quinta-feira, 20 de outubro de 2011


The role of dyking and fault control in the rapid onset of eruption at Chaitén volcano, Chile

Nature
 
478,
 
374–377
 
(20 October 2011)
 
doi:10.1038/nature10541
Received
 
 
Accepted
 
 
Published online
 
Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2May 2008 at Chaitén Volcano, located in Chile’s southern Andean volcanic zone, rhyolitic magma migrated from more than 5km depth in less than 4hours (ref.1) and erupted explosively with only two days of detected precursory seismic activity2. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults.

Figures at a glance