GIANT: Deformations of Earth’s Crust
GIANT-LISSA is an acronym for "Geodesy for Ice in ANTarctica" and "Lithospheric and Intraplate Structure and Seismicity in Antarctica". That project intends on improving scientific knowledge about land mass changes since the last glacial period and climate-related mechanisms, but also to increase our understanding about climate change.
By combining GPS data, gravimetry and seismology techniques, GIANT-LISSA will trace the horizontal and vertical deformation of the Earth's surface and focus on the relation between ice mass variation and crust deformation in the Polar Regions.
Glaciers deform the Earth's crust by either gaining or losing ice mass. Two phenomena have been causing deformation in Antarctica: the first one is rather slow and began 10,000 years ago when the ice started to melt at the end of the last ice age; the second is a lot faster and is caused by current climate change. In order to quantify each component separately, it is necessary to combine measurements of surface deformation from GPS data with measurements of variations in gravity using an absolute gravimeter.
Lead by the Royal Observatory of Belgium and in collaboration with the University of Luxembourg and the Royal Military Academy, the GIANT-LISSA project was launched at the Princess Elisabeth Antarctica station in February 2009.
The Royal Observatory of Belgium proposes to study the internal structure of the Antarctic continent, which has been so far poorly probed and remains thus badly understood. The collected seismological data will provide insight into the crust and upper-mantle structure shedding light into the past tectonic processes of the area in regard of the formation of the Gondwana supercontinent about 500 Ma. Moreover, the recorded data will contribute to the global earthquake monitoring and allow detection of possible local tectonic earthquake or ice-related events due to glacier outlet or ice-sheet movement in regard of the present ice mass change of the continent.
Picture: Olivier Francis at work in a scientific shelter - © International Polar Foundation