III. From precursors to eruption  

III.2 Geophysical multi-parameters techniques for monitoring active volcanoes.

Session organized by IASPEI/IAVCEI Commission on Volcano Seismology and IAGA/IASPEI/IAVCEI Working Group on Electromagnetic Studies of Earthquakes and Volcanoes (EMSEV)

Convenors from EMSEV:
J. Zlotnicki, CNRS, France. EMSEV Chair; jacques.zlotnicki@wanadoo.fr
Malcolm Johnston, U.S. Geol. Survey, USA. IAVCEI Liaison member; mal@usgs.gov
T. Hashimoto, Hokkaido University, Japan; hasimoto@mail.sci.hokudai.ac.jp

Convenors from IASPEI/IAVCEI Commission on Volcano Seismology:
Jurgen Neuberg, Leeds University, United Kingdom; J.Neuberg@leeds.ac.uk
Stephanie Prejean, USGS, USA; sprejean@usgs.gov
Benoit Taisne, EOS, Singapore; btaisne@ntu.edu.sg

This session aims at different geophysical monitoring techniques which can be combined and integrated to achieve two major goals: Firstly, the imaging of volcanic source processes from the surface to the deep plumbing system, and secondly, the interpretation of geophysical signals that enable us to assess the state of volcanic activity. We aim to identify geophysical signals that are characteristic in defining background levels, detecting unrest and evaluating ongoing volcanic activity.

Seismic monitoring, including infra sound, remains at the core of any monitoring program. While well-established seismic monitoring techniques are routinely applied, major advances in volcano seismology have been made in recent years allowing us to identify several categories of volcanic seismic signals, and interpret them in terms of different magmatic or tectonic processes encountered at a volcano. This session will review the wide range of seismic monitoring techniques and interpretation methods from low-cost, basic set-ups to the latest sophisticated seismological applications and modelling methods. Accordingly, we aim to cover the entire seismic frequency range from short-period to ultra-long period seismicity, tilt and other deformation signals in different volcanic settings.

Volcanoes arrive at a critical state after weeks or even years of unrest before the onset of surface activity. During this period electromagnetic and geochemical methods appear to be sensitive to transient anomalous signals caused by the movement of magmatic and hydrothermal fluids. Only at a later stage seismic activity as well as ground deformation become more obvious. Therefore, we particularly welcome case studies that combine monitoring or modelling techniques of seismicity, electromagnetic signals, ground deformation, infrasound, gas monitoring, gravimetry, petrology and fluid dynamics of magmatic systems.