We present an ambient noise tomographic study of the mid-crustal magmatic system in the Katmai area, Alaska. Using multi-component (vertical and radial) seismic records at 70 stations deployed at various times over 20 years, we construct corresponding cross-correlograms and extract ~1010 Rayleigh-wave dispersion curves in the periods between 2 and 30 s. These enable us to obtain corresponding group velocity maps and finally a 3-D shear-wave velocity model to a depth of 25 km. The most striking feature is a ~25 km wide low-velocity anomaly beneath the Katmai area at depths of approximately 10 to 20 km, which we interpret as a mid-crustal magma storage zone. Our study complements previous local-scale tomography studies that unveil small upper crustal reservoirs, revealing the likely deep magma source ultimately responsible for the 1912 Novarupta-Katmai eruption.

我们提出了阿拉斯加卡特迈地区中地壳岩浆系统的环境噪声层析成像研究。使用 20 年来不同时间部署的 70 个台站的多分量（垂直和径向）地震记录，我们构建了相应的互相关图，并提取了 2 到 30 秒之间的约 1010 条瑞利波频散曲线。这些使我们能够获得相应的群速度图，并最终获得 25 公里深度的 3-D 横波速度模型。最显着的特征是卡特迈地区下方约 10 至 20 公里深处的约 25 公里宽的低速异常区，我们将其解释为中地壳岩浆储存区。我们的研究补充了先前的局部尺度层析成像研究，这些研究揭示了小型上地壳储层，