Chapter One Looking at the Earth

Chapter One Section One: Thinking Like a Geographer

I. A Geographer’s View of Place A.Geography is the study of land as well as water, plants, animals, and people. B.Geographers study the physical and human characteristics of places.

C. Landforms are individual features of the land, such as mountains and valleys. D. Geographers study how people interact with their natural surroundings, or their environment. E. Regions are large or relatively small areas that share common cultural characteristics or similar physical environments.

II. The Tools of Geography A. Among the tools that geographers use are maps, globes, Landsat and radar images, GPS, and GIS.

B. The Global Positioning System (GPS) is a group of satellites traveling around the earth. A GPS receiver placed at a particular location on the earth receives signals from these satellites. The satellites can tell the exact latitude and longitude of the receiver’s location.

C. Geographic information systems (GIS) is special computer software used in making maps. Geographers input various kinds of data about a specific place into GIS. The computer can then combine and overlap this information to make a map or to change the focus of the map.

IV. Clues to Our Past A. Historians, archaeologists, and anthropologists try to understand early times. B. Historians rely mostly on written records to learn about the past.

C. To learn about prehistoric times, scientists study artifacts - such as tools, pottery, and weapons - and fossils - such as human remains.

Chapter One Section Two: The Earth in Space

I. The Solar System A. The solar system is made up of the sun, Earth, eight other planets, and thousands of smaller bodies (moons, comets, and asteroids). The planets and smaller bodies revolve around the sun.

B. A planet follows an elliptical path around the sun. This is known as its orbit. C. There are two types of planets - those solid and small like Earth, and those that resemble balls of gas like Jupiter.

D. Earth is surrounded by a layer of air called the atmosphere. Nitrogen and oxygen make up about 99 percent of this layer. E. Earth makes two motions in space. It spins on an imaginary line (axis) that runs through the center of Earth between the North and South Poles. It takes 24 hours for Earth to complete one spin on this axis.

The other motion is its complete orbit around the sun, or revolution. This revolution takes 365 ¼ days, which accounts for our need for a leap year once every four years.

II. The Sun and the Seasons A.Earth is tilted 23 ½ degrees on its axis. Because of this, we have seasons as Earth rotates around the sun. B. The day in which the Northern Hemisphere receives the most amount of sunlight is the summer solstice. On this day, the sun is directly over the Tropic of Cancer.

C. The day in which the Northern Hemisphere receives the least amount of sunlight is the winter solstice. On this day, the sun is directly over the Tropic of Capricorn. D. The two days each year in which the sun is directly over the Equator are known as the equinoxes. Both hemispheres receive the same amount of sunlight on these days.

Chapter One Section Three: Forces Shaping the Earth

I. Inside the Earth A. The inside of the earth is made up of three layers. The core consists of hot iron mixed with other metals and rock. B. The mantle is a layer of rock surrounding the core.

C. When a volcano erupts, melted rock called magma flows to the earth’s surface. D. The crust is the upper layer of the earth. The crust includes the ocean floors as well as the seven land continents.

II. Forces Beneath the Earth’s Crust A. Plate tectonics is a theory that the earth’s crust is made up of plates. These plates can move away from, push against, or slide alongside each other.

B. The pressure between two plates may cause one plate to move suddenly, resulting in an earthquake. Underwater earthquakes can create huge waves called tsunamis.

C. Two plates moving alongside each other create cracks in the earth’s crust, or faults.

4 different faults: 1.) normal fault 2.) reverse fault 3.) left-lateral strike-slip fault 4.) right-lateral strike-slip fault

III. Forces Shaping Landforms A. Weathering is the breaking of surface rock into boulders, gravel, sand, and soil. Water and frost, chemicals, and even plants can cause weathering. B. The process of wearing away or moving the weathered material is called erosion. Erosion can be caused by water, wind, or ice. Giant sheets of ice are known as glaciers.

Chapter One Section Four: Landforms and Waterways

I. Types of Landforms A. Mountains and hills differ in that mountains have high peaks and steep, rugged slopes. Hills are lower and more rounded.

B. Between mountains and hills lie valleys. A valley is a long stretch of land lower than the land on either side. Canyons are steep-sided lowlands that rivers have cut through a plateau.

C. Plains and plateaus are mostly different in elevation, or their height above sea level. Plains are low-lying stretches of flat or gently rolling land. Plateaus are also flat, but they have a higher elevation.

D. A narrow piece of land that connects two larger pieces of land is known as an isthmus. A peninsula is a piece of land with water on three sides. A body of land completely surrounded by water is known as an island. isthmusisland

E. A plateau that stretches for several miles underwater is called a continental shelf. Valleys on the ocean floor, the lowest spots in the earth’s crust, are called trenches.

F. Humans have settled on all types of landforms. Climate and availability of resources are two reasons people might choose to live in a particular area.

II. Bodies of Water A. About 70 percent of the earth’s surface is water. Of that, most is salt water. Oceans, seas, gulfs, and bays are made up of salt water. Humans can drink only freshwater, found in lakes, rivers, ponds, and streams.

B. A strait and a channel are similar in that they are both bodies of water between two pieces of land, and they connect two larger bodies of water. A channel is wider than a strait.

C. A river’s source is where it originates, usually high in mountains. The mouth of a river is where it empties into another body of water. D. Deltas are deposits of soil, which build up over time at the mouth of the river.