Iceland is in the middle of the mid atlantic ridge, which is a divergent boundary. Divergent boundaries are where two plate tectonics are moving away from each other.
Divergent boundaries have stress which depends on which way the plates are going. Since the plates are moving away from each other, the stress being used is tension.
On divergent boundaries earthquakes and volcanoes appear. The crust spreads apart and creates shield volcanoes.
A well known shield volcano is Mauna Loa, in Hawaii.
There was an earthquake in
Convergent boundaries move towards each other until one goes under the other. The oceanic plate(the one in the ocean) goes under the continental plate. That is called subduction. Subduction can make volcanoes and earthquakes.
What happens it the earth uses compression forces to bring the plates together then subduction happens. The oceanic plate goes under the continental plate, but also brings water with it. The water boils, the magma rises through the crakes in the crust. Then once it split through.....a volcano is made.
A land form of volcanoes is the string of volcanoes in Alaska.
The biggest disaster in Alaska is an earthquake with a magnitude of 9.2 that happened on Good Friday March 27, 1964 at 5:36 PM. 131 people died and out of all those people... 119 of them died in the tsunami aftermath.