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

3W_4C-P13

Date/Time: July 23 Poster

The base method for prediction of volcanic activity
Alexander Iv. Malyshev
Institute of Geology and Geochemistry, Urals Branch of RAS, Yekaterinburg, Russia
E-mail: ai-malyshev@yandex.ru

F. Omori had written in May 1911, after the first historical instrumental study of seismic and volcanic activity during
the 1910 Usu (Hokkaido) eruption: "I believe the problem of forecasting of great volcanic eruption is, in some case,not very difficult". Great Japanese seismologist was right, although his modern followers are not so optimistical.
Main feature of volcanic process – excess magmatic pressure. The pressure changes result in deformations ofmagmatic body and volcanic rocks. There are brittle (disjunctive) and plastic (plicative) deformations. Eruptionsof the same volcano may have the clearly marked seismic preparation or not have it at all (for example: the1975–1976 Tolbachik (Kamchatka) eruption was with good seismic preparation, but 2012 Tolbachik eruption
started practically without it). The seismic monitoring may detect brittle deformations as volcanic earthquakes, but
it cannot detect plastic deformation. Therefore seismic monitoring must be use together with methods of Earthsurface monitoring for successful predictions.

I began own investigations from 1981–1987 Bezymianny (Kamchatka) eruptions with mostly plastic deformations.
This eruptions had not significant seismic preparation: only rare weak seismic signals from rock avalanches before
explosive eruption and volcanic tremor during it. During the study of 1980–1987 Bezymianny volcano eruptions I
discovered the fact of hyperbolic increasing of volcanic activity before explosive-effusive eruptions. My attempts ofusing these regularities for the forecast were quite successful for several ordinary eruptions and 1985 Bezymianny
directed blast (3 forecast levels: 8 months, 19 and 5 days before). Subsequently the studying of patterns forincreasing-decreasing of volcanic activity and their comparison with empirical dependencies of the development ofvarious natural processes allowed me to conclude that there is a wide class of self-developing natural processes,
the dynamics of which is described by non-linear differential equation of the second order.

Parameters ofvolcanoseismic activity and deformation volumes may be approximated and may be extrapolated by this equation.
The correspondence between levels of volcanoseismic parameters and real volcanic phenomena must be found forsuccessful prediction of volcanic eruptions’ evolution of observed volcano. Retrospective estimations are executedon the examples of Bezymianny 1955–1970, 1981–1986, Sheveluch 1964, Kizimen 2010–2012 eruptions. Theyshow possibility of the successful predicton of volcanic activity. Time prediction distances are very wide for thismethod: from 15–30 min for predictions on the base of volcanic tremor monitoring through 1–2 weak for ordinary
eruptions up to 2 years (the 2010–c.t. Kizimen eruption). The "approximation–extrapolation" method seems asprimitive, but it is the base (fundamental) primitiveness which must be used for predictions of volcanic activity firstand foremost.

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