Bullerwell lecture on Magma Storage and Ascent: Dr. Juliet Biggs, University of Bristol
Over 800 million people live within 100 km of one of the world’s ~1500 Holocene volcanoes. Improved volcano monitoring has saved tens of thousands of lives and enabled populations to co-exist with erupting volcanoes. Yet, more than a third of historically active volcanoes have no monitoring equipment on the ground, including many close to large populations in developing countries. The growing number of Earth Observation satellites can measure a wide variety of volcanic phenomena, and taken together, they have the potential to form a ‘global volcano observatory’, providing baselines information for every volcano in the world and underpinning the work of local observatories. Here I focus on measurements of surface deformation and their relation to the conditions of magma storage and ascent, considering what we’ve already learned from 25 year of satellite radar observations, and the road ahead.
Dr. Chris Davies, University of Leeds
Short abstract: Seismic tomography and geodynamic modelling both strongly suggest that Earth’s lowermost mantle supports large-scale lateral temperature anomalies. The liquid core must respond to the associated lateral variations in heat flow at the core-mantle boundary (CMB) and there is growing evidence that the response can be observed in the spatial pattern and temporal variations of the geomagnetic field and fluid flow at the top of the core. It has even been suggested that lateral CMB heat flow variations govern the dynamics of the whole core, changing the efficiency of heat transfer, reorganizing the flow pattern, and leaving a detectable imprint on the inner core boundary. These predictions are fundamentally limited by our ability to model rapidly rotating and strongly driven convection with and without magnetic fields. This talk will focus on the latest developments in our understanding of thermal core-mantle interactions.
Prof. Nicholas Rawlinson, University of Cambridge
Short abstract: Cenozoic intra-plate volcanism is widespread throughout much of eastern Australia, and manifests as both age-progressive volcanic tracks and non-age progressive lava-fields. Various mechanisms have been invoked to explain the origin and distribution of the volcanism, but a broad consensus remains elusive. We use results from seismic tomography to demonstrate a clear link between lithospheric thickness and the occurrence, composition and volume of volcanic outcrop. Furthermore, we find that non age-progressive lava-fields overlie significant cavities in the base of the lithosphere. Based on numerical simulations of mantle flow, we show that these cavities generate vigorous mantle upwellings, which promote decompression melting. However, due to the intermittent nature of the lava-field volcanics over the last 50 Ma, it is likely that transient mechanisms must also operate to induce or enhance melting. In the case of the Newer Volcanics Province, the passage of a nearby plume appears to be a likely candidate. Our results demonstrate why detailed 3-D variations in lithospheric thickness, plate motion and transient sources of mantle heterogeneity need to be considered when studying the origin of non age-progressive volcanism in continental interiors.
Mark Webster, Geophysicist at BP Aberdeen, "Life as a geophysicist in the oil & gas industry"
Short abstract: The Clair field, the seismic challenges that we phase on Clair and the role that seismic data has in well planning. The intent would be to provide a good flavour of life as an asset geophysicist, together with some of the seismic technology that’s applied within the team here.