A look back at TALISKER campaigns

Kerguelen is an oceanic island largely made up of basalts, but it has the particularity of containing syenites, rocks normally found on continents. Other oceanic islands on Earth do not. This observation, which dates back to the first geological surveys, continues to raise questions about magmatic processes and the internal structure of Kerguelen’s crust. Having studied in detail the geology of certain regions of Kerguelen, including the massifs containing these syenites, and with the aim of understanding the internal structure of this particular oceanic crust, The TALISKER program’s 2022-2023 and 2023-2024 summer campaigns were mainly devoted to carrying out gravity measurements along several profiles across part of the archipelago, and to setting up a network of autonomous seismic stations (in collaboration with the LISISKER program and the French Polar Institute’s logistics team).
Complementing the field observations made over many years, gravimetry data will enable us to specify the extent and structure of magmatic intrusions by measuring their distribution and quantifying their relative volume within the basaltic crust. Data currently being acquired by seismic stations will then be used to determine the characteristic depths of lithological variations.
For these seismic station installations and the gravimetry profiles, we covered the archipelago from north to south and west to east, from Port Christmas to Hauts de Hurlevent, from Plage du Feu de Joie to Mount Campbell and Pointe Suzanne, covering some 1,000 km in each of the two summer campaigns.

@Hugo Raffet (PhD student in Toulouse University) on the field in Kerguelen doing gravimetric measurements.