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-hayward-fault-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/earthquakes-breaking-new-ground

Earth’s Lithosphere

Crust contains8 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 essentialessential to life as we

know it Carbon is the basic building basic building

blockblock 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 CycleCarbon Cycle It involves naturalnatural 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 recycledrecycled in various chemical forms (cyclic movement of carbon in different chemical forms)

C cycles cycles from the abioticabiotic environment to the living living organisms and back to the abioticabiotic environment

Re-Draw the Carbon Cycle Into Your Notes Now

CARBON DIOXIDECARBON 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 BIOSPHEREBIOSPHERE ( and can

determine temperature & possibly change temperature & possibly change climateclimate)

Some CO2 is utilized to produce biomassbiomass in trees and plants

Which can form fossil fuelsfossil fuels after millions of years of decomposition and compaction (as buried organic material)

When fossil fuels (coal, oil,gas) go through combustioncombustion (burning process), CO2 is released back into the atmosphere

Terrestrial producersproducers (green plants and trees) remove CO2 from the air

PHOTOSYNTHESIPHOTOSYNTHESIS takes place 6CO2 + 6H2O + solar energy is converted into C6H12O6 (glucose)+ 6O2 (oxygen)

ConsumersConsumers and decomposersdecomposers breakdown glucose (consumption) and utilize oxygen for respiration

The Hydrocarbons get converted back to CO2back to CO2 in the atmosphere

Humans and causes of increases in CO2 (all unsustainable practices):

Cut down treestrees (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

AtmosphericAtmospheric cycle

HydrologicalHydrological cycle

SedimentarySedimentary cycle

carbon dioxide

dissolved carbonate and bicarbonate

carbon containing minerals in rocks

Discuss as a team: Should we, as individuals &Should we, as individuals &

as a country, go on a carbon diet? as a country, go on a carbon diet? What does this mean?What does this mean?

A huge amount of carbon is A huge amount of carbon is sequestered in tropical forests. sequestered in tropical forests. What does this mean and why What does this mean and why should we care about this should we care about this information?information?

Should we pay a carbon tax to save Should we pay a carbon tax to save tropical forests? Why or why not?tropical forests? Why or why not?

Write responses in

Your journals!

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.