RAPID: The 2012-2013 eruptions of Copahue volcano, Argentina

火山喷发影响全球气候，地热能来源于火山热，许多矿体是通过火山作用形成的。活火山活动提供了一种研究地球如何运转的直接手段。阿根廷科帕韦火山（37.8华氏度，71华氏度）于2012年12月22日再次喷发，至今仍处于低喷发状态。这座火山喷发出成分极端的热液，这些热液直接来自1-2公里深的一个非常酸和热的岩浆热液系统。这种流体被认为是造成浅成热液矿床的原因。形成斑岩矿体的金、银、铅和其他过量系统。这些流体的组成随着火山活动状态的变化而变化：浅层侵入导致更热、更浓的流体被排出到周围环境中，使当地的河流和湖泊酸化。在火山活动期间监测这些水流的组成有助于开发火山喷发预测工具。2000年科帕韦火山喷发期间收集的流体数据显示，有几个参数表明，在火山喷发之前，有浅层岩浆侵入。2012-2013年的爆发期为测试和完善这些想法提供了一个理想的场所。一个在南部夏季分层的大型冰湖包含了底部水域爆发前流体的成分信息，而地表水则代表了最近的输入。在4月下旬季节翻转之前取样是必要的，那时水柱均质化，所有详细信息都丢失了。来自阿根廷、意大利和美国的科学家将于2013年3月召开研讨会，讨论火山喷发、其危害和监测工作，对科帕韦火山有着广泛研究记录的美国科学家应参与并为该活动做出贡献。这些研究活动将有助于火山喷发监测和预测科学，这对全世界许多生活在火山上的人都是有益的。它还促进了阿根廷当地科学家和美国科学家之间的合作。当地政府计划在科帕韦附近建立一个小型火山观测站，但需要数据来做出最好的监测参数选择。除了双边合作外，两名美国女学生（一名本科生，一名研究生）将在现场收集样本，并在卫斯理大学分析这些样本，以备其大四和硕士论文之用。对美国学生进行活火山研究方面的培训对于保持美国在评估自然灾害和自然资源形成方面的科学领导地位非常重要。

Volcanic eruptions impact global climate, geothermal energy is derived from volcanic heat, and many ore bodies are formed through volcanic processes. Active volcanism provides a direct means to study how our planet functions. Copahue volcano in Argentina (37.8 oS, 71 oW) started a new eruption on December 22, 2012 and is still active at low level today. This volcano emits compositionally extreme hydrothermal fluids that derive directly from a very acid and hot magmato-hydrothermal system at 1-2 km depth. Such fluids are thought to be responsible for epithermal ore deposits, eg. gold, silver and lead and may overly systems that form porphyry ore bodies. The composition of these fluids changes with the state of activity of the volcano: shallow intrusions lead to hotter and more concentrated fluids that are expelled into the ambient and acidify local rivers and lakes. Monitoring the composition of such streams during a period of volcanic activity aids in developing tools for eruption forecasting. Data collected on fluids during the 2000 eruption of Copahue suggested several parameters that indicate the intrusion of shallow magma prior to an eruption. The 2012-2013 eruptive period provides an ideal venue to test and refine these ideas. A large glacial lake that is stratified during the austral summer contains compositional information of the pre-eruptive fluids in the bottom waters, whereas the surface waters represent recent inputs. It is imperative to sample the lake prior to its seasonal overturn in late April, when the water column homogenizes and all detailed information is lost. A workshop with scientists from Argentina, Italy and the USA is convened for March 2013 to discuss the eruption, its hazards and monitoring efforts, and US scientists with an extensive research record on Copahue should participate and contribute to this event. The research activities will contribute to the science of eruption monitoring and forecasting, which is beneficial for many people living on volcanoes worldwide. It also promotes collaboration between local Argentinian and US scientists. The local authorities plan to establish a small volcano observatory near Copahue, but data are needed to make the best possible choices of monitoring parameters. Besides the bilateral collaboration, two female US students (one undergraduate, one graduate) will collect samples on site and analyze those at Wesleyan University for their senior and MA theses. Training of US students in research on active volcanoes is important to keep the USA in a scientific leadership position with respect to assessments of both natural hazards and formation of natural resources.