Quote (Garethsir @ Fri, Mar 27 2009, 02:36pm)
plate tectonics?
supposedly the earths crust moves.
why are the Hawaiian islands formed in a chain???
my teacher says its because there is a radioactive spot under it that actually melts a hole through the crust and spills out lava into the ocean, making a chain of islands as the crust moves
Radioactivity isn't the word you're looking for there....
but anyways, yes, the Earth's crust (outer shell) is formed by a group of plates that shift due to magma circulation underneath. When there is a "leak" or "crack" in the crust, the magma finds its way up -- and since magma is incredibly hot rock, it turns back into a solid when coming into contact with something that absorbs and retains A LOT of heat like water (to put it simply, lava = hot, water = cold, water is in much greater quantity and thus the lava cools down back into rock).
You honestly need to read this stuff up yourself, you always ask these kind of questions which makes me think you're a curious person -- so why not take advantage of your curiousity and actually look at the material in depth. You could learn so much more than what anyone can or is willing to type up on JSP.