A new study from the Cambridge University revealed that the deformation, or the amount of bulging and shrinking, could predict when a volcano will erupt.

The study, published in the journal Science Advances, showed that volcanoes tend to bulge or shrink as magma fills it up. These physical deformities in volcanoes could then serve as reliable indicator of future eruptions.

"We were interested in how the energy travelling between the sensors changes, whether it's getting faster or slower," said Clare Donaldson, a PhD student in Cambridge's Department of Earth Sciences, and the paper's first author, in a press release. "We want to know whether the seismic velocity changes reflect increasing pressure in the volcano, as volcanoes bulge out before an eruption. This is crucial for eruption forecasting."

For the study, the researchers combined a technique called "seismic noise interferometry" and geophysical measurements to measure the energy flowing through a volcano. Using a pair of sensors, the researchers were able to measure the seismic noise across the very active volcano Kīlauea in Hawaii. Because this seismic noise can be caused by everything, from earthquakes to waves in the ocean, a single sensor could read it as a random noise. However, a pair of sensors allows the energy pass between them. This made it possible for the researchers to isolate the seismic noise coming from the volcano.

Over a 4-year period, the researchers measured the seismic noise of the Kīlauea volcano. They then compared their measurements with the data that measured the tiny changes in the volcano's angle over the same period of time. Surprisingly, the researchers observed a good correlation between the speed at which the energy travel and the amount of bulging and shrinking in the rock.

The researchers noted that the result of their study could have a significant impact in predicting eruptions before they cause enormous damage. At present, seismologists monitor tiny earthquakes at volcanoes as indicator of possible eruption. The small quakes are produced when magma moves underground, cracking its way to solid rock. However, pre-existing pathways could allow magma to flow freely without creating tremors. With the result of the study, researchers could develop new methods of predicting possible eruptions using obvious deformities in the surface of the volcano.