Monday, December 16, 2013

Return from the coast

The IceCon and Be:Wise researchers are back at PEA after a long trip (~17 hours with Prinoth). The 12 days spent on the coast were used at their maximum and good weather permitted measurements every day.

GPS measurement on Roi Baudoin ice shelf.

The entire GPS network installed last year on the Roi Baudouin ice shelf has been reoccupied. Some markers were lost during the winter due to high snow accumulation and strong windy conditions but most markers could be recovered. Additionally, a new network of 14 markers has been installed and occupied twice with a time delay of 6 days. The new network is denser than the previous one and focuses on surface depression in the ice shelf which is linked to sub ice-shelf channels: The idea is to measure the velocity gradient across these channels and to check as to whether or not the channeling introduces weak spots in the ice shelf: Actually, on the second reoccupation, unexpectedly (not seen the week before) open crevasses where visible close to this new network. This seems evidence of higher deformation rates in this region.

ROB1 GPS station in 2012 and in 2013 on Derwael

On Derwael ice rise, the team found the ROB1 GPS station as well as the coffee-can marker just a little bit above the snow surface (see pictures). During the winter, the snow accumulation was ~140 cm. The ROB1 station worked during a whole year, without data interruption. The first results show a subsidence of the station of the order of 1m in a year. No significant horizontal motion is detected which confirms that the station is indeed on the top of the ice rise. However, these first results need to be confirmed by more accurate processing when the team will be back in Belgium. In addition to the maintenance of the ROB1 station, the team also reoccupied a strain network installed last year and collected complementary radar data and kinematic GPS profiles.

All in all we completed all major objectives of this field season and – thanks to good weather and excellent logistic support from the station team and field guides Alain and Christophe– it was even possible to fit in additional measurements. Hooray.


1 comment:

  1. Very good work Reinhard, Lionel and all the IceCon-be:Wise team! I'm following your discoveries from Buenos Aires and Patagonia!