Bato Mary Grace, Pinel Virginie, Yan Yajing, Jouanne François, Vandemeulebrouck Jean
Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000, Grenoble, France.
Université Savoie Mont Blanc, LISTIC, 74000, Annecy, France.
Sci Rep. 2018 Aug 3;8(1):11702. doi: 10.1038/s41598-018-29811-x.
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 Grímsvötn and Bárðarbunga volcanoes in Iceland. Using a two-reservoir dynamical model for the Grímsvötn plumbing system and assuming a fixed geometry and constant magma properties, we retrieve the temporal evolution of the basal magma inflow beneath Grímsvötn that drops by up to 85% during the 10 months preceding the initiation of the Bárðarbunga rifting event. We interpret the loss of at least 0.016 km in the magma supply of Grímsvötn as a consequence of magma accumulation beneath Bárðarbunga 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.
到目前为止，附近火山之间可能存在的深层联系仅基于它们喷发活动的相关性或地球化学论据来阐述。由于缺乏跟踪瞬态过程的技术，利用大地测量数据监测岩浆系统的深部动力学及其之间可能的干扰一直受到限制。在此，我们首次在地面位移数据上使用序贯数据同化技术（集合卡尔曼滤波器），以评估冰岛格里姆火山和巴尔达本加火山活动之间可能的相互作用。使用针对格里姆火山管道系统的双储层动力学模型，并假设几何形状固定且岩浆性质恒定，我们获取了格里姆火山下方底部岩浆流入量的时间演化，在巴尔达本加裂谷事件开始前的10个月内，该流入量下降了高达85%。我们将格里姆火山岩浆供应至少减少0.016千米解释为巴尔达本加下方岩浆堆积以及随后为41千米外的霍鲁赫拉乌恩火山喷发提供岩浆的结果。我们证明，除了对预测火山喷发具有重要意义外，大地测量数据的序贯同化在深入了解火山系统根源方面具有独特潜力。
