Development of an Ultra-violet Digital Camera for Volcanic S02 Imaging

火山系统的脱气行为是它所产生的地震活动的一个组成部分。2002年1月，蒙特塞拉特火山观测站（MVO）在Soufriere Hills火山（SHV）安装了一个由两台差分光学吸收光谱仪组成的新的气体监测系统；这些新的传感器可以在一个工作日内每1-6分钟从排放的羽流中连续检索二氧化硫光谱和气体通量值。最初的工作将集中在校准二氧化硫脱气和地震活动的时间，以及从地下和近地表运动中释放的二氧化硫通量变化与地震触发因素的相关性。在MVO地震台网数据库的基础上，将为SHV地震事件开发一个震级。该震级表将用于约束震级-频率关系的SHV事件（长周期和混合地震，岩落）。将地震活跃期的SO2数据与地震资料相结合，将火山SO2通量与地震事件类型、震级、震幅和时间进行关联。高时间分辨率数据集的合并将有助于更好地了解岩浆动力学，评估当前的挥发性和地震特征理论，并通过将气体和地震行为与高度活跃的火山系统的前兆活动联系起来，提高喷发预测能力。随着快速二氧化硫测量系统被纳入其他火山监测工作，该项目将有助于建立最有效利用气体通量数据的基线趋势和方法。这项工作还通过探索从自动化气体通量数据中获得气体警报的可能性，支持MVO的危害缓解基础设施。

The degassing behavior of a volcanic system is an integral part of the seismicity it generates. In January 2002, the Montserrat Volcano Observatory (MVO) installed a new gas monitoring system at Soufriere Hills Volcano (SHV) composed of two Differential Optical Absorption Spectrometers; these new sensors allow continuous retrieval of sulfur dioxide spectra from the emitted plume, and gas flux values every 1-6 minutes over the course of a working day. Initial efforts will focus on calibrating the timing of SO2 degassing and seismic activity, and correlation of changes in emitted SO2 fluxes to seismic triggers from subsurface and near-surface motions. A magnitude scale will be developed for SHV seismic events, based on the MVO seismic network database. This magnitude scale will be used to constrain magnitude-frequency relationships for SHV events (long-period and hybrid earthquakes, and rockfalls). Volcanic SO2 fluxes will be correlated to seismic event type, magnitudes, seismic amplitude and timing by merging the SO2 and seismic data over active periods for SHV.Merging of high temporal resolution datasets will allow better understanding of magma dynamics and evaluate current theories of volatile and seismic characteristics, and improved eruption prediction capabilities, by linking gas and seismic behavior to precursory activities in a highly active volcanic system. This project will help establish baseline trends and methodologies for most effective uses of gas flux data, as rapid SO2 measurement systems are incorporated into other volcano monitoring efforts. This work also supports MVO's hazard mitigation infrastructure, through exploration of the potential for a gas alert derived from automated gas flux data.