Steamboat Geyser in Norris Geyser Basin in the northwestern part of Yellowstone National Park is the highest erupting active geyser in the world with jets of fluids observed to be as high as 115 m. Steamboat eruptions increased from 11 between 2000 and 2017 to 131 between 19 April 2018 and 21 February 2021. Recurrence intervals are now irregular, averaging 8 ± 4 (1σ) days between each event. To examine whether changes in gas emissions could serve as eruption precursors for Steamboat, on June 12, 2019 we made continuous measurements of the diffuse emissions of methane (CH₄) and carbon dioxide (CO₂) ~30 m from the geyser before and after a single eruption event. These results showed steady fluxes during the 2.5 h, except for a sharp decrease of 58% for CH₄ and 50% for CO₂ 10–25 min before the eruption. These precursor measurements were followed by the eruption and 3.5 h of measurements that showed fluxes quickly returning to previously measured values. Similarly, precursor carbon isotope measurements of CH₄ (δ¹³C-CH₄) and CO₂ (δ¹³C-CO₂) were both distinctly lighter (−35.7 ± 2.1‰ and −6.2 ± 0.4‰, respectively) than the non-precursor measurements (−27.5 ± 0.3‰; −3.9 ± 0.1‰, respectively) that reflected a deep source. This suggests that the diffuse emissions of deeply sourced gas was interrupted near the commencement of this one observed eruption at Steamboat.

黄石国家公园西北部诺里斯间歇泉盆地的汽船间歇泉是世界上喷发量最高的间歇泉，其喷射流高达115 m。汽船的喷发次数从2000年至2017年的11次增加到2018年4月19日至2021年2月21日的131次。现在复发间隔是不规则的，每个事件之间的平均间隔为8±4（1σ）天。为了检查气体排放的变化是否可以作为汽船的喷发前兆，我们在2019年6月12日前后对间歇喷泉中甲烷（CH ₄）和二氧化碳（CO ₂）的弥散排放进行了连续测量，测量距离约为30 m一次喷发事件。这些结果表明，在2.5 h内通量稳定，但CH ₄急剧下降了58％。喷发前10–25分钟注入50％的CO ₂。在这些前体测量值之后，进行喷发和3.5小时的测量值，这些测量值显示通量迅速返回到先前的测量值。同样，CH的前体碳同位素测量₄（δ ¹³ C-CH ₄）和CO ₂（δ ¹³ C-CO ₂）均明显更轻（-35.7±2.1‰和-6.2±0.4‰，分别地）比非-反映深源的前体测量值（分别为-27.5±0.3‰；-3.9±0.1‰）。这表明，在汽船上观察到的一次喷发开始之前，深层气体的扩散排放就被中断了。