American Geophysical Union
The annual fall meeting of the American Geophysical Union (AGU) is the world’s largest Earth and space science meeting. Seven CREEPers presented their latest results in december 2017 at the AGU in New Orleans, USA. Early career scientists like PhD’s have a special place in many conferences. Not only can they present their data to a broad audience, there are also many opportunities to introduce oneself to the community and to get judged and mentored in special programs and workshops. Since the conference lasted for an entire week, we explored the city of Jazz in the evenings. Apart from Jazz bars, New Orleans is famous for its Creole architecture and cuisine and it’s Mardi Gras parties. The laid back and open residents, together with the other 20.000 international visitors of the AGU, made it a breeze to get to know new people and views.
After the AGU some CREEPers rented a car to explore a bit the surroundings. First stopping in Memphis to listen to some blues in Bale Street and going around looking for Elvis’s gadgets. Then, after a quick stop in Nashville, home of country music, they started heading south following the Great River Road, a collection of roads that goes along the Mississipi river. Beautiful landscapes (as well as impressive plants!) accompanied this scenic drive that lead the CREEPers to visit an old cotton plantation and the Emerald mound in the Natchez Trace Parkway, a ceremonial center of the pre-columbian age. After visiting Baton Rouge, they came back to New Orleans, where they had the occasion to spend the last weekend looking for alligators in the spectacular swamps south of the city and not missing the last chance of a brass band concert at the Spotted Cat in Frenchmen street!
Paper publications and awards
Elenora won two awards at the AGU with her poster: bravissima!
Wen and Linfeng have published their work and other CREEPers (Manuel, Gianluca and Elenora) are about to have part of their PhD work published soon. Check-out all this in the Publications section!
Gabriel went to Utrecht University in the framework of his secondment last fall. He stayed in the rock deformation/HPT lab for 6 weeks and worked with the team of PhDs there including Caspar. The main goal of the visit was to conduct exploratory wave speed recovery experiments in the ring shear apparatus with calcite gouge. The idea was to try and see if the wave speed recovery phenomenon he observed in Carrara Marble cores in triaxial conditions could be recorded in few millimeters thick calcite gouge layers. And the results were very encouraging! This visit gave Gabriel the opportunity to work on a different machine in a different lab and to expand his skills. The results also opened exciting perspectives which will be investigated next March when Gabriel will go back to Utrecht.
But life is not only work. Gabriel enjoyed the slow canal-life of beautiful Utrecht and everything it has to offer. The team guided him in the myriad of “Brown Cafes” and helped him pick the perfect Belgian beers in the never-ending menus they propose; an experience he is looking forward to enjoy again.
Manuel traveled to Durham, UK in January 2018 to collaborate with fellow CREEPer Giacomo. Both performed high velocity shear experiments on micro- and nano-olivine. They plan to investigate the microstructures of the deformed samples with scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). While performing 33 experiments at different velocities, they also managed to run the 1000th experiment on the rotary shear frictional testing machine. In the end, Manuel and Giacomo try to understand by which mechanisms olivine, the most common mineral in Earth’s mantle, deforms under seismic slip rates and how viscous it is. Apart from the lab, Durham is a city rich in history, with a 1000 years old cathedral and castle, typical english brick houses and a large selection of cozy pubs to relax after work.
During November and December, Beatriz performed part of her work under the supervision of Katrin Plenkers of the company GMuG (Society for Materials Testing and Geophysics). This private company focuses on research and development in fields of acoustic emission and applied geophysics, including design and manufacturing of measuring techniques, installation and maintenance of complex monitoring systems and data analysis and interpretation.
One of GMuG’s current projects is the seismic monitoring within a full scale heater experiment in the underground rock laboratory at Mont Terri (e.g. LUCOEX WP2). The experiment simulates the Swiss disposal concept for highly radioactive waste as closely as possible. Three electrically heated canisters are emplaced in a bentonite backfilled tunnel. Seismic measurements within the bentonite backfill supplement conventional monitoring.
However, the complex internal state and the tunnel geometry of the repository produce complex seismograms that have to be accurately analyzed. For this reason, Katrin thought that it would be a good opportunity for Beatriz to apply her experience in numerical modeling, to help interpret the seismic signals recorded.
The task of Beatriz was to perform numerical simulations of wave propagation inside a 2D model of the experimental tunnel, and analyze how the different parameters of the model impact the signals.
Besides further developing her knowledge about wave propagation, Beatriz had the chance to interact with people from GMuG and learn about how seismic monitoring is performed, and to travel to Switzerland to present the preliminary results to the National Cooperative for the Disposal of Radioactive Waste (Nagra), which is responsible for the full scale experiment.
Summarizing, she is happy to realize how is possible to apply what we are learning during our project to practical and important issues, such as helping with the analysis of data produced by full-scale experiments.
Thomas (University of Bristol) set up and carried out a seismic survey on the beach of fractured limestone, located on the southern margin of the Bristol Channel Basin, UK. The purpose of this active survey is to better understand the seismic wave propagation through fractured media. The selected platform has two interesting features, the first being that the fractures outcrop at the surface and can be easily identified and their orientation characterised. So the seismic velocity behaviour can be related to the fracture pattern. The second interest of the site is that it is affected by the tide. The beach is totally submerged when at high tide. By repeating the same seismic survey at the same place over time, Thomas intends to detect any variations in the rock properties due to the sea water filling the fractures.
Results from this kind of experiments can help us improve our knowledge in fracture-induced anisotropy and better estimate fracture permeability. Thomas will apply similar techniques to process seismic data from a potential geothermal reservoir located in Erythrea.
Written by Gianluca, Manuel, Thomas and Gabriel