ASVAB General Science part 2

What are the three types of plate tectonic boundaries?

1. Transform (Fault) Boundary

2. Divergent Boundary

3. Convergent Boundary

Each boundary describes how tectonic plates move relative to each other.

What is a transform (fault) boundary?

Boundary that occurs when two tectonic plates slide horizontally past each other.

Characteristics and example of a transform (fault) boundary?

Characteristics:

• Plates move sideways

• No major creation or destruction of crust

• Often causes earthquakes

Example:

• San Andreas Fault in California

What is a divergent boundary?

Boundary that occurs when tectonic plates move away from each other.

What happens when a divergent boundary occurs? Example?

What happens:

• Magma rises from Earth's mantle

• New crust is created

• Often forms ridges or rift valleys

Example:

• Mid-ocean ridges

What is a convergent boundary?

Boundary that occurs when tectonic plates move toward each other and collide.

One plate may be forced beneath another through a process called subduction.

What are the effects of a convergent boundary?

• Destruction of old crust

• Formation of volcanoes

• Formation of mountains

• Earthquakes

What is subduction?

Subduction occurs when one tectonic plate moves underneath another plate and sinks into the mantle.

This usually happens at convergent boundaries.

What are the results of a subduction?

• Old crust is recycled into the mantle

• Volcanoes and earthquakes may occur

Where can volcanoes form in relation to tectonic plates?

1. Divergent plate boundaries

2. Convergent plate boundaries

3. Hot spots within tectonic plates

Volcanoes form when magma rises to Earth's surface and cools into solid rock.

What is the process of how volcanoes form at divergent boundaries?

1. Plates separate.

2. Cracks form in Earth's crust.

3. Magma rises from the mantle.

4. Magma cools and forms new crust.

This often creates underwater mountain ranges called mid-ocean ridges.

Example:

• Mid-Atlantic Ridge

How do volcanoes form at convergent boundaries?

Process:

1. One plate sinks into the mantle.

2. Heat causes parts of the plate to melt.

3. Magma forms.

4. Magma rises to the surface.

5. Volcanoes develop.

What is a hot spot in plate tectonics?

An area where a column (plume) of hot magma rises from deep within the mantle and creates volcanoes.

Characteristics and example of a hot spot in plate tectonics.

Characteristics:

• Located away from plate boundaries

• Remains in a relatively fixed location

• Can create a chain of volcanoes as a plate moves over it

Example:

• Hawaiian Islands

How are volcanoes categorized based on activity?

1. Active

2. Dormant

3. Extinct

The categories describe the likelihood that a volcano will erupt.

What is an active volcano?

A volcano that is:

• Currently erupting, or

• Showing signs that an eruption may occur soon

Characteristics of an active volcano.

• Magma is still moving beneath the volcano

• Volcanic activity is occurring

What is a dormant volcano?

A volcano that is currently not erupting but may erupt in the future.

Characteristics of a dormant volcano.

• Still has volcanic activity underground

• Appears inactive but is not considered dead

What is an extinct volcano?

A volcano that is not expected to erupt again.

Characteristics of an extinct volcano?

• No significant volcanic activity remains

• Magma is no longer expected to reach the surface

What are lines of longitude?

Imaginary lines that run vertically from the North Pole to the South Pole around Earth.

They are also called meridians.

What are the characteristics of lines of longitude?

• Run north to south

• Measure locations east or west of the Prime Meridian

• Meet at the Earth's poles

What is the Prime Meridian?

the reference line for measuring longitude.

Where is the Prime Meridian located at and how does it impact Earth?

It is located at:

0° longitude

It divides Earth into:

• Eastern Hemisphere

• Western Hemisphere

How is longitude measured?

Measured in degrees east or west of the Prime Meridian.

Longitude is divided into:

• Degrees (°)

• Minutes (′)

• Seconds (″)

1 degree is how many minutes?

60 minutes

What are the measurements of longitude?

Measurements:

• 0° = Prime Meridian

• Up to 180° East

• Up to 180° West

How are longitude lines spaced around Earth?

Longitude is measured in 15-degree increments because Earth rotates:

• 360° in 24 hours

• 15° of longitude = 1 hour of time difference

This helps determine time zones.

What do longitude lines help determine?

Time Zones

15 degrees is how many hours?

1 hour.

What are longitude lines also called?

Meridians

What are lines of latitude?

Imaginary lines that run horizontally around Earth and are parallel to the Equator.

What are lines of latitude also called?

Parallels

What are the characteristics of lines of latitude?

• Run east to west

• Measure distance north or south of the Equator

• Never intersect each other

What is the Equator?

The reference line for measuring latitude.

What is the Equator located at?

0° latitude

What are the characteristics of the Equator?

• Divides Earth into the:

  • Northern Hemisphere

  • Southern Hemisphere

• Is the widest part of Earth

What does latitude measure?

Measures the distance north or south of the Equator.

What are the measurements of latitude?

• 0° = Equator

• Up to 90° North

• Up to 90° South

Latitude is measured using:

• Degrees (°)

• Minutes (′)

• Seconds (″)

What are the three common states of matter?

1. Solid

2. Liquid

3. Gas

They differ based on how their molecules move and how closely packed their particles are.

What is the definition of solids?

A state of matter where particles are tightly packed and only vibrate around fixed positions.

Characteristics of solids?

Molecular motion:

• Molecules vibrate in place

• Particles have limited movement

Compressibility:

• Very low compressibility

• Particles are already tightly packed

Shape and volume:

• Has a definite shape

• Has a definite volume

Density:

• Usually high density because particles are close together

Definition of liquids.

A state of matter where particles can move freely past one another while remaining close together.

Characteristics of liquids.

Molecular motion:

• Molecules move and slide past each other

Compressibility:

• Very low compressibility

• Particles are still close together

Shape and volume:

• Has a definite volume

• Does not have a definite shape

• Takes the shape of its container

Density:

• Usually high density

Definition of gas.

a state of matter where particles are spread far apart and move freely.

Characteristics of gases.

Molecular motion:

• Molecules move rapidly and freely in all directions

Compressibility:

• Highly compressible

• Particles have large spaces between them

Shape and volume:

• No definite shape

• No definite volume

• Expands to fill its container

Density:

• Low density because particles are far apart

Where are the Tropic of Cancer and Tropic of Capricorn located?

The Tropic of Cancer and Tropic of Capricorn are imaginary latitude lines located near the Equator.

What does Tropic of Cancer and Tropic of Capricorn mark?

They mark the farthest points north and south where the Sun can appear directly overhead at noon.

What is the Tropic of Cancer?

A latitude line located at:

23.5° North latitude

Characteristics of the Tropic of Cancer.

• Located in the Northern Hemisphere

• The Sun is directly overhead at noon on approximately June 21

• Marks the beginning of summer in the Northern Hemisphere

• Occurs during the summer solstice

What is the Tropic of Capricorn?

The a latitude line located at:

23.5° South latitude

Characteristics of the Tropic of Capricorn.

• Located in the Southern Hemisphere

• The Sun is directly overhead at noon on approximately December 21

• Marks the beginning of winter in the Northern Hemisphere

• Occurs during the winter solstice

Where are the Arctic Circle and Antarctic Circle located?

The Arctic Circle and Antarctic Circle are imaginary latitude lines located near Earth's poles.

What does the Artic Circle and Antarctic Circle mark?

They mark the regions where the Sun can be:

• Visible for 24 hours during part of the year (midnight sun)

• Below the horizon for 24 hours during part of the year (polar night)

What is the Arctic Circle?

A latitude line located at:

66.5° North latitude

Characteristics of the Arctic Circle.

• Located in the Northern Hemisphere

• Marks the southern boundary of the Arctic region

• During the winter solstice (around December 21), the Sun does not rise above the horizon for areas north of the Arctic Circle

• During the summer solstice (around June 21), areas north of the Arctic Circle can experience 24 hours of daylight

What is the Antarctic Circle?

A latitude line located at:

66.5° South latitude

Characteristics of the Antarctic Circle.

• Located in the Southern Hemisphere

• Marks the northern boundary of the Antarctic region

• During the winter solstice in the Southern Hemisphere (around June 21), the Sun does not rise above the horizon for areas south of the Antarctic Circle

• During the summer solstice in the Southern Hemisphere (around December 21), areas south of the Antarctic Circle can experience 24 hours of daylight

How is Earth positioned on its axis?

Earth's axis is tilted 23.5° relative to its orbit around the Sun.

How is Earth positioned on its axis

Earth positioned on its axis affects what?

• The seasons

• Changes in temperature

• Differences in the amount of sunlight different areas receive throughout the year

Why does Earth's tilt cause seasons?

Earth's tilt changes the angle and amount of sunlight that reaches each hemisphere as Earth revolves around the Sun.

When a hemisphere is tilted toward the Sun:

• Receives more direct sunlight

• Has longer days

• Experiences summer

When a hemisphere is tilted away from the Sun:

• Receives less direct sunlight

• Has shorter days

• Experiences winter

What happens when the Northern Hemisphere is tilted toward the Sun?

• Northern Hemisphere experiences summer

• Southern Hemisphere experiences winter

• Sunlight is more direct in the Northern Hemisphere

• Days are longer in the Northern Hemisphere

What happens when the Southern Hemisphere is tilted toward the Sun?

• Southern Hemisphere experiences summer

• Northern Hemisphere experiences winter

• Sunlight is more direct in the Southern Hemisphere

What causes spring and fall?

the transition periods when neither hemisphere is tilted strongly toward or away from the Sun.

During spring and fall these times cause:

• Both hemispheres receive more equal sunlight

• Day and night lengths become more similar

What are the eight major biomes?

• Tundra

• Taiga (Boreal Forest)

• Grassland

• Temperate Forest

• Chaparral

• Desert

• Tropical Rain Forest

• Ocean

Biomes are large regions with similar:

• Climate

• Temperature

• Precipitation

• Plants and animals

What causes differences between Earth's biomes?

• Latitude

How does Latitude affect Earth’s biomes?

It effects:

• Amount of sunlight received

• Temperature

• Climate

• Precipitation

What is the climate and amount of sunlight during high latitudes?

• less sunlight

• colder climates

What is the climate and amount of sunlight during low latitudes near the Equator?

• more sunlight

• warmer climates

What biomes are found at high latitudes?

• Tundra

• Taiga (Boreal Forest)

High latitudes receive the least direct sunlight, making them colder

Characteristics of Tundra biome.

Characteristics:

• Extremely cold

• Low precipitation

• Permafrost (permanently frozen ground)

• Few trees

Characteristics of Taiga (boreal Forest) biome.

Characteristics:

• Cold climate

• Large forests of evergreen trees

• Short growing season

What biomes are found in middle latitudes?

• Grassland

• Temperate Forest

• Chaparral

Middle latitudes have moderate temperatures and seasonal changes.

Characteristics of Grassland biome.

Characteristics:

• Dominated by grasses

• Moderate rainfall

• Supports grazing animals

Characteristics of Temperate Forest biome.

Characteristics:

• Four seasons

• Deciduous trees

• Moderate temperatures

Characteristics of Chaparral biome.

Characteristics:

• Hot, dry summers

• Mild, wet winters

• Shrubs and small trees

What biomes are found near the Equator?

• Desert

• Tropical Rain Forest

Low latitudes near the Equator receive the most direct sunlight, creating warmer climates.

Characteristics of Desert biome.

Characteristics:

• Very little precipitation

• Dry conditions

• Large temperature changes

Characteristics of Tropical Rain Forest biome.

Characteristics:

• Warm year-round

• Heavy rainfall

• Extremely high biodiversity

Why is the ocean considered a biome?

• It consists primarily of water

• Covers most of Earth's surface

• Exists across all latitudes

It contains many different environments:

• Coral reefs

• Deep ocean regions

• Coastal ecosystems

What factor determines the distribution of Earth's biomes?

Latitude

Which biome has permanently frozen ground?

Tundra

What causes Earth's seasons?

Earth's 23.5° axial tilt as it revolves around the Sun.

Does Earth's distance from the Sun cause seasons?

No, Earth's tilt is the main cause.

How does the amount of sunlight received differ between the Equator and the poles?

The amount of sunlight received depends on latitude and Earth's 23.5° axial tilt.

• Equator: Receives nearly the same amount of sunlight all year.

• Poles: Experience extreme changes in daylight because they tilt toward or away from the Sun during Earth's orbit.

What type of sunlight do Poles get?

Extreme changes in daylight; extreme sunlight since tilted towards/away from the Sun during Earth’s orbit.

What type of sunlight does the Equator get?

Receives nearly the same amount of sunlight all year; equal sunlight.

How much sunlight does the Equator receive?

• About 12 hours of daylight and 12 hours of night throughout the year

• Nearly the same amount of sunlight every day

How much sunlight does the Equator receive?

Characteristics of the Equator.

• Little seasonal change

• Warm temperatures year-round

• Sunlight is more direct

Why do the poles experience periods with no sunlight?

The poles experience extreme daylight changes because of Earth's 23.5° tilt.

What happens to the Poles during winter?

• A pole is tilted away from the Sun

• It can receive 24 hours of darkness

• This is called polar night

What happens to the Poles during summer?

• A pole is tilted toward the Sun

• It can receive 24 hours of daylight

• This is called the midnight sun

Why do the poles have periods of no sunlight?

Earth's tilt causes them to face away from the Sun.