Benthic storms in the Greenland sea

We present observations of strong, episodic, bottom-intensified currents fr om two current meter moorings, each of a year's duration, placed in the cen tral Greenland Sea at 75 degrees N, 8 degrees W, in a water depth of circa 3340 m. The events, recorded by the current meters placed some 50 m above t he sea floor, occur about 4 times a year and last about a week. They show c urrents of up to 43 cm/s, turning in direction, occasionally modulated by a signal of the frequency of the Coriolis parameter or the semi-diurnal tide . The temperature record at the current meter however remains constant to 0 .01 degrees C. The current direction measured at overlying meters correlate s well with that of the deepest meter - the current speed does not. Indepen dent, geological data also show evidence of strong bottom flows in the area . We discuss possible mechanisms for these 'benthic storms', including the hy pothesis of a sediment driven plume descending from the East Greenland cont inental slope. These high energy events have implications for sedimentation , shelf-basin exchange and boundary mixing processes. Normal mode theory is used to justify the dynamical response of the system to such a bottom-trap ped impulse. (C) 1999 Elsevier Science Ltd. All rights reserved.