Measuring incipient lava dome collapse

在一些火山，熔岩堆积在喷口上方，形成一个熔岩穹顶。这样的穹顶容易坍塌，并产生危险的火山碎屑流和爆炸，因为内部高温和加压的熔岩突然暴露出来。因此，了解这些坍塌可能发生的方式以及重要的时间是至关重要的，特别是对蒙特塞拉特火山天文台负责监测苏弗里尔山火山正在进行的活动的科学家来说。关于苏弗里尔山坍塌的原因，有很多种理论，但有两个因素值得注意。首先，暴雨通常是坍塌的先兆，其次，熔岩到达地表的管道经常发生变化。我们计划开发一种方法来测量这种“管道变化”，以便对坍塌发出一些警告。我们已经开发了一种用于火山的新型便携式雷达仪器，名为AVTIS(全天候火山地形成像传感器)，可以通过云层昼夜测量熔岩穹顶的形状和温度。这项技术是火山的独特应用。这类仪器的进一步开发将使我们能够测量与熔岩穹顶坍塌触发重新铺设管道有关的熔岩挤出速度和位置的变化。这些新的观测数据将与天文台从与这一过程相关的小地震中获得的数据结合起来。将建立一个隐藏在视野之外的重新管道的计算机模型，并运行以帮助理解该过程如何工作的机制。为了实现必要的测量，将建造一台更快、更准确、能够在固定位置自主操作的新仪器。其目标是拥有一台有效地一直处于开启状态的仪器，将数据发送回天文台。此外，我们将升级现有的仪器，从不同的角度使用它，以捕捉从固定仪器上看不到的穹顶部分。

At some volcanoes lava piles up above the vent to produce a lava dome. Such domes are prone to collapse and produce dangerous pyroclastic flows and explosions as the hot and pressurized interior lava is suddenly exposed. So understanding how, and importantly, when, these collapses are likely to occur is of prime importance, specifically to the scientists at the Montserrat Volcano Observatory who are responsible for monitoring the ongoing activity of the Soufriere Hills Volcano. There are many theories as to what causes the collapses at Soufriere Hills, but two factors stand out. Firstly, heavy rainfall often precedes a collapse and secondly, there is often a change in the plumbing that the lava uses to reach the surface. We plan to develop a method of measuring this 'change in plumbing' to give some warning of collapse. We have already developed a new, portable, radar-based instrument for use on volcanoes called AVTIS (All-weather Volcano Topography Imaging Sensor) that can measure the shape and temperature of the lava dome day and night and through cloud. This technology is a unique application for volcanoes. Further development of this type of instrument will enable us to measure changes in the rate and location of lava extrusion associated with the collapse-triggering re-plumbing of the lava dome. These new observations will be coupled with the observatory's data from small earthquakes associated with this process. A computer model of the re-plumbing that is hidden from view will be constructed and run to help understand the mechanics of how the process works. In order to achieve the necessary measurements a new instrument will be built that is faster, more accurate and can operate autonomously from a fixed position. The aim is to have an instrument that is effectively on all the time, sending data back to the Observatory. In addition, we will upgrade the current instrument and use it from different viewpoints, to capture the parts of the dome not visible from the fixed instrument.