FY 1988

Automated display and statistical analysis of interpreted deep-sea bottom photographs

Fox, C.G., K.M. Murphy, and R.W. Embley

Mar. Geol., 78, doi: 10.1016/0025-3227(88)90109-0, 199–216 (1988)

An automated system for interpreting and displaying deep-sea bottom photographs has been developed which allows rapid compilation and analysis of geological information. Initially, collected photographs are classified using a scheme similar to those applied to deep-sea volcanic and hydrothermal terrains by other workers. Towed-camera positions from a transponder navigation system are smoothed using a cubic spline technique to obtain a more accurate model of the two-vehicle track. Line scan recorded data of the camera's height above the seafloor and camera lens characteristics are used to calculate the field of view for each photograph. These data sources are integrated to produce a graphic output which combines the location, orientation, field of view, geological, and biological information for all photographs in a single color display. An illustration of the technique is presented for a photographic data set collected within the caldera of Axial Seamount (45°57'N, 130°03'W), a site of active high and low temperature hydrothermal venting on the central Juan de Fuca Ridge. Results confirm the existence and pinpoint the locations of several areas of known hydrothermal activity within the caldera. Quantitative analyses of the data base indicate statistical associations between various geological and hydrothermal parameters. In particular, rigorous statistical testing indicates that hydrothermal activity is associated with regions dominated by sheet flow lavas and fracturing.