GIVEN how closely Mount St Helens has been monitored since its dramatic eruption in 1980, with sometimes daily if not hourly updates, Americans might be forgiven for thinking that all volcanoes in the US are being closely watched for any signs of danger. They would be wrong.
The US Geological Survey warned on Monday that of the 169 geologically active volcanoes in the country, 13 very-high-threat volcanoes in California, Alaska, Washington, Oregon and Hawaii are not being monitored adequately. The USGS report also pointed out that 19 volcanoes that lie beneath heavily used airspace, mostly in Alaska and the Mariana Islands, have 鈥渘o real-time ground-based monitoring鈥� to detect the onset of eruption. Ash clouds from erupting volcanoes can be dangerous to aircraft.
To keep tabs on this threat, the USGS is proposing a National Volcano Early Warning System, which would detect the telltale signs of magma moving beneath the volcano, such as swarms of earthquakes, the swelling of a volcano鈥檚 surface, or the spewing of volcanic gases. Instruments installed at volcanoes would monitor these phenomena and use phone lines or satellites to transmit the data to scientists. The USGS cautions that interpreting the data will be 鈥渇ar from automatic and requires complex analysis by a variety of volcanological experts鈥�.
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