A View of Earth

Biosphere

is made up of all the life forms on Earth

Lithosphere

A rigid layer made up of the uppermost part of the mantle and the crust. Rocks become partially molten or melted. They are able to slowly flow because of the uneven distribution of heat deep within Earth.

Plate Tectonics

A theory stating that the earth's surface is broken into plates that move.

Plate Tectonics 3

According to the plate tectonics model, Earth's lithosphere is broken into several individual sections called plates. These plates move slowly and continuously across the surface. This motion is driven by the result of an unequal distribution of heat within Earth. Ultimately, this movement of Earth's lithospheric plates generates earthquakes, volcanic activity, and the deformation of large masses of rock into mountains.

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans

Hydrosphere 3

Although these freshwater sources make up a small fraction of the total amount of water on Earth, they are quite important. Streams, glaciers, and groundwater are responsible for sustaining life and creating many of Earth's varied landforms. The properties of water and its distribution are major factors that affect life on Earth. Living things require liquid water. Fortunately, much of Earth has temperatures at which water remains in the liquid state. The availability of water also helps to determine where many organisms, including humans, can live. For example, fewer people live in desert areas than in areas where water is abundant.

The lower mantle.

Beneath the asthenosphere, the rock becomes denser.

Geosphere 1

Lying beneath both the atmosphere and the ocean is the geosphere. Because the geosphere is not uniform, it is divided into three main parts based on differences in composition—the core, the mantle, and the crust.

What are Earth's major spheres?

The Earth is divided into four major spheres—hydrosphere, atmosphere, geosphere, and biosphere.

Which type of force created the Hawaiian islands?

The Hawaiian islands were created over hot spot volcanoes. Constructive forces are responsible for these formations.

The mantle

The layer of hot, solid material between Earth's crust and core.

geosphere

The mostly solid, rocky part of the Earth; extends from the center of the core to the surface of the crust. the layer of Earth under both the atmosphere and the oceans composed of the core, the mantle, and the crust

Which describes the location of Earth's biosphere, which includes all of Earth's living things?

at the boundary of the geosphere and atmosphere, and throughout the hydrosphere

From Earth's center outward, which is the correct order of three of Earth's major spheres?

geosphere, hydrosphere, atmosphere

Atmosphere 1

A life-sustaining, thin, gaseous envelope called the atmosphere surrounds Earth. It reaches beyond 100 kilometers above Earth, yet 90 percent occurs within just 16 kilometers of Earth's surface. This thin blanket of air is an important part of Earth. It provides the air that we breathe. It protects us from the sun's intense heat and dangerous radiation. The energy exchanges between space, the atmosphere, and Earth's surface produce weather and climate.

Plate Tectonics 1

Earth is a dynamic planet. If we could go back in time a billion years or more, we would find a planet with a surface that was dramatically different from what it is today. Such prominent features as the Grand Canyon, the Rocky Mountains, and the Appalachian Mountains did not exist. We would find that the continents had different shapes and were located in different positions from those of today.

According to the plate tectonics theory, what provides the energy for the constructive forces on Earth's surface?

Earth's internal heat

The crust

Earth's outermost layer.

Hydrosphere 2

Groundwater is water that seeps into the earth and is collected and stored underground. As water soaks into the surface, it moves through an upper layer of soil and rock. Eventually, all the cracks and other spaces between rock particles are filled with water. The boundary between the upper and lower layers is called the water table. The water table naturally changes as the weather does. In times of abundant rainfall, the water table rises. When it is dry, the water table falls. Human activity can also affect the water table.

Over the past few decades, Earth scientists have developed the theory of plate tectonics. Why is this theory useful?

It explains constructive forces, such as mountain building and volcanism.

Biosphere 1

The biosphere includes all life on Earth. It is concentrated in a zone that extends from the ocean floor upward for several kilometers into the atmosphere. Plants and animals depend on the physical environment for life. However, organisms do more than just respond to their physical environment. Through countless interactions, organisms help maintain and alter their physical environment. Without life, the makeup and nature of the solid Earth, hydrosphere, and atmosphere would be very different.

The core

The central part of the earth below the mantle

Hydrosphere 1

Water is what makes Earth unique. All of the water on Earth makes up the hydrosphere. Continually on the move, water evaporates from the oceans to the atmosphere, falls back to Earth as rain, and runs back to the ocean. The oceans account for approximately 97 percent of the water on Earth. The remaining 3 percent is fresh water and is present in groundwater, streams, lakes, and glaciers.

Plate Tectonics 2

Within the last several decades, a great deal has been learned about the workings of Earth. In fact, this period is called a revolution in our knowledge about Earth. This revolution began in the early part of the twentieth century with the idea that the continents had moved about the face of the Earth. This idea contradicted the accepted view that the continents and ocean basins are stationary features on the face of Earth. Few scientists believed this new idea. More than 50 years passed before enough data were gathered to transform this hypothesis into a widely accepted theory. The theory that finally emerged, called plate tectonics, provided geologists with a model to explain how earthquakes and volcanic eruptions occur and how continents move.

Constructive forces

such as mountain building and volcanism build up the surface by raising the land and depositing new material in the form of lava. Depend on Earth's internal heat for their source of energy.

Destructive forces

such as weathering and erosion work to wear away high points and flatten out the surface.

atmosphere

the envelope of gases surrounding the earth or another planet.

The asthenosphere

the uneven distribution of heat deep within Earth