Possible deep connection between volcanic systems evidenced by sequential assimilation of geodetic data

• Main Authors: Bato, M. G., Pinel, Virginie, Yan, Y., Jouanne, F., Vandemeulebrouck, J.
• Format: Text
• Language: English
• Published: 2018
• Subjects: Holuhraun; Grimsvotn; Iceland; Islande
• Online Access: http://www.documentation.ird.fr/hor/fdi:010073746

The existence of possible deep connections between nearby volcanoes has so far only been formulated on the basis of correlation in their eruptive activities or geochemical arguments. The use of geodetic data to monitor the deep dynamics of magmatic systems and the possible interference between them has remained limited due to the lack of techniques to follow transient processes. Here, for the first time, we use sequential data assimilation technique (Ensemble Kalman Filter) on ground displacement data to evaluate a possible interplay between the activities of Grimsvotn and Baroarbunga volcanoes in Iceland. Using a two-reservoir dynamical model for the Grimsvotn plumbing system and assuming a fixed geometry and constant magma properties, we retrieve the temporal evolution of the basal magma inflow beneath Grimsvotn that drops by up to 85% during the 10 months preceding the initiation of the Baroarbunga rifting event. We interpret the loss of at least 0.016 km(3) in the magma supply of Grimsvotn as a consequence of magma accumulation beneath Baroarbunga and subsequent feeding of the Holuhraun eruption 41 km away. We demonstrate that, in addition to its interest for predicting volcanic eruptions, sequential assimilation of geodetic data has a unique potential to give insights into volcanic system roots.