Summary of data for gas in bubbles.

We investigate the water sources for a perennial spring, “Little Black Pond,” located at Expedition Fiord, Axel Heiberg Island in the Canadian High Arctic based on dissolved gases. We measured the dissolved O2 in the likely sources Phantom Lake and Astro Lake and the composition of noble gases (3He/4He, 4He, Ne,36Ar, 40Ar, Kr, Xe), N2, O2, CO2, H2S, CH4, and tritium dissolved in the outflow water and bubbles emanating from the spring. The spring is associated with gypsum-anhydrite piercement structures and occurs in a region of thick, continuous permafrost (400–600 m). The water columns in Phantom and Astro lakes are uniform and saturated with O2. The high salinity of the water emanating from the spring, about twice sea water, affects the gas solubility. Oxygen in the water and bubbles is below the detection limit. The N2/Ar ratio in the bubbles and the salty water is 89.9 and 40, respectively, and the relative ratios of the noble gases, with the exception of Neon, are consistent with air dissolved in lake water mixed with air trapped in glacier bubbles as the source of the gases. The Ne/Ar ratio is ~62% of the air value. Our results indicate that about half (0.47±0.1) of the spring water derives from the lakes and the other half from subglacial melt. The tritium and helium results indicate that the groundwater residence time is over 70 years and could be thousands of years.

本研究以溶解气体为分析手段，对加拿大高北极地区埃尔斯米尔岛（Axel Heiberg Island）探险峡湾（Expedition Fiord）内的常年泉眼‘小黑塘（Little Black Pond）’的补给水源展开调查。本研究测定了该泉眼疑似补给源——幻影湖（Phantom Lake）与天文湖（Astro Lake）中的溶解氧（O₂）含量，以及泉眼渗出水流与气泡中溶解的稀有气体（³He/⁴He、⁴He、氖（Ne）、³⁶Ar、⁴⁰Ar、氪（Kr）、氙（Xe））、氮气（N₂）、氧气（O₂）、二氧化碳（CO₂）、硫化氢（H₂S）、甲烷（CH₄）及氚的组成。该泉眼与石膏-硬石膏刺穿构造相关，所处区域发育厚层连续多年冻土（400~600米）。幻影湖与天文湖的水体垂向分布均一，且处于氧气饱和状态。该泉眼渗出水体的盐度约为海水的两倍，高盐度会对气体溶解度产生影响。渗出水体与气泡中的氧气含量均低于检测限。气泡与咸水的氮氩比（N₂/Ar）分别为89.9与40；除氖（Ne）外，其余稀有气体的相对比值与湖水中溶解空气的特征一致，表明气体来源为湖相溶解空气与冰川气泡中捕获空气的混合体。氖氩比（Ne/Ar）约为大气比值的62%。研究结果表明，该泉眼约一半（0.47±0.1）的水源来自上述两湖，另一半则源自冰川下融水。氚与氦同位素分析结果显示，地下水滞留时间超过70年，最长可达数千年。