Transcript Sci8U1WaterSystemsonEarth1example[1]

Science 8
Text: Discovering Science 8
Unit One:
Water Systems on Earth
The Water Cycle
Atmosphere
Hydrosphere
Lithosphere
Earth’s Water Facts
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Water is found all over the earth.
Earth is called the “blue planet”
97% of Earth’s water is saltwater.
3% of Earth’s water is fresh.
2/3 of Earth’s freshwater if frozen (cryosphere)
1% of Earth’s fresh water is in liquid form. In the
atmosphere and the lithosphere) Much of this water
is located underground.
• All areas were water is found on Earth is called the
hydrosphere.
Global Warming – The Ice Age
• Global warming would melt the icecaps
destroying animal habitats and flood huge
tracks of land..
Ice Age
• Glaciers influence the water cycle by slowing
down its evaporation rate.
• 120 000 – 11 000 (most recent ice age).
• It covered about 28% of land on Earth.
• The mean average temperature was 100C.
Macro-Ecosystems
vs. Micro-Ecosystems
Marine Environments: Pelagic zone (areas not
close to the bottom) and benthic zone (ocean
bottom).
Ocean Water vs. Freshwater
Ocean Water
Fresh Water
Ground water, glaciers,
rain, drainage basins
Salinity
More salt
35 g/L
Less salt
0 g/L
Density
More dense
1.022 kg/L
Less dense
1.000 kg/L
Freezing point
Lower
-1.9 0C
Higher
0 0C
Freshwater Environments
• Lakes and ponds
Plankton - Phytoplankton and zooplankton
• Streams and Rivers
Riffles, turdity, …
• Wetlands – A low lying area saturated with water for most of the
year.
Filters, habitat, prevents erosion, water storage, …
• Estuaries – a wetland that builds up where a river meets
the ocean
Distribution of nutrients , brackish, …
Saltwater Environments
• Ocean is the world’s largest saltwater aquatic
habitat.
• Most life found within the first 200 m of water
(continental shelf – penetration of sunlight)
• Bioluminescence
• Largest animals on Earth live in the ocean
The Effects of Abiotic Factors on Plant and
Animal Distribution in Marine and Fresh Water
Ecosystems
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Temperature
Dissolved oxygen
Phosphates
Increased acidity
Turbidity
Pollution
Upwelling
Amount of Sunlight
Salinity
Upwelling
• Upwelling occurs most commonly along the western
coastlines of continents, but may occur anywhere in
the ocean.
• Upwelling results when winds blowing nearly
• parallel to a continental coastline transport the light
surface water away from the coast.
• The upwelling water contains an abundance of
nutrients which support plant life near the surface.
These plants, in turn, attract animal life.
Upwelling
The Development of Ocean Basins and
Continental Drainage Systems
• Plate Tectonics
• Volcanic activity
• Erosion
• Glaciation
The Oceanic Basin
Public and Private Canadian Institutions for
Scientific and technological Research of the
Oceans
• Environment Canada
• Federal Fisheries
• Ocean Sciences Center
• Center for Cold ocean Research (C-CORE) Memorial
University of Newfoundland
Investigative Technologies for
Underwater Ocean Research
• Sonar
• Satellites
• Underwater photography/videography
• Deep sea submarines
• Diving
Ocean Current
• The Labrador Current
• Gulf Stream (.. and North Atlantic Drift)
Surface Currents
Causes:
1.) Wind (Speed and Direction)
2.) Earth’s Spin (Coriolis Effect)
3.) Shape of the continent (circulation is clockwise in northern
hemisphere)
Deep Water Currents
Causes:
1.) Salinity
2.)
Temperature
Tides and Waves
Wave Model
Tsunami
Waves - Swells and Breakers
• Swells – caused by winds and storms far out in
the ocean
• Breakers – The tumbling of water as a wave
breaks on shore.
Waves Interact With Shorelines
• Slope of the Shore:
Rock Type:
Erosion and Deposition
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Beaches
Shoals
Sand Bars
Sea Caves
Sea Stacks
Sea Arches
Neap Tides and Spring Tides
• The gravitational pull of the moon affects tides on Earth
The Influence of Ocean Currents and
Winds on Regional Climates
• Ocean warm the air above it creating thermals. As
the warm air rises, cooler denser air replaces it. This
movement creates wind which bring the warm and
cool air to various parts of the continent.
Convection Currents
• The transfer of heat in the air is called convection.
Currents Effect Climate
• Warm surface currents transfer tropical heat to the
atmosphere and colder currents remove heat from
the atmosphere. When the warm, moist air above
the Gulf Stream blows over the colder water of the
Labrador current, it cools and condenses, producing
fog.
• Temperature fluctuations occur rapidly in
Newfoundland and Labrador due to our location
between warm, tropical winds moving north and
cold, arctic winds moving south. Local atmospheric
temperatures depend on which of these prevail.
Oceans and Temperature
Oceans staying warmer than land masses
through he fall and winter months due to the
high heat capacity of water.
Oceans remain cooler through the spring
months and into the summer. This regulates
the temperature of coastal areas. It prevents
the area from being extremely hot in the
summer and extremely cold during the winter.
El Nino and La Nina
El Nino
La Nina
Trade Winds
Decrease
Increase
Ocean
Temperatures
Weather
Warming
Cooling
More Extreme
Less Extreme
(Drought/Floods)
Marine
Productivity
Decrease
Increase
El Nino
La Nina
“Positive” and “Negative” effects of
Marine Technologies on Ocean
(i) Oil rigs
(ii) Confederation bridge
(iii) Sable gas development
(iv) Fundy tidal power
(v) Factory freezer trawlers
(vi) Oil tankers (113-2)
Negative Effects
* Scouring of the ocean floor destroying marine habitats.
* The introduction of foreign species that can occur when oil
tankers release their bilge water endangering native habitats
and organisms.
- invasive species include the green crab in Placentia Bay and
the violet tunicate in Belleoram.
* Accidental release of organisms into native populations, and
spread of diseases.
- concerning some of the negative impacts that may arise as a
result of increased organic matter from mussel farms, referred
to as detritus rain, which can accumulate on the sea floor.
Neg. Continue
• Oil and gas exploration can result in negative
environmental impacts (e.g., oil spills killing
sea birds or destroying ecosystems),
• Economic impacts (e.g., price of housing
increasing so people can not afford to buy
homes), negative social/cultural impacts (e.g.,
changes in the way of life for many
communities, increases in the gap between
rich and poor, etc),
Positive
• Economic impacts (e.g., good paying jobs,
money for governments to build roads, etc),
• Social/cultural impacts (e.g., better quality
education for everyone, more leisure time for
people, etc).
Answers and Responsibility
Many people have the concept that any problem
can be solved by science if enough time and
money are put into it.
But, …
Understanding
• We need to recognize that science cannot
answer all questions, or solve all problems.
We all need to look at our own behaviors and
take responsibility. Such behaviors as
recycling, reducing and other related activities
all contribute to a healthy planet.