Ocean topography Flashcards
Meridians
intersection at Earth’s surface of a plane perpendicular to the equatorial plane and passing through Earth’s axis
Standard meridian: GMT 0 degrees E or W
Ocean dimensions
1,500-13,000 km width
3-4 km depth
Horizontal dimensions are 1,000 times greater than vertical dimensions
Earth layers
core (inner and outer), lower mantle, asthenosphere, lithosphere
Lithosphere = continental and oceanic crusts
Continents rise about ocean because they’re more buoyant
Seafloor spreading
new seafloor develops at mid-ocean ridges and spreads outward
continents pushed aside
mid-ocean ridges are a heat source
Oceanic crust is younger than continental crust
ocean floor sediments thickest at edge of Atlantic
there are mid-ocean ridges that match the shape of the shorelines
Plate tectonics
convection currents
there is destruction and rearrangement of the crust to compensate for formation
subduction and collision
Plate boundary types
divergent - move apart
convergent - may collide
transverse/transform - slide laterally past each other
Active and passive margins
passive - face the edges of diverging plates
active - face the edges of converging plates
Provinces of ocean floor
continental margin - submerged outer edge of continent consisting of continental shelf, continental slope, and continental rise
Sediment
particles of organic or inorganic matter that accumulate in a loose, unconsolidated form
origin can be living or non-living
broad range of size and type
Sediment types
terrigenous - from land, mainly brought by rivers
biogenous - from bio origin, sinks to ocean bottom
hydrogenous - from minerals in seawater, dissolution and precipitation
cosmogenous - from space, material falling from top of atmosphere
Stratigraphy
discipline that analyzes sed. deposits
