Subduction zones synonyms, subduction zones antonyms. If you dont know anything about plate tectonics you might be wondering about what is a subduction zone. They occur down to depths of around 670 km at some subduction zones. Pages in category subduction zones the following 30 pages are in this category, out of 30 total. Boore abstract groundmotion relations for earthquakes that occur in subduction zones are an important input to seismichazard analyses in many parts of the world.
Air guns give glimpse inside a subduction zone live science. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately 2 to 8 centimeters per year about the rate a fingernail grows 1. Some subduction zones are longlived, such as the andes subduction zone, which is over 100 million years old, whereas others have just initiated, such as. The most important are embedded in the lack of a common behaviour of global subduction zones e. These earthquakes of the benioff zone or wadatibenioff zone occur near the upper surface of the descending plate or slab.
Note that there is a particular depth d at which the sediments are heated sufficiently so that they liberate their volatiles, and that this determines the distance from the trench to the volcano v. As a consequence oceanic magmatic arcs are formed worldwide fig. Because subduction involves movement of material downward, it is difficult to observe the products of subduction in the presentday world. Nov 02, 2009 if you dont know anything about plate tectonics you might be wondering about what is a subduction zone.
Note that there is a particular depth d at which the sediments are heated sufficiently so that they liberate their volatiles, and that this determines the distance from the trench to the volcano. Subduction zone trenches are delineated with black lines, and downgoing caps are labeled with arrows showing the convergence direction. Remote work advice from the largest allremote company. Pdf evidence for miocene subduction beneath the alboran sea. The subduction zone is the place where two lithospheric plates come together, one riding over the other. Empirical groundmotion relations for subduction zone earthquakes and their application to cascadia and other regions by gail m.
Aleutian islands, japan, new zealand, sometimes with a double arc one further back from the subduction zone, and oceancontinent convergence producing cordillera. Subduction zones represent steadystate convergence. During arccontinent and continentcontinent collision, units deformed in subduction zones may be uplifted and exposed. Subduction zone magmatism can be subdivided into three categories based on the difference in the depth of the original mantle activity responsible for the upwelling and the subsequent melting of mantle materials.
Ce magmatisme est lie a lhydratation des peridotites. Shallow subduction zone earthquakes and their tsunamigenic. Empirical groundmotion relations for subductionzone. Tectonic setting two main scenarios are possible oceanocean convergence producing island arcs e. A geologic process in which one edge of one crustal plate is forced below the edge of another. Subduction zones definition of subduction zones by the free. Global bathymetry and topography of the pacific margin illustrates multiple arc. Introduction to the special issue on subduction zones.
This diagram shows the basic ideas regarding the formation of magma at a subduction zone. Evidence for miocene subduction beneath the alboran sea. Physical model of source region of subduction zone volcanics. The fundamental question is whether this source region is the eclogitic subducting slab or the peri dotitic mantle wedge. Plumesubduction interaction forms large auriferous provinces. Pdf caracteristiques geochimique et metallographique du. The farther from the trench, the deeper the earthquakes are. A subduction zone is an area on earth where two tectonic plates move towards one another and subduction occurs.