Data Catalog

Physical characteristics of the aSOAs used in these experiments, such as diameter, shape, color, mass, volume, and density, are provided in table 1. Each individual aSOA has a unique identifier consisting of three characters: a number indicating size, where 1 corresponds to a 0.5-cm diameter, 2 corresponds to a 1-cm diameter, 3 corresponds to a 2.50-cm diameter, 4 corresponds to a 5-cm diameter, and 5 corresponds to a 10-cm diameter; a character indicating shape, with “R” denoting round and “E” denoting ellipsoidal aSOAs; and a unique number to distinguish individual aSOAs with the same size and shape. In the case of the ellipsoidal aSOAs, the diameter is defined as the width of the aSOA rather than the height.

Incipient Motion Experiments (Fixed Floor)

Critical stress values for aSOAs, along with calculated shear stress at the moment of incipient motion, are found in table 2. Provided below are links to the movies created from video and water-velocity data collected during the false-floor incipient motion experiments. For most of the experiments, the BLAST system is used and these videos are of the darkened experimental tank, with one or a few aSOAs intersecting the planar laser line. Video of the illuminated tank and aSOAs are shown for experiments where laser data with the BLAST system were not collected. Except for two time periods when the velocity profiler malfunctioned, time series of velocity data and calculated stress are also provided. A dashed line crossing this time series vertically coincides with the identified instant of incipient motion in the video. A yellow dot on the time series indicates the stress at the current video time. Videos are clipped to the time period surrounding the instant of incipient motion—approximately 30 seconds preceding incipient motion and 12 seconds following incipient motion—when available. Movies that exclude velocity and stress time-series plots have been created for cases in which the first instance of incipient motion occurs outside of the time series of collected velocity data. In cases of multiple aSOAs deployed during the same experiments, separate videos were created, where each was clipped to the time of incipient motion of the individual aSOA. Note that incipient motion may be difficult to detect without a frame-by-frame analysis due to the subtlety of the movement, in particular for ellipsoidal aSOAs that may initially move via a small sliding motion.  

Sea-Floor Interaction Experiments (Movable Sand Bed)

Provided below are links to video data for sea-floor interaction experiments conducted on a movable sand bed. Videos have been compressed to save storage as described in Data Processing, but have not been edited or cropped in time. To accommodate instrument-data record-length capabilities and limit file size to a manageable level, each individual experiment is broken into segments consisting of data from one of the two cameras (delineated as A and B) over a subsection of the experiment time. The aSOAs listed are those in the tank at the time of the experiment and may not be visible in the field of view of one or both cameras. When aSOAs have not moved significantly from their starting position, it is possible to determine their identifiers, as indicated below. In experiment C, a GoPro camera was placed in the tank to provide a unique perspective of aSOA motion and sand-bed evolution, and it is visible in the videos from the external cameras. In cases where the velocity data were offset in time from the video data due to a delay in starting the Vectrino, a time vector corresponding to the video data time is also included in the velocity data file.