Ocean Ography Study Sheet

*e r 6371km, oc d avg. 4k..mx 11k, oc covers 70% of e, lithosphere d 100km *crust-silicate, mantle-denser silicate, core-mostly iron*lithosphere 100km strong crust and mantle, Aesthenosphere weak partly melted mantle*oc-crust(lithosphere)-thinner 7km, denser, basaltic. cont- crust(lithosphere) – 20-70km, granitic*S-waves no water*Isostasy: litho floates on Aestho***Corral F-B-A*CaCo3*water bad/no light-plants leave corral-no rock*Cont. shelf s0.1-0.5 d100-130m w~70km, shelf break, Cont. slope s 4-10, ex 130m d 2000m + w-35, sediment fills-Cont. rise w 200-300km (see Submarine cyn)* Sudmarine cyn – gullies/canyons, cut by river/Turbidity crnts(dense mud/water mixture avalanche downslope) – sediment spreads & stops at end forming Deep sea fan ( as the abyssal fans next to each other combine, they form the continental rise*Abyssal plains –flat oc sediment covers its*guyots- flat top used to b area where breaking waves passed over*SOCAL boarder filled w/ shallow banks(or islands) & deep basins, formed by movements by diffrnt pieces of crust & related volcanic activity(not normal)seismically active still*Divergent (Rifting of continents= it is stretched until it breaks. basalt from the mantle will fill-in between the diverging cont. fragments. If divergent continues, a widening ocean basin is made (water fills in ex..pangea, baja CA, red sea) between cont. pieces, the youngest occurs in the middle of the oc ridge forming a mid-ocean ridge) makes ocean ridge system (balsaltic magma rises into the axial rift valley & is added to each plate, the ridge is younger and less dense so it stands up higher as it ages, cools & becomes denser it slides down sides (divergent makes ocean plate/basin/litho)..Divergent volcanoes are basalt and form oc litho. Convergent –subduction of denser plate, makes oc trench/volcanic arcs ... Andesite (cont. lithosphere) volcanic activity occurs( cont. lithosphere is made by convergent)   (oc plate vs cont. plate – oc plate subducted..Cont vs Cont...