What is a volcano?
A volcano is a mountain that opens downward to a pool of molten
rock below the surface of the earth. When pressure builds up,
eruptions occur. Gases and rock shoot up through the opening
and spill over or fill the air with lava fragments. Eruptions can
cause lateral blasts, lava flows, hot ash flows, mudslides,
avalanches, falling ash and floods. Volcano eruptions have been
known to knock down entire forests. An erupting volcano can
trigger tsunamis, flash floods, earthquakes, mudflows and
rockfalls. Research the different types of volcanoes write a
description of each on the back.
What is the Ring of Fire?
The Pacific Ring of Fire is an area of frequent
earthquakes and volcanic eruptions encircling
the basin of the Pacific Ocean. The Ring of Fire
has 452 volcanoes and is home to over 50% of
the world's active and dormant volcanoes.
Ninety percent of the world's earthquakes and
81% of the world's largest earthquakes occur
along the Ring of Fire. Draw a map of the Ring
of Fire on the back. Label has many countries
effected by as possible.
Why do volcanoes erupt?
The Earth's crust is made up of huge slabs
called plates, which fit together like a jigsaw
puzzle. These plates sometimes move. The
friction causes earthquakes and volcanic
eruptions near the edges of the plates. The
theory that explains this process is called plate
tectonics.
The theory of plate tectonics is a interesting story
of continents drifting from place to place breaking
apart, colliding, and grinding against each other.
The plate tectonic theory is supported by a wide
range of evidence that considers the earth's crust
and upper mantle to be composed of several large,
thin, relatively rigid plates that move relative to
one another. The plates are all moving in different
directions and at different speeds. Sometimes the
plates crash together, pull apart or sideswipe each
other. When this happens, it commonly results in
earthquakes. Draw the major tectonic plates; label
the largest earthquake to date.
What are plate tectonics?
Geologist Notebook
How are volcanoes formed?
Volcanoes are formed when magma from within
the Earth's upper mantle works its way to the
surface. At the surface, it erupts to form lava
flows and ash deposits. Over time as the volcano
continues to erupt, it will get bigger and bigger.
Research and label the parts of the volcano.
Nice Work! ~ Mrs. Flatt & Ms. Rose
What is a pyroclastic flow?
A pyroclastic flow is a fluidized mixture
of solid to semi-solid fragments and hot,
expanding gases that flows down the
sides of a volcano. These awesome
features are heavier-than-air emulsions
that move much like a snow avalanche,
except that they are fiercely hot, contain
toxic gases, and move at phenomenal,
hurricane-force speeds. Research the
effects of pyroclastic flows. List them on
the back.
PLAN FOR A VOLCANO: First of all, have a disaster
plan and know whether or not you are at risk for
danger. Be prepared for mudslides, flash floods,
earthquakes, ash falling, acid rain and tsunamis.
Prepare a disaster supplies kit for your home and car.
Research and list items that should be included:
When did Mount St. Helens
erupt?
On May 18, 1980, Mount St.
Helens erupted. It's located in
southwestern Washington State
in the Cascade Range. The blast
was heard as far away as
Montana, Idaho, Canada and
California. Fifty-seven people
died and the eruption caused
$1.2 billion in damage. Survey
adults and make a graph to show
how many adults remember
where they were when this
event occurred.
What is pumice?
Pumice is a light, porous volcanic rock that forms
during explosive eruptions. It resembles a sponge
because it consists of a network of gas bubbles
frozen amidst fragile volcanic glass and minerals.
All types of magma (basalt, andesite, dacite, and
rhyolite) will form pumice. Research and find 3
uses for pumice rocks.