Search results
Results from the WOW.Com Content Network
Relief map with the East Pacific Rise (shown in light blue), extending south from the Gulf of California. The East Pacific Rise (EPR) is a mid-ocean rise (usually termed an oceanic rise and not a mid-ocean ridge due to its higher rate of spreading that results in less elevation increase and more regular terrain), at a divergent tectonic plate boundary, located along the floor of the Pacific Ocean.
The ridge is a medium rate spreading center, moving outwards at a rate of approximately 6 centimetres (2.4 in) per year. [14] Tectonic activity along the ridge is monitored primarily with the U.S. Navy's Sound Surveillance System (SOSUS) array of hydrophones, allowing for real time detection of earthquakes and eruptive events. [10]
The Pacific is also home to one of the world's most active spreading centers (the East Pacific Rise) with spreading rates of up to 145 ± 4 mm/yr between the Pacific and Nazca plates. [20] The Mid-Atlantic Ridge is a slow-spreading center, while the East Pacific Rise is an example of fast spreading.
At the spreading center on a mid-ocean ridge, the depth of the seafloor is approximately 2,600 meters (8,500 ft). [ 2 ] [ 3 ] On the ridge flanks, the depth of the seafloor (or the height of a location on a mid-ocean ridge above a base-level) is correlated with its age (age of the lithosphere where depth is measured).
In a rift zone, seafloor spreading is underway, accompanied by volcanic and geothermal activity, active faulting [c] and rapid sedimentation. [ 32 ] Since five million years ago, the buildup of sediments in the Colorado River Delta separated the Salton Trough area from the actual Gulf of California , forming a large depression that currently ...
Spreading center and strips. Transform faults move differently from a strike-slip fault at the mid-oceanic ridge. Instead of the ridges moving away from each other, as they do in other strike-slip faults, transform-fault ridges remain in the same, fixed locations, and the new ocean seafloor created at the ridges is pushed away from the ridge.
In Atwater's research on propagating rifts near the Galapagos Islands, [11] she discovered that propagating rifts were created when spreading centers along the seafloor were disturbed by tectonic movement or magma and therefore had to change direction to realign. This helped to explain the complex pattern of the seafloor.
At a seafloor spreading ridge, plates move away from the ridge, which is a topographic high, and the newly formed crust cools as it moves away, increasing its density and contributing to the motion. At a subduction zone the relatively cold, dense oceanic crust sinks down into the mantle, forming the downward convecting limb of a mantle cell ...