Wave Propagation over a Submarine Canyon: Field Observations
Abstract
Although abrupt bottom features such as submarine canyons, reefs, banks and shoals are present on many continental shelves, field measurements of their effects on ocean surface waves are scarce. During September-December 2003 an extensive array of wave-measuring instruments was deployed near La Jolla, California, as part of the Nearshore Canyon Experiment (NCEX). The field site is characterized by two submarine canyons, La Jolla Canyon and Scripps Canyon, that strongly affect the propagation of long period Pacific swell. An array of 7 Datawell Directional Waverider Buoys, 17 bottom pressure recorders and 12 Nortek Vector pressure-velocity sensors was deployed in depths ranging from about 10-100 m. The three-month-long observations include numerous long-period swell arrivals from both southern and northern hemisphere storms. Preliminary analysis indicates extreme spatial variations in wave energy in the vicinity of Scripps Canyon. In particular, swell arriving from the west is effectively blocked by the canyon. The observed amplification of swell energy on the north side of the canyon and extremely low energy levels on the south side are consistent with refraction predictions. This research is supported by the Office of Naval Research and the National Science Foundation.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFMOS14B..02P
- Keywords:
-
- 4219 Continental shelf processes;
- 4546 Nearshore processes;
- 4560 Surface waves and tides (1255)