Secondment at Ifremer, Brest
Tugdual Gauchery (ESR3) | @ IFREMER Brest, France (OCTOBER 2018)
I made a secondment to IFREMER in Brest (France) from late September to beginning of October. The goal of my visit was to do grain size analysis of soft sediments to study the sortable silt (10-63μm) with a MALVER mastersizer 3000. We are particularly interested in this size fraction as it allows us to better understand the action of present and past bottom-currents (McCave et al, 1995). To do so, I sampled every 5 cm on 2 piston cores (9 m and 11 m) recovered from my study area, acidified the samples to destroy the biocomponents (to have only the sediments) and freeze-dried them to dissociate the grains. After the grain size measurement, I started to analyse the data and made some interpretation with the help of my co-supervisor (Antonio Cattaneo). The first results show a very detailed analysis of the grain size corresponding to abrupt climate change between 10 and 20 kyr BP, but are more difficult to interpret in the most recent time as the cores reaches 10 kyr BP around a depth of 1 m. This work will be complemented with analyses on CHIRP sonar profiles and multi-channel seismic profiles to reconstruct the sedimentary dynamics of the Gela Basin (central Mediterranean Sea).