- "Since 1980, more than 100 commercial
jets have suffered significant damage after flying unknowingly into volcanic
ash clouds, the USGS researchers said."
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- SAN FRANCISCO (AP) -- Even as efforts to detect eruptions improve, scientists
still warn that commercial jets face an increasing hazard from clouds of
gritty volcanic ash.
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- Researchers at the American Geophysical
Union meeting said fast-growing flight paths crisscross the Ring of Fire
region rimming the Pacific Ocean that coincidentally contains most of the
world's active volcanoes.
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- In the past year, U.S. Geological Survey
officials said Dec. 9, at least three jets have been damaged by ash, including
an incident on May 20 when a commercial airliner tried to land in Guatemala
City just when the nearby Pacaya volcano was erupting.
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- Since 1980, more than 100 commercial
jets have suffered significant damage after flying unknowingly into volcanic
ash clouds, the USGS researchers said.
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- In at least 10 of those incidents, the
aircraft lost power for minutes after their jet engines sucked in the ash
and it melted in the turbines. Although no crashes or fatalities have been
blamed on ash damage, the incidents are harrowing.
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- Pilots and passengers have reported their
aircraft suddenly being enveloped in a sulfurous darkness, then plummeting
helplessly over rugged terrain and vast, frigid oceans.
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- "Pilots are unlikely to see ash
clouds and radar is not tuned to see them in front of the aircraft,"
said Thomas Casadevall, deputy director of the USGS. "When they got
their engines restarted, they thought the engines would shake themselves
off the wings."
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- An international network of nine volcano
hazard offices analyzes eruption and ash cloud information collected automatically
by satellites and ground-based sensors as well as pilot reports.
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- The information is shared on a daily
basis by major commercial carriers and the military, and pilots are beginning
to receive ash cloud updates in their preflight briefings, officials said.
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- "People who are flying are better
off this holiday season as compared with the last holiday season,"
Casadevall said.
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- But most volcanoes are not regularly
monitored, researchers said. And, ash clouds are difficult to assess because
they travel thousands of miles, resemble harmless weather clouds and can
be difficult to see, even in daylight.
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- "These clouds can drift for thousands
of miles for several days, and we have big holes in our coverage,"
said vulcanologist William Rose of Michigan Technological University. "We
need a bulletproof method of detecting these clouds."
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- None of the scientific satellites orbiting
Earth are now designed to specifically monitor volcanoes.
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- For the first time, researchers are training
the sensors on a variety of satellites to take snapshots of volcanoes and
look for clues of impending eruptions. Right now, their coverage is limited
to the Americas and the Caribbean basin.
-
- At least seven satellites would be needed
to adequately watch volcanoes worldwide, including along busy aviation
routes, they said.
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- Vulcanologists from the University of
Hawaii at the conference used a desktop computer to view an eruption of
Popocatapetyl, a volcano 50 miles southeast of Mexico City, within a few
minutes of the event Dec. 9.
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- Luke Flynn clicked the computer mouse
through snapshots of the eruption recorded by a pair of Geosynchronous
Environmental Satellites operated by the federal government.
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- The GOES use infrared sensors to spot
heat rising from a volcano. The result appears as a red pin dot on the
planet's surface. But in this case, Popocatapetyl appeared as a larger
red blob.
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- "Something pretty hot is going on
there right now," Flynn said. "That's about four times as large
as we usually see."
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- Under most circumstances, it takes about
10 minutes for the Hawaii team to post eruption information on the Internet.
That's because the researchers have forged a close relationship with the
federal agencies that operate GOES.
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- But that's not the same as issuing an
alert to pilots and airports, Flynn acknowledged.
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- "This eruption might have generated
an ash plume," Flynn said. "The hard part is getting the data
across."
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- In cases such as the Pacaya eruption
in Guatemala, satellite information might have generated a precaution.
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- The Hawaii team say they spotted indications
that Pacaya might erupt on May 13, a week in advance. The researchers say
they used the same method on Sept. 15 to predict an eruption in the Galapagos
Islands and alerted the Darwin Research Station there of the impending
danger.
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- "We saw the eruption three hours
before the scientists on the ground," said Peter Mouginis-Mark.
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- The system is not foolproof, however.
The GOES satellites orbit 22,000 miles overhead and can provide only hints
of impending eruptions, since they cannot always distinguish between volcanoes,
forest fires and other heat sources. It might take several days for lower-flying
satellites to view the same volcano using other sensors besides heat thermometers.
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