Earth and Life Science Lesson 4

Questions and Answers

What is the main characteristic of the thermosphere?

Temperature significantly increases with altitude. (correct)

Temperature decreases with altitude.

It is the coldest layer of the atmosphere.

It contains the highest concentration of oxygen.

What phenomenon occurs in the thermosphere?

The Northern and Southern Lights (correct)

Cloud formation

Meteor showers

Ozone depletion

What best describes the exosphere?

The layer responsible for the majority of Earth's atmospheric pressure.

The layer of the atmosphere where weather occurs.

A dense layer rich in oxygen and nitrogen.

The outermost layer, transitioning into outer space. (correct)

Which part of Earth's system is described as the solid Earth?

Geosphere Signup and view all the answers

Which statement accurately represents the hydrosphere?

It encompasses all water on Earth, including oceans and glaciers. Signup and view all the answers

What is the primary composition of the Earth's atmosphere?

78% nitrogen and 21% oxygen Signup and view all the answers

Which layer of the atmosphere is where most weather phenomena occur?

Troposphere Signup and view all the answers

How does temperature change with altitude in the troposphere?

Temperature decreases with altitude Signup and view all the answers

What is the main function of the ozone layer found in the stratosphere?

To filter out harmful ultraviolet radiation Signup and view all the answers

What is a characteristic of the mesosphere?

Most meteors burn up in this layer Signup and view all the answers

Which gas makes up the largest percentage of the atmosphere?

Nitrogen Signup and view all the answers

What role does the atmosphere play in supporting life?

Provides essential gases like oxygen and carbon dioxide Signup and view all the answers

How does air act as a blanket for the Earth?

By retaining heat at night Signup and view all the answers

Study Notes

Subsystems of Planet Earth

Earth comprises four interconnected subsystems: Atmosphere, Biosphere, Geosphere, and Hydrosphere, facilitating matter and energy flow.

Atmosphere

Gaseous layer above Earth's surface, primarily composed of 78% nitrogen and 21% oxygen, with remaining gases (argon, CO2, CO, ozone) making up 1%.
Supports life through oxygen for animals and carbon dioxide for plants; regulates climate by acting as a thermal blanket and a filter for solar radiation.

Layers of the Atmosphere

Troposphere:
- Extends 8-15 km above Earth's surface; where most weather occurs and contains 75% of the atmosphere's mass.
- Temperature decreases with altitude, rich in water vapor.
Stratosphere:
- Ranges from 15 km to 50 km above Earth; contains the ozone layer that absorbs ultraviolet radiation.
- Temperature increases with altitude due to ozone absorption.
Mesosphere:
- Extends from 50 km to 85 km above the surface; known for burning meteors upon entry.
- Coldest layer with decreasing temperature with altitude.
Thermosphere:
- Extends from 85 km to over 600 km above the surface; temperature can reach 2,500°C (4,500°F).
- Contains auroras and is where the International Space Station orbits.
Exosphere:
- Outermost layer extending from the top of the thermosphere to about 10,000 km.
- Very thin air allows particles to travel long distances without colliding.

Biosphere

Zone where all life forms exist, encompassing oceans, land, and freshwater ecosystems.
Considered a thin layer of the Earth that hosts biodiversity.

Geosphere

Solid structure of Earth, comprising the core, mantle, and crust.
Represents all landforms and geological features of the planet.

Hydrosphere

Encompasses all water on Earth, found in oceans, rivers, glaciers, and atmosphere.
Oceans cover 71% of Earth's surface and hold 97.5% of its water, playing a crucial role in climate and life.