4B3 Water and Earth's Surface Processes

Question 1

Define:

hydrosphere

Answer 1

All the water found on, under, and above Earth’s surface.

This includes oceans, rivers, lakes, groundwater, and atmospheric water vapor, forming a continuous water cycle.

Question 2

What percentage of Earth’s water is found in oceans?

Answer 2

Approximately 97%.

The vast majority of Earth’s water is in oceans, leaving only about 3% as freshwater, most of which is frozen in ice caps and glaciers.

Question 3

What is the largest ocean on Earth?

Answer 3

The Pacific Ocean

The Pacific Ocean covers over 63 million square miles, making it the biggest and deepest ocean.

Question 4

Why is ocean water unsuitable for drinking?

Answer 4

Because it contains high levels of salt and minerals.

Ocean water has an average salinity of 3.5%, which makes it undrinkable without desalination.

Question 5

List the major sources of freshwater.

Answer 5

• Glaciers and ice caps
• Groundwater
• Lakes
• Rivers and streams
• Atmospheric water

While freshwater makes up only about 3% of Earth’s total water, much of it is frozen or underground, leaving less than 1% readily available for human use.

Question 6

What percentage of Earth’s freshwater is locked in glaciers and ice caps?

Answer 6

Around 68.7%.

Most freshwater is stored in glaciers and ice caps, mainly in Antarctica and Greenland, making it inaccessible for immediate human use.

Question 7

True or False:

All freshwater sources contain drinkable water.

Answer 7

False

Many freshwater sources, such as rivers and lakes, can be contaminated with pollutants or microorganisms, requiring treatment before being safe for consumption.

Question 8

What is the largest source of liquid freshwater on Earth?

Answer 8

Groundwater

Groundwater accounts for about 30.1% of Earth’s freshwater and is stored in underground aquifers, supplying wells and springs.

Question 9

What type of freshwater forms when rainwater accumulates in depressions?

Answer 9

Lakes

Lakes form in low-lying areas due to precipitation, groundwater seepage, or river inflows, and they can be temporary or permanent.

Question 10

Describe how rivers help distribute freshwater.

Answer 10

They transport water from mountains to lakes, seas, and oceans.

They play a key role in ecosystems, providing habitat and serving as a source of drinking water and irrigation.

Question 11

True or False:

All rivers eventually flow into an ocean.

Answer 11

False

Some rivers, like the Okavango River in Africa, end in inland basins instead of reaching an ocean.

Question 12

Fill in the blank:

A ________ is a low-lying area next to a river that floods periodically.

Answer 12

Floodplain

Floodplains store excess water, reducing the impact of floods but also posing risks to settlements.

Question 13

What is a slow-moving mass of ice formed by accumulated snow?

Answer 13

Glacier

Glaciers flow under their own weight and shape landscapes through erosion and deposition.

Question 14

Why are glaciers important for global freshwater supply?

Answer 14

They store water that can be gradually released to rivers and lakes.

As glaciers melt, they feed freshwater into rivers, supporting ecosystems and human water supplies, but excessive melting due to climate change threatens water security.

Question 15

Why do polar ice and icebergs contribute little to human freshwater use?

Answer 15

They are located in remote regions and difficult to harvest.

While they hold large amounts of freshwater, logistical and environmental challenges prevent their widespread use.

Question 16

True or False:

Glaciers can only form in polar regions.

Answer 16

False

Glaciers can form in any region where snow accumulation exceeds melting, including high mountain ranges near the equator.

Question 17

What is the main difference between glaciers and ice sheets?

Answer 17

Ice sheets are much larger than glaciers and cover vast areas of land.

Ice sheets cover entire continents, like Antarctica and Greenland, whereas glaciers are smaller and typically found in mountainous regions.

Question 18

What is the water cycle?

Answer 18

The continuous movement of water through Earth’s systems.

The water cycle includes processes like evaporation, condensation, precipitation, and runoff that recycle water on Earth.

Question 19

What are the main processes in the water cycle?

Answer 19

• Evaporation
• Condensation
• Precipitation
• Runoff

These processes work together to maintain Earth’s water distribution and support ecosystems.

Question 20

True or False:

Precipitation is when water vapor turns into liquid or ice.

Answer 20

True

Precipitation includes rain, snow, sleet, and hail, which return water to the Earth’s surface.

Question 21

Fill in the blank:

The water cycle is driven by the energy from the ______.

Answer 21

sun

The sun provides the necessary heat for evaporation, which is the starting point for the water cycle.

Question 22

What is runoff in the water cycle?

Answer 22

The movement of water from land to bodies like rivers, lakes, and oceans.

Runoff occurs after precipitation and plays a role in replenishing water sources.

Question 23

How does snow contribute to the water cycle?

Answer 23

It accumulates in winter, melts in spring, and contributes to runoff.

Snowmelt is a significant water source for many rivers and streams.

Question 24

Fill in the blank:

_________ is the process of water vapor turning into liquid.

Answer 24

Condensation

Condensation forms clouds, fog, or dew and is a key step in water returning to Earth’s surface.

Question 25

How do plants **contribute** to the water cycle?

Answer 25

Through transpiration. ## Footnote **Transpiration** is when plants release water vapor into the atmosphere, aiding atmospheric moisture.

Question 26

# True or False: Clouds are **formed** during the process of condensation.

Answer 26

True ## Footnote As water vapor condenses, tiny droplets of water gather to form **clouds**.

Question 27

# Fill in the blank: ________ is the process of water **moving into the ground**, replenishing groundwater.

Answer 27

Infiltration ## Footnote **Infiltration** rates vary based on factors like soil type, vegetation, and land use, affecting groundwater recharge.

Question 28

# True or False: Crystallization is when water vapor **turns directly** into ice or snow.

Answer 28

True ## Footnote **Crystallization** happens in cold temperatures, forming *snowflakes* or *hail* from water vapor in clouds.

Question 29

What is the **relationship** between gravity and the water cycle?

Answer 29

It moves water through **runoff**, **infiltration**, and **precipitation**. ## Footnote **Gravity** drives the movement of water across the Earth's surface and into the atmosphere, pulling it from higher to lower elevations and maintaining the continuous flow of the **water cycle**.

Question 30

# Define: oceanography

Answer 30

The study of Earth's **oceans**, **properties**, **ecosystems**, and **processes**. ## Footnote **Oceanography** integrates knowledge from various disciplines like biology, chemistry, geology, and physics to understand oceanic systems.

Question 31

What is the **rise and fall of ocean water levels** caused by the moon and sun?

Answer 31

Tides ## Footnote **Tides** occur in cycles, with two high and two low tides each day, and are influenced by the relative positions of the moon, sun, and Earth.

Question 32

What is the **difference in height** between high tide and low tide called?

Answer 32

Tidal range ## Footnote The *tidal range* can vary widely depending on **location**, with some places experiencing dramatic tidal fluctuations, like the Bay of Fundy.

Question 33

# True or False: Ocean currents are **large flows of seawater** circulating the oceans.

Answer 33

True ## Footnote *Ocean currents* play a key role in regulating climate, transporting heat, and facilitating the movement of marine organisms.

Question 34

What drives **surface ocean currents**?

Answer 34

1. Wind 2. Earth's rotation ## Footnote The *Coriolis effect* causes the currents to curve, influencing global weather patterns.

Question 35

# True or False: Ocean currents only flow in **one direction**.

Answer 35

False ## Footnote Currents move in *complex, interconnected loops* influenced by wind, gravity, and Earth’s rotation.

Question 36

# Define: Sea ice

Answer 36

Ice that forms on the **surface of the ocean** from freezing seawater. ## Footnote Sea ice is *thinner* and more dynamic than glaciers and ice sheets and does not contribute to sea level rise when it melts.

Question 37

# True or False: Sea ice **contributes** to rising sea levels when it melts.

Answer 37

False ## Footnote Since sea ice is already floating on the ocean, its melting *does not* raise sea levels, unlike ice sheets or glaciers that are on land.

Question 38

What is **ocean circulation**?

Answer 38

The **movement of ocean water** driven by wind, temperature, and salinity. ## Footnote This includes *both* surface currents (like the Gulf Stream) and deep-water currents that distribute heat and regulate climate.

Question 39

Why is ocean circulation **important** for climate regulation?

Answer 39

It **transports heat** and **distributes energy** across the planet. ## Footnote Currents like the *Gulf Stream* carry warm water from the tropics, influencing regional climates.

Question 40

How does **temperature** affect seawater?

Answer 40

Colder water is **denser** than warmer water. ## Footnote The density difference causes the movement of ocean currents and drives the *thermohaline circulation*, which regulates global climate.

Question 41

What is **ocean water movement** caused by temperature and salinity?

Answer 41

Thermohaline circulation ## Footnote *Thermohaline circulation* drives global heat transfer and supports marine ecosystems by moving warm and cold water across the oceans.

Question 42

# True or False: The Gulf Stream is a **warm ocean** current along the North American coast.

Answer 42

True ## Footnote The *Gulf Stream* carries warm water from the Gulf of Mexico to the North Atlantic.

Question 43

# Fill in the blank: ________ form as **wind transfers energy** through water.

Answer 43

Waves ## Footnote The size and strength of **waves** depend on the wind’s speed, duration, and the distance over which it blows.

Question 44

What is the **difference** between wave height and wave length?

Answer 44

* **Wave height** is the distance from crest to trough. * **Wave length** is the distance between crests. ## Footnote They are key **factors** in determining a wave's energy and power.

Question 45

What is a flat, deep-sea region **covering** much of the ocean floor?

Answer 45

Abyssal plain ## Footnote *Abyssal plains* are some of the *flattest, most expansive*, and *least explored regions* on Earth, formed by sediment deposition over millions of years.

Question 46

What is the **continental shelf**?

Answer 46

The shallow, submerged edge of a continent **extending** into the ocean. ## Footnote Continental shelves are **rich** in marine life and resources, supporting fisheries and oil reserves.

Question 47

What is the **steep drop** between the continental shelf and deep ocean?

Answer 47

Continental slope ## Footnote The *continental slope* leads to the abyssal plain and is often a site for underwater geological features like submarine canyons.

Question 48

List *three* **major ocean floor features**.

Answer 48

1. Trenches 2. Seamounts 3. Reefs ## Footnote **Trenches** – Deep, narrow depressions formed by subduction. **Seamounts** – Underwater volcanoes that may become islands. **Reefs** – Coral structures providing marine habitats.

Question 49

What land area **drains water** into a specific river or body of water?

Answer 49

Watershed ## Footnote **Watersheds** are important for managing water resources, as all the water within a watershed flows to a common outlet.

Question 50

# True or False: A watershed **only includes** the river itself.

Answer 50

False ## Footnote A **watershed** includes *all* the land and tributaries that drain into the river, including lakes and streams.

Question 51

What is a layer of rock or sediment that **holds and transmits water**?

Answer 51

Aquifer ## Footnote **Aquifers** are underground layers that store and transmit water, often used for wells and springs.

Question 52

A ________ is a **landform** formed by sediment at the mouth of a river.

Answer 52

delta ## Footnote Famous examples include the *Nile Delta* and the *Mississippi River Delta*, which support rich biodiversity.

Question 53

List the *three* **main types** of deltas.

Answer 53

1. **Arcuate delta** (fan-shaped, like the Nile Delta) 1. **Bird’s foot delta** (branching, like the Mississippi Delta) 1. **Cuspate delta** (pointed, like the Ebro Delta) ## Footnote The type of delta depends on *sediment deposition*, *wave action*, and *tidal influence*.

Question 54

# True or False: All rivers **form** deltas.

Answer 54

False ## Footnote Some rivers empty into *steep coastlines* or *deep waters*, preventing sediment accumulation needed for delta formation.

Question 55

What is **groundwater**?

Answer 55

Water **beneath Earth's surface** in soil and rock. ## Footnote Groundwater is a *major source of fresh water* for wells, springs, and rivers.

Question 56

What are the **primary uses** of groundwater?

Answer 56

1. Drinking water 2. Irrigation 3. Industrial use ## Footnote **Groundwater** is essential for many human activities, especially in areas without reliable surface water sources.

Question 57

What is the **water table**?

Answer 57

The **upper surface of the saturated zone** of groundwater. ## Footnote It marks the **boundary** between the saturated and unsaturated zones in the ground.

Question 58

# True or False: The water table **always** stays at the same level.

Answer 58

False ## Footnote The water table can rise or fall **depending** on *precipitation*, *evaporation*, and *human activity* like groundwater extraction.

Question 59

What is a **natural hazard**?

Answer 59

A natural **event that risks** human health, property, and the environment. ## Footnote Examples include earthquakes, floods, and hurricanes, which can cause *significant damage* and loss of life.

Question 60

How are hazards **classified**?

Answer 60

1. Natural 2. Human-made ## Footnote *Natural* hazards include earthquakes and hurricanes, while *human-made* hazards include industrial accidents and pollution.

Question 61

# Define: Flooding

Answer 61

The **overflow of water** onto normally dry land. ## Footnote It can occur due to heavy rainfall, storm surges, or dam failures, causing *damage* to property and infrastructure.

Question 62

# True or False: Flooding is caused **only** by heavy rainfall.

Answer 62

False ## Footnote **Flooding** can also result from storm surges, snowmelt, or dam failures, not just rain.

Question 63

List **three main causes** of flooding.

Answer 63

1. Heavy or prolonged rainfall 2. Storm surges 3. Dam or levee failure ## Footnote **Heavy or prolonged rainfall** – Exceeds the ground’s absorption capacity. **Storm surges** – Push seawater inland during tropical storms. **Dam or levee failure** – Releases large volumes of water suddenly.

Question 64

# True or False: Flooding can occur in **deserts**.

Answer 64

True ## Footnote *Flash floods* in desert regions occur due to sudden, intense rainfall that the dry ground cannot absorb quickly.

Question 65

What is a **storm surge**?

Answer 65

A **rise in sea level** caused by strong winds from a storm. ## Footnote It can lead to *coastal flooding* and damage, especially during hurricanes or typhoons.

Question 66

# True or False: Storm surges **only occur** in tropical regions.

Answer 66

False ## Footnote Storm surges are most common in *tropical regions* but can also occur in *temperate areas* due to powerful extratropical storms.

Question 67

# Fill in the blank: \_\_\_\_\_\_\_\_ occur when the ground collapses, forming a **depression**.

Answer 67

Sinkholes ## Footnote This *hazard* can occur suddenly and cause significant damage, especially in areas with soluble bedrock.

Question 68

Why are sinkholes **more common** in limestone areas?

Answer 68

Limestone dissolves in water, creating **underground cavities**. ## Footnote As the cavities grow larger, the surface layer may collapse, forming a *sinkhole*.

Question 69

Why do scientists use **flood forecasting models**?

Answer 69

To **predict floods** using rainfall, river levels, and soil moisture. ## Footnote *Advanced models* incorporate satellite data, weather radar, and hydrological sensors for greater accuracy.

Question 70

List **three types** of flood control infrastructure.

Answer 70

1. Dams 2. Levees 3. Drainage systems ## Footnote **Dams** – Regulate river flow and store excess water. **Levees** – Prevent water from overflowing onto land. **Drainage systems** – Redirect floodwaters efficiently.

Question 71

# True or False: Mangroves **help protect coastal areas** from storm surges.

Answer 71

True ## Footnote Mangroves *absorb wave energy*, reduce storm surge impacts, and prevent coastal erosion.