27 research outputs found
Effects of chronic alcoholism in the sensitivity to luminance contrast in vertical sinusoidal gratings
Evolução da mortalidade por homicídio no Estado da Bahia, Brasil, no período de 1996 a 2010
Exceptional mobility of an advancing rhyolitic obsidian flow at Cordon Caulle volcano in Chile:observations from Cordón Caulle, Chile, 2011-2013.
The emplacement mechanisms of rhyolitic lava flows are enigmatic and, despite high lava viscosities and low inferred effusion rates, can result in remarkably, laterally extensive (>30 km) flow fields. Here we present the first observations of an active, extensive rhyolitic lava flow field from the 2011–2012 eruption at Cordón Caulle, Chile. We combine high-resolution four-dimensional flow front models, created using automated photo reconstruction techniques, with sequential satellite imagery. Late-stage evolution greatly extended the compound lava flow field, with localized extrusion from stalled, ~35 m-thick flow margins creating >80 breakout lobes. In January 2013, flow front advance continued ~3.6 km from the vent, despite detectable lava supply ceasing 6–8 months earlier. This illustrates how efficient thermal insulation by the lava carapace promotes prolonged within-flow horizontal lava transport, boosting the extent of the flow. The unexpected similarities with compound basaltic lava flow fields point towards a unifying model of lava emplacement