How does Iceland confirm seafloor spreading?

Answer 1

I've always wondered what is the success rate for folks actually getting correct answers for their homework by using Yahoo Answers? From what I've seen, unless it's a really EASY question, most of the answers given are at least partially incorrect, often wandering or off topic, and I would be embarrassed for anyone that actually submitted an answer they got here without verifying the information...which essentially means doing the homework that one was trying to avoid in the first place.

Answer 2

Iceland is on the mid-Atlantic ridge, and it's mostly tundra, so there isn't much vegetation to conceal geological features. From the air you can easily see a crack running approximately north-south where mantle material is oozing to the surface and spreading out on each side. So the Atlantic Ocean is getting wider by a couple of centimetres a year or so. Sure enough, if you take samples of rock from the floor of the Atlantic, the direction of magnetisation changes as you move eastwards or westwards from the mid-Atlantic ridge. This crack in the Earth's crust runs down the middle of the Atlantic through Iceland, the Azores and Tristan da Cunha, all of which are volcanic.