Combining Magma Flow and Deformation Modeling to Explain Observed Changes in Tilt
Combining Magma Flow and Deformation Modeling to Explain Observed Changes in Tilt
复制标题
结合岩浆流和变形建模来解释观察到的倾斜变化
作者：
L. Marsden;J. Neuberg;M. Thomas;P. Mothes;M. Ruiz
The understanding of magma ascent dynamics is essential in forecasting the scale, style and timing of volcanic eruptions. The monitoring of near-field deformation is widely used to gain insight into these dynamics, and has been linked to stress changes in the upper conduit. The ascent of magma through the conduit exerts shear stress on the conduit wall, pulling up the surrounding edifice, whilst overpressure in the upper conduit pushes the surrounding edifice outwards. Hsout{owever, h}ow much shear stress and pressure is produced during magma ascent, and the relative contribution of each to the deformation, sout{is yet to be fully understood and quantified} extcolor{blue}{has until now only been explored conceptually}. By combining flow and deformation modelling using COMSOL Multiphysics, we sout{are} for the first time sout{able to} extcolor{blue}{present a quantitative model that links magma ascent to deformation. We} quantify how both shear stress and pressure vary spatially within a conduit, and show that shear stress generally dominates observed changes in tilt close to the conduit during activity at Tungurahua volcano, Ecuador, between 2013 and 2014. However, the relative contribution of pressure is not insignificant, and sout{the full stress tensor comprising} both pressure and shear stress must be considered when interpreting deformation data. We demonstrate that significant changes in tilt sout{can occur as magma refills an empty conduit, or} can be driven by changes in the driving pressure gradient or volatile content of the magma. The relative contribution of shear stress and pressure to the tilt varies considerably depending on these parameters. Our work provides insight into the range of elastic moduli that should be considered when modelling edifice-scale rock masses, and we show that even where the edifice is modelled as weak, shear stress extcolor{blue}{generally} dominates the near field deformation over pressurisation of the conduit.
The understanding of magma ascent dynamics is essential in forecasting the scale, style and timing of volcanic eruptions. The monitoring of near-field deformation is widely used to gain insight into these dynamics, and has been linked to stress changes in the upper conduit. The ascent of magma through the conduit exerts shear stress on the conduit wall, pulling up the surrounding edifice, whilst overpressure in the upper conduit pushes the surrounding edifice outwards. Hsout{owever, h}ow much shear stress and pressure is produced during magma ascent, and the relative contribution of each to the deformation, sout{is yet to be fully understood and quantified} extcolor{blue}{has until now only been explored conceptually}. By combining flow and deformation modelling using COMSOL Multiphysics, we sout{are} for the first time sout{able to} extcolor{blue}{present a quantitative model that links magma ascent to deformation. We} quantify how both shear stress and pressure vary spatially within a conduit, and show that shear stress generally dominates observed changes in tilt close to the conduit during activity at Tungurahua volcano, Ecuador, between 2013 and 2014. However, the relative contribution of pressure is not insignificant, and sout{the full stress tensor comprising} both pressure and shear stress must be considered when interpreting deformation data. We demonstrate that significant changes in tilt sout{can occur as magma refills an empty conduit, or} can be driven by changes in the driving pressure gradient or volatile content of the magma. The relative contribution of shear stress and pressure to the tilt varies considerably depending on these parameters. Our work provides insight into the range of elastic moduli that should be considered when modelling edifice-scale rock masses, and we show that even where the edifice is modelled as weak, shear stress extcolor{blue}{generally} dominates the near field deformation over pressurisation of the conduit.
影响因子：
5.3
作者：
J. Neuberg;A. Collinson;P. Mothes;M. Ruiz;Santiago Aguaiza
通讯作者：
J. Neuberg;A. Collinson;P. Mothes;M. Ruiz;Santiago Aguaiza
2014 年 2 月通古拉瓦（厄瓜多尔）火山驱动的中度喷发的动态和类型转变：火山碎屑沉积物和危险因素
影响因子：
3.4
作者：
Romero;Amin Douillet;Vallejo Vargas;Bustillos Arequipa;Troncoso;Díaz Alvarado;Ramón
通讯作者：
Ramón
厄瓜多尔通古拉瓦火山（2013â2014）连续的火山栓形成、火山爆发崩解以及颗粒火山碎屑密度流的产生
影响因子：
2.9
作者：
Hall ML;Steele AL;Bernard B;Mothes PA;Vallejo SX;Douillet GA;Ramon PA;Aguaiza SX;Ruiz MC
通讯作者：
Ruiz MC