The explosive potential of volcanoes is primarily controlled by the quantity of gas in the magma and its ability to escape. Gas can escape from solidified magma through a network of interlinked cracks, and the ease of escape in this way is known as the permeability. In a recent paper published by Gaunt et al. in Bulletin of Volcanology, studies of lava spines at Mount St. Helens volcano, have revealed that although these fracture-networks are relatively permeable at room temperature, at elevated temperatures such as those found in volcanic conduits, this permeability can be substantially reduced. This results was not expect and means that the permeability and explosion potential can change dramatically with changing environmental conditions. More...
The students: Paul Bridger, Sinéad Lyster and Abigail Hunt discuss their experiences of using an ocean core replicate during a practical for the Palaeoceanography course (GeolGG17/M018). The core covers an interval of dramatic climate change around 55.8 million years ago, termed the Paleocene-Eocene Thermal Maximum (PETM). The students studied the colour changes in the core replica, plotted percent carbonate data and answered a series of questions to determine sedimentological changes through this interval. More...
The Ainsa Deepwater Channel Project, Spanish Pyrenees
An Integrated Outcrop Study: Project Manager: Professor Kevin T. Pickering
Introduction to the Ainsa Channel System
The Ainsa Channel System, south-central Pyrenees, occurs in the oldest part of the Campodarbe Group, and it is of Upper Eocene age. The Ainsa Channel Complex is per- haps the most famous of the submarine channel outcrops within Western Europe. The Ainsa channels consist of two principal channel complexes (Ainsa I and Ainsa II) which are separated by thin- and very thin-bedded sandy turbidites and marls. The Ainsa I Channel Complex is an example of an erosional-depositional system. The Ainsa II Chan- nel Complex contains significant erosional cut-downs, with infill of essentially non- erosive sandy facies. The channel dimensions are at a seismic scale.