Oceanography Flashcards
Kapita Selecta
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
green house gases
CO2
methane :CH4
H20 vapor
allow visible light to pass thru which is absorbed by earth and released as heat, but hat cannot pass thru gases and is stuck on earth building up
green house gases
:highest net primary productivity
:pulls highest amount of carbon out of atm or ocean and produce O2
coral reefs
diatoms draw in … to produce …
draw in CO2 to produce glucose
remove carbon from atm
sinks
5 sinks
1) weathering of granite
2) photosynthesis
3) burial of biomass
4) deposition of carbonate sediments
5) CO2 dissolves in sea water
important for life in ocean and is responsible for protein which is used by plants and animals
nitrogen
euphotic zone depth
down to 70m
which of the following organisms makes its skeleton out of silica (glass)
diatoms and radiolarians
tiny animals that disrupt the layers of sediment, making core samples to need preservatives
meiofauna
Benthic zones
Supralittoral Littoral Sublittoral Bathyal Abyssa Hadal
zones by depth
Epipelagic
Mesopelagic
Bathypelagic
Abyssopelagic
Deep ocean currents are driven primarily by
density differences
Which swift-flowing surface current in a major subtropical gyre transports a large volume of warm water from the equator toward mid-latitudes?
Kuroshio Current. Western boundary currents are responsible for the mass transport of warm water toward the poles. The Kuroshio Current is the western boundary current in the North Pacific Subtropical Gyre.
gyres
Surface currents form circular patterns in the major ocean basins
Surface ocean currents are driven primarily by ..
and modifie by….
wind; the Coriolis effect and land
The zone that lies between the lowest tide level and the highest elevation on land that is affected by storm waves is known as the ________.
shore
coast
The zone extends inland from the shore to as far as ocean-related features can be found is known as the
The part of the shore that is exposed at low tide and submerged at high tide is known as the
foreshore
The speed of longshore currents decreases as what increases?
wave period
Which of the following is not considered a pollutant in the marine environment? Phytoplankton Nutrient runoff Sewage sludge Heavy metals such as mercury and silver Hydrocarbons
Phytoplankton
Which of the following kingdoms includes species that function primarily as decomposers in the marine ecosystem?
Fungi
lives on top of benthic sediments
epifauna
Which of the following is not an effect of climate change in the oceans? melting of polar ice decreasing ocean acidity increasing ocean temperatures changes in deep-water circulation increasing hurricane intensity
decreasing ocean acidity
Name the zone of rapidly changing temperature with depth.
Thermocline
The relationship between temperature and density is…
Inverse
This layer has sufficient sunlight for photosynthesis; its depth is usually 20-60 meters, rarely 100 meters.
Photic zone
What is the % of the deep ocean?
80%; except polar region
Average depth of the ocean?
3800m
What’s a term for ‘deep ocean’?
Pelagic
These are a marine autotrophs that photosynthesize organic material from inorganic material.
Phytoplankton
This type of phytoplankton has a silica (silicious) shell.
Diatoms
What are the most common dissolved substances in sea water by percent?
Chlorine (55%) Sodium (30.6%) Sulfate (7.7%) Magnesium (3.7%) Potassium (1.1%)
Density ___ with increasing salt
increases
Density ___ with increasing temp
decreases
Define Deep Currents
High density caused by temperature and salinity differences at the surface
How deep do surface currents exist?
One Kilometer
The thermocline is:
The decrease in temperature with depth.
Halocline is the change in ______ with depth.
Salinity
What is Oligotrophic?
Pelagic environment (water column) that has low plant nutrient concentrations. Subtropical gyres are oligotrophic.
What is Eutrophic?
Pelagic environment (water column) has high plant nutrient concentrations. Coastal upwelling zones are eutrophic.
What is Net Primary Production (NPP)?
Net Primary Production is the difference between the amount of CO2 consumed by photosynthesis and the amount of CO2 produced by respiration.
It is the net gain or net loss of carbon within the cell.
What happens to light levels below compensation light level?
Phytoplankton cells have insufficient light to photosynthesize to meet basal metabolic needs and cell respiration exceeds photosynthesis, leading to negative values of net primary production.
What happens to phytoplankton at low light levels, optimal light levels, and very high light levels?
Phytoplankton cells have insufficient light to photosynthesize to meet basal metabolic needs and cell respiration exceeds photosynthesis, leading to negative values of net primary production.
What is compensation depth?
The depth at which ambient light intensity is equal to compensation light intensity.
What is the main source of nitrogen, phosphorus, and silica to the surface ocean?
Vertically mixing or upwelling of nutrient-rich deep-water to the surface.
What nutrients limit growth of phytoplankton?
Nitrogen limits growth of phytoplankton in the ocean, but iron and phosphate may limit growth in certain oceanic regions.
What is a trophic level (refined grouping)?
A nutritional feeding level within a food chain or food web such as primary producer (autotroph), primary consumer (herbivore), secondary consumer
(first carnivore), and tertiary consumer (second carnivore).
What is Gross Growth (Production) Efficiency?
Amount of CONSUMER BIOMASS produced divided by amount of PREY INGESTED. This efficiency ranges between 20% and 60%.
What are some factors affecting primary productivity?
- nutrient availability
* biogeochemical cycling
* upwelling
* productivity in tropical oceans
* equatorial upwelling
* coastal upwelling
* high-latitude regions
* polar ocean productivity
* temperate ocean productivity
in upwelling there is diverging _______
surface water
is there a high or low biological productivity in upwelling?
High
Why is it important to study the ocean? (8 reasons)
- The ocean is vast.
- The ocean controls Earth’s climate.
- The ocean is diverse.
- The ocean is a valuable human resource.
- Marine organisms produce most of Earth’s O2.
- The ocean is vital to transportation.
- The ocean is a neighbor. More people than ever around the globe are living on or near the cost.
- The ocean offers employment. Many people directly or indirectly make a living from the ocean and it’s resources.
Define physical oceanography.
The study of waves and currents, climate prediction.
Define marine biology.
The study of nature and distribution of marine critters.
Define chemical oceanography.
The study of the gases and solids dissolved in the ocean.
Plankton Net
Collects floaters and drifters, microorganisms, bad swimmers.
IMPORTANT BECAUSE: - animal plankton are food
- oxygen
What are waves caused by?
The interaction between air and water.
What does it take to get such big waves?
- Wind speed
- Duration
- Fetch - area of the ocean
What is a wave?
Winds push water up (wind transports energy)
- Water particles move in circles
- Energy forces waves up when they reach shore
- Waves crash on shore
Technology - Robots
What is ROV?
What is AUV?
???
Why does the moon have more of an impact on the tides than the sun
The moon is closer to the Earth
What is a benefit of downwelling
Export of dissolved oxygen to the deep ocean
The global ocean conveyer belt circulation is most responsible for distributing what?
Heat
What is generating force that starts surface currents?
Wind
What is the driving force behind the generation of deep water currents?
Density difference
Which organism type comprises the majority of earths biomass
Plankton
Why are there more benthic species than pelagic species?
The benthic zone has more potential habitats
The density of water____below 4 degrees C
Decreases
A large influx of carbon dioxide to the ocean over an extended period of time will have what effect on ph?
Decrease the ph
If water temp decreases water density___ if salinity decreases density____
Increases, decreases
Which of the following exerts the greatest control over density at the oceans surface
Temperature
What is a dead zone?
A low oxygen area caused by eutrophication
The rate at which photosynthetic and chemosynthetic organisms convert energy into organic matter is referred to as…
Primary production
Which of the following are the most productive marine algae
Diatoms
Why are Continental margins more biologically productive than the open ocean
There are more available nutrients along the continental margins
What is the major limiting factor to phytoplankton production in the tropical oceans
Lack of nutrients
Why does the mid latitude region usually have to phytoplankton Blooms per year
Phytoplankton are limited by sunlight and nutrients at different times of the year
What is the major limiting factor to phytoplankton production in the pool oceans
Lack of sunlight
Satellites can measure which pigment to determine ocean productivity
Chlorophyll
