What are the Mid-Atlantic Ridge and East Pacific Rise?
Two of the most carefully studied mid-ocean ridges are the Mid-Atlantic Ridge and the East Pacific Rise. The Mid-Atlantic Ridge runs down the center of the Atlantic Ocean, slowly spreading at a rate of two to five centimeters (0.8 to 2 inches) per year and forming a rift valley that is about the depth and width of the Grand Canyon.
What is the East Pacific Rise known for?
East Pacific Rise. The East Pacific Rise forms part of the circumglobal system of active volcanic ridges, all of which define the position of diverging plates where new crust is being created. Such ridges represent the locus of global shallow-water earthquakes.
Is the East Pacific Rise a fast spreading center?
The East Pacific Rise, on the other hand, is a fast spreading center. Why do the walls of the mid-ocean ridge spread apart? Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart.
Where is the East Pacific Rise located in California?
The East Pacific Rise, extending south from the Gulf of California. The East Pacific Rise is a mid-oceanic ridge, a divergent tectonic plate boundary located along the floor of the Pacific Ocean.
Where does the East Pacific Rise start and end?
It runs south from the Gulf of California in the Salton Sea basin in Southern California to a point near 55° S, 130° W, where it joins the Pacific-Antarctic Ridge trending west-southwest towards Antarctica, near New Zealand (though in some uses the PAR is regarded as the southern section of the EPR).
How fast is the East Pacific Rise?
The East Pacific Rise is perhaps the best studied fast-spreading mid-ocean ridge. The ridge segment that creates the Nazca and Pacific plates moves up to 5.6 inches (142 mm) each year.
How was the East Pacific Rise?
The resulting underwater volcanoes spread lava across large areas of seafloor and form the core of the East Pacific Rise. Water percolating down into these lava flows is heated, then rises back toward the seafloor, forming hydrothermal (hot water) vents in the seafloor.
What happens at the East Pacific Rise?
Four characteristics of the Rise especially intrigue scientists: 1) like other ocean ridges, it is the site of many shallow earthquakes; 2) beneath its crest the crust of the earth thins out, becoming two miles thick rather than the three miles of typical ocean basins, and perhaps twenty under the continents; 3) heat ...
Which ocean is growing the fastest?
That's why the Pacific Ocean expands faster than the Atlantic: Most of the Pacific sits atop one tectonic plate, and its boundaries line up almost perfectly with the continental ones on the east and west sides, the North American and Eurasian plates.
What is the depth of Challenger Deep?
35,876 feetChallenger Deep is approximately 10,935 meters (35,876 feet) deep. It is named after the HMS Challenger, whose crew first sounded the depths of the trench in 1875.
Will California become an island?
No, California is not going to fall into the ocean. California is firmly planted on the top of the earth's crust in a location where it spans two tectonic plates.
Where is the fastest spreading center?
The fastest present-day seafloor spreading, ~150 km/Myr, occurs along the Pacific-Nazca boundary between the Easter and Juan Fernandez microplates.
Who Discovered East Pacific Rise?
The East Pacific Rise was first detected during the Challenger Expedition of the 1870s. It was described in its gross form during the 1950s and '60s by oceanographers, including Heezen, Ewing, and Henry W. Menard.
Is the East Pacific Rise a subduction zone?
The islands are a manifestation of intersecting plate boundaries—the spreading center of the East Pacific Rise, which traces south from the Gulf of California, and the subduction zone that consumes the Cocos plate beneath southern Mexico.
What is the tectonic setting for Iceland?
Iceland sits spanning the Mid-Atlantic Ridge tectonic plate boundary which separates the Eurasian and the North American plates. The ridge, an underwater mountain chain, extends about 16,000 km along the north-south axis of the Atlantic Ocean.
What is the difference between a rise and a ridge?
Wiseman and Ovey (1953) present the term oceanic rise as a long and broad elevation of the deep seafloor that rises gently and smoothly, and a ridge is considered to have steeper sides and less regular topography than a rise.
What is the spreading rate of the East Pacific Rise quizlet?
The rate of seafloor spreading at the Mid-Atlantic Ridge is 2 centimeters per year, whereas the rate of seafloor spreading at the East Pacific Rise is 15 centimeters per year.
How deep is the rift in the East Pacific Rise?
Slow-spreading ridges are characterized by a rift valley at the crest. Such a valley is fault-controlled. It is typically 1.4 km (0.9 mile) deep and 20–40 km (about 12–25 miles) wide.
Is the East Pacific Rise a subduction zone?
The islands are a manifestation of intersecting plate boundaries—the spreading center of the East Pacific Rise, which traces south from the Gulf of California, and the subduction zone that consumes the Cocos plate beneath southern Mexico.
What is the name of the fastest spreading ridge in the world?
Pardee, Hydrothermal venting along Earth's fastest spreading center: East Pacific Rise, 27.5°–32.3°S, J.
When did North America override the East Pacific Rise?
North America: 30 to 2.5 million years ago. …America began to override the East Pacific Rise, an oceanic spreading ridge. This activity placed a progressively longer segment of the coast in contact with the plate west of the ridge. The western plate—which contains the Coast Ranges of California—has been moving to the northwest relative ...
What plate is the East Pacific Rise?
The East Pacific Rise and its associated features to the north and southwest form the eastern and southern boundaries of the Pacific Plate, where it abuts (from north to south) the North American, Cocos, Nazca, and Antarctic plates . The crest of the East Pacific Rise is a centre of seafloor spreading; new oceanic crust in the form of basaltic lava is welling up along the crest, cooling, and moving away from the crest in either direction. Offshore from Chile and Peru the rate of spreading is about 6.3 inches (16 cm) per year, one of the most rapid rates on Earth, though it decreases to about 2.4 inches (6 cm) at the mouth of the Gulf of California. Associated with this volcanic activity are a number of hydrothermal vents, upwellings of heated seawater that often carry a variety of sulfide minerals. These vents support organisms that exist through chemosynthesis by sulfur-fixing bacteria.
How fast does the East Pacific Rise spread?
In contrast, the East Pacific Rise spreads fast, at rates of 6 to 16 centimeters (3 to 6 inches) per year. Due to the fast spreading rates, there is no rift valley in the Pacific, just a smooth volcanic summit with a crack along the crest that is much smaller than the Atlantic rift valley.
How fast does the Mid Atlantic Ridge spread?
The Mid-Atlantic Ridge runs down the center of the Atlantic Ocean, slowly spreading at a rate of 2 to 5 centimeters (0.8 to 2 inches) per year and forming a rift valley that is about the depth and width of the Grand Canyon. In contrast, the East Pacific Rise spreads fast, at rates of 6 to 16 centimeters (3 to 6 inches) per year.
What causes mid ocean ridges?
Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt. The speed of spreading affects the shape of a ridge – slower spreading rates result in steep, ...
What is the mid ocean ridge system?
The nearly continuous, global mid-ocean ridge system snakes across the Earth’s surface like the seams on a baseball. It is clearly visible on this map of global topography above and below sea level. The ridge system forms the longest and largest mountain range on Earth, winding its way between the continents. Download image (jpg, 123 KB).
How much of the mid ocean ridge has been explored?
While we have mapped about half of the global mid-ocean ridge in high resolution, less than one percent of the mid-ocean ridge has been explored in detail using submersibles or remotely operated vehicles.
How deep is the mid ocean ridge?
The majority of the system is underwater, with an average water depth to the top of the ridge of 2,500 meters (8,200 feet).
What is the NOAA Office of Ocean Exploration and Research?
By funding expeditions to spreading centers in the Atlantic and the Pacific, the NOAA Office of Ocean Exploration and Research is helping scientists to draw connections between volcanic, tectonic, hydrothermal, and biological systems in order to better understand the Earth’s remarkable, evolving geography.
