Excluding Hawaii, where are most of the volcanoes in the United States located?
Responses

along North America’s Atlantic coast, near the center of tectonic plates
along North America’s Atlantic coast, near the center of tectonic plates - no response given

along North America’s Atlantic coast, near the boundaries of tectonic plates
along North America’s Atlantic coast, near the boundaries of tectonic plates - no response given

along North America’s Pacific coast, near the center of tectonic plates
along North America’s Pacific coast, near the center of tectonic plates - no response given

along North America’s Pacific coast, near the boundaries of tectonic plates
along North America’s Pacific coast, near the boundaries of tectonic plates
Which of the following describes a lahar?
Responses

a type of fast-moving debris flow that forms after a volcanic eruption
a type of fast-moving debris flow that forms after a volcanic eruption - no response given

the occurrence of a large number of earthquakes that can precede a volcanic eruption
the occurrence of a large number of earthquakes that can precede a volcanic eruption - no response given

the movement of a mass of rock, soil, and debris down a slope due to gravity
the movement of a mass of rock, soil, and debris down a slope due to gravity - no response given

a sudden release of gases from molten material inside Earth
a type of fast-moving debris flow that forms after a volcanic eruption
Why do volcanologists use tiltmeters and strainmeters?
Responses
to prevent volcanic eruptions
to prevent volcanic eruptions - no response given
to identify gases released from volcanoes
to identify gases released from volcanoes - no response given
to determine changes to Earth’s surface
to determine changes to Earth’s surface - no response given
to detect earthquake swarms
to detect earthquake swarms - no response given
to determine changes to Earth’s surface
How have early warning systems for volcanic eruptions changed since the eruption of Mount St. Helens in 1980?
Responses

There are more and better instruments for monitoring volcanoes, but scientists cannot identify eruptions any earlier than before because they occur too quickly.
There are more and better instruments for monitoring volcanoes, but scientists cannot identify eruptions any earlier than before because they occur too quickly. - no response given

There are more and better instruments for monitoring volcanoes, and scientists are able to identify eruptions earlier and more accurately than before.
There are more and better instruments for monitoring volcanoes, and scientists are able to identify eruptions earlier and more accurately than before. - no response given

There are fewer and better instruments for monitoring volcanoes, but scientists cannot identify eruptions any earlier than before because they occur too quickly.
There are fewer and better instruments for monitoring volcanoes, but scientists cannot identify eruptions any earlier than before because they occur too quickly.
There are fewer and better instruments for monitoring volcanoes, but scientists cannot identify eruptions any earlier than before because they occur too quickly. - no response given
There are fewer and better instruments for monitoring volcanoes, and scientists are able to identify eruptions earlier and more accurately than before.