Abstract Seismic imaging is used in this work, to reconstruct the shallow structure of the Solfatara crater, a surface marker of deep magmatic activity inside Campi Flegrei caldera (Southern Italy). We analyze the 1D orthogonal seismic arrays deployed in NNE-SSW directions for 400 m through the Solfatara crater during the recent active experiment RICEN (Repeated Induced Earthquake and Noise) performed in the framework of the EU project MEDSUV. Seismic data have been edited in the pre-stack stage by removing the noisy traces, low-frequency noise, and reduce the ground roll phases. Then, a velocity analysis has been carried out starting from the velocity spectrum to obtain a RMS velocity model, which has been followed by NMO, residual statics, and DMO corrections. We used the post-stack Kirchhoff migration technique before the extraction of the energy, root mean square, envelope and sweetness attributes defining the highest amplitude zones, the time-gain attribute in order to interpret the deep reflectors and the variance attribute to define the faults, discontinuities, and chaotic zones. Amplitude Versus Offset (AVO) analysis has been performed to identify the gas-saturated zone using partial angle-stacks, which is a benchmark to verify the presence of gas. The main contribution of this work is to provide a more detailed and improved seismic reflection image of the shallow depth of the Solfatara crater. The reliability of our velocity model has been assessed through the use of the Vp velocity model previously obtained by the non-linear Bayesian technique. This provides a final stack showing that the shallower minor faults and the extension of the major faults represent the main pathways for the uprising fluids. We present the visual evidence for the fluids trapped in the shallower part of the crater at depths between 20 and 50 m below the surface of the crater.

中文翻译：

---

Solfatara 火山口（意大利南部 Campi Flegrei 火山口）的地震成像：浅层结构中流体迁移路径的新证据

摘要 这项工作使用地震成像来重建 Solfatara 陨石坑的浅层结构，这是 Campi Flegrei 火山口（意大利南部）内部深层岩浆活动的表面标志。我们分析了最近在欧盟项目 MEDSUV 框架内进行的 RICEN（重复诱发地震和噪声）活动实验中，通过 Solfatara 陨石坑在 NNE-SSW 方向部署 400 m 的一维正交地震阵列。通过去除噪声痕迹、低频噪声和减少地滚相位，在叠前阶段对地震数据进行了编辑。然后，从速度谱开始进行速度分析以获得 RMS 速度模型，然后进行 NMO、剩余静力学和 DMO 校正。我们在提取定义最高振幅区域的能量、均方根、包络和甜度属性之前使用叠后基尔霍夫偏移技术，时间增益属性用于解释深反射层，方差属性用于定义断层、不连续区和混沌区。已执行幅度与偏移 (AVO) 分析以使用部分角度叠加来识别气体饱和区，这是验证气体存在的基准。这项工作的主要贡献是提供了 Solfatara 陨石坑浅层的更详细和改进的地震反射图像。我们的速度模型的可靠性已经通过使用先前通过非线性贝叶斯技术获得的 Vp 速度模型进行了评估。这提供了一个最终叠加，表明较浅的小断层和主要断层的延伸代表了上升流体的主要通道。我们提供了在陨石坑表面以下 20 到 50 m 深度处被困在陨石坑较浅部分中的流体的视觉证据。