Vailulu'u seamount, Samoa: Life and death on an active submarine volcano
Vailulu'u seamount, Samoa: Life and death on an active submarine volcano
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DOI：
10.1073/pnas.0600830103
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发表时间：
2006-04-25
影响因子：
11.1
通讯作者：
Young, CM
中科院分区：
文献类型：
--
作者：
Staudigel, H;Hart, SR;Young, CM
对萨摩亚热点地区的潜水勘探发现了一个新的 300 米高的火山锥，名为 Nafanua，位于 Vailulu'u 海山的山顶火山口。 Nafanua 在不到 4 年的时间里从 1,000 米深的火山口底部生长出来，并可以在几十年内到达海面。通风口充满了粘稠的颗粒悬浮液和明显有毒的液体，这些液体与从火山口裂口进入的海水混合在一起。低温喷口在许多地方形成氧化铁烟囱，并在纳法努阿形成高达 1 米厚的热液铁絮凝层。北部护城河（水深 945 米）的高温（81 摄氏度）热液喷口产生酸性流体（pH 2.7），并伴随上升的（可能）液态二氧化碳液滴。纳法努阿山顶喷口区域栖息着大量鳗鱼（Dysommina rugosa），它们以中层水域的虾为食，这些虾可能是由火山山顶和边缘的反气旋流集中的。新火山周围的护城河和火山口底部散落着死去的后生动物，这些动物显然是因暴露于热液排放而死亡的。耐酸多毛类动物（Polynoidae）生活在这种环境中，显然以腐烂的鱼尸体中的细菌为食。瓦卢卢乌是一座不可预测且非常活跃的水下火山，存在潜在的长期火山危害。尽管鳗鱼在纳法努阿山顶的热液喷口中繁衍生息，但火山口其他地方的热液喷口却导致大量死亡。矛盾的是，为鳗鱼提供食物的反气旋洋流也可能将各种游动动物集中在有毒热液的死亡陷阱中。
Submersible exploration of the Samoan hotspot revealed a new, 300-m-tall, volcanic cone, named Nafanua, in the summit crater of Vailulu'u seamount. Nafanua grew from the 1,000-m-deep crater floor in < 4 years and could reach the sea surface within decades. Vents fill Vailulu'u crater with a thick suspension of particulates and apparently toxic fluids that mix with seawater entering from the crater breaches. Low-temperature vents form Fe oxide chimneys in many locations and up to 1-m-thick layers of hydrothermal Fe floc on Nafanua. High-temperature (81 degrees C) hydrothermal vents in the northern moat (945-m water depth) produce acidic fluids (pH 2.7) with rising droplets of (probably) liquid CO2. The Nafanua summit vent area is inhabited by a thriving population of eels (Dysommina rugosa) that feed on midwater shrimp probably concentrated by anticyclonic currents at the volcano summit and rim. The moat and crater floor around the new volcano are littered with dead metazoans that apparently died from exposure to hydrothermal emissions. Acid-tolerant polychaetes (Polynoidae) live in this environment, apparently feeding on bacteria from decaying fish carcasses. Vailulu'u is an unpredictable and very active underwater volcano presenting a potential long-term volcanic hazard. Although eels thrive in hydrothermal vents at the summit of Nafanua, venting elsewhere in the crater causes mass mortality. Paradoxically, the same anticyclonic currents that deliver food to the eels may also concentrate a wide variety of nektonic animals in a death trap of toxic hydrothermal fluids.