Volcanoes and Earthquakes
By: Hannah Hanania, Madeline Luong, &
Cily Simson
What is a Volcano?
• An opening in the earth’s crust, which allows molten
rock, ash and toxic gases to erupt onto the Earth’s
surface
• Not all volcanoes erupt with the same intensity
• Some may release lava, while other volcanoes only let
out ash and gases
• Volcanoes can be classified as…
– Active
– Dormant (not currently active)
– Extinct (not expected to erupt again)
What Causes Volcanoes?
• Rock is heated by the extremely high
temperatures underneath the Earth’s surface
• As it melts MAGMA is formed
• The magma becomes less dense
and therefore rises to
the surface, where it
becomes LAVA.
The Ring of Fire
• Located at the borders of the
Pacific Plate and other major
tectonic plates
•The Ring of Fire contains over 75%
of the world's active and dormant
volcanoes
•This huge ring of volcanic and
seismic (earthquake) activity was
discovered before the invention of
the theory of plate tectonics
Effects of Volcanoes…
Bad Effects:
Good Effects:
• Lava, ash fall, and
landslides are some of the
most dangerous hazards of
volcanic eruptions
• Give off harmful gases into
the atmosphere
• Cause acid rain and
pollution
• Can cause Tsunamis
• Create formations and
shape the Earth
• 80% of Earth’s surface has
come from volcanoes
• Examples:
-Hawaiian Islands were
created by five Volcanoes
-Rocky Mountains
Mt. Saint Helens
• Washington State, May 18, 1980
• Blasts started at 220 mph increased to about 670
mph
• 57 people died
• 185 miles of highways
and roads destroyed
• Cost $1.5 billion
• Thousands of animals killed
Fun Facts:
• The term volcano, is derived from the name of the
Roman God of fire, Vulcan.
• Tallest Volcano is Mauna Loa (Kilauea)
• Merap, a 9,500 ft high peak on the Indonesian Islandmost dangerous volcano
• The Krakatoa volcano erupted on August 26, 1883 and
destroyed most of the island of Krakatoa. It is still active
now.
Earthquakes
What is an Earthquake?
• A trembling or shaking movement of the Earth's
surface
• May dramatically change surface of land, and the
floor of the ocean
• Two main causes of Earthquakes:
– Can be linked to explosive volcanic eruptions and are very
common in areas of volcanic activity where they occur during
or after volcanic eruptions
– Can be triggered by Tectonic activity associated with plate
boundaries and faults.
• The majority of earthquakes world wide are of this type
How are Earthquakes Measured?
• Measured on the Richter
scale
• Richter scale was developed
in 1935 By Charles F. Richter
• Less than 2.0 are called micro
earthquakes
• Earthquakes greater than 4.5
can be recorded around the
world
• Richter Scale is based on the
intensity of seismic waves
which travel through the
earth as energy.
Effects of an Earthquake
• Can cause landslides and floods
• Earthquakes that take place under the ocean
can sometimes cause tsunamis, or tidal waves.
• Can destroy buildings and cities, as well as the
lives of many people
Recent Earthquakes
• Japan earthquake caused a tsunami
– 8.9 on the Richter Scale
– Over 18,000 people killed
– March 11, 2011
• The Haiti Earthquake caused a terrible tsunami
- Killing thousands of people and uprooting the
lives of millions
- January 12, 2010
- 7.0 on the Richter Scale