Transcript Properties of Water

Biogeochemical Cycles
Energy Flows
Matter Cycles
Matter Cycles
A cycle is a group of processes in which matter
repeatedly moves through a series of reservoirs.
A reservoir is a place where matter or energy is
stored. (atmosphere, hydrosphere, geosphere,
biosphere)
Many elements on Earth move between reservoirs.
These cycles rely on energy sources to drive them.
The length of time that energy or matter spends in a
reservoir can vary from a few hours to several million
years.
Biogeochemical Cycle
Click below to watch the Visual Concept.
The Water (Hydrologic) Cycle
If there is magic on this planet it is water
-Loren Eisley
“All the rivers run into the sea, yet the sea
is not full…”
- Ecclesiastes 1:7
The Water Cycle
The movement of water from the atmosphere to Earth’s surface
and back to the atmosphere is called the water cycle.
In the water cycle, water changes from liquid water to water
vapor through the energy transfers involved in evaporation and
transpiration. During these processes, water absorbs energy
and changes state.
When the water loses energy, it condenses to form water
droplets, such as those that form clouds. Eventually, water falls
back to Earth’s surface as precipitation.
Important Concepts
Oceans – more evaporation than precipitation
Land – more precipitation than evaporation
(Runoff). Land is watered by the system.
Water Quantity
The Earth’s water supply
Oceans
Atmosphere
Cryosphere (Ice caps/Glaciers)
Salt Lakes
Freshwater Lakes
Rivers/Streams
Groundwater & Soil
97 %
.0010 %
2.23 %
.007 %
.009 %
.0001 %
.609 %
Water Quantity cont’d
99.4% of Earth’s water is in the Oceans or Cryosphere (icecaps
and glaciers) Of the remaining .6% only about .3 % is available
to humans with current technology.
Freshwater lakes
Rivers & Streams
Shallow Groundwater
– Total
.009 %
.0001 %
.303 %
.3121 %
This totals approximately 21 billion gallons per person, which
may sound like enough. However, the problem is that
freshwater is not evenly distributed geographically.
Humans now, as a GEOLOGIC force are able to affect (usually
short-circuit) the hydrologic cycle.
It is estimated that 60 % of all water withdrawn worldwide is
“consumed” (or diverted from its normal water cycle pathway).
Human interactions with the Water Cycle
Excessive evaporation losses from irrigated land.
Water diverted from one river or watershed to
another.
Groundwater pumped faster than it can be recharged
into natural aquifers.
Contamination of groundwater, lakes or rivers. (silt,
sewage, fertilizers, pesticides, radioactive waste,
toxic waste, heavy metals, pathogens, heat.)
Excessive evaporation from reservoirs.
Water Cycle (summary)
Because freshwater on the planet is a
renewable resource (as long as the Sun
shines) we will never run out.
However Human activity may modify
the distribution and storage capacity in
certain regions.
The Water Cycle
http://earthguide.ucsd.edu/earthguide/
diagrams/watercycle/
The Water Cycle
Check up
What source of energy drives the water
cycle? Explain.
Describe how water moves through the water
cycle.
From what sources does water evaporate?
List 3 ways that humans interact with the
water cycle.
The Carbon Cycle
Carbon moves through all four spheres through the carbon
cycle.
In the short-term carbon cycle, plants convert carbon dioxide,
CO2, from the atmosphere into carbohydrates(photosynthesis).
When organisms’ bodies break down the carbohydrates and
release some of the carbon back into the air as CO2 or through
their organic wastes as CO2 (respiration),or methane CH4
(decomposition).
In the long-term carbon cycle, carbon is stored in the geosphere
in a type of rock called a carbonate.
The Carbon Cycle
Check up
What source of energy ultimately drives the carbon cycle?
Explain
In what form is carbon found in the atmosphere? Where does it
come from?
Cellulose, which makes up the walls of plant cells contains
carbon. What is the source of this carbon?
How does carbon become part of the body of an animal?
How is carbon released from the body of an animal?
Briefly explain two ways that humans are interacting or
impacting the natural carbon cycle.
Nitrogen Cycle
78% of Earth’s Atmosphere is Nitrogen
Used to build proteins
Most organisms cannot use atmospheric
form, it must be changed or “fixed”
N2  NO3- or NH4+
The Nitrogen Cycle
In the nitrogen cycle, nitrogen moves from the air to soil, from
soil to plants and animals, and back to air again.
Nitrogen is removed from air mainly by the action of nitrogenfixing bacteria in the soil.
The nitrogen then is taken up (absorbed) by plants.
Plants are then are eaten by animals. Animals use the Nitrogen
for building proteins and amino acids.
Nitrogen Cycle
The nitrogen is returned to the soil by decay
and by animal wastes.
Chemical processes that occur in the soil then
release the nitrogen back into the air.
Nitrogen in the atmosphere can also be fixed
by the occurrence of lightning.
Nitrogen cycle
Check up
What source of energy ultimately drives the
nitrogen cycle? Explain
How do animals obtain nitrogen?
In what form is nitrogen found in the
atmosphere?
What form of nitrogen are most plants able to
absorb? How does it get into that form?
List and explain two processes that return
nitrogen to the atmosphere.
Human interaction
All natural cycles can be altered by
human activities.
The carbon cycle is affected when
humans use fossil fuels.
Deforestation removes the Earth’s
ability to naturally “metabolize” CO2.
The nitrogen and phosphorus cycles are
affected by agriculture.
What is meant by the phrase:
Humans have become a Geologic Force
Credits
Fred Montague, Environment Notebook,
pp 108-112, Mountain Bear Ink, 2003
Holt Earth Science 2010 edition