VIEWS OF EARTH

Landforms, Viewpoints and Maps

LANDFORMS

What are landforms?

• A feature that makes up the shape of the land at Earth’s surface

• Three basic types:– Plains– Plateaus– Mountains

Plains

• Plains- large, relatively flat areas– Can be found near the ocean or on land– Many plains are used to grow crops– Together, the two types of plains make up one-half

of all the land in the United States

Coastal Plains• Coastal Plains- broad plains along the ocean’s shore• They are often called lowlands because of their low

elevations– Elevation is the distance above or below sea level

• Characterized by low rolling hills, swamps, and marshes.• It isn’t perfectly flat-many low hills and valleys have

been carved by rivers• Examples:

– Atlantic Coastal Plain– Gulf Coastal Plain

Coastal Plains

Interior Plains

• Interior Plains- plains found on the inner part of the United States

• Example: Great Plains– Lie between the Mississippi lowlands and the

Rocky Mountains– Flat, grassy, dry plains with few trees– High elevation

Interior Plains

Plateaus

• Plateaus- relatively flat, raised areas of land• Areas made up of nearly horizontal rocks that

have been uplifted by forces within Earth• Example: Colorado Plateau

Plateaus

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=&url=http://claretscience3.wikispaces.com/FLAT%2BLANDSCAPES&bvm=bv.103388427,d.eXY&psig=AFQjCNHyu78Vhxs2AKyOY5-ss4QsXUzToQ&ust=1443575979831084

Decide whether each picture is a coastal plain, interior plain or plateau.

Mountains• Rise high above the surrounding land• The world’s highest mountain peak is Mount

Everest in the Himalayan Mountains• Mountains vary greatly in size and in how they are

formed• The four main types:– Folded– Upwarped– Fault-Block– Volcanic

Folded Mountains• Folded Mountains- mountains created when rock

layers are squeeze from opposite sides, causing them to buckle and fold

• Rock layers are folded and look like a rug that has been pushed up against a wall1. Tremendous forces inside Earth force rock layers together.2. Rock layers buckle and fold into folded mountains

• Example:– Appalachian Mountains

• Used to be higher than the Rocky Mountains, but weathering and erosion have worn them down

Folded Mountains

Upwarped Mountains• Upwarped Mountains- mountains formed when

Earth’s crust is pushed up and eroded, forming sharp peaks and ridges

• Formed when crust was pushed up by forces inside Earth. Over time, the sedimentary rock on top of the crust eroded and left behind the igneous and metamorphic rock underneath.

• Examples:– Southern Rocky Mountains, Black Hills, and

Adirondak Mountains

Upwarped Mountains

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=&url=http%3A%2F%2Fwww.slideshare.net%2FSteven_iannuccilli%2Fchapter-6-landforms&psig=AFQjCNGsvRdu57Cdz6V7IXw0aXGgKlHP9A&ust=1443653707818777

Fault-Block Mountains

• Fault-Block Mountains- jagged mountains formed from huge, tilted blocks of rock that are separated from surrounding rock by faults.

• A fault is a large crack in rocks along which there is movement

• Examples:– Sierra Nevada Mountains

Fault-Block Mountains

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCI7f-MmqncgCFQsZPgodkAkK6w&url=http%3A%2F%2Fwww.buzzle.com%2Farticles%2Fhow-are-fault-block-mountains-formed.html&bvm=bv.103627116,d.eXY&psig=AFQjCNFLsmL_MlEm0fvnVELDYB8FjLfbqw&ust=1443653294614004

Decide whether each picture is a folded, upwarped or fault-block mountain.

Volcanic Mountains

• Volcanic Mountains- mountains that begin when molten material reaches the surface

• The materials pile up, one layer on top of another, until a cone-shaped structure forms

• Examples:– Mount St. Helens in Washington– Mauna Loa in Hawaii

What else is important to know?

Volcanoes are often cone-shaped, but they can take other shapes too.

They are formed when molten, sticky rock called magma, forces its way through a crack in the Earth’s crust.

The melted rock that spills out of the crater on the top of the volcano is called lava. The lava destroys everything in its path because it is very, very hot!

Where do volcanoes happen?

• Most volcanoes are formed on land, but there are some volcanoes that are on the ocean floor. Some of these volcanoes emerge from the water because they are very high.

• A volcano erupts when magma and gases find a way to escape, so they burst to the surface through a vent. An eruption can be quite gentle or very violent.

Types of Volcano

Volcanoes can be active, dormant or extinct.

• A volcano is active, or alive, when it erupts often.

• When a volcano is dormant, or sleeping, it has not erupted for a long time – but it might in the future.

• A volcano is extinct, or dead, when it hasn’t erupted for at least 100,000 years.

Eruption patterns

There are three different levels of eruption:

1. If it easy for the gases to escape, then the eruption is very gentle. However, the lava is very runny and can move very fast.

2. Gas builds up and lumps of rock (‘bombs’) and ash burst out of the volcano. This makes the lava thick and sticky. This is the fiercest eruption of all because the gases and magma become trapped inside the volcano. This causes a huge explosion, which can be big enough to remove the top of the whole mountain!

What are the parts of a Volcano?

1. VENT- the vent is the opening from which lava flows. Dust, ash, and rock particles can also be thrown out of the vent!

2. Crater- the top of the volcano. It is a funnel shaped pit. It is formed when the material explodes out of the vent!

3. Volcanic cone- is the pile of lava, dust, ashes, and rock around the vent. It can be found in different shapes!

Did you know?

Pumice stone, which comes from volcanoes, is very light because it contains lot of tiny bubbles. If there are enough bubbles, then pumice stone can float on water!

Mount Kilauea, in Hawaii, is the most active volcano on Earth because it has been erupting since 1983!

The word, ‘volcano’ comes from the name Vulcan, who was the Roman god of fire.

GLOSSARYBomb – a lump of rock thrown out in an eruptionCrater – a deep hollow at the top of a volcanoCrust – The top layer of the EarthEruption – the release of gases, magma and rock from a

volcanoLava – melted rock that flows down the volcanoMagma – melted rock inside the EarthMolten – melted, liquidVent – a crack on the side of a volcano where magma can

escape

VIEWPOINTS

Latitude and Longitude

If you are going to explore landforms, you might want to learn how to find locations on Earth! If you

wanted to go to the Hawaiian Islands, how would you describe their location? You might say that

they are located in the Pacific Ocean. That’s correct, but there is a more precise way to locate

places on Earth. You could use lines of latitude and longitude. These lines form an imaginary grid

system that enables points on Earth to be located exactly.

Latitude• Equator- imaginary line

that circles Earth exactly halfway between the North and South Poles

• The equator separates Earth into Two equal halves, called the northern hemisphere and the southern hemisphere.

Latitude• The lines running

parallel to the equator are called lines of latitude, or parallels.

• Latitude- refers to the distance in degrees either north or south of the equator

• Lines of latitude do not intersect

Latitude• The equator is numbered

0◦ latitude.• The poles are numbered

90◦ latitude.• Locations north of the

equator are referred to by degrees north latitude.

• Locations south of the equator are referred to by degrees south latitude.

Longitude• Longitude- refers to

distances in degrees east or west of the prime meridian

• Prime Meridian- an imaginary line running from the North pole to the South pole– This imaginary line

represents 0◦ longitude

Longitude

• The prime meridian does not circle Earth like the equator– It runs from the North

Pole to the South Pole through England

– The line of longitude at the other side is known as the International Date Line

• A=

Honolulu= 20◦N, 180◦WPerth= 35 ◦S, 115◦E

Practice!

Earth Time

• We keep track of time by measuring Earth’s movement in relation to the sun.

• Earth rotates one full turn every 24 hours.• One half is always facing the sun while one

half is facing away from it.

Time Zones• How can you know what time it is at any particular location on Earth?• Earth is divided into 24 time zones (because it takes 24 hours to rotate

once!)• There are 6 different time zones in the United States.

Calendar Dates

• One day ends and another begins at 12:00 midnight.– If it is 11:59 pm Tuesday, two minutes later it is

12:01 am Wednesday• Every time zone experiences this transition

from one day to the next.• You gain or lose time each time you travel

through a time zone until at some point you gain or lose a whole day

Sum it up!

1. How do lines of latitude and longitude help us find locations on Earth?

2. Which lines are latitude and which are longitude?

3. Why do different places around the world have different time zones?

4. What is the name for the line at 0◦ latitude? What about 0◦ longitude?

MAPS

Types of Maps

• Map Projections– Mercator Projections– Robinson Projections– Conic Projections

• Topographic Maps

Mercator Projections

Mercator Projection• Is a map that has parallel

lines of longitude and latitude

• Flaws– Land Near Poles is

exaggerated – Shapes are correct, but

land area is distorted• Mercator Projections are

mainly used on ships

Robinson Projections

Robinson Projection• A map that has

accurate continent shapes and shows accurate land areas

• Lines of latitude remain parallel and lines of longitude are curved– Results in more accuracy

near the poles

Conic Projections

Conic Projection• Is made by projecting

points and lines from globe onto a cone.

• Very Little Distortion, High Degree of accuracy

• Best for Mapping Small Areas

• Used to make road and weather maps

Topographic Maps

Topographic Maps• Detailed maps that

show the hills and valleys of an area– Good for when you go

hiking

• Use Lines, Symbols, and Colors to represent change in elevation

Topographic Maps

• Show landforms such as…– Mountains– Hills– Plains– Lakes– Rivers

• Show cultural features such as…– Roads– Cities– Dams

Contour Lines

• Contour Line- a line on a map that connects points of equal elevation– Elevation- the distance of a location above or

below sea level

Contour Intervals

• Contour Interval- the difference in elevation between two side-by-side contour lines– If the contour interval was 10 meters, then when

you walked between those two lines on the trail, you would have climbed 10 meters.

• The elevation of the contour interval can vary.– For mountains, they may be very close.– For hills or landforms that aren’t as steep, the

contour lines may be far apart.

Index Contours

• Some contour lines (called index contours) are marked with their elevation.

• If the contour interval is 5 meters, you can tell the elevation of other lines around the index contour by adding or subtracting 5 meters from the elevation on the index contour.

1. Color the elevations on the topographic map.

2. What is the height of the tallest landform shown?

3. What is the height of the second highest landform shown?

4. What is the difference between the two landforms?

5. How many feet are between each hill?

6. Which hill has a more gradual (less steep) slope?

Map Features

• Map Legends• Map Scales

Map Legends

• Most maps have a legend that explains what the symbols used on the map mean.

Map Scales

• Map Scale- the relationship between the distances on the map and actual distances on Earth’s surface.

• Scale is often in a ratio – For example, a map of the Grand Canyon may have

a scale that reads 1:80,000. This means that one unit on the map represents 80,000 units on land.

• A scale may also be a small bar graph that is divided into a number of units

Uses of Maps

• The map you choose will depend on what you need to use it for

• Cartography is the word for mapmaking• Cartographers can now use remote sensing

and computers to make maps!

Mapping Our Planet

• Remote Sensing from Space:

https://www.youtube.com/watch?v=xIsUP1Ds5Pg

Landsat Satellites

• Landsat- detect different wavelengths of energy reflected or emitted from Earth’s surface.

• Each Landsat has a mirror that moves to scan Earth’s surface– On the mirror are rows of detectors that measure

the intensity of the energy they receive from the planet

– The information is converted into computer images

Landsat Satellite

Topex-Poseidon Satellite

• Topex-Poseidon Satellites- uses radar to compute the distance to the ocean’s surface– Radio signals are beamed fro the satellite to the

ocean– A receiving device picks up the returning echo

bouncing off the water– The distance to the water’s surface is calculated

using the radar speed and the time it takes for the signal to be reflected.

Topex-Poseidon Satellite

Global Positioning System

• The Global Positioning System, or GPS, is a satellite-based radio navigation system that allows users to determine their exact position anywhere on Earth.

• 24 satellites orbit 20,200 km above the planet

Remote Sensing Under Water

• Sonar- the use of sound waves to detect ocean-bottom features