Surface Nuclear Magnetic Resonance (NMR) Soundings on Drained Lake Basins, North Slope, Alaska, 2015-2016

This dataset contains surface nuclear magnetic resonance (NMR) geophysical soundings acquired on five drained lake basins and two control sites on terrestrial upland permafrost (primary surface sites) during spring fieldwork 2015 - 2016. Measurements were made using a Vista Clara GMR (Mukilteo, Washington, Unites States of America) with a circle coincident transmitter/receiver loop either 75 meters (m) or 90 m diameter. Raw data for nine soundings are provided in the proprietary format created by the instrument, and results after processing and inversion with the GMR software (Mukilteo, Washington, Unites States of America; Walsh, 2008) are included as tabular values. The purpose of this research is to identify unfrozen bodies or taliks below drained lake basins to better understand the process of permafrost aggradation after lake drainage. Surface NMR is the only non-invasive geophysical method that is able to directly detect unfrozen water as it measures the response of hydrogen protons on liquid water (Walsh, 2008).
Walsh, D. O. (2008). Multi-channel surface NMR instrumentation and software for 1D/2D groundwater investigations. Journal of Applied Geophysics, 66(3–4), 140–150. https://doi.org/10.1016/j.jappgeo.2008.03.006

本数据集包含2015-2016年春季野外作业期间，在5个疏干湖盆以及2处位于陆地高地永久冻土区的原生地表对照站点，所获取的地面核磁共振（surface nuclear magnetic resonance, NMR）地球物理测深数据。本次测量使用美国华盛顿州穆基尔蒂奥市Vista Clara公司生产的GMR仪器，采用直径75米或90米的圆形重合式发射/接收线圈。9组测深的原始数据以该仪器自带的专有格式提供，同时附带使用该GMR软件（美国华盛顿州穆基尔蒂奥市；Walsh, 2008）完成处理与反演后的结果，以表格值形式呈现。

本研究旨在识别疏干湖盆下方的未冻水体与融穿体（taliks），以更深入地理解湖盆疏干后永久冻土的加积过程。地面核磁共振是目前唯一可直接检测未冻水的非侵入式地球物理方法，其原理是检测液态水中氢质子的响应（Walsh, 2008）。

Walsh, D. O. (2008). 用于1D/2D地下水调查的多通道地面核磁共振仪器与软件. 《应用地球物理学杂志》, 66(3–4), 140–150. https://doi.org/10.1016/j.jappgeo.2008.03.006