2. Plate tectonics
J.T. Wilson discovered Plate tectonics in 1960
Sea- floor spreading continually adds new material to the ocean floor.
Sea floor spreading creates mid ocean ridges which forms a crack in the
oceanic crust.
Mountains and volcanoes are caused by plates toward each other
(convergent boundary).
Rift valley are caused by plates grinding (transform boundary).
Earthquakes are caused by plates moving away from each other
(divergent boundary).
3. Volcanoes
A volcano is a weak spot in the crust where, magma comes to the
surface
Volcanoes are located above “hot spots ” where magma erupts through
the crust.
There is four types of volcanoes; cinder cones, composite, shield, lava
domes.
The dangers of a volcano are, lava flow, ash fall, pyroclastic flows, and
climate changes.
Effects of a volcano are, buildings, roads, and fields covered in ash. If
the ash is very heavy people may not be able to breathe.
Volcanic belts form along the boundaries of Earth’s plates.
Volcanoes can occur on divergent and convergent boundaries.
A volcano occurs when the boundaries slide together.
4. Earthquakes
Earthquakes form when tectonic plates slide against
each other and while there doing that energy builds up
in the crust and eventually bursts and causes
earthquakes.
There are for different types of earthquakes tectonic,
volcanic, collapse, and explosion.
The affects of earthquakes are fires, loss of life, tidal
waves that cause tsunami, avalanches, flooding,
broken gas lines, destroy of roads and bridges, and
buildings.
5. Earthquakes
Earthquakes really pose little direct danger to a person.
People cant be shaken to death by earthquakes. They
can break limbs in your body.
The magnitude of most earthquakes are measured on
the Richter scale. Invented by Charles f. Richter in
1934.
