IAVCEI 2013 Scientific Assembly - July 20 - 24, Kagoshima, Japan
Forecasting Volcanic Activity - Reading and translating the messages of nature for society

4P1_4H-O16

Room B2Date/Time: July 24 15:15-15:30

First results from the Volcano Deformation Database Task ForceMatthew E Pritchard1 , Francisco Delgado1 , Jennifer A Jay1 , Juliet Biggs2 , Susanna Ebmeier3
Department of Earth and Atmospheric Sciences, Cornell University, USA, 2 COMET+, School of EarthSciences, University of Bristol, UK, 3 COMET+, Department of Earth Sciences, University of Oxford, UK1E-mail: pritchard@cornell.edu

Observations of surface displacements at volcanoes (both uplift and subsidence) are only one tool used to study
volcanic activity, but they have played an important role in understanding magma movements and in forecasting
during many eruptions (e.g. Kilauea, Mt. St. Helens, and Mt. Augustine, Alaska). On the other hand, many
volcanoes also exhibit deformation without leading to an eruption, and some eruptions may not produce grounddeformation or it might have been missed with the limited available datasets.
Forecasting can be improved from our aggregate knowledge of volcano behavior – for example, what are theproperties of a deformation episode at a volcano that do or do not lead to eruption? It is currently difficult toassemble this type of aggregate knowledge, especially on a short timescale in response to a volcanic crisis. At thesame time, we now have the opportunity to monitor all of the volcanoes of the world for ground deformation thanks
to satellite Interferometric Synthetic Aperture Radar (InSAR). Although appropriate InSAR data have not yet beenanalized over all of the world’s volcanoes, the number of known deforming volcanoes has more than tripled since1997.
Thus, recognizing the need for global information on volcano deformation and the opportunity to address it (withInSAR and other techniques), we have established a Volcano Deformation Database Task force as part of GlobalVolcano Model.
The three objectives of our organization are:1) to compile deformation observations of all volcanoes globally into a database that will be part of WOVOdat and
the Global Volcanism Program of the Smithsonian Institution.
2) document any relation between deformation events and eruptions for the Global assessment of volcanic hazard
and risk report for 2015 (GAR15) for the UN.
3) to better link InSAR and other remote sensing observations to volcano observatories.
We present the first results from our global study of the relation between deformation and eruptions, focusing on
the southern Andes. We find that available InSAR data are rarely available in the critical days to weeks before theeruption of a volcano that has been dormant for decades to millenia. For example, while ground deformation wasobserved before the 2011 eruptions of Cordon Caulle and Cerro Hudson, the observations were too infrequent tosee any change in the pattern or rate of deformation before the eruptions. Before 2011, Cordon Caulle and Cerro
Hudson both erupted in the 20th century, but the 2008 eruption of Chaiten was preceeded by millenia of dormacy
and still had no measured precursury deformation up to two weeks before eruption. New InSAR missions with more
frequent observations along with ground observations from tiltmeters and GPS are essential to constrain whether
there is a reliable deformation signal before eruption.

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