Submarine volcanism from satellite imagery

地球上的大多数火山都位于海底，但对海底火山喷发的直接观测非常罕见。这意味着海底火山活动的基本特征，包括喷发重复次数，在很大程度上仍然未知。虽然只有一小部分海底事件会导致海洋表面的变化，但其中许多都可以在卫星图像中检测到。当喷发的物质足够浅时，以及在喷发后的一段时间内，当火山物质可能刺激藻华时，都会发生局部的海洋颜色变化（例如，Urai &町田，2005）。突破海洋表面的喷发可以产生以蒸汽为主的独特的亚空中羽流（例如，Carey等人，2014年），以及新的，往往是短暂的，土地。最独特的卫星信号是由浮石筏产生的，浮石筏可以持续很长一段时间，传播很远，并对航运构成危险（Mantas等人，2011年）。过去从卫星图像观测海底喷发需要对卫星图像进行人工分析，而且仅限于个案研究。该项目将开发一种系统方法，从全球卫星数据集中探测海底火山事件。

The majority of the Earth's volcanoes are on the ocean floor, but direct observations of submarine eruptions are very rare. This means that fundamental characteristics of submarine volcanism, including eruption repeat times, remain largely unknown. Although only a small subset of submarine events will result in changes at the ocean surface, many of these are detectable in satellite imagery. Localised ocean colour change occurs both when erupted material is sufficiently shallow, and in the period after an eruption, when volcanic material may stimulate algal blooms (e.g., Urai & Machida, 2005). Eruptions that breach the ocean surface can produce distinctive sub-aerial plumes dominated by steam (e.g., Carey et al., 2014), as well as new, often transient, land. The most distinctive satellite signals are produced by pumice rafts, which can persist for long periods of time, travel great distances and pose a hazard to shipping (Mantas et al., 2011). Past observations of submarine eruptions from satellite imagery have required the manual analysis of satellite images and are limited to individual case studies. This project will develop a systematic approach to detecting submarine volcanic events from global satellite data sets.