Search results for "Caldera collapse"
showing 3 items of 3 documents
Explosive eruptive history of Pantelleria, Italy: Repeated caldera collapse and ignimbrite emplacement at a peralkaline volcano
2018
A new, pre-Green Tuff (46 ka) volcanic stratigraphy is presented for the peralkaline Pantelleria Volcano, Italy. New 40Ar/39Ar and paleomagnetic data are combined with detailed field studies to develop a comprehensive stratigraphic reconstruction of the island.We find that the pre-46 ka succession is characterised by eight silicarich peralkaline (trachyte to pantellerite) ignimbrites,many ofwhich blanketed the entire island. The ignimbrites are typically welded to rheomorphic, and are commonly associated with lithic breccias and/or pumice deposits. They record sustained radial pyroclastic density currents fed by lowpyroclastic fountains. The onset of ignimbrite emplacement is typically prec…
Architecture and 15 ka to present volcano-tectono-sedimentary evolution of the Neapolitan Yellow Tuff caldera offshore the Campi Flegrei, (Naples, Ea…
2012
The Campi Flegrei area is structurally dominated by the caldera associated with the eruption of the Neapolitan Yellow Tuff (NYT), a 40 km3 DRE ignimbrite dated at ca 15 ka BP [Deino et al., 2004], The volcanological evolution of the NYT caldera as been long described on the basis of outcrop and subsurface studies onland [Rosi & Sbrana, 1987; Orsi et al., 1996, and references therein; Di Vito et al., 1999; Perrotta et al., 2006; Fedele et al., 2011], but its offshore morphology, the stratal geometry of the volcaniclastic products and structures and the late-stage geodynamic evolution of the inner caldera resurgence are still poorly known. We integrate geological and geophysical data obtained…
Gradual caldera collapse at Bardarbunga volcano, Iceland, regulated by lateral magma outflow
2016
Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption.We usemultiparameter geophysical and geochemical data to show that the 110-square kilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014–2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurfac…