Ice Flexure Forced by Internal Wave Packets in the Arctic Ocean
PETER V. CZIPOTT 1,
MURRAY D. LEVINE 2,
CLAYTON A. PAULSON 2,
DIMITRIS MENEMENLIS 3,
DAVID M. FARMER 3, and
ROBIN G. WILLIAMS 4
1 SQM Technology, Inc., Post Office Box 2225, La Jolla, CA 92038
2 College of Oceanography, Oregon State University, Oceanography Administration Building 104, Corvallis, OR 97331
3 Institute of Ocean Sciences, Post Office Box 6000, Sidney, British Columbia, Canada V8L 4B2
4 Department of Oceanography, U.S. Naval Academy, Annapolis, MD 21402
Tiltmeters on the Arctic Ocean were used to measure flexure of the ice forced by an energetic packet of internal waves riding the crest of diurnal internal bores emanating from the Yermak Plateau, north of the Svalbard Archipelago. The waves forced an oscillatory excursion of 36 microradians in tilt of the ice, corresponding to an excursion of 16 micrometers per second in vertical velocity at the surface and of 3.5 millimeters in surface displacement. Strainmeters embedded in the ice measured an excursion of 3 x 10–7 in strain, consistent with ice flexure rather than compression. The measured tilt is consistent with direct measurements of excursions in horizontal current near the surface (12 centimeters per second) and in vertical displacement (36 meters) of the pycnocline 100 meters below the surface.
Submitted on May 22, 1991
Accepted on July 31, 1991
