Bathymetry: Mapping the Sea Floor Why might mapping be an essential part of ocean exploration? Maps are models – accuracy improving Land based topographic map So how do we map the seafloor? 1

Topo-maps 2

Contour map of Monterey “Submerged Valley” 1897 3

Geologic Provinces of the Ocean

Continental Shelf

Submarine Canyon off Monterrey

Geologic Provinces of the Ocean

Shelf Break off New Jersey

Geologic Provinces of the Ocean

Continental Slope Oregon Coast (from the west – looking east)

Geologic Provinces of the Ocean

Geologic Provinces of the Ocean

Geologic Provinces of the Ocean

Abyssal Plain off New Jersey (4000-6000 m)

SHALLOWER >>>> DEEPER Color Spectrum ROYGBIV SHALLOWER >>>> DEEPER

Astoria Canyon off Washington/Oregon 16

Flat-topped Bear Seamount ~200 miles from Woods Hole, MA Rises ~2000 m from the ocean floor to a depth of 1100 m 17

What is this? 18

Above Sea Level 400’ 300’ 200’ 100’

Below Sea Level 100’ 200’ 300’ 400’ 500’

Land or Sea? Land or Sea? 400’ 300’ 200’ 100’ 200’ 300’ 100’ 400’

Land or Sea? Land or Sea? 400’ 300’ 200’ 100’ 200’ 300’ 100’ 400’ 23

400’ 300’ 200’ 100’ 100’ 200’ 300’ 400’ 500’