A 3D shear wave velocity model of the subsurface of Popocatépetl volcano was obtained using ambient noise tomography, employing the principal cross-terms of the empirical Green’s function. Daily cross-correlation waveforms were computed from the data recorded by four seismic broadband stations in 2012. Dispersion curves were estimated from the stack of anti-causal and causal parts for the three ground motion components. In the period ranging between 0.5 and 7 s, the radial component provided the most well-defined group velocity dispersion curves for Rayleigh waves. Dispersion curves for long paths (> 9.5 km) suggested the presence of a layered structure with group velocity values ranging from 0.5 to 3.0 km/s. Dispersion curves for short paths (< 7 km) and close to the volcano showed values similar to those for long paths but with a velocity inversion occurring between 3- and 5-s periods. Despite the scarce ray-path coverage, a tomography inversion provided the means to image an S-wave velocity anomaly (2.5–3.0 km/s) in the northern part of the crater at depths not larger than 6 km. The volcano-tectonic seismicity during 2012–2013 was found to be concentrated in the southern segment of this anomaly, which seems to mark a boundary between a solidified body (possibly a product of ancient volcanic craters) and the softer material.

波波卡特佩特火山地下的 3D 横波速度模型是使用环境噪声断层扫描获得的，采用经验格林函数的主要交叉项。每日互相关波形是根据 2012 年四个地震宽带站记录的数据计算的。色散曲线是根据三个地震动分量的反因果部分和因果部分的叠加来估计的。在 0.5 到 7 秒的周期内，径向分量为瑞利波提供了最明确的群速度色散曲线。长路径（> 9.5 公里）的色散曲线表明存在层状结构，群速度值范围为 0.5 至 3.0 公里/秒。短路径的色散曲线 (< 7 公里）和火山附近显示的值与长路径的值相似，但速度反转发生在 3 到 5 秒的周期之间。尽管射线路径覆盖率很低，但断层摄影反演提供了在不大于 6 公里深度处对火山口北部的 S 波速度异常（2.5-3.0 公里/秒）进行成像的手段。发现 2012-2013 年期间的火山构造地震活动集中在该异常区的南段，这似乎标志着凝固体（可能是古代火山口的产物）和较软物质之间的边界。