The eruption in the northern part of the range Erta Ale (Ethiopia) in 2008 in terms of satellite Formosat (image Cheng-Chien Liu, National Cheng-Kung University / An-Ming Wu, National Space Organization, Taiwan / Ralph Harrington, Volcanism Blog).
Two new studies in the "plumbing" that lie beneath volcanoes may help scientists predict major eruptions.
International group, led by experts from the University of Leeds (UK), studied the magma chambers of the mid-ocean ridges — a huge chain of volcanoes that creates new crust. Experts working in Afar (Ethiopia) and Iceland — the only place where the mid-ocean ridges rise above sea level.
Similar formations are the result of rifting, ie differences of tectonic plates. The bark is weakened and molten rock breaks the surface. Cools, the magma forms new crust. Such areas, researchers compared to the plumbing system, because under high pressure magma also moves to a kind of "pipes."
Specialists have received new information about where magma is stored and how it passes through this geological plumbing. For example, have found that the land in Afar began to rise in four months before the eruption, which occurred in November 2008, as one of the underground chambers of magma came and pressure increased.
Magma chamber that fed the eruption was only a kilometer underground, while the standard model predicted more than 3 km.
It is very strange that the magma chamber lies at such a shallow depth in the area of slow-spreading (tectonic plates diverge there at about the same rate as human fingernails grow).
The researchers also found that magma chambers may be placed horizontally or vertically, and it allows the magma to shoot in several directions. Sometimes several of these lesions became one cause of the eruption.
The study was conducted with the help of images taken by the European satellite Envisat, able to show how the earth moves, before, during and after the eruption. These data allowed us to build a new computer model of rifting.
The results were published in the journal Nature Geoscience (1 and 2).
Prepared according to the University of Leeds.