Define the following volcano terminology:
Viscosity volcanic bombs crater pyroclastic flow
Volatiles Nuee-Ardente vent summit
Pahoehoe lava lahars shield volcano volcanic pipe (diatreme)
Aa lava volcanic flank composite volcano parasitic cone
Ash volcanic conduit cinder cone dike
Sill laccolth batholith stock
Mt. St. Helens is the only volcano that has erupted in the Continental US within the last 100 years.
Relationship Question:
Draw a map showing California, Oregon and Washington State and show the geographical location of Mt. St.
Helens
Which mountain range is Mt. St. Helens part of?
- Types of volcanic lava eruptions, type of volcano and if the volcano is either explosive or non-explosive is all
about VISCOSITY
Relationship Questions:
In your own words, describe a liquid that has viscosity -- What is viscosity?
Describe at least 3 types of liquids with high viscosity and 3 types of liquids having low viscosities that you
have interacted with over your lifetime
How can you change the high viscosity of chocolate sauce to low viscosity?
Why does heating up a liquid change most liquids to a lower viscosity
What happens to oil viscosity in a car as the engine heats to operation temperature?
Does molasses and peanut butter have viscosity? (explain)
Does glass have viscosity? (explain) - Factors influencing the volcanic eruption and type of volcano
Relationship Questions: Using terms High or Low viscosity, High or Low temperature, low or high silica,
volatiles, explosive, fluid, and Low or High viscosity, fill in the blanks to make the statements below correct.
A mafic lava flow creates a __________viscosity flow that is concentrated with______
____ and forms ___ types of lava flows
A felsic lava flow creates a _______ viscosity flow that is concentrated with _
and forms __ types of lava flows.
______ content in a felsic type volcano inhibits the movement of ___ creating an
___ type of volcanic eruption.
______ content in a mafic type volcano allows free movement of ___ creating a
_ type volcanic eruption
__ is controlled with temperature. High temperature creates ___ eruptions and
_____ and lower temperatures create _____ eruptions. - Typically, volcanoes will emit a combination of volatile compositions.
Relationship Questions:
List in order of highest to lowest percentage of gas concentrations emitted by a typical volcanic eruption.
Explain what is meant by “gas content of a typical eruption is 1-6% of total magma weight”
How does volcanic eruptions worldwide contribute to our current composition of the earth’s atmosphere??
Mafic type lava flows:
Explain the differences between a basaltic Aa and basaltic Pahoehoe lava flow in terms of high/low volatile
content.
What is a “good” way to differentiate the differences between an Aa and pahoehoe flow?
Would you regard an Aa and Pahoehoe a “fluid” or “pasty” type flow --- Explain
Felsic type lava flows:
Describe the following types of “felsic” eruptions: Volcanic bombs, Nuee-Ardente, lahar and ash type eruptions
What is a “good” way to differentiate the differences between the type of flows described above?
What “volcanic” factors are involved in differentiating between a mafic (basaltic) lava from a felsic (rhyolitic)
lava? Think: viscosity, silica content, volatile content, temperature, fluid flow, explosive flow.
How does the factors above (number 3) give rise to various types of volcanoes found on earth? - Draw a diagram showing a picture of a typical volcano and label the following characteristics: flanks,
volcanic conduit, crater, volcanic base, magma chamber, vent, parasitic cone, and volcanologist that studies
volcanoes. - There a three major types of volcanoes (stratocomposite, shield, cinder cone)
Relationship Questions:
Discuss why three major types of volcanoes are found on the earth’s surface
Draw a picture depicting each volcano type and draw the diagram accurate to the characteristics described in
the above answer.
Fill in the chart below: - Research the internet and find 3 “famous” volcanoes that have been in the news. For each volcano you find,
describe the “geological” characteristics using the above chart. In other words, what type of volcano does your
choice reveal? - Throughout geologic history, live volcanic activity does not last forever, however evidence of volcanic activity
is present on the earth’s surface by observing various types of volcanic landforms.
Relationship Questions:
Construct and draw diagrams depicting caldera’s, volcanic fissures and exposed volcanic features such as
volcanic necks, pipes, volcanic flows, diatremes, and lava domes (plug domes).
For each volcanic feature above list at least 3 distinctive characteristics that differentiates each type of volcanic
feature.
For each feature listed in (a), research and find a representative geographic location on earth where that
feature exists.
Draw a diagram that shows the following igneous rock features associated with volcanism and non-volcansim.
Given each term, indicate if the feature is extrusive or intrusive bodies of solidified igneous rocks.
Batholith
Laccolith
Stock
Dike
Sill - Plate tectonic processes are paramount when describing the physical and compositional characteristics of
volcanoes and volcanic activity.
Relationship Questions.
Using the completed chart in question 6, add a new column, to the left of the volcanic description, that says
“plate tectonic setting”. In the plate tectonic setting column, “briefly” describe the typical plate boundary setting
responsible for each type of volcano.
How does each tectonic boundary (divergent/convergent) provide the “chemistry (mafic or felsic” -- ie silica
content) that allows the composite and shield volcano to exist? ---- Loaded critical thinking question. If you can
answer this, you are in the league of volcanologists!! And the forefront of plate tectonics
List at least three famous, in the news, volcanoes and describe the plate tectonic setting. Based on the news
descriptions, how does this now match your knowledge of the occurrence and activity of volcanos? - Are Volcanoes and volcanic activity geologic hazards? Explain
Relationship Questions
When does volcanic activity become hazardous? Think: population
All volcanic activity is potentially dangerous ----- however, which of the two (shield or composite) poses the
biggest threat? WHY? And explain
How do volcanologists begin to predict a volcanic eruption threat?
Which volcanoes today, in the news, are currently being monitored and pose a potential threat?
Which volcanoes are active today in the continental US?
Sample Solution