Mythology• Myths are society’s
oldest stories that
explain different
aspects of life and
the natural world.
They usually
reflected ancient
religious beliefs.
How would you explain these?
Madame Pele
The Hawaiian Islands
What causes the Hawaiian Islands?
Is there a plate boundary in the middle of the Pacific?
Fixed Hot Spot
Hawai’ian Volcanoes 101https://www.youtube.com/watch?v=i4W2CW4G_Do
A baby island…
What is a volcano?
• A volcano is a
weak spot in the
crust where
magma has come
to the surface.
http://alaskadestination.com/alaska-volcano-images/
What are some of the things that can happen during an explosive eruption ?
• Explosion breaks lava into fragments of different sizes.
a. volcanic ash
b. cinders
c. bombs http://www.gc.maricopa.edu/earthsci/imagearchive/bombs.htm
• Pyroclastic flow: a mixture of hot gases, ash, cinders, and bombs.
http://www.volcano.si.edu/volcanoes/region15/peru/ubinas/3110ubi7.jpg
What is pahoehoe?• Pahoehoe is
lava that flows
easily and
hardens into a
rippled surface.
http://seismo.berkeley.edu/~manga/EPS214/rope.jpg
What is A’a?• A’a flows
slowly and
hardens into
rough chunks.
http://www.decadevolcano.net/photos/keywords/a_a_lava.htm
http://www.livingwilderness.com/hawaii/hawaii-pahoehoe-flow.html
http://volcanoes.usgs.gov/hazards/lava/index.php
http://www.earlham.edu/~bestan/Graphics/aa1.jpg
http://stevekluge.com/geoscience/images/
What is the life cycle of a volcano?
• Active: one that is
erupting or
showing signs of
erupting
• Dormant:
scientists expect
eruption in the
future
• Extinct: unlikely to
erupt again.
http://maps.unomaha.edu/Peterson/funda/Pictures/Japan-2/Japan_files/image001.jpg
Mt Fuji in Japan
How many active volcanoes are there?• There are about 600 active volcanoes on land
and more under the ocean where it is hard for scientists to observe or map them.
What causes a volcano to erupt?• Dissolved gases are trapped in magma. As the
magma rises, the pressure decreases, and the gases expand causing bubbles that increase in size as they rise to the top. The bubbles push the magma from the chamber into the pipe until it comes out a vent.
Are earthquakes and volcanoes related?
• When a volcano erupts,
the pressure of the
rising magma forcing
its way through the
crust to the surface will
often trigger earthquake
activity.
• Scientists have been
able to demonstrate
this link and also know
what type of earthquake
to look for.
Are earthquakes and volcanoes related?
• Scientists have observed that 75% of the world’s volcanoes and
80% of the world’s earthquakes occur along plate boundaries.
• If you follow the locations of active volcanoes and the sites where
earthquakes occur you can begin to see the boundaries of the
tectonic plates lining up around the globe. This supports the theory
because true earthquakes only occur around these areas.
What kind of landforms are made by volcanoes?
Mauna Kea is a shield volcano.
http://cimss.ssec.wisc.edu/sage/geology/lesson3/concepts.html
Diamond Head is a tuff coneTuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption.
Lava Pillow
Lava Tube, Volcano National Park, Hawai’i
http://www.traveltohawaiireviewed.com/bigisland/Attraction/Thurston_Lava_Tube.html
Lava tube from above
San Francisco Peaks - the remnants of the only stratovolcano
A cinder cone - Sunset Crater, AZ
http://cimss.ssec.wisc.edu/sage/geology/lesson3/concepts.html
San Francisco Peaks volcanic field
Superstition Mountains -resurgent dome
Mount St. Helens in Washington State is an active composite volcano.
http://www.worldbook.com/wb/Students?content_spotlight/volcanoes/how_kinds
Crater Lake caldera in Oregon.
http://www.swisseduc.ch/stromboli/glossary/caldera-en.html
Formation of a caldera
Lava plateau in Colorado.
http://www.photos-of-the-year.com/contest/08/potm/showphoto.php?photo=1459
Ship Rock, New Mexico is a volcanic neck or plume.
http://www.scienceclarified.com/landforms/Ocean-Basins-to-Volcanoes/Volcano.html
Half Dome Mountains in Yosemite national Park, CA
http://www.answers.com/topic/batholith
Devil’s Peak - columnar joints in Wyoming
Hot Springs
National Park in
Arkansas
http://www.viewpoints.com/Hot-Springs-National-Park-review-11871
Castle Geyser in
Yellowstone National Park in
Wyoming
http://geology.about.com/library/bl/images/blgeyser.htm
Yellowstone Volcano