Frequently Asked Questions
Below are links to answers for general questions we frequently receive from people interested in volcanoes. If you are interested in questions about a specific volcano or volcano observatory, you can find answers to your questions on the observatory FAQs linked at the bottom of this page.
About Volcano Monitoring
- Why is it important to monitor volcanoes?
- Why is monitoring volcanoes important to aviation?
- How does the USGS monitor volcanoes in the United States?
- Does the USGS have a team of volcanologists that can respond to volcanic unrest on short notice?
- Does the USGS have a team for rapid response to volcano emergencies abroad?
- How are earthquakes monitored?
- How are ground movements measured?
- How are volcanic gases measured?
- How are volcanic thermal features measured?
- What else do scientists measure at volcanoes?
About Volcano Hazards
- What kinds of hazards are associated with volcanic eruptions?
- Can volcanoes be dangerous even when they don't erupt?
- How can residents who live near volcanoes prepare for future eruptions?
- How does the USGS provide eruption warnings?
- How many active volcanoes are there in the United States?
- How many active volcanoes are there on Earth?
About Volcanic Eruption Precursors
- Can scientists really anticipate volcanic eruptions?
- What kinds of unusual activity might be noticed before an eruption?
- What is volcanic tremor, and how does it differ from earthquakes?
- Do volcanoes produce different kinds of earthquakes?
- What kind of gases escape from volcanoes?
About Volcanic Eruptions
- Can an eruption at one volcano trigger an eruption at another nearby volcano (for example, within about 10 km)?
- Is there evidence for a cause and effect relationship between eruptions that occur at about the same time from volcanoes located hundreds to thousands of kilometers apart?
- Is there a relationship between large earthquakes (>M 6) that occur along major fault zones and nearby volcanic eruptions?
About Studying and Working on Volcanoes
- Are you "scared" when working on an active volcano?
- Is it dangerous and what precautions do scientists take?
- What's it like to work on volcanoes?
- What kind of school training do you need to become a volcanologist?
- What instruments, tools, and methods do you use to study volcanoes?
Movies - Fact or Fiction
- Is the eruption depicted in Dante's Peak realistic?
- Can eruptions really threaten helicopters, as in the movie, and other aircraft?
- Do earthquakes large enough to collapse buildings and roads accompany volcanic eruptions?
- Can a town's water supply become contaminated when a volcano is restless?
- Do scientists drive across moving lava flows?
- Can carbon dioxide gas from volcanoes kill trees and wildlife?
- Can volcanoes suddenly become restless and erupt within one week of the first signs of activity?
- Are robots used by the USGS to monitor volcanoes?
- Can volcanoes produce large explosive eruptions and rivers of fluid lava at the same time?
- Can lakes near volcanoes become acidic enough to be dangerous to people?
Use of information on this site
- Can the images on this website be used in "my" brochure, publication, presentation, or program?
- For the images that are in the public domain, are they available from the webmaster in a higher resolution?