the world ocean Flashcards
definition ocean
- body of saline water covering earth
- belongs to hydropshere, containing more than 97% of it
- subdivided into 5 major oceans > pacific, atlantic, indian, arctic, southern antarctic
definition sea
- body of saline water associated w/ one of five oceans
- strictly speaking: partly or fully enclosed by land
types of sea
• marginal seas (randmeere) > sea partially enclosed (islands or peninsulas) > labrador sea
• mediterranean seas (mittelmeer) > completely enclosed
• regional seas > named by a region, near a region
• epeiric seas (inland) > completely surrounded by dry land or connected to ocean by river > black sea
hypsographic curve
• land: 29,2%
• ocean: 70.8%
• average elevation land: 840m
• average elevation depth ocean: 3729m
why is mapping floor of important?
- safety of ships
- improve weather predictions (tsunami predictions)
- better understanding (on how to protect ocean) of ocean
- expand knowledge ocean life
- exploitation of resources
why is it a two edged sword?
-mapping ocean will encourage others to help and protect ocean while some will take advantage of it and destroy and exploit ocean/resources > double edged sword
how can both sides benefit from exploration?
- make it possible that others have access to it (share it) but still not exploit it, by limiting the access > will still profit from it but also protect it
- find common ground
ways to map floor
- satalite mapping
- solar echoes > send sound waves, calculate depth
- drones
- sonar (vessels) > submarines on floor
distribution of earth’s water
- total global water:
• oceans: hold 96,5%
• other saline water: 0.9% > other storage for salt water
• fresh water: 2,5% > consists of 70% glaciers and ice caps, and 30% ground water
the water cycle
- cycle which represents the path water can take in its different states within the spheres: ocean, land, atmosphere
the water cycle explained:
- water from water bodies evaporates and rises to atmosphere
- ice on mountains sublimates and rises to atmosphere
- plants, humans, surfaces release water trough transpiration
- > condenses to form clouds > clouds release precipitation (rain, snow)
- surface flow > rivers
- deposits on mountainz
- absorbed through soil > ground water
- ground water taken up by planets again
- cycle repeats
water budget elements: water balance equation
- precipitation (P): both over water and land surfaces
- runoff (R): surface flow, interflow, groundwater flow .> flowing back into ocean
- evapotranspiration (E): evaporation + transpiration
- Storage (S): lentic water, ice, glaciers, infiltration (stausee)
ocean currents - the global ocean conveyer belt:
- what is it?
- system of ocean that transport water around world
- ocean currents: patterns of water movement, which influence climate zones and weather patterns around world
- primarily driven by sea water density and by wind > two currents: surface and deepwater currents
how do ocean currents work?
- at poles, cold ocean water becomes saltier/denser and then this cold, dense, salty water sinks to seafloor, creating deep currents
- currents flows freely towards equator and starts to warm up > becoming less dense, rising to surface in upwellings > surface current
- warm water flows towards pole completing cycle
what is the importance of ocean currents?
- keeps earth’s climate stable (regulate them)
- hugely impact humankind and biosphere in general
ocean currents - the gulf stream
what is it?
- one of the largest currents, bringing warm water from Gulf of Mexico to North West of Europe and Northw. of Africa
how does the gulf stream work?
- originates from mexico > water flows towars nw europe > while traveling to nw europe: gets colder and saltier > thus becoming denser > this cold, dense, water sinks, creating chimneys which travel to both sides
- water gets slightly warmer, flows back to origin, rises to surface: upwellings
- cycle completed
how does climate change affect gulf stream?
- ice bergs/sheets melt bc of CC > fresh water (sweet) enters salt water > salinity of water **decreases ** but temperature of cold water increases
- since water gets less dense bc of intrusion of fresh water > not able to sink > chimneys become smler and maybe extinct
- cycle will break
what are the consequences of CC?
- temperatures will rapidly decrease in Europe > higher chance that we’ll face another “ice age”
- longer winters
topography -
-
pacific ocean:
• bering sea
• east china sea
• gulf of alaska
• sea of japan -
atlantic ocean:
• caribbean sea
• gulf of mexico
• gulf of guinea
• labrador sea -
indian ocean:
• arabian sea
• bay of bengal
• persian gulf
• gulf of aden -
arctic ocean:
• beaufort sea
• hudson bay
• laptev sea
• greenland sea -
other seas:
• black sea
• caspian sea
• baltic sea -
straits:
• bering strait
• bass strait
• formosa strait
• sunda strait
topography of the ocean floor
(1) continent/seashore
(2) continental shelf > edge of continent that lies under ocean, part of continental margin
—— sea level ——
(3) continental slopes > edge between continent and oceanic crust, plunges steeply into abyss
-> submarine canyon: V-shaped valleys, created by falling ocean waters
(4) rise > gently sloping transition between continental slope and deep ocean floor
(5) guyot > undersea mountain with a flat too
(6) magma > hot fluid or semi-fluid material
(7) mid-ocean ridge > seafloor mountain system formed by plate tectonics > two plates diverge
(8) seamount > submarine mountain
(9) abyssal plain > ocean floor
( abyssal hill > small hill, rises from abyssal plain)
(10) island arc + volcanic island > chain/ group of islands that forms from volcanic activity
(11) trench > long, narrow depressions on seafloor > plates moving towards each other
