APES – UNIT 3
HYDROSPHERE
HYDROLOGY
-the study of the distribution and movement of water on Earth
a There are five
processes by which
water moves
throughout each of the
earth’s spheres
a condensation
a precipitation
a infiltration
a runoff
a evapo-transpiration
Water Properties
1.
2.
3.
4.
5.
6.
Strong hydrogen bonds
Temperature changes slowly (high heat capacity)
High boiling and evaporation point
Universal solvent
Filters harmful UV radiation
Expands when it freezes
HYDROSPHERE
75% of Earth is covered by water
97% of all water is in the Ocean
3% of all water is freshwater
• Fresh water distribution:
•
•
•
•
Ice: 1.762%
Groundwater: 1.7%
Surface Fresh Water: 0.014%
Atmosphere and soil: 0.002%
AQUATIC BIOMES
TWO BROAD CATEGORIES:
1. MARINE/SALT WATER
(Ex. OCEANS, ESTUARIES)
2. FRESHWATER
(Ex. RIVERS, LAKES, WETLANDS)
PHYSICAL CHARACTERISTICS USED TO
CATEGORIZE INCLUDE:
SALINITY, DEPTH, WATER FLOW
SALINITY– salt (sodium chloride)
Salinity levels are written in parts per thousand (ppt)
*ocean salinity = 35 ppt (3.5% salt content)
(is affected by rainfall, evaporation, runoff, depth)
*freshwater is less than .5 ppt
*brackish water has between .5 – 17 ppt
NOTE: when salt water cools
and freezes, it gets denser with
salt and then it sinks. Ocean
salinity increases with depth.
OCEANS - FACTS
**ALL THE OCEANS ARE CONNECTED**
ATLANTIC OCEAN
PACIFIC OCEAN
ARCTIC OCEAN
SOUTHERN OCEAN
INDIAN OCEAN
*The largest ocean is the Pacific
*The deepest part of the Pacific is
at the bottom of the Mariana Trench
*The saltiest ocean is the North Atlantic (3.7 ppt)
*The salt comes from rocks & underwater volcanic eruptions
OCEAN – GLOBAL TEMPERUTURE REGULATOR
*the function of the oceans is to absorb sunlight energy which
regulates temperatures in the Earth’s atmosphere
(without oceans, the temperatures would be too extreme for life)
*ocean temperatures affect climate and wind patterns
*currents that circulate warm waters moderate the climate of
northern lands EX. British isles are warmed by the Gulf Stream
*ocean evaporation accounts for most of the Earth’s precipitation
OCEAN – ZONATION by light & temperature
Pelagic = all open ocean region
Neritic = from low tide to edge of continental shelf, shallow depth to 650 ft,
well oxygenated, low pressure, lots of light
Oceanic = open sea beyond continental shelf
Epelagic / Photic = upper layer, depth (to 200 m) exposed to sunlight for
photosynthesis, warmest region, highest level of DO (dissolved oxygen)
Bathyal /Disphotic = dimly lit zone, not enough for photosynthesis
Abyssal zone / Aphotic = deep area, no sunlight, no photosynthesis, extremely
cold, very low DO, high pressure, high level of nutrients from
decaying organisms
Benthic = lowest level, ocean floor
OCEAN – ZONATION
OCEAN – TEMPERATURE ZONES
Surface zone = top layer , 300 meters deep, warmed by sun
Thermocline = 300 m to 700 m, temperature falls rapidly with depth
Deep zone = below thermocline to ocean bottom, dark and cold
OCEAN – INTERTIDAL ZONE
COASTLINE BETWEEN HIGH TIDE & LOW TIDE
• Organisms here are exposed to sunlight, high
temperatures and desiccation during low tide
• Organisms are adapted to waves
• Ex. Barnacles, algae, mussels, crabs, sea stars
OCEAN CURRENTS
*Surface currents are steam-like movements of water near the
surface driven by wind patterns
-can be warm or cold (do not mix)
*Deep currents are steam-like movements of water that flow
very slowly along ocean floor
* driven by difference in density due to temperature and
salinity (Denser, saltier water sinks and less dense water rises)
OCEAN CIRCULATION
https://www.youtube.com/watch?v=UuGrBhK2c7U
*The Ocean Conveyor Belt is driven by thermo-haline currents
*Gulf Stream carries warm Caribbean water to North Europe
(when it gets to Iceland, it cools, becomes denser and saltier, then
sinks creating a powerful, southbound current to Antarctica)
*Cold bottom waters warm and rise in Pacific & Indian oceans
GYRES = high vortex currents caused by
Corioliseffect
https://www.youtube.com/watch?v=h6i16CrI8ss
OCEANS - UPWELLING
*where prevailing winds from Coriolis effect
push warmer, nutrient poor surface water away
from coastline
*this surface water is replaced by cooler, nutrient
rich, deeper waters (deeper waters have high
levels of nitrates and phosphates that come from
decomposition and sinking of surface waters
plankton
*upwellings provide nutrient supply for photic
regions
*Densest water will be at 4 ° C, when ice
melts , surface water will sink, bottom water will
move to surface overturning oxygen to bottom
and nutrients to top
Currents, Waves & Shorelines
a currents carried on the surface of
the water are called waves
a when waves meet the land shorelines
are created
a the interaction between the sea and
the land causes some erosion of the
land which creates sediment
a sediment is carried into the ocean
from the waves
Fresh Water—Rivers
• What is a river?
• A large channel
along which
water is
continually
flowing down a
slope—made of
many streams
that come
together.
Fresh Water — Lakes
• What is a lake?
• A body of water
of considerable
size contained
on a body of
land.
LAKE STRATIFICATION
Lakes are divided into three categories
dystrophic lakes
a low food value
a full of soil particles
a water is usually brown
oligotrophic lakes
a lake nourishment
a very clear water
MESOTROPHIC LAKES
aSomewhat Clear water
aMedium level of nutrients
aHas beds of submerged plants
eutrophic lakes
a well nourished
a intense birdlife
a lots of plankton
POND STRATIFICATION
Littoral Zone= shallow area of soil and water near
shore where algae & plants grow, most
photosynthesis occurs here
Limnetic zone= open water, floating algae called
phytoplankton found here, extends as deep as
sunlight can penetrate
Profundal Zone= in deeper lakes, below Limnetic,
no sunlight , no photosynthesis, bacteria
decompose the detritus consuming oxygen
Benthic Zone= muddy bottom of lake/pond
Other Surface Waters
• What is a wetland?
• An area where the water table
is at, near or above the land
surface long enough during the
year to support adapted plant
growth.
Other Surface Waters
• What are the types of wetlands?
• Swamps, bogs, and marshes
• Swamp: a wetland dominated by trees
• Bogs: a wetland dominated by peat moss
• Marshes: a wetland dominated by grasses
Fresh Water --Groundwater
• The water found in cracks
and pores in sand, gravel and
rocks below the earth’s
surface.
• zone of aeration= layer
closest to the soils surface
• Zone of saturation= under
surface layer (all open
spaces fill with water)
Additional Vocabulary
• Artesian Well – a well in
which water rises because
of pressure within aquifer.
• Reservoir – a lake that
stores water for human use.
• Tributary-a stream feeding
a larger stream or a lake
The Water Table
• saturated zone: the subsurface zone in
which all rock openings are filled with
water
• water table: the upper surface of the
zone of saturation
• perched water table: the top of a body of
ground water separated from the main water
table beneath it by a zone that is not saturated
The Movement of Ground Water
• most ground water moves relatively slowly
through rock underground
• because it moves in response to differences in
water pressure and elevation, water within the
upper part of the saturated zone tends to move
downward following the slope of the water table
Movement of ground water beneath a sloping water table in uniformly permeable
rock. Near the surface the ground water tends to flow parallel to the sloping water table
Aquifer
• aquifer: a body of saturated rock or sediment
through which water can move easily
• good aquifers include sandstone, conglomerate,
well-joined limestone, bodies of sand and gravel,
and some fragmental or fractured volcanic rocks
such as columnar basalt
Aquifers (cont.)
• unconfined aquifer: a partially filed aquifer
exposed to the land surface and marked by a rising
and falling water table
• confined aquifer (artesian aquifer): an aquifer
completely filled with pressurized water and
separated from the land surface by a relatively
impermeable confining bed, such as shale
Fresh Water —Streams
• What is a stream?
• A small channel
along which
water is
continually
flowing down a
slope—made of
small gullies.
Springs and Streams
• spring: a place where water flows naturally from
rock onto the land surface
• some springs discharge where the water table
intersects the land surface, but they also occur
where water flows out from caverns or along
fractures, faults, or rock contacts that come to the
surface
Water enters caves along joints
in limestone and exits as springs
at the mouths of caves
Water moves along fractures in
crystalline rock and forms springs
where the fractures intersect the
land surface
Springs can form along faults
when permeable rock has been
moved against less permeable rock.
Arrows show relative motion
along fault
Springs form at the contact between
a permeable rock such as sandstone
and an underlying less permeable rock
such as shale