Introduction to Volcanoes
This unit introduces volcanology and the relationship between the occurrence of volcanoes and plate tectonics. In addition, factors that affect the mode of eruption (tectonic setting, viscosity, etc.) are also described. Lastly, volcanic hazards are reviewed.

Workshop Presentations

Volcano Basics - reviews the basics about volcanoes, lava composition and viscosity and the relationship with plate tectonics. .

PowerPoint Click to download the MS Powerpoint file (21.1 Mbytes)

PDF Click to view or download the presentation in PDF (5.5 Mbytes)

HTML Click to view the presentation in html format.

Online Lecture. Click here to view a streaming lecture covering the basics of volcanoes (~51 minutes).

Volcano Hazards - reviews volcano monitoring and volcano hazards.

PowerPoint Click to download the MS Powerpoint file (39 Mbytes)

PDF Click to view or download the presentation in PDF (28 Mbytes)

HTML Click to view the presentation in html format.

Online Lecture. Click here to view a streaming lecture that discusses the monitoring of volcanoes and volcanic hazards (~23 minutes).

Classroom Activities

Flour Box Volcano Deformation Model PDF In this classroom activity or demo, volcanic deformation can be modeled including inflation, formation of a caldera and the development of fractures from rising magma. From the Teacher’s Interactive Resource Guide to the DVD Lava Flows and Lava Tubes: What They Are, How They Form. Click here to view a video demonstration of a version of this demonstration from the U.S. Geological Survey

Gelatin Model of Magma Instrusion PDF This activity demonstrates the intrusion of magma (chocolate sauce into country rock (plain gelatin). Click here to view a video demonstration of this activity. This activity is from Teachers on the Leading Edge

The Great Viscosity Race. In this activity, students modle the effect of composition, temperature and partial crystallization on the viscosity of magma/lava.

How Fast is the Pacific Plate Moving? PDF Word Document In this activity, students examine geochronological data for lava flows that form the Hawaiian Islands and use that data and the distances of the islands from the Hawaiian mantle hotspot to detemine the rate that the Pacific Plate is moving over. This activity permits students to apply mathematical concepts (e.g. rate) to a scientific question about the rate of motion of the Pacific plate over the Hawaiian hotspot. Teacher Key

Online Media Resources

Plate Tectonics: The Hawai'ian Archipelago This video introduces the formation of Hawai'i from a mantle hot spot. WGBH Educational Foundation

Lava Sampling on Kilauea Volcano, Hawai'i This video introduces volcanism at Kilauea and how volcanologists sample lava for analysis. WGBH Educational Foundation and Peace River Films, Inc.

Volcanic Views This short excerpt discusses volcanism at Kilauea and includes eruption video from the recent vent Pu'u O'o. WNET.ORG

Mount St. Helens This video summarizes volcanic activity at Mt. St. Helens since the large 1980 eruption. Idaho Public Television

Possible Ice Volcano on Titan This video discusses radar imagery from Titain and the possible existence of an ice volcano (cryovolcano). NASA

Sibley Volcanic Regional Preserve This video discusses Sibley Volcanic park in Berkeley. KQED Quest This website contains spectacular images of volcanic eruptions (and penguins!).

Videos of Volcanic Eruptions

Mt. Lassen 1915 Eruption. The YouTube video above shows rare film footage of the eruption of Mt. Lassen in 1915. Lassen is one of only two historic volcanic eruptions to occur in the lower 48 (Mount St. Helens is the other).

Pahoehoe basalt lava flow. This YouTube video shows a low viscosity basalt lava flow.

Aa basalt lava flow. This YouTube video shows a high viscosity aa basalt lava flow. Note how viscous this lava flow is compared to the pahoehoe flow.

Pahoehoe flow over aa flow. This YouTube video shows a fluid pahoehoe lava flow covering an older aa surface. The volcanoes of Hawaii are built from successive pahoehoe and aa flows.

Pillow lava flow. This YouTube video shows a submarine pillow basalt lava flow. When the lava is extruded into water, it forms a glassy crust. The force of the flowing lava fractures the crust and the flow surges forward. Submarine basalt flows form pillow-shaped or lobate shapes.

Mount St. Helens 1980 Eruption. This YouTube video shows the massive 1980 eruption. This video was created from a series of still photos. Careful examination of the video shows the sequence of events that resulted in this eruption. As lava intruded into the volcano, a visible bulge formed on the flank of the volcano. An earthquake (due to the movement of magma) caused a landslide on the unstable bulge. As the flank of the volcano slid down, it exposed the lava inside the volcano. The sudden decompression caused the gas dissolved in the lava to be released and resulted in a large pyroclastic eruption. The blast flattened trees and stuctures for a 230 square mile area.

Mount St. Helens Lava Dome. This YouTube video from the USGS shows a 4-year time lapse movie of the growth of the lava dome inside the central crater on Mount St. Helens. The andesitic lava extruding in the crater is very viscous forming steep domes that collapse and are replaced by more lava pushed up from the interior of the volcano.

Unzen Pyroclastic Flow. This dramatic YouTube video shows a pyroclastic flow on Mt. Unzen in Japan that results from the collapse of the lava dome.

Batu Tara Volcano Pyroclastic Flow. This YouTube video shows a small pyroclastic flow. Note how the pyroclastic flow travels down the volcano within a stream valley until it reaches the ocean.

Mt. Ontake 2014 Pyroclastic Flow. This dramatic YouTube video shot by mountain climbers records a pyroclastic flow which resulted in 34 casualties.

Mt. Kuchinoerabujima 2015 Eruption. This YouTube video shows a pyroclastic eruption caught by a webcam. Note the pyroclastic flows down the flanks of the volcano.

Japanese Lahar Flows. This YouTube video shows three lahars (volcanic mud flows). Lahars can travel long distances from an eruption and represent a significant hazard.

Mt. Semeru Lahar Flow 2003. This YouTube video shows a small lahar flowing down a stream valley on Mt. Semeru in Indonesia.

Useful Websites

USGS Volcano Hazards Program This USGS site is the main entry point for information on volcanoes including realtime maps of eruption alerts.

United States Geological Survey (USGS) The USGS is a federal agency within the U.S. Department of the Interior and has primary responsibility for geological (hazards, resources, etc.) and environmental issues of national and regional importance.

The Educational Multimedia Visualization Center This website contains terrific animations illustrating tectonic plate motion. UCSB

Teachers on the Leading Edge There are many resources and activities developed by this professional development program for middle school science teachers.

NGSS Disciplinary Core Ideas

Grade 2
ESS2.B: Plate Tectonics and Large-Scale System Interactions. Maps show where things are located. One can map the shapes and kinds of land and water in any area.

Grade 4
ESS2.B: Plate Tectonics and Large-Scale System Interactions. The locations of mountain ranges, deep ocean trenches, ocean floor structures, earthquakes, and volcanoes occur in patterns. Most earthquakes and volcanoes occur in bands that are often along the boundaries between continents and oceans. Major mountain chains form inside continents or near their edges. Maps can help locate the different land and water features areas of Earth.

Middle School
ESS1.C: The History of Planet Earth. Tectonic processes continually generate new ocean sea floor at ridges and destroy old sea floor at trenches. (HS.ESS1.C GBE),(secondary) ESS2.B: Plate Tectonics and Large-Scale System Interactions. Maps of ancient land and water patterns, based on investigations of rocks and fossils, make clear how Earth's plates have moved great distances, collided, and spread apart.

High School
ESS1.C: The History of Planet Earth. Continental rocks, which can be older than 4 billion years, are generally much older than the rocks of the ocean floor, which are less than 200 million years old.

ESS2.B: Plate Tectonics and Large-Scale System Interactions. Plate tectonics is the unifying theory that explains the past and current movements of the rocks at Earth's surface and provides a framework for understanding its geologic history.

SS2.A: Earth Materials and Systems. Evidence from deep probes and seismic waves, reconstructions of historical changes in Earth's surface and its magnetic field, and an understanding of physical and chemical processes lead to a model of Earth with a hot but solid inner core, a liquid outer core, a solid mantle and crust. Motions of the mantle and its plates occur primarily through thermal convection, which involves the cycling of matter due to the outward flow of energy from Earth's interior and gravitational movement of denser materials toward the interior.

Common Scientific Misconceptions

Magma comes from molten layer beneath Earth's crust (older cosmologies, Franklin's idea, as well as popular literature such as Dante's Inferno, and some religious tracts).

Magma comes from deep within Earth's mantle (common textbook and earth science educational movies use of 'deep' terminology, older cosmology of passage-filled Earth')

Magma comes from Earth's outer core (this one tends to increase as students realize there is no molten layer in the mantle).

Basalt's origin is connected to the presence of seawater (original concept and name, coupled with its association with oceanic crust and oceanic hotspots vs. continental) Volcanic eruptions are rare events (media coverage is biased by location and death tolls).

Volcanoes are dominantly tropical features (Gilligan Island phenomena, common depiction)

Most deaths during volcanic eruptions are due to suffocation from smoke or poisonous gases (older scientific hypothesis until 1902 Pelee eruption, real life knowledge that many deaths in fires due to smoke inhalation, as well as being specifically mentioned as such in secondary education earth science films, all primarily legacy of Pompeii casts).

Most deaths during volcanic eruptions are due to fear and panic during evacuation (real life knowledge of crowds, Hollywood depictions).

Most magma forms as rock melts due to an increase in temperature (in real life this is the way most things melt, coupled with knowledge that temperature rises within Earth).

Most magma forms as rock is subjected to great pressure deep within the Earth (since increased pressure makes rock easier to deform or convect, even greater pressure should turn it to liquid - or so it seems).

Wind blowing across the tops of volcanic mountains can cause eruption, similar to wind blowing over opening of a flute (older cosmology dating back to Greeks)

Most volcanoes are tall peaks with craters at summit (bias of photographic record, pretty volcanoes most photographed, subduction volcanoes more accessible than submarine)

Whole idea of common use of active, dormant and extinct terms having geologic validity. Volcanoes are only hazards, not important long-term resources.

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