The water they collected was not from a typical mountain stream or tropical wetland, but instead from the recently formed and historically unprecedented crater lake at the summit of Kīlauea Volcano. Further, the sample was not obtained by merely walking to the lakeshore and filling a bottle; its retrieval required the use of unoccupied aircraft systems (UAS)—drones in everyday language—operated by a pilot a kilometer away, high above on the crater rim.
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The association of surface water with enhanced explosive potential only heightens the need to sample and study the water regularly. But the lake is located at the base of a steep, unstable crater, hundreds of meters below the crater rim, which makes sampling on foot impossible and deployment of geophysical and geochemical sensors for continuous monitoring very difficult. Those steep sides, a lack of emergency landing sites, and the potential for dangerous volcanic gases to pool in the crater also make sampling via helicopter inadvisable.
From the article:
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