An overflow of water onto normally dry land, often after heavy rains:

(a)  

Giant waves caused by earthquakes or volcanic eruptions under the sea:

(a)  

A long period when there's little or no rain:

(a)  

Hot gases and melted rock from deep within Earth find their way up to the surface:

(a)  

Severe tropical storm with high winds and heavy rain:

(a)  

An uncontrolled fire in a wooded area:

(a)  

A tube of violently rotating air that touches the ground:

(a)  

A large amount of soil or rock that moves down a steep slope:

(a)  

A large amount of snow that quickly moves down a slope:

(a)