Deep Earth at Leeds

SEDI2016 special issue

dergleeds — Mon, 05 Feb 2018 09:53:18 +0000

The special issue of Physics of the Earth and Planetary Interiors containing the proceedings of the 15th Symposium of the Study of the Earth’s Deep Interior (in Nantes, France, from 24th to 29th July 2016) has now been formally published. Members of the Deep Earth group in the School of Earth and Environment and the Department of Applied Mathematics contributed three papers covering the dynamics of the outer core, the Earth’s magnetic field, and the dynamics of the lower mantle:

- - K. Hori, R.J. Teed and C.A. Jones “The dynamics of magnetic Rossby waves in spherical dynamo simulations: A signature of strong-field dynamos?” https://doi.org/10.1016/j.pepi.2017.07.008
  - M.C. Metman, P.W. Livermore, and J.E. Mound “The reversed and normal flux contributions to axial dipole decay for 1880–2015” https://doi.org/10.1016/j.pepi.2017.06.007
  - A.M. Walker, D.P. Dobson, J. Wookey, A. Nowacki, and A.M. Forte “The anisotropic signal of topotaxy during phase transitions in image D″” https://doi.org/10.1016/j.pepi.2017.05.013

We look forward to the 16th Symposium in Edmonton, Canada.

Deep Tectonics

dergleeds — Mon, 29 Jan 2018 10:32:14 +0000

During February 2018 we will start a series of four meetings together with the tectonics research group on deep earthquakes. These are earthquakes with a source below 60 km depth, and often much deeper, which have unusual source mechanisms. They can also be particularly useful for the study of deep Earth structure. The series of discussions is being coordinated by Andy Nowacki and will take place alternately in the meeting times set aside for the Deep Earth and Tectonics Research Groups.

On Friday 2nd February (2 pm in 10.125) we began with a discussion of Tibi et al. (2003) and Andy will give some background on deep earthquakes (greater than ~60 km deep) using the paper as a starting point. We also discussed the content of the rest of the meetings.

On Tuesday 6th February our topic will be the mechanisms of deep earthquakes. Andrew Walker will lead this discussion based on Dobson et al. (2002). By the end of the session we should have answers to some of the questions posed last week. We will probably also have new questions to ask.

Plans for future sessions are:

Fri 16 Feb (2pm in meeting room 3):Geophysical observations of deep earthquakes
Tue 20 Feb (1pm, location to be confirmed): Lab and numerical experiments

We will update this blogpost as the series progresses.

References

Rigobert Tibi, Douglas A. Wiens and Hiroshi Inoue (2003) “Remote triggering of deep earthquakes in the 2002 Tonga sequences”. Nature 424:921–925 https://dx.doi.org/10.1038/nature01903

Dobson, Meredith and Boon (2002) “Simulation of subduction zone seismicity by dehydration of serpentine” Science 298:1407-1410 http://dx.doi.org/10.1126/science.1075390

New term, new meetings: Tidal tomography

dergleeds — Sun, 21 Jan 2018 10:43:15 +0000

Deep Earth research group discussion meetings will restart on Friday (26/1/2018) at 14:00 in seminar room 3 (8.119, behind reception in the School of Earth and Environment) and continue until the end of term. Feel free to come along if you are interested in the science of the deep Earth.

Our first discussion will be lead by Sebastian Rost, and we will discuss a recent Nature paper by Lau et al. (2017) looking at the density of the deep mantle using tidal tomography. There is a News and Views article (Romanowicz 2017) to help put the paper into context.

References

Lau et al. (2017) Tidal tomography constrains Earth’s deep-mantle buoyancy. Nature 551:321–326. http://dx.doi.org/10.1038/nature24452

Romanowicz (2017) Geophysics: The buoyancy of Earth’s deep mantle. Nature 551:308–309. http://dx.doi.org/10.1038/551308a

Deep Earth meetings for the new term

dergleeds — Fri, 29 Sep 2017 15:24:01 +0000

Deep Earth discussion meetings will start for the new term at 2 pm on Friday 6th October. Our first two meetings will include short introductory talks from our new PhD students who will tell us something about their new projects and previous research that they have undertaken.

On 6/10/2017 we will meet in seminar room 3 (room 8.119 behind reception in the ‘new’ north building in the School of Earth and Environment) when Jamie, Andrew and Itahisa will talk. The following week (13/10/2017) we will meet in room 10.125 (two floors above reception in the School of Earth and Environment) when Rob and Colin will talk.

Our meetings will continue most weeks of term, and will be announced here and on the deep Earth email list.

An accelerating high-latitude jet in Earth’s core: new paper and bbc coverage

dergleeds — Mon, 19 Dec 2016 17:10:14 +0000

Phil Livermore is lead author on a new paper just out in Nature Geoscience on “An accelerating high-latitude jet in Earth’s core”, doi:10.1038/ngeo2859. This work was discussed in a group meeting earlier in the year and is the subject a University news coverage. Congratulations to Phil, Rainer Hollerbach (School of Mathematics) and Chris Finlay (Technical University of Denmark).

There is some BBC coverage at http://www.bbc.co.uk/news/science-environment-38372342 and the full article can be read at http://rdcu.be/nYf7. Thanks to all of DERG (you are in the acknowledgements!)

A Boussinesq Model of a Slurry

dergleeds — Wed, 23 Nov 2016 09:32:52 +0000

This week Jenny Wong will tell us about “A Boussinesq Model of a Slurry”. The work aims to explain the anomalous high density of the F-layer (a ~150 km-thick layer at the base of the liquid core) using a 2-component fluid containing a suspension of solid particles.

Comparison of molecular dynamics techniques for predicting the thermal conductivity of lower mantle minerals

dergleeds — Fri, 18 Nov 2016 09:23:53 +0000

This week Ben will present his poster entitled “Comparison of molecular dynamics techniques for predicting the thermal conductivity of lower mantle minerals”. We will meeting in Meeting Room 3, at 2pm

Physical and Thermodynamic Properties of Carbonate Phases in the Mantle

dergleeds — Fri, 04 Nov 2016 10:32:49 +0000

At out next meeting Zhi Li will tell us about his recently completed work on carbonates in the mantle leading to an MSc by Research. Zhi made use of atomic scale simulations, density functional theory, lattice dynamics, and structure prediction methods to investigate the stability of MgCO₃ and FeCO₃ in the mantle, and to evaluate the physical properties of these phases.

We will meet in seminar room 3 at 14:00 on Friday 11 November.

Discussion 21/10/2016: Using archaeomagnetic ﬁeld models to constrain the physics

dergleeds — Mon, 17 Oct 2016 09:49:06 +0000

In this week’s deep Earth discussion we will consider a recent paper by Terra-Nova et al. in GJI: “Using archaeomagnetic ﬁeld models to constrain the physics of the core: robustness and preferred locations of reversed flux patches” (2016; vol 206, pp.1890-1913, http://dx.doi.org/10.1093/gji/ggw248 ).

Maurits Metman will lead the discussion which will take place at 2pm on Friday 21st October in SEE seminar room 3.

A jet in Earth’s core?

dergleeds — Tue, 02 Feb 2016 09:59:54 +0000

This week Phil Livermore will lead the discussion of a manuscript he has in preparation with Rainer Hollerbach (School of Mathematics) and Chris Finlay (Technical University of Denmark). We will meet at 2pm on Friday 5th February in seminar room 3 (8.199, behind reception in SEE).