Liu Ying, Kendall John Michael, Zhang Haijiang, Blundy Jonathan D, Pritchard Matthew E, Hudson Thomas, MacQueen Patricia
Department of Geophysics and Planetary Sciences, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, Anhui, China.
State Key Laboratory of Precision Geodesy, University of Science and Technology of China, Hefei 230026, China.
Proc Natl Acad Sci U S A. 2025 May 6;122(18):e2420996122. doi: 10.1073/pnas.2420996122. Epub 2025 Apr 28.
For a volcanic system, evaluating potential eruption probability requires understanding the extent of melt and gas accumulation in the upper crustal reservoir, which is challenging to resolve. Here, we jointly use geophysical imaging and petrophysical analysis to unravel the current state and pathway of gas or supercritical fluids in the upper crust beneath Uturuncu volcano in Bolivia. Although it last erupted 250 ± 5 ka ago, Uturuncu remains active with observable deformation and seismicity. To assess its current state, we have determined high-resolution isotropic and anisotropic seismic velocity structures of the volcanic system in the upper crust using local seismic networks. Combining our seismic analysis with previous geophysical imaging results and rock physics modeling, we delineate pathways of migrating fluids traveling toward the surface and a shallow gas accumulation zone beneath the crater. This fluid migration and accumulation explains why Uturuncu volcano still shows signs of activity. Our study exemplifies how seismology combined with rock physics models and petrological analysis can resolve the detailed structure and composition of a volcanic system, critical for assessing eruption hazard.
对于火山系统而言，评估潜在喷发概率需要了解上地壳储层中熔体和气体的聚集程度，而这一点很难确定。在此，我们联合运用地球物理成像和岩石物理分析方法，来揭示玻利维亚乌图伦库火山下方上地壳中气体或超临界流体的当前状态及运移路径。尽管乌图伦库火山上次喷发是在25万±5千年以前，但它仍处于活跃状态，有可观测到的变形和地震活动。为评估其当前状态，我们利用本地地震台网确定了上地壳中火山系统的高分辨率各向同性和各向异性地震速度结构。将我们的地震分析与先前的地球物理成像结果及岩石物理模型相结合，我们描绘出了流体向上迁移至地表的路径以及火山口下方的一个浅层气体聚集区。这种流体的迁移和聚集解释了为什么乌图伦库火山仍然显示出活动迹象。我们的研究例证了地震学如何与岩石物理模型及岩石学分析相结合，从而解析火山系统的详细结构和组成，这对于评估喷发危险至关重要。
