Stuart Crampin (1935 - 2024)

Prof. Stuart Crampin, born 23 rd October 1935, peacefully passed away on 3 rd May 2024 at his home in Glasgow, surrounded by his family. Stuart was a seismologist who achieved international acclaim for his research on the theory and applications of seismic wave propagation in anisotropic media, particularly those exhibiting stress- aligned crack-anisotropy, first at the British Geological Survey, and latterly at the University of Edinburgh.

Stuart’s university career began at the University of London, followed by Cambridge where he was later awarded a ScD. During his studies he suffered a serious climbing accident, and it was several months before he was ready to resume work. At this point he decided to change his research topic to one that was little known, to allow him to progress more slowly. Prof. Markus B?th of Uppsala University had observed surface waves from large earthquakes exhibiting anisotropic characteristics. With Markus’s encouragement, Stuart joined him in Uppsala for two years and began the research work which would last his lifetime – seismic wave propagation in anisotropic media. This would become an indispensable tool for earthquake and exploration seismology.

After joining the British Geological Survey (then the Institute of Geological Sciences) as Gassiot Fellow in 1966, Stuart became involved in organising earthquake detection and analysis using small networks of seismometers in Scotland, Iran, and Turkey. His collaboration with Dr Balamir U?er in Turkey, the first of many successful international collaborations, initiated the MARNET seismic network around the Marmara Sea which was the basis for later projects in Turkey investigating stress-aligned crack-anisotropy using local earthquake data.

Stuart’s first work on anisotropy was mainly theoretical. With Colum Keith, he devised computer algorithms to describe the behaviour of seismic body waves through, and at interfaces with, anisotropic media. This provided the knowledge that seismic body wave seismograms would give diagnostic information on the type of anisotropy the body waves encountered, and in particular shear waves would exhibit birefringence andpolarization alignments characteristic of that anisotropy. Stuart’s crucial insight was that the ubiquitous cracks and pore spaces in the Earth’s crust would tend to be aligned by the stresses they are subjected to, and thus possess seismic anisotropy capable of being analysed and described most effectively by shear wave studies. This type of anisotropy he called extensive dilatancy-anisotropy, or EDA. With Dr Russ Evans and others, he conducted a series of earthquake monitoring projects in Turkey, which first demonstrated the existence of EDA in the early 1980s; since then, EDA has been observed worldwide in many studies.

Realising the significance of his studies for characterising aligned cracks and pore space in the sub-surface., Stuart persuaded the oil industry to commission a research project devoted to this purpose. Founded in 1986, the Edinburgh Anisotropy Project, led by Stuart and later Drs. Xiang-Yang Li and Mark Chapman, was extraordinarily successful throughout its long duration in developing innovative techniques for oil reservoir description.

Latterly, Stuart returned to his interest in earthquake seismology, helping to establish stress monitoring sites in Iceland, and working on the possibility of stress-forecasts for earthquakes using temporal changes in shear-wave splitting. He also continued to work on theoretical models for understanding of fluid-rock deformation in the Earth's Crust.

A prolific researcher, Stuart published over 300 papers in collaboration with a large number of staff and PhD students whom Stuart motivated and supervised; all of them will readily attest to his enthusiastic and committed support. He also organised several sponsored international anisotropy workshops and symposia, the first of which was in the former Soviet Union in 1982.

Stuart was an Honorary Fellow and Honorary Professor at Edinburgh University, and a Fellow of the Royal Society of Edinburgh. Among many honours and awards, Stuart received the Price Medal of the Royal Astronomical Society and the Virgil Kaufmann Gold Medal from the Society of Exploration Geophysicists.

Brian Baptie, BGS, Edinburgh, UK