With what type of plate boundary are the following places or features associated himalayas aleutian islands red sea andes mountains san andreas fault iceland japan mount st helen's?

Answer 1

(1) Himalayas -- Convergent between continental-continental collision of Indo-Australian and Eurasian plates.

(2) Aleutian islands -- Convergent between oceanic-oceanic collision of Pacific plate beneath North American plate.

(3) Andes Mountains -- Convergent between oceanic-continental collision of Pacific plate beneath South American plate.

(4) San Andreas Fault (Zone) -- Transform boundary (sometimes called a conservative boundary) between Pacific and North American plates.

(5) Iceland -- Divergent boundary along the Mid-Atlantic Ridge arm of the Mid-Ocean Ridge, separating North America to the west and Eurasia to the east. *Also* a large hot spot, which is what brought Iceland to the surface, rather than remaining undersea.

(6) Japan -- Convergent boundary between Pacific plate beneath North American plate (yes, Japan is on the North American plate).

(7) Mount St. Helens -- Convergent boundary between Juan de Fuca beneath North Americna plate.

Convergent boundaries build mountains (technically divergent do too, but no one ever thinks about them -- but they're lots and lots of small volcanoes)

Continental-continental --> crust slams together like two buses, neither plate can subduct, rock squirts up and out, you get the Himalayas (Indo-Australian and Eurasia)

Oceanic-oceanic --> crust meets and the older, denser, cooler one subducts. It reaches a depth that it melts, the new magma rises to the surface, pops out as a volcanic lava flow. Thousands of flows later, you have dry volcanic islands poking out of the surface. Because this is happening along a plane, you get a whole chain - an volcanic island arc like the Aleutians (Pacific plate below North American plate)

Oceanic-continental --> crust meets and the oceanic will *always* subduct. Just like oceanic-oceanic, it melts and rises and pops out, but this time on a dry continental surface. Again, thousands of flows later, you have a volcano. Again, as it's on a plane, you get a whole mountain range.