The TIMEleSS project aims at studying interfaces in the Earth’s mantle combining observations from seismology, mineral physics experiments, microstructures, and wave propagation modeling. It is supported through a bilateral grant, from the ANR in France and the DFG in Germany. The project is led by Sébastien Merkel and Nadège Hilairet at the Université de Lille, Christine Thomas and Carmen Sanchez-Valle from the Westfälische Wilhelms-Universität, Münster, and Sergio Speziale from the Deutsche GeoForschungsZentrum, Potsdam.
Project launch: March 2018
Duration: 36 months
Total ANR-DFG funding: 700 000 €
First publication for the TIMEleSS team: Kinetics and detectability of the bridgmanite to post-perovskite transformation in the Earth’s D″ layer.
Bridgmanite is a magnesian-iron mineral ((Mg,Fe)SiO3) with a crystal structure that is not stable under ambient conditions. It forms about 660 kilometers below the surface of the Earth, and transforms to a new structure at even greater depth, approximately 2700 km depth, just above the Core-Mantle boundary.
During his PhD, C. Langrand, PhD student at the Université de Lille studied the kinetics of such transformation. It is fast on geological timescales: about 10 to 10,000 seconds, depending on pressure and temperature. Thanks to the collaborations in the TIMEleSS project, the authors realized that this includes the timescales of seismic waves. As such, seismic waves can trigger the transformation and, in turn, the transformation can amplify the seismic signal from D” seismic reflections.
These results from a collaboration between the Université de Lille, the université Clermont-Auvergne, the université de Lyon, the Westfälische Wilhelms-Universität, Münster, CNRS, and the PETRA III / DESY synchrotron source were published on 12 decembre 2019 in Nature Communications.
Full reference : C. Langrand, D. Andrault, S. Durand, Z. Konôpková, N. Hilairet, C. Thomas, S. Merkel, Kinetics and detectability of the bridgmanite to post-perovskite transformation in the Earth’s D″ layer, Nature Communications, 10, 5680 (2019) [doi: 10.1038/s41467-019-13482-x].
2019 is a special year that marks the Centennial for AGU. Monday dec. 9th was a celebration day for Earth Interior studies with a special Centennial session in which TIMEleSS PI S. Merkel was in charge of organizing and chairing part of the day.
Things return to a normal AGU now, with the usual layout for sessions and presentations. The TIMEleSS project will be presented on Thursday morning in session DI41C – A Deep Dive into Lowermost Mantle Processes. Please come by to see the state of our current research!
The TIMEleSS project is looking for a post-doctoral fellow. The position is available for 1 year and extendable. The position is attached to the Earth and Planetary Materials group the Unité Matériaux et Transformations, at the Université de Lille, France, with strong collaborations with the Institute for Geophysics at the University of Münster.
The post-doc will be in charge of simulating wave propagation in structures and microstructures with the aim of interpreting deep Earth seismic observables.
The candidate should have a strong background in deep Earth seismology and/or wave propagation in complex media and/or mineral physics and will be in charge of connecting mineral physics knowledge of phase transformations and microstructures in the Earth’s mantle to potential observations of seismic reflections and scattering.
Details on the position, conditions, and requirements can be found in the following document. The review of of applications will start by January 31st 2020 and will continue until the position is filled. The position is expected to start in the spring or the summer of 2020.
The second Deep Earth Mini Symposium was held at the Institute for Geophysics of the University of Münster on November 18th 2019.
The one day symposium has presentations from local and international speakers who all came to Münster for a day of science and discussions. The workshop was organized by TIMEleSS PI C. Thomas.
TIMEleSS PI S. Merkel gave a presentation entitled Phase transitions in the lowermost mantle : Effect
on microstructures and seismic reflections. TIMEleSS students F. Rochira and M. Krug presented posters on their most recent works.