Transcript Chapter-1-Introduction1

Earth Science, 13e
Edward J. Tarbuck &
Frederick K. Lutgens
Five Minutes University
• Don’t go to a 5 minutes University:
• I hope this is not going to be a 5 minutes
university, that you are not here just to pass
the class but to acquire knowledge you can
use in your lifetime and pass on to people
around you, who have not been fortunate
enough to get a college education. Please do
more than just pass the tests, LEARN.
Five Minutes University
• You have spent a great deal of money to
forget everything you learn, right after you
pass this class.
• http://www.youtube.com/watch?feature=pla
yer_detailpage&v=kO8x8eoU3L4
Important Websites
• USGS: US Geological Survey http://www.usgs.gov/
• NOAA: National Oceanic Atmospheric
Administration http://www.noaa.gov/
• EPA: Environmental Protection Agency
http://www.epa.gov/
Websites
• IPCC: Intergovernmental Panel on Climate
Change
http://ipcc.ch/
• UNEP: UN Environmental Program
http://www.unep.org/
Earth's “Spheres"
Earth Science
Encompasses all sciences that seek to
understand the Earth and its neighbors in
space .
Earth Science disciplines are
Geology
• Geology - literally the “study of Earth”
comprises Physical Geology and Historical
Geology
• Physical geology: the study of Earth
materials, resources, and processes
• Historical geology: the study of Earth’s
evolution through time, its origin and its
evolution. Uses isotopes and fossils to date
rocks
Oceanography
• Oceanography – a study of the oceans
- Marine geology: study of ocean rocks and
ocean currents.
- Marine biology: study of life in the oceans;
not part of earth sciences.
Meteorology
• Atmospheric sciences: study of physics and
chemistry of the atmosphere and how its
variations impact climate and life on Earth.
• Meteorology - the study of the changes in
weather processes
Astronomy
• Astronomy - the study of the universe. Earth
science includes the study of the solar system
and its planets, earth neighbors in space.
Earth's “Spheres"
• There are 4 majors spheres that form the
Earth system.
• Hydrosphere: All waters on Earth
• Atmosphere: Gaseous envelop around the
Earth
• Geosphere: All land masses
• Biosphere: All living things on Earth.
Hydrosphere
Hydrosphere: all waters on earth.
• Oceans – the most prominent feature of the
hydrosphere
• Represent nearly 71% of Earth's surface
• And about 97% of Earth's water
• Also includes fresh water found in streams,
lakes, and glaciers, as well as groundwater.
- Groundwater represent 90% of our
consumption and <1% of the hydrosphere.
Atmosphere
Atmosphere: Thin, tenuous blanket of air
around the earth with 21% oxygen, 78%
nitrogen, and carbon dioxide and others
<1% . Structure of the atmosphere:
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Ionosphere: top layer where air is rare;
Mesosphere: not well studied; inaccessible
Stratosphere: site of the ozone layer
Troposphere: bottom layer, site of all weather
phenomena.
Biosphere
Biosphere
• Includes all life on earth.
• Concentrated near the surface in a zone that
extends from the ocean floor upward for several
kilometers into the atmosphere
• Earth scientists do not study living things, but
understanding the interaction between living
organisms and earth processes is crucial to our
survival.
Geosphere
Solid Earth
• Based on compositional differences, it consists
of the
• Crust solid (continental crust- Oceanic crust)
• Mantle solid (deformable/partial melting)
• Core
• Outer core (liquid iron) – Earth magnetic field
• Inner core (Solid, heavy metals, nickel and iron)
Lithosphere
• Divisions of the outer portion are based on how
materials behave
• Lithosphere – behaves like solid; is the rigid outer
layer made of crust + upperpart of upper mantle.
• The lithosphere is broken in tectonic plates that ride
on top of the asthenosphere.
Earth’s layered structure
Earth system science
Earth is a dynamic body with many separate
but highly interacting parts or spheres
Earth system science studies Earth as a
system composed of numerous parts, or
subsystems
System - any size group of interacting parts
that form a complex whole.
Earth system science
Feedback mechanisms
• Negative feedback mechanisms resist change
and stabilize the system
• Positive feedback mechanisms enhance the
system
Earth as a system
• Consists of a nearly endless array of
subsystems (e.g. hydrologic cycle)
The hydrologic cycle
Earth system science
Earth as a system
• Sources of energy
• Sun – drives external processes such as weather,
ocean circulation and erosional processes
• Earth’s interior – drives internal processes including
volcanoes, earthquakes and mountain building
• Humans are part of the Earth system
People and the environment
Environment
• Surrounds and influences organisms
• Physical environment encompasses water, air,
soil, and rock
• Term “environmental” is usually reserved for
those aspects that focus on the relationships
between people and the natural environment
People and the environment
Resources
• An important focus of the Earth sciences
• Includes water, soil, minerals, and energy
• Two broad categories
• Renewable – can be replenished (examples include
plants and energy from water and wind)
• Nonrenewable – metals (examples include metals
and fuels
People and the environment
Population
• Population of the planet is growing rapidly
• Rate of mineral and energy usage has climbed
more rapidly than the overall growth of
population
Environmental problems
• Local, regional, and global
Growth of world population
People and the environment
Environmental Problems
• Human-induced and accentuated
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Urban air pollution:
Acid rain:
Ozone depletion:
Global warming:
Air Pollution
Six common Air pollutants in USA
http://www.epa.gov/airquality/urbanair/ and http://www.epa.gov/air/airpollutants.html
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Carbon Monoxide (CO)-63%
Nitrogen Oxides (NOx)- 13%
Sulfur Dioxide (SO2)- 9%
Particulate Matter (aerosol/photochemical
smog)
• Ozone (ground level ozone)
Acid Rain
• Also known as “Wet Deposition” is a
mixture of moisture and primarily Nitrogen
oxides (NOx) and Sulfur dioxide (SO2) and
carbon dioxide (CO2) from fossil fuel
burning. http://www.epa.gov/acidrain/what/
• Dry deposition: these chemicals mixing
with dry air and falling to the ground to end
up with runoff after rain storm.
(Tropospheric) Ozone Depletion
• Ozone formation: UV interaction with
Oxygen to form O3 (ozone)
• Ozone depletion: Chlorofluorocarbons (CFCs)
interact with O3 to produce O2
• Montreal Protocol 1987 (ratified by USA) to
phase out ozone depleting substances (ODS) like
CFCs, HCFCs, HFCs
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http://www.epa.gov/ozone/science/sc_fact.html
• Ozone layer protect us against harmful UV radiations.
• Good (tropospheric) ozone vs. Bad (ground level) Ozone
Global Warming
Definition: aka “Climate Change” is the
increase in Global temperatures due in
part to human activities through the
increase in concentration of greenhouse
gases.
“The (IPCC) report, based on the work of some 2,500 scientists in more than 130 countries, concluded that
humans have caused all or most of the current planetary warming. Human-caused global warming is often
called anthropogenic climate change.”
http://www.aip.org/history/climate/timeline.htm
Timeline
http://www.aip.org/history/climate/links.htm
Greenhouse Gases/Greenhouse
Effect
• Definition: Gaseous constituents in the
atmosphere that can trap heat and cause the
“Greenhouse effect” and Global Warming.
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Carbon dioxide - CO2
Methane - CH4
Nitrous Oxide - N2O
Tropospheric Ozone – O3
Chlorofluorocarbons - CFCs
The Kyoto Protocol
• Definition: treaty to reduce the production of
greenhouse gases from 2008 to 2012
• Japan, on 11 December 1997
Under the Protocol, countries must meet their targets
primarily through national measures through the first
commitment period starting in 2008 and ending in
2012. However, the Protocol also offers them an
additional means to meet their targets by way of
three market-based mechanisms.
The Kyoto mechanisms are:
• International Emissions Trading
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http://unfccc.int/kyoto_protocol/mechanisms/emissions_trading/items/2731.php
• Clean Development Mechanism (CDM)
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http://unfccc.int/kyoto_protocol/mechanisms/clean_development_mechanism/i
tems/2718.php
• Joint implementation (JI)
• http://unfccc.int/kyoto_protocol/mechanisms/joint_implementation/ite
ms/1674.php
• Cap and Trade: A mandatory cap on emissions while providing
sources flexibility in how they comply
https://www.youtube.com/watch?v=oR3ELe4qPAU&feature=player_d
etailpage
• Carbon caption and Storage:
https://www.youtube.com/watch?v=ROEFaHKVmSs&feature=player_detailpage
Supporting Graphs
Other GW causes
• Solar Radiance: Decrease in solar activity
lead to Little Ice Age between 1650 and
1850. Sunspots increase with GW,
However, current global warming cannot be
explained by changes in energy from the
sun: Since 1870 solar activity is about the
same but GW increased
• Models with solar radiance only cant
explain GW without greenhouse gases.
Mega City: Mexico City
Mega City
Definition: City with a population equal or
over 10 million. Examples: Mexico city,
Tokyo, New York, etc…
Map of Mega Cities
Air Pollution over Mexico City
Natural hazards
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Earthquakes
Landslides
Volcanic eruprions
Tsunami
Floods
Droughts
Hurricanes, Tornadoes
People and the environment
Environmental problems
• Natural hazards continued
• Floods
• Hurricanes
• World population pressures
Replacement Rate
• Definition: aka “Fertility Rate” is the
average number of children born to a woman
in her life time:
• In Developed Nations: 2.1
• In Poor countries: 3.1
• http://www.youtube.com/watch?v=HsArac
LBCxI&feature=player_embedded#!
World Replacement Rates
Decline in US Fertility
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http://www.prb.org/Publications/Datasheets/2012/world-population-data-sheet/factsheet-us-population.aspx
• The Latina fertility rate dropped sharply in recent
decades, from 3.0 births per woman in 1990 to 2.4
births per woman in 2010; and for black women
from 2.5 to 2.0. Fertility rates among white and
Asian women have also dropped, but at a slower
pace, resulting in similar fertility rates among
different racial and ethnic groups.
Early evolution of Earth
Origin of Earth
• Most researchers believe that Earth and the
other planets formed at essentially the same
time
• Nebular hypothesis
• Solar system evolved from an enormous rotating
cloud called the solar nebula
• Nebula was composed mostly of hydrogen and
helium
Early evolution of Earth
Origin of Earth
• Nebular hypothesis continued
• About 5 billion years ago the nebula began to
contract
• Assumes a flat, disk shape with the protosun (preSun) at the center
• Inner planets begin to form from metallic and rocky
clumps
• Larger outer planets began forming from fragments
with a high percentage of ices
The Nebular hypothesis
Early evolution of Earth
Formation of Earth’s layered structure
• As Earth formed, the decay of radioactive
elements and heat from high-velocity impacts
caused the temperature to increase
• Iron and nickel began to melt and sink toward the
center
• Lighter rocky components floated outward, toward
the surface
• Gaseous material escaped from Earth’s interior
to produce the primitive atmosphere
Scientific inquiry
Science assumes the natural world is
• Consistent
• Predictable
Goal of science
• To discover patterns in nature
• To use the knowledge to predict
Scientific inquiry
An idea can become a
• Hypothesis (tentative or untested explanation)
• Theory (tested and confirmed hypothesis)
• Paradigm (a theory that explains a large number
of interrelated aspects of the natural world)
Scientific method
• Gather facts through observation
• Formulate hypotheses and theories
Scientific inquiry
Scientific knowledge is gained through
• Following systematic steps
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Collecting facts
Developing a hypothesis
Conduct experiments
Reexamine the hypothesis and accept, modify, or
reject
• Theories that withstand examination
• Totally unexpected occurrences
End of Introduction