Earth Science

Chapter One – Mapping Earth’s Surface

St. Stephen School

St. Stephen SchoolNorth

Flat Land(North Arlington)

WestPassaic River

EastKearny Marsh Land

SouthHarrison – Flat Land

Section One – Exploring Earth’s Surface

• Topography is the shape of the land. An area’s topography may be mountainous, flat, sloping, or hilly. Topography is determined by elevation, relief, and landform.– Landforms: this is the shape of Earth’s surface.

All landforms have elevation and relief.

Landforms

• There are three main types of landforms:

– Plains – a landform made up of flat or gently rolling land with low relief. A plain that lies along a seacoast is called a coastal plain, with low elevation – and a plain away from the coast is called an interior plain with both high or low elevations.

– Mountains: is a landform with high elevation and high relief. Mountains usually occur in a group called mountain ranges.

– Plateau: a landform that has high elevation and a more or less level surface. Streams and rivers usually cut into the plateaus surface – this is why the surface is not smooth.

Plains, Mountains, and Plateaus

Landforms

Rocky Mountains

Canyons

• The Grand Canyon

Sand Dunes

Volcanoes

Examples of Landforms

• http://www.enchantedlearning.com/geography/landforms/glossary.shtml

Relief Map

Four Spheres

• Scientists divide Earth into four spheres:– Lithosphere: Litho=Land; Earth’s solid, rocky outer

layer. The lithosphere is made of the continents as well as smaller landmasses called island. The lithosphere included the entire ocean floor.

– Atmosphere: the outermost sphere, which includes a mixture of gases that surrounds the planet.

– Hydrosphere: Hydro=water; this includes Earth’s lakes, rivers, oceans, and ice.

– Biosphere: Bio=living; All living things in the air, oceans, or on and beneath land.

Animation of Spheres

• http://www.classzone.com/books/earth_science/terc/content/visualizations/es0102/es0102page01.cfm?chapter_no=01

Earth’s Three Layers

• Earth is made up of three layers.– The core is the center of the Earth. There is the

inner core and the outer core.– The mantle is the thick layer that surrounds the

core.– The Crust is the thin, outer layer made of rock.

Diagram of the Earth’s Layers

Section Two – Mapping Earth’s Surface

• A map is a model on a flat surface of all or part of Earth’s surface – seen from above.

• A globe is a sphere that represents Earth’s entire surface.

• Symbols are used on a map with an explanation of their meaning – symbols represent topography and other features on Earth’s surface. The map key lists all the symbols used on the map.

Map

Globe

Using a Map or Globe

• Maps and globes show a grid based on two imaginary lines. Half way between the North and South poles is the equator. The equator divides Earth into the Northern Hemisphere and the Southern Hemisphere.

• The second imaginary line is the prime meridian – this line makes a half circle from the North Pole to the South Pole – dividing the Earth’s surface into the Western Hemisphere and the Eastern Hemisphere.

• We live in the North-Eastern Hemisphere.

Equator

Prime Meridian

Latitude/Longitude

• The equator is the starting point for measuring latitude – the distance in degrees north and south of the equator.

• The distance in degrees east or west of the prime meridian is called longitude.

Map with longitude/latitude

• Latitude Longitude

Longitude/Latitude

Section Three – Maps in the Computer Age

Satellites are designed to observe Earth’s surface. Satellites use electronic devices to collect information about the land surface in the form of computer data Satellite images are pictures of the surface based on these data.

A Satellite image is made up of thousands of tiny dots called pixels.

Satellites

• Image taken by a satellite in space

This image consists of 196 separate photographs taken with a 6 megapixel digital camera, and then stitched together into one seamless composite. The final image is 40,784 x 26,800 pixels in size, and

contains about 1.09 billion pixels

Section Four – Topographic Maps

• A topographic map is a map showing the surface features of an area.

• To represent elevation, relief, and slope on topographic maps, mapmakers use contour lines.

– Closely spaced lines indicate a steep slope.

– Widely spaced lines indicate gentle slopes.

– A contour line that forms a closed loop with not other contour lines inside it indicates a hill.

– A closed loop with dashes inside indicates a depression.

– V-shaped contour lines pointing uphill indicate a valley.

Topographic Map

Examples of Contour Lines