Nature. 1990 Mar 1;344(6261):51-3. doi: 10.1038/344051a0.
RECENT investigations on Mount Etna (Sicily)(1-3) have revealed that volcanoes may release abundant carbon dioxide not only from their active craters, but also from their flanks, as diffuse soil emanations. Here we present analyses of soil gases and air in water wells on Vulcano Island which provide further evidence of such lateral degassing. Nearly pure carbon dioxide, enriched in helium and radon, escapes from the slopes of the Fossa active cone, adding a total output of 30 tonnes per day to the fumarolic crater discharge ( 180 tonnes CO(2) per day). This emanation has similar He/CO(2) and (13)C/(12)C ratios to those of the crater fumaroles (300%ndash;500 degrees C) and therefore a similar volcanic origin. Gases rich in carbon dioxide also escape at sea level along the isthmus between the Fossa and Vulcanello volcanic cones, but their depletion in both He and (13)C suggests a distinct source. Diffuse volcanic gas emanations, once their genetic link with central fumarole degassing has been demonstrated, can be used for continuous volcano monitoring, at safe distances from active craters. Such monitoring has been initiated at Vulcano, where soil and well emanations of nearly pure CO(2) themselves represent a threat to the local population.
最近在西西里岛埃特纳火山（Mount Etna）的研究（1-3）表明，火山不仅可能从其活跃的火山口，而且还可能从其侧面（如漫散土壤释放）释放大量的二氧化碳。在这里，我们分析了武尔卡诺岛上水井中的土壤气体和空气，这些分析为这种侧向脱气作用提供了进一步的证据。几乎纯净的二氧化碳，富含氦气和氡气，从 Fossa 火山口的斜坡逸出，每天向喷气孔排放（每天 180 吨二氧化碳）增加了 30 吨的总排放量。这种逸出物与喷气孔（300%-500°C）中的火山气体具有相似的 He/CO2 和 (13)C/(12)C 比值，因此具有相似的火山起源。在 Fossa 和 Vulcanello 火山锥之间的地峡处，海平面也有富含二氧化碳的气体逸出，但它们在 He 和 (13)C 上的耗尽表明存在不同的来源。一旦证明了弥散火山气体释放与中心喷气孔脱气的成因联系，就可以在远离活跃火山口的安全距离处，对其进行连续的火山监测。这种监测已经在武尔卡诺火山开始实施，那里几乎纯净的 CO2 的土壤和井喷排放本身就对当地居民构成了威胁。
