Oceanography Flashcards
Kapita Selecta (104 cards)
What factors affect the density of ocean water
The density of a material is given in units of mass per unit volume and expressed in kilograms per cubic metre in the SI system of units. In oceanography the density of seawater has been expressed historically in grams per cubic centimetre. The density of seawater is a function of temperature, salinity, and pressure.
What is importance of oceanography
a) oceanography tells our about ocean and climate system
b) “ocean provides almost half of global oxygen “
c) ocean covers about 71 % of earth surface.
d) ocean is source of life , energy and resources
e) ocean is essential for life on Earth.
f) Oceans are a critical source and absorber of heat, moderating worldwide temperatures.
g) Ocean is considered as the source of food, minerals that are valuable, big place for business, place for recreation and disposal of waste.
h) Ocean waters are used for extracting minerals like salt, magnesium and bromine which can be utilized for commercial purpose. It is found that about 60 different elements are available in Oceans.
What are the explanations of sea waves?
There are many types of waves, all depend of its oscillation period and restore forces
what percent of total water is salt water
97.5%
measures how deep water is
bathymetry
how to measure bathymetry/depth
- rock and rope
- single beam sonar
- multi bean sonar
- satellite altimetry (doesnt measure depth)
average depth of ocean
12500 ft = 3.81 km
describes how temp of water changes
thermocline
describes change in salinity
halocline
average ocean temp
39 degrees F = 3,89C
any body of water with specific temp, salinity and density characteristics
water mass
below about ….. water is all about the same in relation to……
below about 2000m water is all about the same in relation to TEMP and SALINITY
:zone where theres enough light to see colors
: 100-600m in clear water
: 40m coastal waters (sediment cloudy and stirred)
photic zone
aphotic zone
below photic zone
zone where theres not enough light to see
water cycle
- Evaporation
- Condensation
- Precipitation
- Ground water
- Run off
- Transportation
- Respiration
sea water is made of (elements)
hydrogen
oxygen
sodium
chlorine
gases in water
carbon dioxide
nitrogen
oxygen
***cold water holds more gas
where does salt in seawater come from
- crustal rocks
- excess volatiles- volcanoes
- hydrothermal vents on mid ocean ridges
- mineral formation
- biological effects
biological effects –> salt in sea water
- formation of skeletons and shells
2. dissolution of dead organisms
:this occurs when trade winds slaken and even reverse direction
:cold water moves to western pacific (drought)
and hot water moves to Eastern pacific (rain)
El Niño
weather change in asia during El Niño
droughts
:occurs with worse normal conditions
:increasing speed of upwelling
:trade winds strengthen
La Niña
depth of surface water
down to 660ft =0.2 km
what causes tides
1) earth rotation: centrifugal force
2) gravitational pull of moon and sun