The hazards from the volcanoes include lava and pyroclastics, tephra and , lahars and climate alteration. Fertile soil and geothermal energy are beneficial results of volcanic eruptions. Much of El Salvador for example is convered with volcanic ash and this has been a fertile growing medium for coffee plants.
The Earth rumbles and a hiss of steam issues from the top of Mt Ruapehu. Are these two events related? Is the earthquake caused by the volcano? Or is the steam caused by the earthquake?
Tectonic plates
When Alfred Wegener first proposed the idea of continental drift (the precursor idea to plate tectonic theory), it didn’t quite explain the full story. While he correctly showed that Africa and South America fitted together, his model wasn’t able to explain the violent forces that occur around the Earth’scrust.
A majority of the worlds population tends to concentrate on coastal regions primarily for access to trade or business with other countries.
