OVERVEW OF THE LESSON

Which characteristic of magma mainly determines its explosiveness?

• color

• amount

• temperature

• silica content

Which of the following characteristics of a volcano depends on its magma emission?

• age

• size

• shape

• location

A thick layer of volcanic ash can be heavy enough to collapse the roofs of buildings because ash _______________.

• is solid

• cannot be blown by winds

• becomes heavier as it cools

• consists of tiny fragments of rocks that becomes heavy as they pile up.

A volcano has a summit,slope, and base. Which summit has a funnel shaped opening at the top of a volcano?

• Crater

• Caldera

• Vent

• Shield

Which of the following best describes an active volcano based on PHIVOLCS?

• Active volcanoes are those that have erupted for the last 10,000 years.

• Active volcanoes are those that erupted 10,000 years ago based on analyses of their materials.

• Active volcanoes are those that have a record of eruption within the last 8000 years.

• None of the above

According to PHIVOLCS,which of the following is a sign of impending volcanic eruption?

• Increase in the frequency of volcanic quakes with rumbling sounds.

• Increased steaming activity.

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

• All of the above.

Molten rocks on the surface of volcano are oozing out. Which volcanic material best describes this?

• Magma

• Lava

• Pyroclastic materials

• Silica

Philippines is ranked second on world's production of energy coming from volcanoes. What energy is this?

• Solar energy

• Wind energy

• Geothermal energy

• Nuclear energy

According to PHIVOLCS,which of the following is a sign of impending volcanic eruption?

• Increase in the frequency of volcanic quakes with rumbling sounds.

• Increased steaming activity.

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

• All of the above.

The following are things that a person should do before volcanic eruptions in order to avoid loss of lives and properties.Which is the exception?

• Know the behavior of the past eruption.

• Setting an exclusion zone.Be strict in following the off limit ordinance.

• Be always ready with emergency supplies.

• No need for visual check of cracks and other structural damages.