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Methods of monitoring volcanoes
By Lee Siegel
Science Writer
posted: 07:00 am ET
04 August 2000
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volsat_sidebar_000804_MB_ Some methods of monitoring volcanoes: - Ground-Based Monitoring -- Seismic monitoring provides short-term warning of eruptions by detecting movement of molten rock. Other devices can detect tilting of a volcanos slopes as it inflates with molten rock. But the instruments must be placed on volcanoes and require power and phone links, so seismic monitoring is expensive and impractical for many remote volcanoes.
Satellite Thermal Monitoring -- Using weather satellites to make infrared pictures of heat from volcanoes can provide medium-term warning that an eruption may be weeks to days away. The method is particularly useful for monitoring remote volcanoes. But the satellites can miss an imminent eruption if weather obscures their view, or if they pass too far from the volcano. | Future Effects of Volcano Eruptions Detected | | Scientists accidentally discovered - with the aid of European Remote Sensing satellites - Naples' downward movement as the satellites monitored nearbyCampi Flegrei caldera, a large volcanic crater. Read on about this discovery! | - Global Positioning System (GPS) Satellites -- Precision surveying with GPS satellites can detect bulging of volcanoes months to years before an eruption, but is not useful for short-term eruption forecasting.
- Satellite Radar Interferometry Satellites can bounce radar beams off volcanoes over periods of months to years to detect how the mountains inflate as hot rock is injected beneath them.
Satellite Optical Cameras -- Cameras on some private satellites can photograph volcanoes, but the pictures are expensive and the satellites cannot see anything during bad weather or during long or perpetual winter nights at high latitudes.
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