The Lorca earthquake (May 11th, 2011, Mw 5.2) stands as the most destructive one in Spain over the last 50 years, interpreted as having occurred in an intersegment zone of the strike–slip Alhama de Murcia Fault (AMF) (Eastern Betics, Spain). Magnetotelluric data were acquired along a profile to the SW of Lorca (La Torrecilla profile), to characterize its signature at depth, as part of the multidisciplinary project “INTERGEOSIMA”. Given the short distance between stations, some station pairs were recorded simultaneously, with magnetic sensors in only one of them. In order to properly understand the resulting impedances (called interstation impedances), and the effects of inverting them, we used synthetic models to compare the impedances and the interstation impedances and to analyze the corresponding inversion results, together with the inversion of the quasi-impedance (inversion of the interstation impedances, considering them as impedances). The results are sensitive to the location of the magnetic sensors and the resistivity underneath, but in general the use of the quasi-impedances in the inversion can be considered a valid procedure. Both the 2D and the 3D resistivity models obtained through the inversion allowed us to complement the previous ERT models and represent the continuation of the main fault gouge in depth showing its extension towards the SE.

中文翻译：

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Alhama de Murcia 断层（Eastern Betics，西班牙）的大地电磁特征和大地电磁站间阻抗反演的研究

洛尔卡地震（2011 年 5 月 11 日，Mw 5.2）是过去 50 年来西班牙最具破坏性的地震，被解释为发生在走滑 Alhama de Murcia 断层 (AMF) (Eastern Betics,西班牙）。作为多学科项目“INTERGEOSIMA”的一部分，大地电磁数据沿洛尔卡西南剖面（La Torrecilla 剖面）采集，以表征其深度特征。鉴于站点之间的距离较短，一些站点对被同时记录，其中只有一个磁传感器。为了正确理解产生的阻抗（称为站间阻抗）及其反演的影响，我们使用合成模型来比较阻抗和站间阻抗并分析相应的反演结果，连同准阻抗的反演（站间阻抗的反演，将它们视为阻抗）。结果对磁传感器的位置和下方的电阻率很敏感，但通常在反演中使用准阻抗可以被认为是有效的程序。通过反演获得的 2D 和 3D 电阻率模型使我们能够补充之前的 ERT 模型，并代表主断层泥在深度上的延续，显示其向东南延伸。