1. Lesson 6: Exploring the Seafloor

3. Bathymetry Definition: Underwater topography
Only 10% of ocean has been mapped
As varied as the land’s surface
Contains Earth’s tallest mountain
Contains Earth’s widest plains
Contains Earth’s deepest valleys

4. Bathymetry Definition: Underwater topography
Only 10% of ocean has been mapped
Earth’s final frontier
As varied as the land’s surface
Contains Earth’s tallest mountain (Mauna Kea)
Contains Earth’s widest plains
Contains Earth’s deepest valleys (Mariana Trench)

5. How is the topography mapped?

6. Instruments Used
1. Plumb lines

7. Instruments Used
2. SONAR (Sound Navigation & Ranging) * Utilizes knowledge of speed of sound in water * Equation: Sea Depth = ½ TV T – time for sound to return to transmitter V – velocity of sound in water (1500 m/sec) * 2 types : a) side scan b) multibeam

8. Instruments Used Dragged behind ship Image related to echo’s intensity
Side scan
Multibeam
Dragged behind ship
Image related to echo’s intensity
Pulse emitted from ship’s hull
Image related to echo’s travel time

9. Instruments Used
3. Orbiting satellites * sea surface is directly related to seafloor features

10. Figure 6.29 Identify each seafloor feature represented with
the letters

11. Figure 6.29 A – Continental shelf B – Continental slope
C – Continental rise
D – Abyssal plain
E – Seamounts
F – Mid-ocean ridge
G – Trench
H – Submarine canyon

12. Figure 6.30

13. Figure 6.31 Describe the topography of the seafloor near the
Mississippi River
Delta in the Gulf of
Mexico

14. Figure 6.32
Name two seafloor
features that are
evident in this
image.

15. Give one similarity and one difference

16. Seafloor sediment

17. Seafloor Sediment What is sediment? 4 types seen in the ocean
a) terrigenous sediment
* originates from land
* primarily abiotic materials
* erosion carries particles downstream to the ocean (watershed)
* composition based on where the sediment originates

18. Seafloor Sediment 4 types seen in the ocean b) biogenous sediment
* originates from living organisms
* primarily phytoplankton
*also weathering & erosion of coral reefs

19. Seafloor Sediment 4 types seen in the ocean c) hydrogenous sediment
* originates as precipitates out of seawater
* contains many minerals
d) cosmogenous sediment
* originates from space

20. HI MOMMY ITS MICHELLE LOVE YOU!!!!! <3

21. Why study bathymetry?

22. Bathymetry influences where marine organisms live
Gray Seal
Southern Elephant Seal