An Inside Perspective on Magma Intrusion: Quantifying 3D Displacement and Strain in Laboratory Experiments by Dynamic X-Ray Computed Tomography
An Inside Perspective on Magma Intrusion: Quantifying 3D Displacement and Strain in Laboratory Experiments by Dynamic X-Ray Computed Tomography
复制标题
岩浆侵入的内部视角：通过动态 X 射线计算机断层扫描量化实验室实验中的 3D 位移和应变
DOI：
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发表时间：
2019
影响因子：
2.9
通讯作者：
M. Kervyn
中科院分区：
文献类型：
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作者：
S. Poppe;E. Holohan;O. Galland;N. Buls;G. Van Gompel;Benyameen Keelson;Pierre;J. Brancart;D. Hollis;A. Nila;M. Kervyn
岩浆侵入体通过使地壳内部变形和使地球表面移位而形成最终的几何形状。根据侵入体几何形状解释相关位移是预测火山爆发的关键。虽然缩放的实验室模型使我们能够研究地表位移和侵入体几何形状之间的关系，过去的方法涉及的实验室模型内部的成像或模拟地壳流变学的简单性方面的限制。在这里，我们应用尖端的医学宽束X射线计算机断层扫描（CT）在4D中量化实验室模型中由岩浆模拟物（金糖浆）侵入流变学复杂的颗粒状宿主岩石模拟物（沙子和石膏）引起的变形。我们提取的表面变形，我们量化的应变场的整个实验体积在3D随着时间的推移，通过使用数字体积相关（DVC）。通过改变宿主材料的强度和高度以及侵入速度，我们观察了对比几何形状的侵入体-隐圆顶，杯形，锥片和堤坝-如何生长，并在4D中诱导对比应变场特征和表面变形。我们观察到占主导地位的混合模式（开放和剪切）断裂定位在低内聚力材料覆盖层与开放模式断裂定位在高内聚力材料覆盖层。结果表明，CT和DVC的组合可以大大提高利用光学不透明的地壳岩石类似物在获得洞察浅地壳变形过程。这一前所未有的观点的时空相互作用的侵入增长加上主机岩石变形提供了一个概念框架，可以测试的地质实地观测侵蚀火山系统和不断增加的空间和时间分辨率的大地测量数据在活火山。
Magma intrusions grow to their final geometries by deforming the Earth’s crust internally and by displacing the Earth’s surface. Interpreting the related displacements in terms of intrusion geometry is key to forecasting a volcanic eruption. While scaled laboratory models enable us to study the relationships between surface displacement and intrusion geometry, past approaches entailed limitations regarding imaging of the laboratory model interior or simplicity of the simulated crustal rheology. Here we apply cutting-edge medical wide beam X-ray Computed Tomography (CT) to quantify in 4D the deformation induced in laboratory models by an intrusion of a magma analogue (golden syrup) into a rheologically-complex granular host rock analogue (sand and plaster). We extract the surface deformation and we quantify the strain field of the entire experimental volume in 3D over time by using Digital Volume Correlation (DVC). By varying the strength and height of the host material, and intrusion velocity, we observe how intrusions of contrasting geometries– cryptodomes, cup shapes, cone sheets and dikes – grow, and induce contrasting strain field characteristics and surface deformation in 4D. We observe dominantly mixed-mode (opening and shear) fracture localisation in low-cohesion material overburden versus opening-mode fracture localisation in high-cohesion material overburden. The results demonstrate how the combination of CT and DVC can greatly enhance the utility of optically non-transparent crustal rock analogues in obtaining insights into shallow crustal deformation processes. This unprecedented perspective on the spatio-temporal interaction of intrusion growth coupled with host rock deformation provides a conceptual framework that can be tested by geological field observations at eroded volcanic systems and by the ever increasing spatial and temporal resolution of geodetic data at active volcanoes.
影响因子：
2.5
作者：
Fedorov, Andriy;Beichel, Reinhard;Kalpathy-Cramer, Jayashree;Finet, Julien;Fillion-Robin, Jean-Christophe;Pujol, Sonia;Bauer, Christian;Jennings, Dominique;Fennessy, Fiona;Sonka, Milan;Buatti, John;Aylward, Stephen;Miller, James V.;Pieper, Steve;Kikinis, Ron
通讯作者：
Kikinis, Ron