Geoscience Reference
In-Depth Information
facilities should be encouraged, including applications to hydrology and meteorology,
to broaden the support base for these data collection efforts.
Box 2.5
Volcanic Systems
Volcanic eruptions provide spectacular and frequent (more than 70 different
volcanoes erupt every year) reminders that Earth is a dynamic and evolving planet. Lava
flows, pyroclastic flows, and ash fall are proximal hazards; gases and dust lofted into the
atmosphere have global effects on climate, life, and air traffic. Volcanic hazard does not end
with the eruption—lahars and landslides create hazards long after an eruption ends. Despite
a long history of investigation, numerical models of volcanic processes, laboratory
characterization of the properties of magmas, and real-time monitoring of active volcanoes
are only now beginning to show their promise to both predict eruptions and quantitatively
interpret volcanic deposits.
Volcanic eruptions are the end product of a complex set of interacting processes:
melting Earth's interior, the storage and chemical evolution of magma, the ascent of magma
through the crust, and the fragmentation of magma during explosive eruptions. Several key
questions remain the subject of active research. Why do volcanoes erupt in so many different
ways? Can the duration and style of eruption be predicted from pre-eruption signals? Why do
supervolcanoes exist? Why do earthquakes sometime trigger volcanic eruptions? What
processes govern the speed and distance traveled by pyroclastic flows?
Modern research in volcanology relies on integrating complementary approaches:
remote sensing from space with InSAR and spectroradiometers; distributed high-frequency
monitoring of GPS, tilt, seismic, infrasound, acoustic, and electromagnetic signals; gas
sampling; measuring the rheological properties and phase equilibria of magmas in the lab;
numerical simulations of conduit processes, the multiphase dynamics of eruption columns
and pyroclastic flows, and the thermal and chemical evolution of magma within the crust.
Additionally, large-scale laboratory experiments offer an important opportunity for validating
the new generation of numerical models for conditions and properties that are well
constrained. At the present time, NSF does not support either such large-scale laboratory
facilities for community use or experimental facilities for studying magma properties at
relevant deformation rates and temperatures.
Monitoring of volcanoes in the United States is performed by the USGS and its
volcano observatories. NSF-supported research adds to these activities by supporting
complementary principal investigator-led monitoring, theoretical work, and laboratory
analyses. Partnerships and collaborations between NSF and other agencies, such as the
USGS, may be vital for making full use of the data and addressing questions that are beyond
the primary objective of hazard assessment. Support is also needed to rapidly respond to
new eruptions and to ensure that instruments are available.
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