What Is a Converging Oceanic Plate Boundary?

Oceanic Trenches

• When two oceanic plates collide with each other, the denser plate subducts, or goes under, the other. When one plate subducts, a trench forms. Once the denser plate is approximately 100 miles under the other plate, it reaches melting temperature. One of the most well-known convergence of oceanic plates is where the fast-moving Pacific plate converges with the slower-moving Phillipine plate, forming the Marianas Trench, which plunges more than 36,000 feet into the Earth's surface. Converging oceanic plates also causes destruction of the oceanic lithosphere as it reaches melting temperatures.

Undersea Volcanoes

• Another result of two Oceanic plates converging is the formation of undersea volcanoes. The lava and debris pile up on the ocean floor until they reach sea level to form a volcanic isle. The debris spreads out over time and forms island arcs, such as the Aleutian Islands. Since they exist along a plate boundary, they're subjected to frequent earthquakes when the plates shift.

Oceanic - Continental Convergence

• When an oceanic plate converges with a continental plate the oceanic plate pushes the continental plate up, forming a mountain range. The oceanic plate generally shifts under the continental plate as a whole, but at the deepest part of the subduction zone the plate breaks apart into pieces and shifts the land up as much as a few meters at a time. The West Coast of the United States is an example of oceanic and continental convergence.

Continental - Continental Convergence

• When two continental plates collide with each other, neither of them subducts since they're both less dense than oceanic plates. The plates buckle and push either up or sideways. When continental plates converge folding and faulting, earthquake activity and plate thickening occur. The most well-known collision of continental plates is the Himalayan mountain range, where the Indian and Eurasian plates actively collide with each other.

Plates

• The major plates, for the most part, identify the continent that sits on top of them. They are the African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American plate. There are seven smaller tectonic plates that don't cover a large land mass; they are the Arabian, Caribbean, Cocos, Juan de Fuca, Nazca, Philippine Sea and Scotia plates.