chapter 13 Flashcards
(23 cards)
Challenger Deep
deepest spot in the ocean floor
bathymetry
topography of the ocean floor
sonar
using sound energy to measure depth of sea floor
echo sounders
bounce a sound off an object to determine distance
3 major areas of the ocean floor
continental margins
deep ocean basins
oceanic ridges
Continental margins
outer margins of the continents and the transition to oceanic crust
Deep ocean basins
between the continental margins and the oceanic ridges
Ocean ridges
a broad, linear swell at a divergent plate boundary
Passive Continental Margins
Found along coastal areas that surround the Atlantic Ocean
Not associated with plate boundaries
Experience little volcanism and few earthquakes
Continental shelf
gently sloping, flooded portion of continent
Passive continental margin
Continental slope
steep structure that marks the boundary between the continental and oceanic crust
Passive continental margins
Continental rise
thick accumulation of sediment from the continental slope
carried by turnidity currents down sub-marine canyons
Passive continental margins
Active Continental Margins
where the oceanic lithosphere is being subducted beneath the continent
associated with the deep-ocean trenches
Located primarily around the Pacific Ocean
Deep-Ocean Trench
Long narrow creases that represent the deepest part of the seafloor
Associated with volcanic activity
Mostly found in the Pacific Ocean
Abyssal Plains
Flat features of the ocean floor
most level places on earth
thick accumulations of sediment
most found in atlantic ocean
seamounts
submarine volcanoes
some can grow into volcanic islands
Guyots
submerged, flat-topped seamounts
oceanic plateaus
vast outpourings of basaltic lavas on the ocean floor
Ocean ridge
longest topographic feature on Earth Occupy elevated positions offset by transform faults extensive faulting and earthquakes a rift valley exists on the axis of most ridges
seafloor spreading
melt escapes to sea floor and erupts as lava
Layers of the ocean floor
- Deep-sea sediment
- Basaltic pillow lavas
- Sheeted dike complex
- Gabbro
- Mantle
black smokers
particle filled clouds that percipitate from various metals from the rock
continental rift
elongated depression where the lithosphere is stretched and thinned