This paper describes an approach to analyze ground deformation data collected by InSAR (Interferometric Synthetic Aperture Radar) imaging the volcano feeding system (VFS) beneath a caldera. The approach is applied to the Campi Flegrei caldera in southern Italy, a densely populated area at high risk for volcanic eruption. The method is a 4D tomographic inversion that considers a combination of 3D pressure sources and dislocations (strike-slip, dip-slip and tensile) acting simultaneously. This is in contrast to traditional methods that assume a priori geometries and type for the volcanic source. Another novelty is that we carry out a time-series analysis of multifrequency InSAR displacement data. The analysis of these multiplatform and multifrequency InSAR data from 2011 to 2022 reveals an inflating source at a depth of 3–4 km that is interpreted as a pressurized magmatic intrusion. The source broadens and migrates laterally over time, with a possible new magmatic pulse arriving in 2018–2020. The model also identifies a shallow region (at 400 m depth) that may be feeding fumaroles in the area. The analysis also reveals a zone of weakness (dip-slip) that could influence the path of rising magma. This method provides a more detailed dynamic 4 - dimensional image of the VFS than previously possible and could be used to improve hazard assessments in active volcanic areas.

中文翻译：

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Campi Flegrei 火山口市区下方火山补给系统的 4D 成像


本文描述了一种分析InSAR（干涉合成孔径雷达）对火山口下方火山补给系统（VFS）成像收集的地面变形数据的方法。该方法适用于意大利南部的 Campi Flegrei 火山口，这是一个人口稠密的地区，火山喷发的风险很高。该方法是一种 4D 断层扫描反演，它考虑了 3D 压力源和位错（走滑、浸滑和拉伸）的组合同时作用。这与假设火山源的先验几何形状和类型的传统方法形成鲜明对比。另一个新颖之处在于，我们对多频 InSAR 位移数据进行了时间序列分析。对 2011 年至 2022 年的这些多平台和多频 InSAR 数据的分析揭示了 3-4 公里深度的膨胀源，该膨胀源被解释为加压岩浆侵入。随着时间的推移，该源头会扩大并横向迁移，可能会在 2018-2020 年出现新的岩浆脉冲。该模型还确定了一个浅水区（400 m 深），该区域可能在该地区为喷气孔提供水源。分析还揭示了可能影响岩浆上升路径的薄弱区域（倾滑）。这种方法提供了比以前更详细的 VFS 动态 4 维图像，可用于改进活跃火山区域的危害评估。