1. Bathymetry Lab Adam Fox Coastal Carolina University

2. What is Bathymetry? Bathymetry: the measurement of water depth. Multiple measurements of depth can used to visualize the topography of the sea floor. Bathymetry: the measurement of water depth. Multiple measurements of depth can used to visualize the topography of the sea floor.

3. Why Map the Sea Floor?

4. To learn about the deep parts of the ocean that are hard to observe To learn about the deep parts of the ocean that are hard to observe To gather information about plate tectonics To gather information about plate tectonics To find shipwrecks and other items of interest To find shipwrecks and other items of interest To aid in navigation To aid in navigation

5. Mapping the Sea Floor How do we map the sea floor today? How do we map the sea floor today?

6. Satellite Altimetry Satellite Altimetry Use satellites to measure sea surface height Use satellites to measure sea surface height Sea surface height corresponds to sea floor height Sea surface height corresponds to sea floor height Graphic: topex.ucsd.edu

7. Side-Scan Sonar Side-Scan Sonar Very detailed images of small areas of sea floor Very detailed images of small areas of sea floor

8. Photo: NOAA Satellite Altimetry Satellite Altimetry Use satellites to measure sea surface height Use satellites to measure sea surface height Sea surface height corresponds to sea floor height Sea surface height corresponds to sea floor height AUVs can also be used to map the sea floor AUVs can also be used to map the sea floor

9. Mapping the Sea Floor How did we map the sea floor before satellites? How did we map the sea floor before satellites?

10. Echo-sounding Echo-sounding Send sound waves down to sea floor Send sound waves down to sea floor Listen for them to bounce back. Listen for them to bounce back. Use a formula to calculate water depth Use a formula to calculate water depth Multi-beam bathymetry Multi-beam bathymetry Use lots of sound beams at once Use lots of sound beams at once Graphic: saddleback.edu

11. Mapping the Sea Floor What about before then? What about before then?

12. Mapping the Sea Floor Lead Lines Lead Lines A weighted rope with depth markings A weighted rope with depth markings Photo: NOAA

13. Graphic: Fugro Pelagos

14. Maps of the Ocean Floor Contour Map Contour Map Contour lines (isobaths) connect areas of similar height/depth Contour lines (isobaths) connect areas of similar height/depth Bathymetric Cross-Section Bathymetric Cross-Section Shows what it would be like if you walked along the sea floor on a specific line Shows what it would be like if you walked along the sea floor on a specific line Depth often exaggerated to make features more visible Depth often exaggerated to make features more visible

15. Maps of the Ocean Floor Image: NOAA Contour Map Cross-Section

16. * We would like to know more about our local water body. What questions do we have about the pond itself?