Structure of Active Fumarole Fields: An Integrated Geophysical and Geochemical Approach

中高温孔隙流场的物理模型表明，在大多数情况下，质量流将对孔隙温度产生强烈的控制作用。PI计划持续监测温度和质量流量，以在三个活跃字段中测试这种关系。这些油田位于墨西哥的火山科利马、哥斯达黎加的波阿斯和哥伦比亚的加莱拉斯，并包括一系列热液体系。在Galeras，年轻的陨石坑可能是岩浆和深循环陨石流体强制对流的表现。在波阿斯，浅层自由对流可能占主导地位的流动。科利马代表了介于其他两个之间的流动状态。温度、质量流和地球化学的时间尺度和相互依赖性在这些系统之间会有所不同。地球化学数据，特别是稳定的和宇宙成因的同位素，将有助于更清楚地区分浅层自由对流和相对较深或岩浆源的强迫对流所产生的对流。这些运输机制的差异是重要的理解和解释观察到的变化在活火山的火山口活动。

Physical models of flow in medium- and high-temperature fumarole fields suggest that mass flow will exert a strong control on fumarole temperature in most circumstances. The PIs plan to monitor temperature and mass flow continuously to test this relationship in three active fields. These fields are on Volcano Colima, Mexico, Poas, Costa Rica, and Galeras, Colombia, and encompass a range of hydrothermal regimes. At Galeras, young fumaroles are likely a manifestation of forced convection of magmatic and deeply circulating meteoritic fluids. At Poas, shallow free convection likely dominates flow. Colima represents a flow regime intermediate between the other two. The time scales and interdependence of temperature, mass flow, and geochemistry will vary between these systems. Geochemical data, particularly stable and cosmogenic isotopes, will help distinguish more clearly between shallow free convection and fumaroles fed by forced convection from relatively deep or magmatic sources. Differentiation of these transport mechanisms is important to the understanding and interpretation of observed changes in fumarole activity at active volcanoes.