Volcanoes, Earthquakes and Tidal Waves Notes

INTRODUCTION

•      A natural disaster is the consequence or effect of a natural, hazardous event, occurring when human activities and natural phenomenon become entangled.

For example:

•      A physical event, such as a volcanic eruption, earthquake, hurricane, tsunami,  landslide, etc.

VOLCANOES

•      A volcano is a landform (usually a mountain) where molten rock erupts in the Earth’s crust.

•      A lot of pressure underground pushes up the molten rock.

•      As pressure in the molten rock (magma) builds up, it needs to escape somewhere.

•      This pressure in the molten rock (magma) comes from the mantle of the Earth and reaches the crust through cracks.

•      The molten rock rushes out through a vertical tunnel called a vent and fills a hollow crater at the top.

•      Once the magma erupts through the earth’s surface, it’s called lava.

FACT

•      The world's largest active volcano is Mauna Loa in Hawaii, where famous coffee is grown in the rich volcanic soils.

•      Mauna Loa is 13,677 feet above sea level.

Dormant Volcanoes:

•      Dormant volcanoes are those that have not erupted in a long time but may erupt in the future.

•      Some of the well known examples of dormant volcanoes are:

1. Mt. Baker (Washington; USA)
2. Mt. Hood (Oregon; USA)
3. Nisyros (Greece)