EAPS 105: Homework 5
In Wikipedia, look up "Caldera" and answer this question: How does a volcanic caldera form?
A large depression in the ground results from the surface falling into an emptying magma chamber.
In Wikipedia, look up "Ring of Fire" and answer this question: What is the ring of fire?
A region around much of the rim of the Pacific Ocean where many volcanic eruptions occur.
In Wikipedia, look up "Cryovolcano" and answer this question: What is a cryovolcano?
A type of volcano that erupts volatiles such as water, ammonia, or methane instead of melted rock.
In Wikipedia, look up "Hotspot (geology)" and answer this question: Why do hot spots lead to a chain of volcanoes?
Because tectonics plates move over stationary hot spots
In Wikipedia, look up "Stratovolcano" and answer this question: How do stratovolcanoes formed?
By alternate lava flows and tephra
In Wikipedia, look up "Tephra" and answer this question: What is Tephra?
Fragmental material (as opposed to lava) produced by a volcanic eruption
In Wikipedia, look up "Types of volcanic eruptions" and answer this question: Which is the calmest type of volcanic event?
Hawaiian
In Wikipedia, look up "Magma", scroll down to "Effects of water and carbon dioxide", and answer this question: What does the addition of water to hot rocks in the mantle cause?
It causes their melting (solidus) temperature to decrease
In Wikipedia, look up "Flood basalt" and answer this question: What is a flood basalt?
It is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or ocean floor with basalt lava.
In Wikipedia, look up "Shield volcano" and answer this question: What is the viscosity of the lava that forms shield volcanoes?
Low viscosity (highly fluid)
In Wikipedia, look up "Lava" and answer this question: What is the difference between lava and magma?
Magma is melted rock beneath the surface, lava is melted rock extruded onto the surface.
In Wikipedia, look up "Types of volcanic eruptions" and answer this question: Which is the most explosive type of volcanic eruption?
Plinian
In Wikipedia, look up "Volcanic arc" and answer this question: In which tectonic settings is magma caused by water lowering the melting temperature of rock?
Subduction zones
In Wikipedia, look up "Soft drink", scroll down to "Carbonated drinks" and answer this question: Carbonated drinks contain dissolved carbon dioxide, mean that the carbon dioxide is in liquid form due to them being under pressure. What happens when the pressure is removed? (In case you are wondering, this process is exactly analogous to what happens to dissolved gas in magma when the pressure on the magma is reduced.)
The carbon dioxide is released from the solution as small bubbles.
In Wikipedia, look up "Viscosity" and answer this question: What is viscosity a measure of?
The resistance of a fluid to flow
In Wikipedia, look up "Magma", scroll down to "Decompression", and answer this question: What is decompression melting?
When decreasing the pressure on rocks lowers their melting temperature
In Wikipedia, look up "Enceladus" and answer this question: Which of the following statements about Enceladus is NOT accurate?
a. It has more than 100 geysers that erupt water vapor. b. Some of the erupting water vapor escapes and supplies most of the material making up Saturn's E ring. c. Enceladus is thought to have a subsurface ocean. d. ANSWER: ALL THE ABOVE ARE ACCURATE STATEMENTS.
In Wikipedia, look up "Eruption column", scroll down to "Structure", and answer this question: An explosive volcanic eruption creates a rising column of material that evolves due to several processes. Which of the following is NOT one of those processes?
a. Material is violently forced upward out of the crater by the pressure of rapidly expanding gases. b. Convection carries hot, buoyant material to higher altitudes. c. When the rises column cools sufficiently to no longer be buoyant, it ceases to rise and instead spreads out into what is called the umbrella region. a. ANSWER: ALL THE ABOVE ARE COMPONENTS OF AN ERUPTION COLUMN
In Wikipedia, look up "Olympus Mons" and answer this question: Which of the following is NOT a true statement about Olympus Mons?
a. TRUE: It is almost 22 km in height (two and a half times that of Mt. Everest) b. TRUE: It is the largest and tallest volcano in the Solar System. c. FALSE: It is currently erupting. d. TRUE: It is a shield volcano.
In Wikipedia, look up "Venus", scroll down to "Volcanism", and answer this question: Which of the following is NOT a true statement about volcanism on Venus?
a. TRUE: Venus has several times as many volcanoes as Earth. b. TRUE: Venus' surface is 300-600 million years old (meaning that there has not been significant volcanism since that time). c. FALSE: Venus is currently much more volcanically active than Earth. TRUE: Venus has far more giant volcanos (over 100 km across) compared to Earth.
