1. Word Bank for PT WS Ridges trenches (slide past) deconstruction Earthquakes boundary magma constructive Divergent convergent transform less more Crust (more dense) (Mid Ocean Ridge) Rocks plates moving asthenosphere

2. Ocean Bathymetry Topography of the ocean floor

3. Bathymetry Bathymetry is the study of underwater depth of lake or ocean floors.

4. Video http://www.extremescience.com/challe nger-deep-video.htm

5. Main Regions Continental Margins – drowned edges of the continents Deep-ocean Basins – the ocean floor that lies deeper than 2000 m Mid-ocean Ridges – a continuous underwater mountain range that winds its way through all the oceans

6. Video http://www.youtube.com/watch?v=pTG -pvAzNJI&feature=related http://oceanexplorer.noaa.gov/explorati ons/02fire/logs/magicmountain/welcom e.html

7. Continental Margins From the land: Continental shelf – almost flat, gradual slope seaward at the edges of the continents; covered with sediments from the land Continental slope – steeper slope seaward; contains submarine canyons Continental rise – shallower slope composed of sediments that have fallen from slope.

8. Continental Margin

9. Deep-Ocean Basins Lie beyond the continental margins and contain: Abyssal plains – very flat areas at depths of 3-5 km Seamounts – underwater volcanoes, some > 1000 m high Deep-sea trenches – steep-sided, long, narrow depressions. Deepest regions on earth; found near continental margins

10. Deep-Ocean Basins

11. Mid-Ocean Ridges Underwater mountain ranges that are the longest on earth Occupy 1/3 of the ocean floor Not all are “mid-ocean” Contain rift valleys at the summits as well as many fracture zones, where rocks have cracked and slid past one another

12. Mid-Ocean Ridges

13. Video on Ridges http://www.montereyinstitute.org/noaa /lesson02.html

14. Mid-Ocean Ridge Locations

17. Which coast has the wider shelf?