Mount Etna, on the Italian island of Sicily, is one of the world's most active volcanoes, but this is not the only thing that worries scientists, as a recent study warned that the mountain is sliding into the sea which will cause a massive tsunami wave that could destroy much of the eastern Mediterranean.

“Etna is a big and heavy volcano, so gravity is pulling it down,” Morelia Urlaub, a research scientist at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany, and the study’s lead author, told NBC News MACH in an email. “It can spread more easily towards the sea as there is nothing to 'stop' it.”

Scientists have been recording the slow subsidence of Etna since the 1990s by 2 to 3 centimeters per year, according to the report published by researchers in October. Sensors have also detected movement in parts far from the center of volcanic activity, which excludes the hypothesis that magma is responsible.

“Etna’s flank movement poses a much greater hazard than previously thought,” the report read, noting that the risk of collapse might be underestimated at other volcanoes as well.

The researchers rule out the possibility of a rapid slide of the mountain into the sea, even though such collapses are common in the life cycle of volcanoes, especially with volcano such as Etna, estimated to be 500 thousand years old.

Despite the assurances of scientists, history has recorded cases of sudden and rapid volcanic eruptions. In May 1980, the northern side of Mount St. Helen, Washington, collapsed following an earthquake measuring 5.1 on the Richter scale, causing landslides that resulted in 57 deaths and economic losses Valued at $ 1.1 billion.