Title: Impact of vegetation die-off on spatial flow patterns over a tidal marsh
Authors: Stijn Temmerman and Jonas Schoelynck: Ecosystem Management Research Group, University of Antwerpen, Wilrijk, Belgium;
Gerard Govers and Pieter Moonen: Research Group for Physical and Regional Geography, Katholieke Universiteit Leuven, Heverlee, Belgium;
Tjeerd J. Bouma: Royal Netherlands Institute for Sea Research (NIOZ), Yerseke, Netherlands.
2. Capsizing icebergs release earthquake-sized energies
A large iceberg can carry a large amount of gravitational potential energy. While all icebergs float with the bulk of their mass submerged beneath the water's surface, some drift around with precarious orientations-they are temporarily stable, but an outside push would send them tumbling over. Large icebergs, like those that split from the Jakobshavn Isbrae glacier in Greenland, can release the energy equivalent to a magnitude 6 or 7 earthquake when they capsize. A 1995 event demonstrated the potential for destruction, as a tsunami spawned from a capsizing iceberg devastated a coastal Greenland community. Measuring how energy is dispersed during capsizing is crucial to understanding the risk associated with these events but is also key to determining their larger role in surface ocean dynamics.
Using a laboratory model fjord and 27 x 10 centimeter (10.6 x 4 inch)
polyethylene iceberg analogues with varied widths, Burton et al. measured how
energy is released to the surrounding water during capsizing. A camera tracking a
floating buoy measured the height of any tsunami waves, and analysis of the
iceberg's movement let them determine the kinetic energy involved in the
rotation. Corroborating earlier research, the authors find that the size of any
tsunami waves will be at most
|Contact: Kate Ramsayer|
American Geophysical Union