Seismic and volcanic activity of mount Etna is correlated with the periodic movement of the Earth’s poles, which leads to small deformations of the earth’s surface. This conclusion was made by scientists from France and Italy, analyzing the data about the activity of mount Etna during the last decades. Article published in the journal Geophysical Research Letters.
The land is periodically deformed at small time scales due to several phenomena. The biggest impact of tidal forces that arise due to the impact of the Sun and moon on the Earth. This interaction leads to a deformation of the surface at about 30 centimeters per day. In addition, deformation of the surface by about a millimeter also cause periodic changes in length of day. Finally, another significant factor of deformation is the movement of the Earth’s poles. The fact that the axis of rotation of the Earth periodically shifts, in fact spiraling. This movement has a period length of about a year, and also beating with a period of 6.4 years, during which the amplitude of motion reaches a maximum.
The deformation of the surface of the Earth due to the movement of its poles depends on the latitude and the 45th parallel reaches a maximum of about a centimeter. This may seem an insignificant amount to affect large-scale processes, but studies showthat the deformation of the Earth due to the movement of poles affects the seismic processes.
Sebastien Lambert (Sebastien Lambert) from the University of Paris and Gianluca Sottili (Gianluca Sottili) from the University of Rome Sapienza decided to check, does the motion of the poles of the Earth in volcanic processes. As the object of study they chose mount Etna, for which there is a large amount of data. In addition, it is convenient because it is located on the 37th parallel, where the deformation from the movement of poles close to the maximum.