Cunningham K I, LaRock E J
U.S. Geological Survey, Denver, CO 80225-0046.
Health Phys. 1991 Oct;61(4):493-500. doi: 10.1097/00004032-199110000-00004.
Radon concentrations range from less than 185 to 3,515 Bq m-3 throughout Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico. Concentrations in the entrance passages and areas immediately adjacent to these passages are controlled by outside air temperature and barometric pressure, similar to other Type 2 caves. Most of the cave is developed in three geographic branches beneath the entrance passages; these areas maintain Rn levels independent of surface effects, an indication that Rn levels in deep, complex caves or mines cannot be simply estimated by outside atmospheric parameters. These deeper, more isolated areas are subject to convective ventilation driven by temperature differences along the 477-m vertical extent of the cave. Radon concentrations are used to delineate six microclimate zones (air circulation cells) throughout the cave in conjunction with observed airflow data. Suspected surface connections contribute fresh air to remote cave areas demonstrated by anomalous Rn lows surrounded by higher values, the presence of mammalian skeletal remains, CO2 concentrations and temperatures lower than the cave mean, and associated surficial karst features.
在新墨西哥州卡尔斯巴德洞穴国家公园的莱丘吉拉洞穴内，氡浓度范围在每立方米小于185贝克勒尔至3515贝克勒尔之间。入口通道以及紧邻这些通道的区域中的浓度受外界气温和气压控制，这与其他2类洞穴类似。洞穴的大部分区域是在入口通道下方的三个地理分支中形成的；这些区域的氡水平不受地表影响，这表明深部复杂洞穴或矿井中的氡水平不能简单地通过外界大气参数来估算。这些更深、更孤立的区域会受到沿洞穴477米垂直范围的温差驱动的对流通风影响。结合观测到的气流数据，利用氡浓度来划分整个洞穴的六个小气候区（空气环流单元）。疑似与地表相连的区域为偏远洞穴区域提供新鲜空气，这表现为较高值包围下的异常低氡值、哺乳动物骨骼遗骸的存在以及低于洞穴平均值的二氧化碳浓度和温度，还有相关的地表岩溶地貌。
