IODP Proceedings    Volume contents     Search
iodp logo



Routine high-resolution digital imaging of individual core sections began during Leg 198 of the Ocean Drilling Program in 2001. The images collected are of extremely high resolution at ~10 pixels per millimeter of core. They represent an excellent visual record of a core section soon after it is split and are a welcome addition to the ocean drilling database. These images, however, have not been fully exploited as a valuable source of quantitative data. In this study, we extract from the digital images only the sediment portion of the pictures. The extracted section images are then scaled to a common depth resolution and combined to form compound core images. The intervals of the compound core images used in the composite section are then extracted to form a composite site image.

Images are stored in the Integrated Ocean Drilling Program (IODP) database as three-dimensional matrixes with red, green, and blue (RGB) layers. The images can also be transformed into other color schemes, such as hue, saturation, and lightness (HSL). Full maps or profiles of these properties can be extracted and compared to discrete core analysis data. The images can be color-enhanced to highlight features that are not easily seen in the raw data or in the actual cores themselves.

As a demonstration of the use of depth-calibrated digital core images we examined how well the meters composite depth (mcd) scale of features in the composite site section match with the mcd scale of those same features in core that was not used in the composite. We examined 18 holes from five sites (U1304–U1308) cored during Expedition 303. The results suggest that most cores are in reasonable agreement within and outside of the composite.