Karin Sigloch

Research Profile

Seismology and Geodynamics. My group studies the structure of the earth’s interior, from crust to core. We want to understand its heat and material flows, which move slowly on a human timescale, but vigorously on geological time scales. These flows drive the motions of tectonic plates, formation of oceans, volcanism, and continental tectonics — surface observables that we link to 3-D images of mantle structure at depth.

Our primary tool is seismic tomography, an imaging technique that computes three-dimensional models of the earth’s interior. Essentially, it maps out the anomalously hot, cold, or dense regions that drive convection in the mantle. We specialize in cutting-edge methods for waveform inversion. PhD projects would typically advance the techniques of seismic tomography, and/or apply these tools to new, rapidly growing data sets.

We also do field experiments, including novel recordings on the ocean bottom. The RHUM-RUM experiment in the western Indian Ocean is a passive seismic experiment designed to image an oceanic mantle plume – or lack of plume – from crust to core beneath La Réunion Island, and to understand these results in terms of material, heat flow and plume dynamics. We deployed 57 broadband ocean-bottom seismometers and 30 island stations to record earthquakes and ambient noise between 2011 and 2014. The data analysis is ongoing and the growing list of publications can be found here on ResearchGate or by searching for “RHUM-RUM” in Google Scholar.

The Farallon plate that subducts into the mantle beneath western North America, as imaged by 3-D seismic tomography down to 1,500 kilometres depth. This paleo-oceanic lithosphere once occupied the proto-Pacific basin but has been recycled back into the mantle over the past 180+ million years. Colours represent 200 kilometre depth intervals.

Linking our findings to neighbouring fields (plate reconstructions, field geology, geodynamic modelling) is the ultimate challenge and a source of great intellectual excitement. My ERC-funded project DEEPTIME matches deep slab structure to the geological surface record of subduction – volcanic arcs and other crustal slivers that stayed afloat, survived collisions, and form the world’s largest mountain belts. Integrating these two direct records of subduction, the project will:

• Add paleo-trenches to existing plate reconstructions and extend them 2-3 times longer into the past.
• Produce a 3-D atlas of the mantle that matches subducted seafloor with paleo-oceans inferred by land geology.
• Rigorously test the hypothesis of vertical slab sinking, which may yield an absolute mantle reference frame.

Additional funding for this paleogeography work comes from the Leverhulme Trust, via a Philip Leverhulme Prize received in 2015.

Links

Publications: To download PDFs of most of my papers, scroll down to section “Selected Publications” or see here. Alternatively, browse and download on my ResearchGate pages, or view the list on Google Scholar.

DEEPTIME, my ERC grant: Deep Earth Evolution and Paleogeography Through Tomographic Imaging of the Mantle.

Seismology@Oxford research pages

NERC Doctoral Training Programme in Environmental Research

Earth Sciences at Exeter College, my college within the University of Oxford, where I am a Tutorial Fellow.

Teaching Profile

• Geophysical Methods (in 2nd year, with Conall MacNiocaill)
• Seismology (in 3rd year, with Tarje Nissen-Meyer)
• Solid Earth seminar (in 4th year, with Richard Katz, Lars Hansen, and Tarje Nissen-Meyer)
• Module in the NERC Doctoral Training Programme (“Solid Earth — Linking the brittle shell to the viscous mantle”)