SCIENCE Q4

Earth's Subsystems Reviewer

The Earth is composed of four main subsystems that interact with each other. These subsystems are:

### 1. Lithosphere

   - Definition: The rigid outer layer of the Earth, consisting of the crust and the upper part of the mantle.

   - Components:

     - Crust: Earth's outermost solid layer. It is divided into continental and oceanic crust.

     - Mantle: Layer beneath the crust, made of semi-solid rock that flows very slowly.

   - Key Features: 

     - Tectonic plates are part of the lithosphere.

     - Earthquakes and volcanic activity originate in the lithosphere.

### 2. Atmosphere

   - Definition: The layer of gases surrounding the Earth, held by gravity.

   - Components: 

     - Troposphere: The layer closest to the Earth, where weather occurs.

     - Stratosphere: Contains the ozone layer that absorbs harmful ultraviolet radiation.

     - Mesosphere: Where meteors burn up as they enter the atmosphere.

     - Thermosphere: Contains ionized gases and is the region where auroras occur.

     - Exosphere: The outermost layer, where the atmosphere transitions into space.

   - Key Features:

     - Provides oxygen and carbon dioxide, supporting life.

     - Protects Earth from harmful solar radiation.

     - Regulates temperature through greenhouse gases.

### 3. Hydrosphere

   - Definition: All of Earth's water, in liquid, solid, and gas form.

   - Components: 

     - Oceans: Cover 70% of Earth's surface and regulate temperature.

     - Rivers and Lakes: Freshwater bodies that support ecosystems and human activities.

     - Glaciers and Ice Caps: Store a significant amount of Earth's fresh water.

     - Groundwater: Water stored beneath Earth's surface.

   - Key Features:

     - Supports life by providing water for plants, animals, and humans.

     - Drives the water cycle, including precipitation, evaporation, and infiltration.

### 4. Biosphere

   - Definition: The zone of life on Earth, including all living organisms and their interactions with the other subsystems.

   - Components:

     - Biota: All living organisms, including plants, animals, fungi, and microorganisms.

     - Ecosystems: Interactions between living organisms and their environment.

   - Key Features:

     - Supports biodiversity, ensuring ecosystems remain balanced.

     - Dependent on the lithosphere, atmosphere, and hydrosphere for resources like food, air, and water.

### 5. Geosphere

   - Definition: The solid portion of the Earth, including the crust, mantle, and core.

   - Components: 

     - Crust: Earth's outermost layer made of solid rock.

     - Mantle: Semi-solid rock layer beneath the crust.

     - Core: The innermost part of the Earth, consisting of a liquid outer core and a solid inner core.

   - Key Features:

     - Responsible for Earth’s internal heat and tectonic activity.

     - Plays a role in the recycling of nutrients and minerals.

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### Interactions Between Subsystems

- Lithosphere & Hydrosphere: Ocean currents are influenced by the Earth's crust and topography.

- Atmosphere & Biosphere: Plants depend on atmospheric gases (oxygen, carbon dioxide) for survival.

- Hydrosphere & Biosphere: Water bodies provide essential resources for life and ecosystems.

- Geosphere & Atmosphere: Volcanic eruptions release gases that affect the atmosphere.

- Biosphere & Geosphere: Organisms, including humans, modify the land through activities like farming, construction, and mining.

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### Key Points to Remember:

1. The lithosphere includes Earth’s solid outer layers (crust and mantle), where tectonic movements occur.

2. The atmosphere is composed of different gas layers that protect and sustain life.

3. The hydrosphere includes all water on Earth, which is essential for sustaining life and regulating climate.

4. The biosphere represents all living organisms and their ecosystems.

5. The geosphere is the solid Earth, which supports the other subsystems.

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### Review Questions:

1. What is the main difference between the lithosphere and the geosphere?

2. How does the hydrosphere contribute to Earth’s climate?

3. What role does the atmosphere play in protecting life on Earth?

4. Describe how the biosphere is dependent on the lithosphere and hydrosphere.

5. How do the subsystems of Earth work together to support life?

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TroSMITE: Layers of the Atmosphere

TroSMITE is an acronym representing the layers of the Earth's atmosphere from the surface to outer space.

### 1. Troposphere

   - Location: The layer closest to Earth's surface.

   - Characteristics: 

     - Extends about 8-15 km above sea level.

     - Weather events like clouds, rain, and storms occur here.

     - Temperature decreases with altitude.

     - Contains most of Earth's air (about 75% of the atmosphere's mass).

     - The highest concentrations of water vapor are found here.

### 2. Stratosphere

   - Location: Above the troposphere, extending up to about 50 km above sea level.

   - Characteristics:

     - Contains the ozone layer, which absorbs and scatters ultraviolet solar radiation.

     - Temperature increases with altitude due to the absorption of UV radiation by ozone.

     - Commercial jet aircraft typically fly in the lower stratosphere.

     - Little to no weather occurs in this layer, and air is more stable.

### 3. Mesosphere

   - Location: Above the stratosphere, extending from 50 km to about 85 km above sea level.

   - Characteristics:

     - This is the coldest layer of the atmosphere.

     - Temperature decreases with altitude.

     - Meteors burn up in this layer due to friction with the air.

     - Very little water vapor is present, and air density is low.

### 4. Ionosphere

   - Location: Extends from the mesosphere to the exosphere, roughly from 50 km to 1,000 km above Earth.

   - Characteristics:

     - A region where solar radiation ionizes gases, creating charged particles (ions).

     - Responsible for phenomena like auroras (Northern and Southern Lights).

     - Important for radio communication, as it can reflect radio waves back to Earth.

     - Divided into sub-layers like the D, E, and F layers based on ion density.

### 5. Thermosphere

   - Location: Above the mesosphere, extending from 85 km to about 550 km above Earth's surface.

   - Characteristics:

     - Temperature increases significantly with altitude, reaching up to 2,500°C (4,500°F) or higher.

     - The air is very thin, and molecules are spread far apart.

     - The ionosphere overlaps with this layer, where auroras occur.

     - Satellites and the International Space Station (ISS) orbit in this layer.

### 6. Exosphere

   - Location: The outermost layer of the atmosphere, extending from about 550 km up to 10,000 km.

   - Characteristics:

     - Composed of extremely thin air, mainly hydrogen and helium.

     - This layer transitions into outer space, and particles in the exosphere can escape into space.

     - Satellites in geostationary orbit are located in the exosphere.

     - The density of particles is very low, and they can travel long distances before colliding with each other.

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### Summary of Layers (TroSMITE):

- T: Troposphere (weather occurs, temperature decreases with altitude)

- S: Stratosphere (ozone layer, temperature increases with altitude)

- M: Mesosphere (coldest layer, meteors burn up here)

- I: Ionosphere (ionized particles, auroras, and radio waves reflect)

- T: Thermosphere (hot, satellites orbit here)

- E: Exosphere (outermost layer, very thin air, transition to space)

This breakdown should help you understand the characteristics and importance of each atmospheric layer!

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Earthquake Hazards & Safety

### Ground Shaking

   - This refers to the feeling we experience when energy, built up due to stress applied to the lithosphere, is released by faulting during an earthquake.

### Ground Rupture

   - The creation of new fractures or the renewed movement of old fractures, often causing two blocks on either side to move in opposite directions.

### Liquefaction

   - Occurs when loosely packed, waterlogged sediments at or near the ground surface lose their strength due to strong ground shaking.

### Earthquake-induced Landslide

   - When an earthquake causes seismic waves that shake and vibrate the ground, resulting in a landslide.

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### What to Do Before a Landslide

1. Avoid building near steep slopes, mountain edges, drainage ways, or natural erosion valleys.

2. Have a ground assessment conducted on your property.

3. Familiarize yourself with the emergency-response and evacuation plans in your area.

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### Tsunami

   - Tsunamis occur when ocean water is displaced suddenly, forming waves that travel toward the shore with large heights.

### Causes of Tsunami

1. Landslides

2. Volcanic eruptions or explosions

3. Meteorite impact

### Signs of Impending Tsunami

1. Unusual ocean behavior

2. Change in animal behavior

3. A sound similar to an incoming train

### How to Stay Safe When a Tsunami Threatens

#### Prepare NOW

1. If you live near or visit coastal areas, learn about tsunami risks in your area.

2. Learn to recognize the signs of a potential tsunami.

3. Know and practice community evacuation plans, and map out routes from home and work.

4. Create a family emergency communication plan with an out-of-state contact.

#### Survive DURING

1. If you are outside the tsunami hazard zone and receive a warning, stay where you are unless officials advise otherwise.

2. If you're in the water, grab something that floats, such as a raft, tree trunk, or door.

#### Be Safe AFTER

1. Listen to local authorities for information.

2. Avoid wading through floodwater, as it may contain dangerous debris.

3. Be aware of the risk of electrocution.

4. Stay away from damaged buildings, roads, and bridges.

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### Seiche

   - Seiche refers to standing waves that form on rivers, reservoirs, ponds, and lakes when seismic waves from an earthquake pass through the area.