Volcanoes are both beneficial and destructive?

Question

Waht are some examples of each?

New land?

Answer 1

When earth first formed, there was no oceans.  As volcanoes erupted, they released steam which caused rain for thousands of years.  This rain created our oceans.

They also created many of the land masses we see today, such as Hawaii.  They have also created mountains.  

Watch the Natural Geographic series about Earths Biography.  The first show of the series is Vocanoes and discusses the many ways volcanoes have influenced the earth.

Answer 2

yup.

volcanic ash is extremely fertile. there is a certain type of tree that needs volcanic ash in order to reproduce.

yeah it forms new land...that's how Hawaii and other islands were formed. Hawaii is still growing too.

and obviously they're destructive as well...the lava burns down everything in it's path. the ash pollutes the air and buries whatever is in its path and its harmful to breathe.