Scientists launch a major warning about the world’s most dangerous volcanoes
Scientists launch a major warning
about the world’s most dangerous volcanoes
Scientists have warned that some of the world’s most dangerous volcanoes
are not sufficiently studied, making it difficult to predict the extent of
their eruption or when they might erupt.
The arc of successive volcanoes
or “The Cascade arc”
extends from Northern California in
the United States to British Columbia in Canada
and includes more than a dozen volcanoes
11 of which
including Mount Baker and Mount Hood
are classified
by the United States Geological Survey as a “very significant threat”
meaning they pose significant risks to people and infrastructure.
Despite
the potential for significant danger
scientists have little data on
where magma is stored under the “Cascade Arc”
knowledge that can help scientists better understand
and predict future explosions
Prediction of eruption
is still far from accurate science
with different volcanoes exhibiting different
behaviors before the eruption and
in some cases, giving little warning.
A key aspect of explosion forecasting is the size
location and flow of magma under the volcano
which scientists say is missing in the “Cascade Arch” area.
A team led by Associate Professor Penny Weiser
said in the journal Geochemistry, Geophysics
Geosystems:
“Cascade’s arc contains a number of large volcanoes that
pose a significant risk to the population and infrastructure
for example Mount St.
Helens and Mount Rainier.
To date, there has been no widespread review of where magma
(molten rock) is stored in the Earth’s crust under these volcanoes
although understanding where magma is stored is very important to
help monitor disturbances in these volcanoes and predict future activity. “
In 1980
a devastating eruption from Mount St. Helens in Washington
State killed 57 people. However, the behaviour of
this volcano is fairly well understood
so its future eruptions can be predicted.
A number of other volcanoes are located in the
“Cascade Arch”
near populated areas and pose a significant risk to people
but the team found their understanding to be very weak.
“We have compiled all available data on magma storage for each volcano
and found that many volcanoes had very few studies to look at
despite the risks they pose to society.”
Seismic data
tilt scale readings and satellite information can detect Earth’s
distortions indicating that magma is moving beneath the surface.
However
most research focuses on a few cascading volcanoes that
have already been well described.
Practical constraints can also
hinder scientists’ understanding of volcanoes.
Sometimes magma does not move enough to be detected
and other times, noise from different geological processes
(including earthquakes from cracks) reduces the signal from magma.
The Panel recognizes that
owing to factors including inaccessible terrain
snow and ice cover, cost and difficulty in establishing surveillance
networks in land
areas have hampered data collection
but argues that understanding the depth of
magma storage is critical to interpreting signs of future explosions.