Current Postgraduate Students
Ms Emma Gregory, BSc
2014 - Present: PhD in Marine Geophysics, Department of Earth Sciences, Durham University.
2011 - 2014: BSc in Geophysics with Geology, Department of Earth Sciences, Durham University.
Geophysical analysis of fractured crust at mid-ocean ridges
My research is focussed on characterising the velocity structure of young oceanic crust, and understanding this structure in terms of lithology, alteration, fracturing, porosity and permeability.
A large geophysical survey conducted in 2014-2015 (JC114) collected a suite of data over the Costa Rica Rift area in the Pacific Ocean. This included a grid of seismic reflection and wide-angle refraction data over DSDP/ODP borehole 504B, in young, 5.9 Ma crust. The inversion of seismic travel time data to create 3D velocity models of the oceanic crust at 504B enables comparison of velocity structure with in-situ drilling observations. Both Vp and Vs structure, along with anisotropy and particle motion studies will allow a comprehensive investigation of the fracturing and therefore fluid flow patterns in young oceanic crust.
This research is part of the OSCAR project (http://community.dur.ac.uk/oscar.nerc/), the aim of which is to understand the interaction between the oceanic crust and overlying ocean through heat transfer and fluid flow. On the solid Earth side, this means characterising the changing structure of oceanic crust from formation at the Costa Rica Rift, to 5.9 Ma at DSDP/ODP borehole 504B, and relating this to hydrothermal circulation patterns.
Gregory, E.P.M., Hobbs, R.W., Peirce, C., Wilson, D.J. & Zhang, L., 2016. Understanding fracturing and alteration at ODP borehole 504B: 3D seismic structure and anisotropy of 5.9 Ma oceanic crust. AGU Fall Meeting, 2016. Poster presentation T13B-2712.
Gregory, E.P.M., Hobbs, R.W., Peirce, C. & Wilson, D.J., 2016. Fracturing and alteration in young oceanic crust from 3-D seismic velocity structure and anisotropy analysis. SEISMIX 2016, Aviemore, Scotland. Oral presentation.
Gregory, E.P.M., Hobbs, R.W., Peirce, C. & Wilson, D.J., 2015. Seismic structure of oceanic crust at ODP borehole 504B: Investigating anisotropy and layer 2 characteristics. AGU Fall Meeting, 2015. Poster presentation V21A-3025.
JC114 – OSCAR (20th January – 10th March, 2015)
The second leg of the three OSCAR cruises, JC114 acquired a suite of geophysical data within the Panama Basin, primarily between the Costa Rica Rift and borehole 504B 200 km to the south. This involved active seismic reflection and wide-angle (WA) seismic refraction surveys, using a 4.5 km multi-channel streamer and a total of 75 OBS deployments, and also included synthetic-aperture-profile shooting with the R/V Sonne (SO238). I assisted with the on-board processing of the MCS and WA refraction data to help assess data quality and identify features of interest, as well as being the lead Marine Mammal Observer and aiding with the deployment and recovery of the OBSs. Please take a look at the cruise blog (http://oscar-nerc.blogspot.co.uk/) for more information.
JC112/113 – OSCAR (5th December 2014 – 16th January 2015)
The first cruise leg of the OSCAR project, JC112/113 collected oceanographic data throughout the Panama Basin in the Eastern Equatorial Pacific, measured a series of heat flow profiles from the Costa Rica Rift to borehole 504B, and deployed moorings and magnetotelluric landers to be collected on the following cruises. My roles during the cruise were to process the raw swath bathymetry data to remove acquisition artefacts; collect water samples from the Conductivity-Temperature-Depth (CTD) instrument for dissolved oxygen content (DOC) analysis and conduct this analysis onboard in the lab; and assist with the heat flow instrument and measurements.