Deployment of a bottom monitor at a 30 meters deep site in the New York Bight Apex during the summer of 1993

Abstract

A bottom instrument was deployed on May 5,1993, recovered and redeployed on June 22, 1993 and finally recovered on July 28, 1993 at a 30 meter site in the New York Bight Apex. The instrument measured currents, suspended sediment concentrations, pressure, temperature and conductivity. The data storage was filled in only seven days on the first deployment as in 18 days in the second. The averaging sampling process worked well, producing hourly (first deployment) and half hourly (second deployment) values of all sensors and instrument internal diagnostics to obtain background environmental information. The burst sampling scheme sampled once a day for waves, and identified 6 and 10 second waves present. The event sampling scheme was tested for the first time. During deployment one, high frequency pressure signals were allowed to trigger events, and bad cabling caused excessive events to be recorded, filling the memory prematurely. For deployment two, only the optical sediment sensors were allowed to trigger events, and 146 events were recorded. Many of the events were only seen in one or the other optical sensor and probably associated with fish or floating debris. Other events had unique signatures, one type possibly due to passing ships.