Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawaii, USA.
Department of Information and Computer Sciences, University of Hawai'i at Mānoa, Honolulu, Hawaii, USA.
Geobiology. 2024 Mar-Apr;22(2):e12591. doi: 10.1111/gbi.12591.
Studies of the effects of volcanic activity on the Hawaiian Islands are extremely relevant due to the past and current co-eruptions at both Mauna Loa and Kīlauea. The Big Island of Hawai'i is one of the most seismically monitored volcanic systems in the world, and recent investigations of the Big Island suggest a widespread subsurface connectivity between volcanoes. Volcanic activity has the potential to add mineral contaminants into groundwater ecosystems, thus affecting water quality, and making inhabitants of volcanic islands particularly vulnerable due to dependence on groundwater aquifers. As part of an interdisciplinary study on groundwater aquifers in Kona, Hawai'i, over 40 groundwater wells were sampled quarterly from August 2017 through March 2019, before and after the destructive eruption of the Kīlauea East Rift Zone in May 2018. Sample sites occurred at great distance (~80 km) from Kīlauea, allowing us to pose questions of how volcanic groundwater aquifers might be influenced by volcanic subsurface activity. Approximately 400 water samples were analyzed and temporally split by pre-eruption and post-eruption for biogeochemical analysis. While most geochemical constituents did not differ across quarterly sampling, microbial communities varied temporally (pre- and post-eruption). When a salinity threshold amongst samples was set, the greatest microbial community differences were observed in the freshest groundwater samples. Differential analysis indicated bacterial families with sulfur (S) metabolisms (sulfate reducers, sulfide oxidation, and disproportionation of S-intermediates) were enriched post-eruption. The diversity in S-cyclers without a corresponding change in sulfate geochemistry suggests cryptic cycling may occur in groundwater aquifers as a result of distant volcanic subsurface activity. Microbial communities, including taxa that cycle S, may be superior tracers to changes in groundwater quality, especially from direct inputs of subsurface volcanic activity.
由于莫纳罗亚和基拉韦厄火山的过去和当前共同喷发，对夏威夷群岛火山活动影响的研究极其相关。夏威夷大岛是世界上监测地震最频繁的火山系统之一，最近对大岛的调查表明火山之间存在广泛的地下连通性。火山活动有可能将矿物污染物添加到地下水生态系统中，从而影响水质，并使火山岛的居民特别脆弱，因为他们依赖地下水含水层。作为对夏威夷科纳地下水含水层的一项跨学科研究的一部分，2017 年 8 月至 2019 年 3 月，在 2018 年 5 月基拉韦厄东裂谷带破坏性喷发之前和之后，每季度对 40 多个地下水井进行了采样。采样地点与基拉韦厄火山相距甚远（约 80 公里），这使我们能够提出有关火山地下水含水层如何受到火山地下活动影响的问题。大约 400 个水样进行了分析，并根据喷发前后的时间进行了生物地球化学分析。虽然大多数地球化学成分在季度采样中没有差异，但微生物群落随时间变化（喷发前和喷发后）。当在样本中设置盐度阈值时，在最新鲜的地下水样本中观察到最大的微生物群落差异。差异分析表明，具有硫 (S) 代谢作用的细菌家族（硫酸盐还原菌、硫化物氧化和 S 中间体的歧化）在喷发后富集。在硫酸盐地球化学没有相应变化的情况下，S 循环者的多样性表明，由于遥远的火山地下活动，可能会在地下水含水层中发生隐式循环。微生物群落，包括循环 S 的分类群，可能是地下水质量变化的更好示踪剂，尤其是由于地下火山活动的直接输入。
