handout 3

What does ground deformation refer to?

• Eruption of gases

• Changes in the weather

• Surface changes on a volcano

• Movement of tectonic plates

What is the primary indicator of volcanic unrest?

• Temperature drops

• Animal behavior changes

• Increased rainfall

• Ground deformation

What type of gas emissions can indicate an impending eruption?

• Carbon dioxide

• Sulfur

• Oxygen

• Methane

What visual observation might indicate an impending eruption?

• Change in wind direction

• Rise in temperature

• Crater glow at the summit

• Increased cloud cover

What auditory sign might people hear before a volcanic eruption?

• Rumbling sounds

• Birds chirping

• Water flowing

• Wind howling

What is a common method scientists use to measure gas emissions?

• Infrared and correlation spectrometers

• Thermal imaging

• Seismographs

• Weather balloons

What might a change in steam color from white to gray indicate?

• Change in atmospheric pressure

• Cooling of the volcano

• Increase in ash presence

• Decrease in volcanic activity

What is a sign of ground movement felt by people near a volcano?

• Rise in water levels

• Change in soil color

• Volcanic earthquakes

• Increased bird activity

What phenomenon is associated with the release of gases from a volcano?

• Fumaroles

• Lava flows

• Mudslides

• Ash clouds