Glaciers may be a powerful tool for monitoring some volcanoes, according to a new study that shows for the first time how the height of glaciers at volcanoes can signal future disturbances, including the threat of eruption. Monitoring volcanoes is dangerous, expensive and logistically difficult. Approximately 250 volcanoes worldwide are covered by glaciers, which poses an additional challenge when it comes to monitoring.

But scientists have now shown how glaciers can provide important clues about the behavior of volcanoes by sensing their temperatures. A team led by scientists from the University of Aberdeen’s School of Earth Sciences studied 600 glaciers in South America and found that glaciers around volcanoes were limited to higher altitudes, while glaciers around volcanoes reached lower altitudes.

This is because rising temperatures on or near the volcano cause more ice to melt, leaving glaciers at higher elevations.

Before a period of unrest, a volcano’s temperature often rises, and by establishing a connection between volcanoes and the glaciers above them, scientists can now determine which volcanoes have higher temperatures and more likely eruptions and can therefore prioritize monitoring. It can be used even when other monitoring methods are not possible.

Professors Matteo Spagnolo and Brice Rhee from the university’s Faculty of Earth Sciences led the research together with colleagues from other universities. Their findings were published in a journal Geology. Professor Spagnolo said: “Volcanoes are one of the greatest geological hazards on Earth, causing more than 500 human deaths each year and huge financial costs estimated at billions of dollars.

“Ground-ground and remote sensing techniques play a critical role in monitoring volcanoes, but there are challenges in monitoring the 16% of the Earth’s glacier-covered volcanoes, and they are often located in remote areas – particularly because the glaciers themselves make monitoring access difficult.

“Among other signs, the temperature of volcanoes generally increases five or more years before the eruption begins. Our study is the first time the quantitative relationship between glacier height and volcano temperature has been established over a large area, creating exciting monitoring opportunities.”

Professor Rhee added: “By establishing a relationship between volcano temperature and glacier height, by analyzing glaciers we can identify volcanoes that have higher temperatures and are likely to erupt in the near future, and therefore where additional remote sensing efforts can be applied to ground monitoring. These should be targeted and prioritized.”

“This technique can be used to supplement existing monitoring efforts or may be a better option if other monitoring methods are not possible.” Source