3
Descriptive Oceanography
500 and an average width of 65 km. The break in slope is the outer limit of the shelf and
has a slope of about 1 to 20 and an average depth of 130 m. The continental slope is about
4000 m from the shelf to the deep- sea bottom. In some places, it extends as much as 9000 m
vertically over a relatively short horizontal distance (e.g., off the western coast of America).
The deep- sea bottom represents the most extensive topographic area (76% of ocean basins)
Sea Level
Break in Slope
Deep Sea Bottom
Basin
Sea
Mount
Island Arc
Trench
Sh elf
S lo p e
Low Water
High Water
Shore
Continent
Figure 1.1
Structure of the ocean floor.
Okinawa
Trough
Mariana Trough
Manus & Woodlark
Basins
Guaymas Basin
Gorda Ridge
S.Explorer Ridge
Juan de Fuca Ridge
Lau Basin
Galápagos Rift
East Pacific Rise
C h il e R is e
N. Fiji Basin
Havre
Trough
Southeast Indian Ridge
Pacific Atlantic Ridge
Azores
Red
Sea
Central
Indian
Ridge
SE Indian
Ridge
Bouvet
T.J.
Scotia
Plate
E. Scotia Ridge
M id A tl an ti c
Ridge
S .W
. In d ia n R id g e
Rodrigues
T.J.
Locations of known hydrothermal activity along the global mid-ocean ridge system
= Known active sites
= Active sites indicated by midwater chemical anomalies
Figure 1.2
Active ridge systems in the oceans.
Descriptive Oceanography
500 and an average width of 65 km. The break in slope is the outer limit of the shelf and
has a slope of about 1 to 20 and an average depth of 130 m. The continental slope is about
4000 m from the shelf to the deep- sea bottom. In some places, it extends as much as 9000 m
vertically over a relatively short horizontal distance (e.g., off the western coast of America).
The deep- sea bottom represents the most extensive topographic area (76% of ocean basins)
Sea Level
Break in Slope
Deep Sea Bottom
Basin
Sea
Mount
Island Arc
Trench
Sh elf
S lo p e
Low Water
High Water
Shore
Continent
Figure 1.1
Structure of the ocean floor.
Okinawa
Trough
Mariana Trough
Manus & Woodlark
Basins
Guaymas Basin
Gorda Ridge
S.Explorer Ridge
Juan de Fuca Ridge
Lau Basin
Galápagos Rift
East Pacific Rise
C h il e R is e
N. Fiji Basin
Havre
Trough
Southeast Indian Ridge
Pacific Atlantic Ridge
Azores
Red
Sea
Central
Indian
Ridge
SE Indian
Ridge
Bouvet
T.J.
Scotia
Plate
E. Scotia Ridge
M id A tl an ti c
Ridge
S .W
. In d ia n R id g e
Rodrigues
T.J.
Locations of known hydrothermal activity along the global mid-ocean ridge system
= Known active sites
= Active sites indicated by midwater chemical anomalies
Figure 1.2
Active ridge systems in the oceans.