Geophysics

Science and Engineering at The University of Edinburgh

School of GeoSciences

Earth and Planetary Science

Section Contents

Study

Geophysics

Geophysics forms a major theme-based grouping within the subsurface Research area. A variety of field, laboratory, analytical, numerical and computational methods are used to determine the structure and elucidate the dynamics of the Earth and other planets at a range of scales. Academic staff contribute to teaching the undergraduate geophysics degree, and many to the geology and environmental geoscience streams. A regular series of research seminars provides a focus for the use of quantitative mathematics and physics for the study of the Earth.

Earthquake Seismology, Seismotectonics and Seismic Hazard

Ian Main and Patience Cowie study the fundamental mechanics and population dynamics of seismogenic faults by analysing primary seismograms, evaluating the statistical properties of earthquake catalogues, detailed field mapping , laboratory experiments, and by developing numerical models for fault growth and interaction. Of prime interest is the link between structural geology and tectonics and the spatial and temporal evolution of earthquakes and fault patterns, and the influence of subsurface fluids on the mechanics (and vice versa), and the effect of faulting on surface drainage. The results are applied to pin down long-term seismic hazard from sattelite data, to evaluate the predictability of earthquakes and volcanoes, and to predict the response of the Earth to anthropogenic stress changes.

Geomagnetism and Palaeomagnetism

Kathy Whaler, Roy Thompson and Wyn Williams study the generation and evolution of the magnetic field of the Earth and other planets. This involves analysing land and sattelite-based data to elucidate the structure of the lithosphere, determining palaeomagnetic properties for inferring past tectonic states, or more recently for dating sedimentary horizons in oilfields; running numerical codes to explain the origin and nature of the geodynamo or the primary development of magnetism in mineral grains in response to an external field.

Geodesy

Roger Hipkin applies the study of gravity and elevation to a variety of fields, from determining the presence of underground cavities to the direction of ocean currents. He has used an absolute gravity meter to calibrate ongoing studies of the response of the UK to glacial unloading and tectonic effects, and to tie the UK database to the rest of Europe via measurements in the channel tunnel.

Exploration Geophysics

Andrew Curtis has interests in Exploration Seismology, and studies the optimal design of surveys and experiments, the use of receiver functions, and the application of interferometry to passive seismics. Anton Ziolkowski, Roger Scrutton and Bruce Hobbs use seismic and electromagnetic methods to probe the subsurface, with application to oil exploration and production; marine geophysics, or environmental problems such as imaging landfill or archaeological sites. In seismology the group specialises in using measurements of the seismic source to improve reservoir imaging and characterisation, for example to explore beneath basalt layers. In electromagnetism forward and inverse modelling techniques have been developed to reveal the subsurface structure and to detect hydrocarbons directly, leading to the setting up of a new company - MTEM, to whom Prof. Ziolkowski and Dr Hobbs are currently seconded. Marine geophysics, particularly what the subsurface tells us about past geological events, is studied in an integrative way with a range of techniques by Roger Scrutton. There are strong links with exploration groups at the Edinburgh Anisotropy Project at the British Geological Survey (including joint research studentships), and an emerging collaboration with the Reservoir Geophysics Group at Heriot-Watt University.

Non-linear dynamics and complexity

While the linear assumption holds for many of the applications above, members of the group have also pioneered the quantitative investigation of non-linear phenomena, from the self-organisation of magnetic domains and fault patterns to earthquake nucleation and the mechanics of the core dynamo. This has been made possible by the local presence of a large high-performance computing resource at the Edinburgh Parallel Computing Centre. Examples include the NERC consortium GEOSPACE, examining the Earth's magnetic field, and the NANIA consortium, examining a range of complex dynamical systems using novel computational techniques.

Data analysis

Another theme crossing the disciplines mentioned above is the development and use of methods of inversion and statistical analysis. For example statistical techniques developed by Roy Thompson to analyse environmental magnetism are now being used to examine first-flowering dates for signs of global warming. Bayesian and Fisherian statistics are being used to infer the degree of predictability of earthquakes and volcanoes.