Plinian and subplinian volcanic eruptions can be accompanied by tephra falls which may last hours or days, posing threats to people, buildings and economic activity. Numerous historical examples exist of tephra damage and tephra casualties. The mechanisms and consequences of roof collapse from static tephra load are an important area of tephra damage requiring more research. This paper contribu...

We present a multifractal analysis of Mount St. Helens seismic activity during 1980–2002. The seismic time distribution is studied in relation to the eruptive activity, mainly marked by the 1980 major explosive eruptions and by the 1980–1986 dome building eruptions. The spectrum of the generalized fractal dimensions, i.e. Dq versus q, extracted from the data, allows us to identify two main eart...

Diffusion is due to thermally activated atomic-scale random motion of particles (atoms, ions and molecules) in minerals, glasses, melts, fluids, and gases (Fig. 1). The random motion leads to a net flux when the concentration (more strictly speaking, the chemical potential) of a component is not uniform. Even though diffusion is a microscopic process, it can lead to macroscopic effects. For exa...

[1] From October 2008 until present, dozens of small impulsive explosive eruptions occurred from the Overlook vent on the southeast side of Halema‘uma‘u Crater, at Kīlauea volcano, USA. These eruptions were triggered by rockfalls from the walls of the volcanic vent and conduit onto the top of the lava column. Here we use microtextural observations and data from clasts erupted during the well-ch...

Large explosive eruptions inject volcanic gases and fine ash to stratospheric altitudes, contributing to global cooling at the Earth's surface and occasionally to ozone depletion. The modelling of the climate response to these strong injections of volatiles commonly relies on ice-core records of volcanic sulphate aerosols. Here we use an independent geochemical approach which demonstrates that ...

The Medusae Fossae Formation (MFF) has long been thought to be of Amazonian age, but recent studies propose that a significant part of its emplacement occurred in the Hesperian and that many of the Amazonian ages represent modification (erosional and redepositional) ages. On the basis of the new formational age, we assess the hypothesis that explosive eruptions from Apollinaris Patera might hav...

Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. [1] During explosive eruptions, volcanic plumes inject ash into the atmosphere and may severely affect air traffic, as illustrated by the 2010 Eyjafjallajö...

Silicic volcanic eruptions range in style from gently effusive to highly explosive, and may switch unpredictably during a single eruption. Direct observations of subaerial rhyolitic (Chaiten 2008, Cordón Caulle 2011–2012, Chile) challenged long-standing paradigms explosive eruptive styles led the formulation new models hybrid activity. However, processes that govern such explosive–effusive acti...