A stroke is a brain attack â a sudden interruption of blood flow to part of the brain causing it to stop working and eventually damaging brain cells. The effects can be devastating and may last a lifetime. A stroke is also known as a cerebrovascular accident (CVA). There are several different types of stroke, with different causes. Ischaemic stroke: This is the most common type of stroke, particularly in older people.
Examples of some deep ocean trenches that are subduction zones are off the West coast of South America, in the Peruvian Trench. The Aleutian Trench, in the North Pacific Ocean, and the deepest, most famous one in the world, the Marianas Trench off the coast of the Marianas Islands in the Southeast Pacific.
The ocean's deepest area is the Mariana Trench (also called the Marianas Trench), which is about 11 km (almost 7 miles, or almost 36,000 feet) deep. The trench is 1,554 miles long and 44 miles wide, and is like the Grand Canyon of the ocean, although it is 120 times larger.he Mariana Trench is so deep because it is an area where two of the Earth's plates converge and one (the Pacific plate) is subducted, or dives underneath, the other (the Philippine plate). During this slow process, the Philippine plate also gets pulled down.