Question 1

What happens to a mountain root as erosion removes material from the summit?&#10;A) It gets deeper&#10;B) It gets shallower&#10;C) It stays the same

Accepted Answer

As erosion removes material from the summit, the mountain root becomes shallower because the weight of the mountain decreases, leading to isostatic rebound which causes the root to rise.

Question 2

Use the graph below to answer this question. One point represents basalt, one andesite and one rhyolite.

-Which point on the graph is most likely to form andesite?

A) Point a
B) Point b
C) Point c

Point b

Accepted Answer

Basalt is an extrusive igneous rock that forms from the rapid cooling of low-viscosity lava rich in magnesium and iron at the Earth's surface, typically at mid-ocean ridges or volcanic hotspots. Point a is likely at the surface where such conditions exist.

Question 3

Use the graph below to answer this question. One point represents basalt, one andesite and one rhyolite.

-Which point on the graph is most likely to form andesite?

A) Point a
B) Point b
C) Point c

Point b

Accepted Answer

Point b&#10;

Question 4

Use the graph below to answer this question. One point represents basalt, one andesite and one rhyolite.

-Which point on the graph is most likely to form andesite?

A) Point a
B) Point b
C) Point c

Point b

Accepted Answer

Rhyolite is an extrusive igneous rock that forms from the rapid cooling of high-silica magma. On a graph of magma composition, it would be represented by a point with high silica content, which is typically found at the felsic end of the spectrum.

Question 5

Use the following map to answer this question.&#10;  &#10;&#10;-Identify a volcano that is most likely to have both basalt and rhyolite as products of its eruption.&#10;A) G&#10;B) F&#10;C) C&#10;D) H

Accepted Answer

The answer of Use the following map to answer this...

Question 6

Use the following map to answer this question.&#10;  &#10;&#10;-Identify a stratovolcano.&#10;A) E&#10;B) G&#10;C) C&#10;D) D

Accepted Answer

The answer of Use the following map to answer this...

Question 7

The following excerpt is from: Ewert and Miller, June 1995, The USGS/OFDA Volcano Disaster
Assistance Program: USGS Open-File Report 95-553. Use the excerpt to answer this question.
The strategy employed by the Volcano Disaster Assistance Program (VDAP) is to reduce loss of life and minimize economic disruption. It includes instrumental monitoring to detect the movement of magma (molten rock) toward the surface and thereby forecast eruptions and assessments of volcano hazards and risk based on past eruptive events at a volcano.
A great majority of the world's potentially active volcanoes are unmonitored. Less than twenty-five percent of volcanoes that are known to have had eruptions in historical time are monitored at all, and, of these, only about two dozen are thoroughly monitored. Moreover, seventy-five percent of the largest explosive eruptions since 1800 occurred at volcanoes that had no previous historical eruptions (Simkin and Siebert, 1994). Thus, until regular volcano surveillance is much more widespread, a mobile crisis-response capability is needed to quickly assess hazards and install monitoring equipment when a volcano becomes restless.
VDAP sends groups of scientists to active volcanoes about to erupt that also pose a threat to humans.

-Which volcanoes are most likely to explode and why?

A) Strato- because the magma is more viscous than in shield volcanoes
B) Strato- because the magma is less viscous than in shield volcanoes
C) Shield- because the magma is less viscous than in strato-volcanoes
D) Shield- because the magma is more viscous than in strato-volcanoes

Accepted Answer

Convergent plate boundaries are most likely to have volcanoes of interest to VDAP because they are associated with subduction zones, where one tectonic plate is forced under another, leading to magma formation and potential volcanic eruptions.

Question 8

The following excerpt is from: Ewert and Miller, June 1995, The USGS/OFDA Volcano Disaster
Assistance Program: USGS Open-File Report 95-553. Use the excerpt to answer this question.
The strategy employed by the Volcano Disaster Assistance Program (VDAP) is to reduce loss of life and minimize economic disruption. It includes instrumental monitoring to detect the movement of magma (molten rock) toward the surface and thereby forecast eruptions and assessments of volcano hazards and risk based on past eruptive events at a volcano.
A great majority of the world's potentially active volcanoes are unmonitored. Less than twenty-five percent of volcanoes that are known to have had eruptions in historical time are monitored at all, and, of these, only about two dozen are thoroughly monitored. Moreover, seventy-five percent of the largest explosive eruptions since 1800 occurred at volcanoes that had no previous historical eruptions (Simkin and Siebert, 1994). Thus, until regular volcano surveillance is much more widespread, a mobile crisis-response capability is needed to quickly assess hazards and install monitoring equipment when a volcano becomes restless.
VDAP sends groups of scientists to active volcanoes about to erupt that also pose a threat to humans.

-Which volcanoes are most likely to explode and why?

A) Strato- because the magma is more viscous than in shield volcanoes
B) Strato- because the magma is less viscous than in shield volcanoes
C) Shield- because the magma is less viscous than in strato-volcanoes
D) Shield- because the magma is more viscous than in strato-volcanoes

Accepted Answer

Basalt is typically less explosive and poses less immediate threat to human life compared to rhyolite and andesite, which are more viscous and can lead to more explosive eruptions.

Question 9

The following excerpt is from: Ewert and Miller, June 1995, The USGS/OFDA Volcano Disaster
Assistance Program: USGS Open-File Report 95-553. Use the excerpt to answer this question.
The strategy employed by the Volcano Disaster Assistance Program (VDAP) is to reduce loss of life and minimize economic disruption. It includes instrumental monitoring to detect the movement of magma (molten rock) toward the surface and thereby forecast eruptions and assessments of volcano hazards and risk based on past eruptive events at a volcano.
A great majority of the world's potentially active volcanoes are unmonitored. Less than twenty-five percent of volcanoes that are known to have had eruptions in historical time are monitored at all, and, of these, only about two dozen are thoroughly monitored. Moreover, seventy-five percent of the largest explosive eruptions since 1800 occurred at volcanoes that had no previous historical eruptions (Simkin and Siebert, 1994). Thus, until regular volcano surveillance is much more widespread, a mobile crisis-response capability is needed to quickly assess hazards and install monitoring equipment when a volcano becomes restless.
VDAP sends groups of scientists to active volcanoes about to erupt that also pose a threat to humans.

-Which volcanoes are most likely to explode and why?

A) Strato- because the magma is more viscous than in shield volcanoes
B) Strato- because the magma is less viscous than in shield volcanoes
C) Shield- because the magma is less viscous than in strato-volcanoes
D) Shield- because the magma is more viscous than in strato-volcanoes

Accepted Answer

Seismicity typically decreases immediately after an eruption because the release of pressure and magma reduces the stress and movement within the volcano.

Question 10

The following excerpt is from: Ewert and Miller, June 1995, The USGS/OFDA Volcano Disaster
Assistance Program: USGS Open-File Report 95-553. Use the excerpt to answer this question.
The strategy employed by the Volcano Disaster Assistance Program (VDAP) is to reduce loss of life and minimize economic disruption. It includes instrumental monitoring to detect the movement of magma (molten rock) toward the surface and thereby forecast eruptions and assessments of volcano hazards and risk based on past eruptive events at a volcano.
A great majority of the world's potentially active volcanoes are unmonitored. Less than twenty-five percent of volcanoes that are known to have had eruptions in historical time are monitored at all, and, of these, only about two dozen are thoroughly monitored. Moreover, seventy-five percent of the largest explosive eruptions since 1800 occurred at volcanoes that had no previous historical eruptions (Simkin and Siebert, 1994). Thus, until regular volcano surveillance is much more widespread, a mobile crisis-response capability is needed to quickly assess hazards and install monitoring equipment when a volcano becomes restless.
VDAP sends groups of scientists to active volcanoes about to erupt that also pose a threat to humans.

-Which volcanoes are most likely to explode and why?

A) Strato- because the magma is more viscous than in shield volcanoes
B) Strato- because the magma is less viscous than in shield volcanoes
C) Shield- because the magma is less viscous than in strato-volcanoes
D) Shield- because the magma is more viscous than in strato-volcanoes

Accepted Answer

Strato-volcanoes are most likely to explode because their magma is more viscous, leading to pressure build-up and explosive eruptions.

Question 11

Use the Venn diagram below for this question.

-This is composed of multiple layers of ash and rock.

A) Strato-Volcano
B) Shield-Volcano
C) Cinder Cone
D) All of the choices are correct.

Accepted Answer