Rivers/Oceans Flashcards
(27 cards)
Stream
Any body of water that flows through a channel or trough
Braided Streams
Form when there is more sediment than the stream can carry
-carries course sediment during flooding events but cannot carry the load during normal flow which chokes the channel
*Gravel sediment doesnt stick together so stream divides and interweaves like a brain instead of forming a single channel
Mountain Streams
coarser sediment and river has a steeper gradient
Meandering Streams
Exist where stream gradient (slope) is gentle -flat/almost flat planes
Landforms along meandering stream?
1.) Levees
2.) Point-Bars
3.) Flood plains
4.) Cut-Banks
Continental Margins
No tectonic activity, boarders continental shelf
Active Margins
Tectonically active, trenches, thin shelf
North American Margins
Active=West coat
Passive=East coast
Passive Margins
Shelf-Thinned continental crust overlain by sediment
slope-transition ocean->crust
Rise-Sediment accumulation @ edge of slope
Coriolis Effect
NH: deflects moving air and water right (east)
SH: deflects moving air and water left (west)
Atmospheric Cells
Polar Cells: Poles
Hadley Cells: Equator
Ferrell: mid-latitude cells
(two types)
Climate Belts
1.) Tropical-Low pressure, high precipitation, heat
2.) Subtropical desert-> 30 degrees N & S latitude : Dry Air (where deserts exist)
Global Wind Patterns
Atmospheric circulation + Earth’s Rotation (Coriolis Effect )
Surface Currents
form due to movement of wind over the oceans
Generated by:
1.) Ekman Transport
-Coriolis Effect causes net flow to be perpendicular to wind direction
Ocean Gyres
Mound of water surrounded by circular currents
Sub-Tropical Gyres
redistribute heat from equator towards the poles.
-lead to upwelling of cold, nutrient rich water along CA coast
-Surface currents impact upper 100-200 m of the oceans
Western -Boundary Currents
Gyre-mounds build up on west side of ocean basins due to
1.) Earths Rotation
2.) Convergence of Trade winds along equator.
=strong, focused western boundary currents
El Nino
Weakens trade winds which causes warm waters from western pacific to move into Eastern Pacific -> decreases cold upwelling
*Reverses trade winds:
(normally E-> W)
3-8 yr cycle
Thermohaline Circulation
driven by water temp and salinity
-shallow currents=warm, lower salinity
-deep currents=cold, high salinity
100-1000yr for full cycle
Trade-winds
E-> W
Westerlies
W->E
Tides
2 high tides, 2 low tides per day
Spring Tides
max diff between low and high tides
Neap Tides
min diff between low and high tides
(T/F) Spring and Neap Tides occur during a full Moon
True