Forecasting the evolution of an ongoing eruption is a task of great importance for Earth scientists, as insights into possible future scenarios are critical for volcano disaster management, and allow our scientific understanding of magmatic processes to be critically assessed and, potentially, validated. Geochemical monitoring of eruptive products (gases, pyroclasts, lavas) coupled with modelling of magma ascent, degassing and eruption can produce quantitative constraints on the volumes and physical properties of magma in play and the magma ascent rate. Such constraints can be compared with both geophysical and volcanological observations, increasing confidence in our knowledge of the state of the volcanic system. Potentially, these measurements can be integrated into a time-dependent model of magma dynamics, allowing the future state of the volcano to be forecasted.

This is especially true for volcanoes that do not erupt as frequently, such as Ploski Tolbachik, in Kamchatka. On Nov 27 2012 a new eruption began on the south flank of Ploskii Tolbachik volcano, along the same fissure system that produced the 'Great Tolbachik eruption' in 1975-76. While the new eruption appears to have now ended, effusive activity was ongoing for almost nine months. This eruption produced a significant volume of fluid lava, and, while fluidal basaltic eruptions are not typical for subduction zone settings, they do occur and present a unique set of hazards. Contributions documenting the evolution of this specific eruption provide overviews of observations and measurements made during the course of the eruption, including field volcanology, geophysical measurements, remote sensing monitoring of the eruption, as well as the first results from ongoing geochemical and petrological studies of lavas, tephras and volcanic gases.

Within this framework, this session aims at presenting and discussing observations, modeling and monitoring methods that improve our understanding of the processes that control the evolution of eruptive dynamics.

We therefore welcome contributions related to i) detailed and multidisciplinary descriptions of case studies representative of the evolution of eruptive dynamics, 2) technical developments providing innovative and critical information of time and space evolution of eruptive dynamics 3) modelling of magma transfer and eruption linked with eruptive style changes, 3) case studies reporting the societal impact of eruptive style changes.