Integrating Magnetotelluric and Seismic Images of Silicic Magma Systems: A Case Study From the Laguna del Maule Volcanic Field, Central Chile
Integrating Magnetotelluric and Seismic Images of Silicic Magma Systems: A Case Study From the Laguna del Maule Volcanic Field, Central Chile
复制标题
整合硅质岩浆系统的大地电磁和地震图像：智利中部 Laguna del Maule 火山场的案例研究
DOI：
10.1029/2020jb020459
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
C. Thurber
中科院分区：
文献类型：
--
作者：
Darcy Cordell;M. Unsworth;Benjamin Lee;D. Díaz;N. Bennington;C. Thurber
使用光物理学的成像系统是具有挑战性的，因为许多相互关联的因素（例如，温度、熔体分数、熔体组成、几何形状）可以有助于测量的地球物理异常。多种地球物理方法模型的联合解释可以更好地约束地下结构的解释。以前出版的电阻率和剪切波速度（Vs）模型，分别来自大地电磁（MT）和面波地震数据，分别已被用来模拟不安分的拉古纳德尔Maule火山场，智利中部。Vs模型包含一个450 km 3的低速区（LVZ），解释为平均熔体分数为5- 6%的区域。电阻率模型包含导体（C3），其被解释为熔体分数> 35%的区域。LVZ和C3的空间范围重叠，但这些特征的几何形状和解释不同。为了解决这些差异，本研究采用假设检验和约束MT反演研究MT数据的分辨率。结果表明，MT数据是最好的适合与嵌入较大的LVZ内的离散导体。MT和地震模型之间的差异反映了两个数据集之间的分辨率差异以及对物理特性的不同敏感性。MT数据对含有连接良好的贫晶体熔体（C3）的较小体积的可浸提糊状物敏感。地震数据的空间分辨率较低，但可以成像连接不良的富含晶体的岩浆储存系统的全部范围。综合图像表明，LdMVF岩浆管道系统是热不均匀的共存区的温暖和寒冷的存储。
Imaging silicic systems using geophysics is challenging because many interrelated factors (e.g., temperature, melt fraction, melt composition, geometry) can contribute to the measured geophysical anomaly. Joint interpretation of models from multiple geophysical methods can better constrain interpretations of the subsurface structure. Previously published resistivity and shear wave velocity (Vs) models, derived separately from magnetotelluric (MT) and surface wave seismic data, respectively, have been used to model the restless Laguna del Maule Volcanic Field, central Chile. The Vs model contains a 450 km3 low‐velocity zone (LVZ) interpreted as a region with an average melt fraction of 5–6%. The resistivity model contains a conductor (C3) interpreted as a region with a melt fraction >35%. The spatial extents of the LVZ and C3 overlap, but the geometries and interpretations of these features are different. To resolve these discrepancies, this study investigates the resolution of the MT data using hypothesis testing and constrained MT inversions. It is shown that the MT data are best fit with discrete conductors embedded within the larger LVZ. The differences between the MT and seismic models reflect resolution differences between the two data sets as well as varying sensitivities to physical properties. The MT data are sensitive to smaller volumes of extractable mush that contain well‐connected crystal‐poor melt (C3). The seismic data have lower spatial resolution but image the full extent of the poorly connected crystal‐rich magma storage system. The combined images suggest that the LdMVF magma plumbing system is thermally heterogeneous with coexisting zones of warm and cold storage.
Laguna del Maule 流纹岩的储存和演化：熔体包裹体中挥发性和微量元素含量的见解
DOI：
10.1029/2020jb019475
发表时间：
2020
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
--
作者：
Klug, Jacob D.;Singer, Brad S.;Kita, Noriko T.;Spicuzza, Michael J.
通讯作者：
Spicuzza, Michael J.