Transcript Earth`s Lithosphere

Earth’s Lithosphere
“In the developed world. . We no longer honor
our relationship to the soil. . . Soil has simply
become one more resource - a substance
necessary for crop production and for holding
up buildings. . . “
(Elena Wilken. . . World Watch article, 1995)
Let’s start with the Lithosphere
3
major zones of Earth:
Core - very hot, solid & liquid
Mantle - solid zone, largest (68% of its mass,
rich in iron, silicon, oxygen & Magnesium
Crust - outermost & thinnest portion, consists
of continental crust (29%) & oceanic crust
(covers 71% of Earth’s surface)
Plate Tectonics and Macroevolution
– The continents are not locked in
place.
• They drift about Earth’s
surface on plates of crust
floating on a flexible layer
called the mantle.
– California’s infamous San
Andreas fault
• Is at a border where two plates
slide past each other.
KQED Quest: Hayward Fault

http://www.kqed.org/quest/television/the-haywardfault-predictable-peril
 About
250 million
years ago
• Plate movements
formed the
supercontinent
Pangaea.
• Many extinctions
occurred, allowing
survivors to diversify.
 About
180 million
years ago
• Pangaea began to
break up, causing
geographic isolation
& new species
Tectonic Movement is A Natural
Part of Planet, but Can we predict
earthquakes?

http://www.kqed.org/quest/television/earthquakesbreaking-new-ground
Earth’s Lithosphere
Crust
contains
8 elements make up 98.5% of weight of Earth’s
crust (O, Si, Al, Fe, Ca, Na, K, Mg)
–Minerals (any naturally occurring inorganic
substance found in Earth’s crust as a crystalline
solid)
–Nonrenewable fossil fuels
–Potentially renewable soil nutrients (eroded rock,
mineral nutrients, decaying organic matter, water, air
& living organisms)
Earth’s “continental crust”
Earth’s
land surface:
–Only 11% arable (useable
for agriculture)
•Rest too nutrient poor, cold,
wet, dry, etc.
–Possible to add 24% more to
arable land category if we
irrigate & use fertilizers
–Total to possibly 35% of
land surface potentially arable
Element = Carbon
Carbon is essential to life as we
know it
 Carbon is the basic building
block for all organic compounds
necessary for life (carbohydrates,
proteins, fats, DNA)
 To study life is to study Carbon
Chemistry!

Organic Compounds

Compounds which contain :
–
–
–
–
–
–
–
–

C (Carbon) combined with :
H (Hydrogen
O (Oxygen)
N (Nitrogen)
S (Sulfur)
P (Phosphorus)
Cl (Chlorine)
F (Fluorine)
All other compounds are called inorganic
compounds
Carbon Cycle




It involves natural processes
A global gaseous cycle
(atmospheric cycle in which a large
portion of a given element (C)
exists in gaseous form (C02) in
atmosphere
Nutrients (like Carbon) are recycled in various
chemical forms (cyclic movement of carbon in
different chemical forms)
C cycles from the abiotic environment to the living
organisms and back to the abiotic environment
Re-Draw the Carbon Cycle Into Your Notes Now
CARBON DIOXIDE





C02 Cycles fairly rapidly from the atmosphere,
through soil and organisms, and back to
atmosphere
Key component of nature’s thermostat
If too much C02 removed from atmosphere, the
atmosphere will cool
If cycle generates too much C02, the atmosphere
will get warmer
So C02 does affect the BIOSPHERE ( and can
determine temperature & possibly change
climate)
Some CO2 is utilized to produce
biomass in trees and plants
 Which can form fossil fuels after
millions of years of decomposition
and compaction (as buried organic
material)
 When fossil fuels (coal, oil,gas) go
through combustion (burning
process), CO2 is released back
into the atmosphere





Terrestrial producers (green plants and trees)
remove CO2 from the air
PHOTOSYNTHESIS takes place 6CO2 +
6H2O + solar energy is converted into
C6H12O6 (glucose)+ 6O2 (oxygen)
Consumers and decomposers breakdown
glucose (consumption) and utilize oxygen for
respiration
The Hydrocarbons get converted back to CO2
in the atmosphere
Humans and causes of increases
in CO2 (all unsustainable practices):
 Cut
down trees (producers of oxygen
and users of CO2)
 Industries
 Transportation (i.e.,cars)
 Buildings
Increased amounts of carbon:

Global warming (rising sea/water level)

May lead to extinction of certain plants,
insect and animals, which could cause an
imbalance in the food chain.

Acidification on oceans
There are three
types of C Cycles

Atmospheric cycle

carbon dioxide

Hydrological cycle

dissolved carbonate
and bicarbonate



Sedimentary cycle

carbon containing
minerals in rocks
Discuss as a team:
 Should
we, as individuals &
as a country, go on a carbon
diet? What does this mean?
 A huge amount of carbon is
sequestered in tropical forests.
What does this mean and why
Write
responses
should we care about this
in
information?
Your journals!
 Should we pay a carbon tax to
save tropical forests? Why or
why not?
Science News Reading Activity
Read the article “Soils Hidden Secrets”
(Charles Pet tit)
 We will have a QUIZ on Wednesday

– You may use HANDWRITTEN notes, but you
may not use the printed article or typed notes.