Plate Tectonic - Hazards (3)
Pre Lab 

  • Comparing the different types of volcanic hazards.
  • Discovering historical volcanic disasters.
  • ash
  • debris
  • eruption
  • lava flow
  • mud flow
  • Internet
  • reference books

Students draw pictures of different types of volcanic eruptions.

Casts of humans killed by the eruption of Pompeii, Italy, in AD 79.


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.

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 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.

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.

  1. 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.
  2. 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 sites are given below.
    Information on currently erupting volcanoes around the world, with links to each site.
    Michigan Technological University - volcano sites from around the world.

    The US Geological Survey Cascades Volcano Observatory. Excellent information on US volcanoes, as well as plate tectonics and geologic hazards.

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