BACKGROUND:
Volcanic activity has played a predominant role in
shaping the surface of the Earth. As described in the lab, not all volcanic
activity is the same, some types of eruptions are more harmful than others.
Volcanoes like Mt. St. Helens and Nevado del Ruiz (Colombia) erupt much more
violently that do Mt. Etna (Italy) and Kilauea (Hawaii) volcanic eruptions.
These differences reflect variations in the chemistry and gas content of the
erupting lava.
POMPEII, MT. VESUVIUS, ITALY
In 79 AD, Mt. Vesuvius erupted an enormous
volume of pumice and ash. This material flowed very quickly down the side of
the volcano as hot ash flows. The ash flows covered the Roman city of
Pompeii in a few hours. Many people were trapped by the hot ash. Almost the
entire population of the city was killed.
CRATER LAKE, OREGON
Crater Lake erupted about 7770 years ago. It
was a gigantic eruption of ash flows. So much material erupted that the top
of this volcano collapsed. This formed a great hole where the top of the
volcano had been. The hole was gradually filled with water from rainfall and
melting snow. A new eruption in the middle of the lake formed a tiny cinder
cone volcano, now called Wizard Island. No one was hurt in this prehistoric
volcanic eruption.
PARICUTIN, MEXICO
A cinder cone grew to a height of more than 1500 feet. It first began in
a cornfield in 1943. The volcano grew and erupted a lot of lava, eventually
covering more than 10 square miles. It frightened farmers, but enough
warning was given for most of the local population to escape without harm.
PROCEDURE:
- Read the information on Mt. Vesuvius, Crater Lake, and Paricutin. Have
the students draw pictures of what they think the volcanoes looked like
after the eruptions. You may want the students to do only one volcano,
or all three. You may want them to hold their pictures up and have the
rest of the class decide which eruption has been illustrated.
- As a related assignment, students could find their own volcanic
eruption in the library or on the Internet, and write a paragraph with a
picture about it. Suggested Internet site is given below.
http://www.geo.mtu.edu/volcanoes/
Michigan Technological University - volcano sites from around the world.
