Volcanoes and Geothermal Energy Quiz

What are the classifications of volcanoes as adapted by the Philippine Institute of Volcanology and Seismology (PHIVOLCS)?

• Active and inactive

• Active and dormant

• Dormant and inactive

• Inactive and dormant

Which of the following best describes an active volcano?

• An active volcano has had no record of eruption for the last 600 years.

• An active volcano has no record of eruption but has the potential to erupt.

• An active volcano erupted 20,000 years ago and has evidence of volcanic activities.

• An active volcano has a record of eruption within the last 600 years or has erupted 10,000 years ago based on analyses of its materials.

What type of eruption occurred in Pinatubo volcano in Zambales in the year 1991, wherein gas and pyroclastic were excessively exploded?

• Phreatomagmatic

• Plinian

• Strombolian

• Vulcanian

Which type of volcano is formed from ejected lava fragments? It has a wide crater, has a steep slope, and is the most abundant of the three major types.

• Cinder cones

• Composite cones

• Crater cones

• Shield cones

Which type of volcano has a nearly perfect sloped structure which is formed from alternate solidification of both lava and pyroclastic deposits?

• Cinder cones

• Composite cones

• Crater cones

• Shield cones

What do you call the weak spot in the crust where molten material or magma comes to the surface?

• Lava

• Magma

• Lithosphere

• Volcano

Which of the following factors does not help determine whether a volcanic eruption will be violent or relatively quiet?

• Temperature of magma

• Composition of magma

• Amount of dissolved gases

• There is no record of quakes

You and your classmate are talking about active and inactive volcanoes. She claims that "Inactive volcanoes pose no threat to humans or to the environment." Do you agree with her? Why or why not?

• Yes, because inactive volcanoes have not erupted in at least 10,000 years.

• No, because inactive volcanoes have a higher probability of erupting soon than active volcanoes.

• No, because inactive volcanoes can still produce volcanic gases and ash, which can be hazardous to human health and the environment.

• Yes, because inactive volcanoes have a gentle slope and a broad base, which makes them less prone to producing pyroclastic flows and lahars.

According to Philippine Institute of Volcanology and Seismology (PHIVOCS), the government agency tasked with monitoring earthquakes and volcanoes in the country, which of the following are commonly observed signs that a volcano is about to erupt?

• I. Drying up of the spring or wells around the volcano.

• II. Crater glows due to the presence of magma at or near the crater.

• III. Development of new thermal areas and reactivation of old ones.

• IV. Decrease in the temperature of hot springs, wells and crater lake.

Mount Pinatubo in Zambales is a dormant volcano since it has no sign of activity for the last 600 years, but who could forget its terrible eruption in 1991? Based on existing data, what causes a volcanic eruption?

• It is caused by the movement of tectonic plates by pushing under the other plate.

• It occurs when hot materials from the Earth’s interior are thrown out of a volcano.

• Increase in temperatures can cause magma to crystallize and sink to the bottom of the chamber.

• An increase in external pressure can trigger an eruption as it may minimize the volcano’s activity to hold back.