Motion and pressure data recorded with Benthic Event Detectors (BEDs) in Monterey Canyon, offshore California

Benthic Event Detectors (BEDs) were placed in Monterey Canyon as part of the Monterey Canyon Coordinated Canyon Experiment (CCE). The CCE was set up to measure the passage of sediment gravity flows down Monterey Canyon. BEDs are "smart boulders" that record time-stamped acceleration, rotation, and ambient pressure data. Each BED device is a 43 cm diameter sphere with 1.8 g/cc density in air, weighing 81.5 Kg in air and 35 Kg in water. The experimental design of the CCE called for having BEDs on the canyon floor at 200, 300 and 400 m water depth. Within logistical constraints, after BEDs moved during sediment flows, these depths were repopulated with newly-deployed BEDs. A total of 11 BEDS and two AMT/BED deployments took place during the CCE. BEDs deployed multiple times are denoted with A, B and C for each deployment. CU indicates a cubic-shaped bed. BED deployment locations are listed under the station Acquisition Information tab. There are two types of data files presented here. The pressure data file, called MBCCE_BED_Depths_Time.xlsx, is an Excel spreadsheet that includes tide-adjusted depth of the BEDs during sediment gravity flows. The rotational data files are Excel spreadsheets that contain the raw quaternion data recorded by the inertial motion unit once the BED started to move due to the arrival of a sediment gravity flow. The four columns in each of the rotational data files are the quaternion components: quaternion component 1 (rotation angle parameter), quaternion component 2 (vector coordinate), quaternion component 3 (vector coordinate), and quaternion component 4 (vector coordinate). BED rotational data retrieved wirelessly from BEDs deployed on the seafloor have a sample resolution of 5 samples per second. The resolution of rotational data from BEDs that were physically recovered is 50 samples per second, except for BED05. Pressure changes were recorded 5 seconds after the initiation of motion. Thus, there is no depth information for the first 5 seconds of rotational motion. The rotational data file names are structured as BED ID_date of event (yyyymmdd)_sampling rate (5 Hz or 50 Hz)_optional (segment of the event or none if full event). For additional information about the BEDs, review the "Science Report" and download the file "CCE BED Deployment Locations" under the Documents tab. Funding for the project was provided by The David and Lucile Packard Foundation, Natural Environment Research Council (NE/K011480/1), U.S. Geological Survey,