A new permanent seismic observatory in Antarctica: the Concordia station at Dome C

Jean-Jacques Lévêque1, Andrea Morelli2 and Luis Rivera1

1 Ecole et Observatoire des Sciences de la Terre, Strasbourg
2 Istituto Nazionale di Geofisica e Vulcanologia, Rome


The École et Observatoire des Sciences de la Terre de Strasbourg (formerly IPGS) and the Istituto
Nazionale di Geofisica e Vulcanologia (INGV, Rome) are engaged for years in a common geophysical
initiative at Dome C, as part of the Concordia project. The Dome C site is situated at 75S, 123E
on a 3200 m high plateau, about 1000 km away from the coast. The general aim of Concordia project
is to set up a permanently operated base for multiple scientific disciplines like glaciology,
atmospheric studies, medicine, geomagnetism, seismology, etc. Within this framework, we conduct
two seismological projects: (1) the establishment of a permanent broad-band seismic station,
and (2) the deployment of an array of autonomous BB stations, typically 10 stations spaced
by 10 km along a line.

The permanent station, aiming at a better coverage of the Antarctic continent, is close to
achievement. It will be equipped with a STS2 sensor and a Quanterra Q4120 data logger. The
infrastructure installation has been completed on december 2002, and the station can start
recording as soon as the Concordia base is able to permanently provide power supply.
Unfortunately, very few events have been recorded up to now during the summer campaigns due to
the short time alloted, to the technical tests and installation work we had to made, and to the
noise generated by the construction work of the main base. However, we made extensive noise
analyses showing that installing the station in a 10 m deep vault, about 1 km away from the
main buildings, should provide a reasonably good site as compared to the standard noise models.

The array deployment is currently at a very preliminary stage. Its scientific goal is to allow for
a better study of the low-energy seismic phases, like tiny inner core phase (PKjKP for instance).
Due to the presumably very homogeneous site conditions (same altitude, more than 3 km ice coverage)
and to the distance from the coast, the stacking techniques could be pushed to farther limits.
However, finding an energy source compatible with the very low winter temperatures and the long
polar night is still an unresolved problem. Data transmission is another problem we began to
investigate.