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=player_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 Agencyhttp://www.epa.gov/

Websites

• IPCC: Intergovernmental Panel on Climate Change

http://ipcc.ch/

• UNEP: UN Environmental Programhttp://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.

AtmosphereAtmosphere: Thin, tenuous blanket of air

around the earth with 21% oxygen, 78% nitrogen, and carbon dioxide and others <1% . Structure of the atmosphere:– 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

• Urban air pollution:

• Acid rain:

• Ozone depletion:

• Global warming:

Air PollutionSix common Air pollutants in USA http://www.epa.gov/airquality/urbanair/

and http://www.epa.gov/air/airpollutants.html

•Carbon Monoxide (CO)-63%•Nitrogen Oxides (NOx)- 13%•Sulfur Dioxide (SO2)- 9%•Particulate Matter (aerosol/photochemical smog)•Ozone (ground level ozone)

• • Lead

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

• 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.

• 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 • http://unfccc.int/kyoto_protocol/mechanisms/emissions_trading/items/2731.php

• Clean Development Mechanism (CDM)• http://unfccc.int/kyoto_protocol/mechanisms/

clean_development_mechanism/items/2718.php

• Joint implementation (JI)

• http://unfccc.int/kyoto_protocol/mechanisms/joint_implementation/items/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_detailpage

• 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

• 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=HsAracLBCxI&feature=player_embedded#!

World Replacement Rates

Decline in US Fertility

• http://www.prb.org/Publications/Datasheets/2012/world-population-data-sheet/fact-sheet-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 (pre-Sun) 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 hypothesisThe 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

• 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