We estimated Moho depths from data recorded by permanent and temporary broadband seismic stations deployed in northern Baja California, Mexico, using the receiver function technique. This region is composed of two subregions of contrasting geological and topographical characteristics: the Peninsular Ranges of Baja California (PRBC), a batholith with high elevations (up to 2,600 m); and the Mexicali Valley (MV) region, a sedimentary environment close to sea level. Crustal thickness derived from the P-to-S converted phases at 29 seismic stations were analyzed in three profiles: Two that cross the two subregions, in ∼W-E direction, and the third one that runs over the PRBC in a N-S direction. For the PRBC, Moho depths vary from 35 to 45 km, from 33°N to 32°N; and from 30 to 46 km depth from 32°N to 30.5°N. From a profile that crosses the subregions in the W-E direction; Moho depths vary from 45 to ∼34 km under western and eastern PRBC, respectively; with an abrupt change of depth under the Main Gulf Escarpment (30°), from ∼32 to 30 km; and depths of 17–20 km under the MV. Moho depths of the profile in an ∼ W-E direction at ∼31.5°N are from ∼30 to 40 km, under topography that increases from 0 to 2,600 m; and became shallower (16 km depth) as the profile reaches the Gulf of California. These results show that deeper Moho is related to higher elevations with an abrupt change under the Main Gulf Escarpment, except for western PRBC where the Moho depth is not simply reflecting isostatic compensation.

中文翻译：

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墨西哥下加利福尼亚州北部莫霍面深度，来自远震接收器功能

我们使用接收器函数技术，根据部署在墨西哥下加利福尼亚州北部的永久和临时宽带地震台站记录的数据估计莫霍面深度。该地区由两个地质和地形特征对比鲜明的次区域组成：下加利福尼亚半岛山脉 (PRBC)，一个高海拔（高达 2,600 m）的基岩；墨西卡利河谷 (MV) 地区，一个接近海平面的沉积环境。从P到S得出的地壳厚度在三个剖面中分析了 29 个地震台站的转换相位：两个在〜WE 方向上穿过两个子区域，第三个在 NS 方向上穿过 PRBC。对于 PRBC，莫霍面深度从 35 到 45 公里不等，从 33°N 到 32°N；32°N 至 30.5°N 深度 30 至 46 公里。从沿 WE 方向穿过子区域的剖面；在 PRBC 西部和东部，莫霍面深度分别从 45 到 34 公里不等；主海湾悬崖下的深度突然变化（30°），从 32 公里到 30 公里；和 MV 下 17-20 公里的深度。在～31.5°N ～ WE 方向的剖面莫霍面深度为～30 至 40 km，地形从 0 增加到 2,600 m；并随着剖面到达加利福尼亚湾而变浅（16 公里深）。