Moho morphology in orogens provides important constraints on the rheology and density structure of the crust and underlying mantle. Previous studies of Moho geometry in the northern Canadian Cordillera (NCC) using very sparse seismic data have indicated a flat and shallow (⁠∼30–35 km⁠) Moho, despite an average elevation of >1000 m above sea level attributable to increased thermal buoyancy and lower crustal flow due to elevated temperatures. We estimate Moho depth using receiver functions from an expanded dataset incorporating 173 past and recently deployed broadband seismic stations, including the EarthScope Transportable Array, Mackenzie Mountains transect, and other recent deployments. We determine Moho depths in the range 27–43 km, with mean and standard deviations of 33.0 and 3.0 km, respectively, and note thickened crust beneath high‐elevation seismogenic regions. In the Mackenzie Mountains, thicker crust is interpreted as due to crustal stacking from thrust sheet emplacement. The edge of this region of thickened crust is interpreted to delineate the extent of the former Laurentian margin beneath the NCC and is associated with a transition from thrust to strike‐slip faulting observed in regional seismicity. More geographically extensive seismograph deployments at EarthScope Transportable Array density and scale will be required to further extend crustal‐scale and lithosphere‐scale imaging in western Canada.

中文翻译：

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加拿大北部山脉的莫霍面变化

造山带中的莫霍面形态对地壳和下地幔的流变学和密度结构提供了重要的限制。以前使用非常稀疏的地震数据对加拿大北部山脉山脉（NCC）进行的Moho几何研究表明，尽管平均海拔高于1000 m是由于热量增加，但Moho却是平坦而浅的（⁠〜30-35km⁠）由于温度升高而产生的浮力和地壳流量降低。我们使用接收器函数从包含173个过去和最近部署的宽带地震台站的扩展数据集中估算Moho深度，包括EarthScope可移动阵列，Mackenzie山样带和其他近期部署。我们确定Moho深度在27-43 km之间，均值和标准差分别为33.0和3.0 km，并注意高海拔地震发生区下方的地壳变厚。在Mackenzie山脉中，较厚的地壳被解释为是由于冲断片的堆积引起的地壳堆积。地壳增厚区域的边缘被解释为划定了NCC下方的前Laurentian边缘的范围，并与区域地震活动中观察到的从逆冲断层到走滑断层的过渡有关。为了进一步扩大加拿大西部的地壳规模和岩石圈规模的成像，将需要在EarthScope可移动阵列的密度和规模上进行更广泛的地域地震仪部署。地壳增厚区域的边缘被解释为划定了NCC下方的前Laurentian边缘的范围，并与区域地震活动中观察到的从逆冲断层到走滑断层的过渡有关。为了进一步扩大加拿大西部的地壳规模和岩石圈规模的成像，将需要在EarthScope可移动阵列的密度和规模上进行更广泛的地域地震仪部署。地壳增厚区域的边缘被解释为划定了NCC下方的前Laurentian边缘的范围，并与区域地震活动中观察到的从逆冲断层到走滑断层的过渡有关。为了进一步扩大加拿大西部的地壳规模和岩石圈规模的成像，将需要在EarthScope可移动阵列的密度和规模上进行更广泛的地域地震仪部署。