Interferometric Synthetic Aperture Sonar (ISAS) offers the possibility of high resolution, three-dimensional images of objects on the ocean floor. The height of objects is identified from the phase difference between two synthetic aperture images of the object obtained using two receivers separated by a short distance. A central problem is the need to unwrap the phase difference in the presence...

Some of Earth's largest iron-nickel (Fe-Ni) sulfide ore deposits formed during the Archean and early Proterozoic. Establishing the origin of the metals and sulfur in these deposits is critical for understanding their genesis. Here, we present multiple sulfur isotope data implying that the sulfur in Archean komatiite-hosted Fe-Ni sulfide deposits was previously processed through the atmosphere a...

-Ti, V, Cr, Fe, Co, Ni, Cu, and Zn have been analyzed from Sites 211,213,214,215,and 216 of DSDP Leg 22 of the Clomar Challenger in the northeastern lndian Ocean. According to these trace elements, three different types of source material are broadly defined: the basin floor basalts with a composition sirnilar to tholeiites from mid-oceanic ridges, the basalts and the differentiated rocks from ...

When underwater vehicles perform navigation close to the ocean floor, computer vision techniques can be applied to obtain quite accurate motion estimates. The most crucial step in the vision-based estimation of the vehicle motion consists on detecting matchings between image pairs. Here we propose the extensive use of texture analysis as a tool to ameliorate the correspondence problem in underw...

Unknown planet: Around 72% of the Earth’s surface is covered by oceans, and much of that surface is still unchartered territory for science. (Graphic: SuperStock.) More than seventy percent of the surface of our planet is covered by oceans. 88 percent of their area is deeper than 1,000 metres and thus difficult to access for research. There are only a handful of research submersibles that can d...

Abstract Understanding the recent history of Thwaites Glacier, and processes controlling its ongoing retreat, is key to projecting Antarctic contributions future sea-level rise. Of particular concern how glacier grounding zone might evolve over coming decades where it stabilized by sea-floor bathymetric highs. Here we use geophysical data from an autonomous underwater vehicle deployed at Glacie...