Icy thermometers: the use of glaciers to measure and monitor volcano temperature (HOT ICE)

Volcanic eruptions can destroy infrastructure, displace communities, disrupt air travel, damage businesses and, unfortunately too often, take people's lives. Thus, predicting volcanic eruptions has real-world life and death implications. Eruptions are often preceded by increased thermal anomalies, with volcanoes sometimes showing signs of large-scale thermal unrest for years prior to an eruption. These anomalies can be detected from satellite borne infrared sensors data such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Moderate Resolution Imaging Spectroradiometers (MODIS). One of the issues with remote sensing based monitoring of volcanoes, is the presence of glaciers, which can mask or distort the thermal signal. This is of particular relevance, given that ice-clad volcanoes can lead to some of the most dangerous eruptions (e.g. triggering of lahars). It is precisely these volcanoes that this proposal is targeting, through the development of a new, international, and truly multidisciplinary collaboration between UK glaciologists, and US and Italian volcanologists. This project will be paradigm shifting as it will use glaciers located on volcanoes as "thermometers", which could (and should) therefore be utilised to improve the monitoring of dangerous, ice-clad volcanoes. The novel idea is based on a preliminary study conducted by the UK team which indicates that the calculated equilibrium line altitude (cELA) of glaciers that sit on volcanoes (volcanic-glaciers from now on) is considerably higher than for proximal "normal" glaciers. This suggests that volcanic-glaciers are impacted by enhanced basal melting due to elevated geothermal heat flux from the underlying volcano such that their dimensions and elevation are restricted. The "hotter" the volcano, the higher the cELA of volcanic-glaciers.

In this project we will use state of the art remote sensing techniques developed by our international project partners to analyse ASTER and MODIS thermal imagery and extract the median thermal anomaly of ice-clad volcanoes in South America over a period of 19 years (2002-present). At the same time, we will calculate and analyse the cELA offset between volcanic-glaciers and proximal "normal" glaciers and correlate our results with the volcano thermal anomalies, using state of the art GIS tools developed by the UK team and applied to high resolution digital terrain models. The overall purpose of our project is to develop a much improved, robust, quantitative relationship between volcano thermal anomalies and volcanic-glacier cELAs. Our study aims to analyse all South American volcanoes, active at some point during the Holocene, that host one or more glaciers and also have proximal glaciers from which to extract the regional climate-controlled cELA. First, we will undertake a glaciological analysis to highlight the difference in cELA between volcanic glaciers and proximal, "normal" glaciers. We will then compare our glaciological results with an analysis of both the long- and short-term volcano thermal anomalies.

The purpose of this proposal is to foster a productive, international collaboration that will outlast the 2 year duration of the project. Results will constitute a paradigm-shift for the study of ice-clad volcanoes, such that glaciers will no longer be perceived as a hindrance to imaging of longer term thermal anomalies, but may represent a tool with which to measure them. The ultimate ambition is to improve the monitoring of volcano unrest, thus preventing loss of life for many people that live nearby dangerous ice-clad volcanoes.