Volcanoes are produced by mantle plumes. ( http://en.wikipedia.org/wiki/Volcano )
Some are. Most volcanoes on land are produced by convergent boundaries while others form over hot spots.
Most of the time, its because of the fertile land produced by the lava flow.
Land Volcanoes eat lamas and underwater volcanoes eat camals
Volcanoes underwater erupt in much the same way as those on dry land. They erupt when pressure builds up. The difference between these two types of volcanoes is that the lava produced in an underwater volcano cools dramatically faster than the lava on land.
Lahars
They were all produced by volcanoes.
under the earth
Earthquakes and volcanoes both occur in land and ocean. =)
There are about 1500 volcanoes on land that are known to have have been active .
Land is probably the most valuable thing volcanoes produce. Volcanoes typically erupt and magma bursts out and when it flows on the land it forms newly required land. This land is made then by the magma cooling off.
it turns into rock and forms a new land
Volcanoes and earthquakes