding. Garibaldi in southern British Columbia, through Washington and Oregon, to Lassen Peak in northern California. Nazca plate, Pacific plate, North America plate, Caribbean plate. Dramatic examples of these layers in tilted and contorted forms can be found in Olympic National Park and elsewhere along the coast and in the mountains. Redwood National and State Parks, California Transform boundaries exist where one plate slides past another without production or destruction of crustal material. Subduction zones form where a plate with thinner (less-buoyant) oceanic crust descends beneath a plate with thicker (more-buoyant) continental crust. They contain explosive volcanoes formed as fluids rise from the top of the subducting plate and generate magma as they melt their way to the surface. Photo courtesy of Robert J. Lillie. Photo courtesy of Robert J. Lillie. The best example is the San Andreas Fault on the Pacific coast of the United States. Mount Rainier is a 14,000 foot (4,300 meter) volcano in the Cascade Range developed above the place where the subducting Juan de Fuca Plate reaches sufficient depth to release hot fluids into the overriding North American Plate. The Coast Ranges, including the Olympic Mountains, are made of oceanic sediments and hard rocks that were caught in the vise between the converging plates, uplifted, and added to the edge of the continent. Convergent boundaries, where two plates are moving toward each other, are of three types, depending on whether oceanic or continental crust is present on either side of the boundary. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. A subduction zone will develop, and the oceanic plate will begin to descend under the continent. Expert Answer. Drum (right). The eruption of Aniakchak Volcano about 3,500 years ago rivals the eruption and collapse of Mt. The Cascadia Subduction Zone has two parallel mountain ranges separated by a low region near sea level. 40 Million Years Ago Mazama, Aniakchak spewed lava across its caldera floor for centuries after its collapse. Pillow basalts attest to the oceanic origins of the rock layers, as they formed from lava flows that cooled on the ocean floor. This plate is small. What type of plate boundary is Antarctic and Australian plate? The Nazca plate is a large tectonic plate that underlies the Pacific Ocean near the western coast of South America. Africa plate, Nazca plate, Scotia plate, Caribbean plate, Antarctic plate, North America plate. The Nazca plate is a large tectonic plate that underlies the Pacific Ocean near the western coast of South America. A divergent boundary occurs when two tectonic plates move away from each other. This plate includes all of North America, Greenland, the eastern most part of Russia, northern Japan, and the northwestern part of the Atlantic ocean. Examples of continent-continent convergent boundaries are the collision of the India Plate with the Eurasian Plate, creating the Himalaya Mountains, and the collision of the African Plate with the Eurasian Plate, creating the series of ranges extending from the Alps in Europe to the Zagros Mountains in Iran. Silica-rich ash melted and coated the hot engine turbines with glass, causing all four of them to shut down. , Divergent boundaries where two plates are moving apart. In the past, that was true. National Park Service sites in the Cascades reveal colorful landscapes that result from a varity of volcanic processes.
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