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 deepest point in the ocean is, not surprisingly, in the Mariana Trench. It is called the Challenger Deep, after the British ship Challenger II, which discovered this point in 1951 while surveying. The Challenger Deep lies along the southern end of the Mariana Trench near the Mariana Islands.he 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. Contrary to what you might picture, the trench is wide-according to NOAA, almost 5 times wider than it is deep. The Mariana Trench is located in the western North Pacific Ocean.