GEOLOGY 103 Lecture Notes - Lecture 5: University Of Manchester, Echo Sounding, Sound

• School: UMASS-Amherst
• Department: Geology
• Course: GEOLOGY 103
• Professor: Stephen Burns

Document Summary

Bathymetry describes the spatial variations of water depth. 98% of us import by weight come by sea. For resources exploration and explanation: oil, gas and other minerals, fisheries, habitat. Bathymetric maps: depict topography of seafloor; isobaths connect points of equal points of elevation. Sound source & receiver (hydrophone) on hull ship. High frequency sound wave travel through water, reflect off the seafloor, and are recorded by hydrophone. Provide continuous depth profiles along a ships track. Typical profile from the eastern coast of the untied state. What we know: v (speed of sound ~1460 m/s) =d/t. What we measure: t= times it takes for sound for sound to bounce of ocean floor and return, twt (two way traveling time) What we can calculate: d= depth, d= v*(t/2) Side scan sonar: like echo sounder, but it images a 60km swaths of seafloor, overlapping swaths= completely coverage 3d images.