introduction to earth science (1) nxpowerlite

7/31/2019 Introduction to Earth Science (1) NXPowerLite

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PrenticeHallEARTH SCIENCE

Tarbuck Lutgens


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Chapter

1Introduction to

Earth Science


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Overview of Earth Science

1.1 What Is Earth Science?

Encompasses all sciences that seekto understand

Earth

Earth's neighbors in space


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Overview of Earth Science

Earth science includes

4. astronomy, the study of the universe

3. meteorology, the study of the atmosphereand the processes that produce weather

1. geology, the study of Earth

2. oceanography, the study of the ocean



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Formation of Earth

The solar system evolved from an enormousrotating cloud called the solar nebula.

Most researchers conclude that Earthand the other planets formed atessentially the same time.

Nebular Hypothesis



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Formation of Earth

The nebula was composed mostly of

hydrogen and helium.

Nebular Hypothesis


About 5 billion years ago, the nebula began

to contract.

It assumed a flat, disk shape with the

protosun (pre-Sun) at the center.


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Formation of Earth

Inner planets begin to form from metallic androcky clumps.

Nebular Hypothesis


Larger outer planets began forming from

fragments with a high percentage of ices.


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The Nebular HypothesisA

C

D

E

B


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Formation of Earth

Layers Form on Earth


As Earth formed, the decay of radioactiveelements and heat from high-velocity impactscaused the temperature to increase.

Lighter rocky components floated outward,

toward the surface.

Gaseous material escaped from Earths interior

to produce the primitive atmosphere.


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Earth's Major Spheres

1.2 A View of Earth

1. Hydrosphere

Ocean is the most prominent feature of the

hydrosphere.

- Is nearly 71% of Earth's surface

- Holds about 97% of Earth's water

Also includes fresh water found in streams,lakes, and glaciers, as well as that foundunderground


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1.2 A View of Earth

2. Atmosphere

Thin, tenuous blanket of air

One half lies below 5.6 kilometers (3.5 miles)

3. Biosphere

Includes all life Concentrated near the surface in a zone that

extends from the ocean floor upward forseveral kilometers into the atmosphere


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1.2 A View of Earth

4. Geosphere

Based on compositional differences, itconsists of the crust, mantle, and core.

- Crustthe thin, rocky outer layer of Earth.

- Mantlethe 2890-kilometer-thick layer of

Earth located below the crust.

- Corethe innermost layer of Earth, locatedbeneath the mantle.


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Earths Layered Structure


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Plate Tectonics

1.2 A View of Earth

Plate tectonics is the theory thatproposes that Earths outer shell

consists of individual plates that interactin various ways and thereby produce

earthquakes, volcanoes, mountains, andEarths crust itself.


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Determining Location

1.3 Representing Earths Surface

Latitude and longitude are lines on the

globe that are used to determinelocation.

Latitude is distance north or south of theequator, measured in degrees.

Longitude is distance east or west of theprime meridian, measured in degrees.


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Maps and Mapping


No matter what kind of map is made,some portion of the surface will alwayslook either too small, too big, or out ofplace. Mapmakers have, however, foundways to limit the distortion of shape, size,distance and direction.


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Topographic Maps


Topographic maps represent Earthssurface in three dimensions; they showelevation, distance directions, and slopeangles. Contour lines are lines on a topographic map

that indicate an elevation.

Contour interval is the distance in elevationbetween adjacent contour lines.


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What Is a System?

1.4 Earth System Science

Closed systems are self contained(e.g., an automobile cooling system).

Open systems allow both energy and matterto flow in and out of the system

(e.g., a river system).

A system is any size group of interactingparts that form a complex whole.


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Earth as a System


Earth is a dynamic body with manyseparate but highly interacting partsor spheres.

Earth system science studies Earthas a system that is composed ofnumerous parts, or subsystems.


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Earth as a System


Sources of Energy Sundrives external processes such as

weather, ocean circulation and erosionalprocesses

Earths interiordrives internal

processes including volcanoes,earthquakes and mountain building


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Earth as a System


Humans are part of the Earth system.

Consists of a nearly endless array ofsubsystems (e.g., hydrologic cycle)


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People and the Environment


Environment Surrounds and influences organisms

Physical environment encompasses water,air, soil, and rock

The term environmental is usually reserved forthose aspects that focus on the relationshipsbetween people and the natural environment.


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Resources Include water, soil, minerals, and energy

Two broad categories

2. Nonrenewablecannot be replenished inthe near future (e.g., metals, fuels)

1. Renewablecan be replenished (e.g.,

plants, energy from water and wind)


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Population Population of the planet is growing rapidly

Use of minerals/energy has climbed more

rapidly than the overall growth of population


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Growth of World Population


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Environmental Problems


Caused by people and societies Urban air pollution

Acid rain

Caused by natural hazards Landslides

Ozone depletion

Global warming

Earthquakes

Local, regional, and global


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Science

1.5 What Is Scientific Inquiry?

Science assumes the natural world is consistent

predictable

Goals of science are

to use the knowledge to predict

to discover patterns in nature


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Hypothesis and Theory


An idea can become a hypothesistentative or untested explanation

theorytested, confirmed, supported hypothesis

Scientific Method Formulate hypotheses Gather facts through observation

Test hypotheses to formulate theories


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Science Methods


Scientific knowledge is gained through following systematic steps

1. Collecting facts

theories that withstand examination

totally unexpected occurrences

2. Developing a hypothesis

3. Conducting experiments

4. Reexamining the hypothesis and accepting,modifying, or rejecting it

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