The analysis of seismic ambient noise has been recently proven a viable alternative to the analysis of seismic waves generated by earthquakes. Although seismic ambient noise had traditionally been discarded from earthquake records, it has now been shown that the cross-correlation of the seismic ambient noise allows for the recovery of the Green’s function between the receivers. Furthermore, seismic noise has the ability to propagate continuously and independently of the occurrence of earthquakes, allowing for high-resolution tomographic studies in regions of low seismicity. Over the last two decades, the cross-correlation of continuous seismic noise recordings between pairs of stations has been widely utilized in surface-wave tomography studies. For the Northeast Brazil region, tomographic studies have been exclusively performed with seismic data from broadband stations; however, in addition to those stations, there exists a large volume of short-period data that might potentially improve the resolution of existing ambient noise tomographies. Thus, the goal of this work is to utilize, in addition to broadband data, short-period data recorded by 22 short-period stations in the Borborema Province. Through cross-correlation and stacking of ambient seismic noise, the emergence of the fundamental mode of the Rayleigh waves and their dispersive character was observed. Once the empirical Green's functions were retrieved, the accuracy of (phase and group) dispersion curves for periods up to 10 s and its tomographic inversion were assessed. Our results demonstrate that short-period dispersion measurements can be successfully integrated in regional tomographic studies for improved resolution.

最近已证明，对地震环境噪声的分析可替代分析由地震产生的地震波的可行方法。尽管传统上已经从地震记录中丢弃了地震环境噪声，但是现在已经表明，地震环境噪声的互相关可以恢复接收器之间的格林函数。此外，地震噪声具有连续且独立于地震发生而传播的能力，从而允许在低地震活动性地区进行高分辨率层析成像研究。在过去的二十年中，连续波噪声记录在站对之间的互相关已被广泛用于表面波层析成像研究中。对于巴西东北部地区，仅对宽带站的地震数据进行层析成像研究；但是，除了这些站外，还存在大量的短期数据，这些数据可能潜在地改善现有环境噪声层析成像的分辨率。因此，这项工作的目标是除了利用宽带数据之外，还利用由Borborema Province的22个短周期台站记录的短周期数据。通过互相关和环境地震噪声的叠加，观察到了瑞利波的基本模式及其色散特性。一旦检索到格林经验函数，就可以评估（相位和群）色散曲线在10 s内的准确性以及其X线断层图像的倒置。