Taking the planet to the IMAX: Diving into the volcano and other stories

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• Dr Katherine Dobson - Durham University
• Monday 19 November 2018, 17:30-18:30
• Harker 1, Department of Earth Sciences, Downing Street.

If you have a question about this talk, please contact Ben Johnson.

Geology is inherently dynamic, and full understanding of the geological system can only be achieved by considering the processes by which change occurs. Analytical limitations mean that most of our knowledge has been developed from ex situ analyses of the products of geological change, rather than by observing and measuring the processes themselves. Most of what we do as geoscientists is “snap shot” sampling. From the simplest thin section petrography analysis to the latest high resolution crystal chemical stratigraphy methods, we are capturing a 2D image of a spatially and temporally variable system. Even with detailed experimental work, we can usually only analyse the sample before and after we have performed the experiment, as most routine analysis methods require us to cut up our samples. Serial sectioning and experiments stopped at different stages can give some insight into the third and fourth dimension, but the true scaling of the processes from the laboratory to the 4D geosphere is still poorly understood.

Micro computed tomography (XCT) can visualise the internal structures and spatial associations within samples non-destructively. With image resolutions down to 50 nanometres, XCT has the ability to provide a detailed 3D textural information. Image analysis then lets us quantify mineral associations, porosity, grain orientations, fracture alignments and many other features in 3D. This 3D data gives us much better understanding of the role of the complex geometries and associations within the samples; but the challenge of capturing the processes that generate these structures remains. Using synchrotron x-ray tomography to acquire a full 3D image in a fraction of a second, we can now take quantification of geological processes into 4D. In this talk I will present how we have been pushing the experimental boundaries, to perform in situ experiments on geological materials – allowing us to visit magma chambers and follow eruptions as they happen, and develop new quantitative understand of many other dynamic geological processes.

This talk is part of the Sedgwick Club talks series.

This talk is included in these lists:

• Harker 1, Department of Earth Sciences, Downing Street
• Department of Earth Sciences seminars
• Sedgwick Club talks

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