Fri 9th August @ 11 am, Rm 312.222

Abstract:

Generated by a dynamo process in the Earth’s liquid iron outer core, the global geomagnetic field surrounds and protects our entire planet creating a bubble in interplanetary space. The chaotic nonlinear nature of this geodynamo process leads to the magnetic field being highly variable on a range of timescales and the shortest of these can be observed directly by networks of observatories and satellites. For longer timescale variations, we must turn to palaeomagnetic records made possible by the extreme ferromagnetic stability of ferrous grains occurring naturally in many rocks. This talk will focus on how Earth’s magnetic field has changed through geological time and the variations that appear to have occurred on the very longest timescales (tens to thousands of millions of years).  It will present recent key palaeomagnetic observations and new modelling results that support strong inter-relations between the different parameters used to characterise magnetic field behaviour. This joint observation-modelling approach promises to provide fundamental new insights into the operation of the geodynamo through geological time and its sensitivity to changing conditions in Earth’s core and lowermost mantle.

Short Bio:

Andy Biggin is Professor of Palaeomagnetism at the University of Liverpool in the UK. He works in the Geomagnetism Lab in the School of Environmental Sciences where he has worked since obtaining an Advanced Fellowship from the Natural Environment Research Council (NERC) in early 2009. He got his BSc in geophysics from Liverpool in 1997, his PhD in palaeomagnetism from Kingston (Surrey, not Jamaica) in 2001, and since then has worked as a post-doc in UNAM (Mexico), Montpellier (France), and Utrecht (the Netherlands). Between contracts, he also worked for the Bradford and Bingley financial services company for a couple of years before the big crash (coincidence?). Andy’s research is based around the study of the ancient geomagnetic field through its record preserved in rocks and archaeological materials. He is particularly interested in understanding if, when, and how long term variations in the field’s behaviour tie in with simultaneous changes in conditions in the Earth’s core and mantle. In his spare time, Andy enjoys reading, gaming, eating/drinking out, watching rugby league (Leeds Rhinos in particular) and spending time with his son and with his wife – an English teacher and arts graduate who has little to no interest in geomagnetism.