Win 2016: Are Volcanoes More Dangerous than Earthquakes?

Question 1

Which are more dangerous volcanoes or earthquakes?

Answer 1

There are many different types of volcano and earthquake and they have different dangers. Volcanoes and be shield or composite type. Shield are less dangerous with thin lava and gently sloping sides. Composite are found on destructive plate boundaries and are more explosive. Monitoring for volcanic eruptions can be done in a number of ways. Satellites can track the distortion on the shape of a volcano from space. tiltmeters can be used on a volcano to detect change in shape. Before an eruption there are many tiny earthquakes around the volcano. These all give some warning of eruption. Hazard maps and well prepared evacuation plans can help make sure casualties are reduced. Earthquakes are more problematic. Scientists have discovered that radon gas is given off before an earthquake so this could be monitored. An earthquake is also likely to have foreshocks but it can be difficult to distinguish a foreshock from the earthquake itself. An added complication is when an earthquake produces a tsunami wave. In the case of the Japanese earthquake in 2011 it was the wave that killed and damaged rather than the quake itself.

Question 2

What is the pattern of distribution of volcanoes in the diagram?

Answer 2

Around the edge of the pacific plate. This is called the Pacific Ring of Fire.

Question 3

In what way might volcanoes in area A differ to those in area B in this diagram?

Answer 3

Volcanoes in area A are around a destructive plate boundary and so they will be composite volcanoes.

(Pacific Ring of Fire)

Volcanoes in area B are around a constructive plate boundary and so they will be sheild volcanoes.

(North Altantic Ridge)