Volcanoes around the globe strengthen and weaken their activity remarkably synchronously and with a strict period. On the discovery of the planetary rate reported by scientists from the University of Bergen (UiB), Hawaii (University of Hawaii) and Sydney (University of Sydney).
The authors analyzed data on the frequency and strength of eruptions in all the major hot spots (Hotspot) for the entire Cenozoic. Geography included Hawaii, Easter Island, Iceland, Reunion, Tristan, the Galapagos Islands, Samoa, the Azores, Madeira, Canary Islands, Cape Verde Islands and St. Helena, Yellowstone and many other items.
So showed synchronized to scale the peaks of volcanic globe at levels 10, 22, 30, 40, 49 and 60 million years ago. Also revealed a series of secondary bursts of activity by 4, 15, 34, 45 and 65 million years ago. It turned out that the volcanoes in these areas have a watch with a main period of about 10 million years, and an additional, approximately 5 million years.
Since these regions are spaced from each other, synchronization can not be the explanation for the variations in voltages attract tectonic plates of the lithosphere changes in thickness and the like processes. A single volcanic metronome should look deeper — on the border of the mantle and core of the Earth (which, as it is known from digesting itself).
Scientists suggest that the regular fluctuations in heat flux transferred to the core mantle, causing an increase and decrease in the activity of hot streams — plumes. Those already affected by bursts of volcanism. If this version is confirmed, long-term changes in the global volcanism will be a valuable "window" into the world of the Earth's core.
Details of the new work are described in an article in the journal Lithosphere.