German and Russian scientists say they have documented the life cycle of a volcano for the first time, revealing that it has a kind of “memory”.
The volcano in question is Bezymianny, an active stratovolcano on the Kamchatka peninsula in eastern Russia which suffered a collapse in its eastern sector back in 1956.
Photographs of helicopter overflights from Soviet times have now been analysed alongside more recent satellite drone data using state-of-the-art methods at the German Research Centre for Geosciences (GFZ) in Potsdam.
The series shows the rebirth of the volcano after its collapse.
Writing in the journal Nature Communications Earth and Environment, the researchers say the initial re-growth began at different vents about 400 metres apart.
After about two decades, the activity increased and the vents slowly moved together. After another three, the activity concentrated on a single vent, which allowed the growth of a new and steep cone.
The team determined an average growth rate of 26,400 cubic metres per day – equivalent to about a thousand large dump trucks.
The results, they say, make it possible to predict when the volcanic building may once again reach a critical height, and possibly collapse again under its own weight.
The numerical modelling also explains the changes in stress within the volcanic rock and thus the migration of the eruption vents, says GFZ volcanologist and co-author. Thomas Walter.
“Our results show that the decay and re-growth of a volcano has a major impact on the pathways of the magma in the depth. Thus, disintegrated and newly grown volcanoes show a kind of memory of their altered field of stress”.
For future prognosis, Walter adds, this means that the history of birth and collapse must be included to be able to give estimates about possible eruptions or imminent collapses.