Earthquakes
Earthquakes are caused when
tectonic plates shift. This motion causes the ground to move and
sometimes open up. Earthquakes can range from very weak to
catastrophic.
Volcanoes
Volcanoes are created when
pressure builds up in the mantle of the earth. This causes lava to
rise higher and higher underground. The pressure finally becomes so
intense that a small fissure opens up and molten lava spews out.
The large blast also ejects dirt and ash into the air, which later
settles around the fissure, forming a hill. After each eruption,
more and more debris builds up until a mountain forms.
Tornadoes
Tornadoes are caused when high
and low pressures in the air intermingle, causing a spinning motion.
Tornadoes may stay in the clouds, but if they touch down to Earth,
they can cause great destruction.
Hurricane
Hurricanes develop from areas of
low pressure forming over the ocean in tropical regions. It causes
strong winds and heavy rain. The winds swirl around the eye, a
calm area in the center of the storm.
Floods