The numerical value of the convergent boundary in Chaldean numerology is: 1 A converging boundary (also known as a destructive boundary) is an area on Earth where two or more lithospheric plates collide. One plate eventually slides under the other, a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, the Wadati-Benioff zone. [1] These collisions occur on scales ranging from millions to tens of millions of years and can lead to volcanism, earthquakes, orogeny, destruction of the lithosphere and deformation. Converging boundaries occur between the oceanic-oceanic lithosphere, the oceanic-continental lithosphere and the continental-continental lithosphere. The geological characteristics associated with converging boundaries vary depending on the type of crust. It is a difficult line to draw. First, it is complex and second, it is poorly understood compared to other types of plate boundaries. In this type of converging boundary, a strong collision occurs. The two thick continental plates collide, and both have a much lower density than the mantle, which prevents subduction (there may be a small subduction, or the heavier lithosphere beneath the continental crust could detach from the crust and subduction). Ocean trenches are narrow topographic depressions that mark converging boundaries or subduction zones. Ocean trenches average 50 to 100 km (31 to 62 miles) wide and can be several thousand kilometers long.
Ocean trenches form as a result of the curvature of the subduction plate. The depth of the ocean trenches appears to be controlled by the age of the subducted oceanic lithosphere. [5] Sediment filling in ocean trenches varies and generally depends on the abundance of sediment inputs from surrounding areas. An ocean trench, the Mariana Trench, is the deepest point in the ocean at a depth of about 11,000 m (36,089 ft). When a converging boundary occurs between two oceanic plates, one of these plates submerges beneath the other. Usually, the older plate will subduce due to its higher density. The subduction plate is heated when driven deeper into the mantle, and at a depth of about 100 miles (150 km), the plate begins to melt. This melting creates magma chambers, and the magma has a lower density than the surrounding rock materials.
It begins to rise by melting and making its way through the overlying rock material. Magma chambers that reach the surface pierce the surface, forming a volcanic eruption cone. In the early stages of this type of boundary, the cones will be deep below the sea surface, but later grow higher than sea level. This creates a chain of islands. As development progresses, the islands become larger, merge and form an elongated landmass. Visit the interactive plate boundary map to explore satellite imagery of the converging boundaries between the oceanic and continental plates. Two sites are marked to show this type of plate boundary – the cascading volcanoes along the coast of Washington and Oregon in North America and the Andes at the western tip of South America. Subduction zones are areas where one lithospheric plate slides below another at a converging boundary due to differences in lithospheric density.
These plates fall on average by 45°, but can vary. Subduction zones are often characterized by an abundance of earthquakes that are the result of internal plate deformation, convergence with the opposite plate, and curvature at the ocean trench. Earthquakes were recorded at a depth of 670 km (416 mi). The relatively cold and dense subduction plates are pulled into the mantle and help drive mantle convection. [6] Some of the deadliest natural disasters are due to converging border processes. The 2004 Indian Ocean earthquake and tsunami was triggered by a mega pusher earthquake along the converging border of the Indian plate and Burmese microplate, killing more than 200,000 people. The 2011 tsunami off the coast of Japan, which claimed 16,000 lives and caused $360 billion in damage, was caused by a magnitude 9-mega-surge earthquake along the converging boundary of the Eurasian Plate and the Pacific Plate. The effects of a converging boundary between an oceanic and continental plate include: a zone of seismic activity that is flat along the continental margin but deepens beneath the continent; sometimes a sea trench just off the coast of the continent; a series of volcanic eruptions a few hundred kilometres inland from the coast; Destruction of the oceanic lithosphere. The Himalayan mountains are the best active example of this type of plate boundary. Visit the interactive map of the plate boundaries to explore satellite imagery of the Himalayas, where the Indian and Eurasian plates are currently colliding. Appalachia is an early example of this type of collision and is also marked on the map. Earthquakes are common along converging borders.
A region with high seismic activity, the Wadati Benioff zone, generally drops 45° and marks the subduction plate. The earthquakes will occur at a depth of 416 miles (670 km) along the Wadati-Benioff margin. The breaking stones slide the mother plate over part of the laxative plate along the fault line. The movement of the plate on the seafloor can cause a tsunami. The 2004 Indian Ocean tsunami was triggered by a mega-thrust earthquake on a converging border. A converging boundary is an area on Earth where two or more lithospheric plates collide. One plate eventually slides under the other, causing a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, the so-called Benioff zone. These collisions occur on scales ranging from millions to tens of millions of years and can lead to volcanism, earthquakes, orogeny, destruction and deformation of the lithosphere.
Converging boundaries occur between the oceanic-oceanic lithosphere, the oceanic-continental lithosphere and the continental-continental lithosphere. The geological characteristics associated with converging boundaries vary depending on the type of crust. Plate tectonics is driven by convection cells in the mantle. Convection cells are the result of heat generated by the radioactive decay of mantle elements escaping to the surface and the return of cold materials from the surface to the mantle. These convection cells bring warm mantle material along the spreading centers to the surface and create a new crust. When this new crust is pushed away from the center of spread by the formation of new crusts, it cools, thins and becomes denser. Subduction begins when this dense crust converges with the less dense crust. Gravity helps push the subduction plate into the mantle. There is evidence that gravity increases the speed of the plate. When the relatively cold subduction plate sinks deeper into the mantle, it is heated, resulting in drying out of the aqueous minerals. As a result, water is released into the warmer asthenosphere, resulting in partial melting of the asthenosphere and volcanism.
Dehydration and partial melting take place along isotherms at 1000°C, usually at depths of 65 to 130 km. Some lithospheric plates consist of continental and oceanic lithospheres. In some cases, initial convergence with another plate destroys the oceanic lithosphere, resulting in the convergence of two continental plates. Neither continental plate will submerge. It is likely that the plate can break up along the boundary of the continental and oceanic crust. Seismic tomography shows parts of the lithosphere that ruptured during convergence. Effects observed at this type of plate boundary include: an area of progressively deeper earthquakes; an ocean trench; a chain of volcanic islands; the destruction of the oceanic lithosphere. Effects observed at a converging boundary between continental plates include: intense folding and faulting; a wide folded mountain range; shallow seismic activity; Shortening and thickening of plates inside the collision zone. Some lithospheric plates consist of continental and oceanic lithospheres. In some cases, initial convergence with another plate destroys the oceanic lithosphere, resulting in the convergence of two continental plates. Neither continental plate will submerge.
It is likely that the plate can break up along the boundary of the continental and oceanic crust. Seismic tomography shows parts of the lithosphere that ruptured during convergence. [ref. needed] Two continental crusts collideThe last converging boundary is where two continental crusts collide.