Question

The majority of the water found on Earth is: a. ice b. water vapor c. fresh water d. salt water

Short answer

The majority of the water found on Earth is d. salt water, which accounts for 97.5% of Earth's total water.

Step-by-step solution

Recognize Different Types of Water on Earth

The question has presented four types of water: ice, water vapor, fresh water, and salt water. Consider each type and its presence on Earth.

Analyze the Percentage Distribution of Water on Earth

Look into the Earth's water distribution using available data. According to the United States Geological Survey (USGS), the distribution of water on Earth is as follows: - 97.5% Salt water - 2.5% Fresh water - 1.8% in glaciers and ice caps - 0.7% in groundwater, including soil moisture, swamp water, and permafrost - 0.009% in lakes and rivers - 0.001% in the atmosphere (water vapor)

Compare the Percentages

Now that you have the percentages available, compare the available options: a. ice: Glaciers and ice caps make up 1.8% of the Earth's total water b. water vapor: It accounts for only 0.001% of Earth's total water c. fresh water: In total, fresh water makes up 2.5% of the Earth's total water d. salt water: Salt water accounts for 97.5% of Earth's total water

Choose the Correct Answer

As we can see from the percentages, the majority of the Earth's water is found in the form of salt water (97.5%). So, the correct answer is: d. salt water

Key concepts

Earth's Water Cycle

Understanding the Earth's water cycle is crucial because it represents the continuous movement of water on, above, and below the surface of the Earth. This cycle is dynamic and includes processes such as evaporation, condensation, precipitation, infiltration, and runoff.

Water vaporizes into the atmosphere from surfaces like oceans, rivers, and the ground through evaporation. Plants also contribute through transpiration, releasing water vapor into the air. Next, water condenses to form clouds and eventually falls back to Earth as precipitation—rain, snow, sleet, or hail—completing one phase of the cycle.

Some of the water that reaches the ground infiltrates into the soil, replenishing aquifers and contributing to groundwater reserves. The cycle is pivotal for maintaining life as it regulates weather and climate, distributes heat, and ensures the continuous supply of fresh water.

Types of Water

On Earth, water exists in different forms, each playing a significant role in the water cycle and the overall hydrosphere. Let's break down the types of water highlighted in the textbook exercise:

• Ice: This type includes glaciers and ice caps, which are solid, freshwater reserves that release water during warmer seasons.
• Water vapor: This gaseous form of water involves tiny water droplets or ice crystals suspended in the atmosphere, contributing to weather patterns.
• Fresh water: This is typically found in lakes, rivers, groundwater, and ice. It's pivotal for human consumption, agriculture, and maintaining ecosystems.
• Salt water: Found in oceans and seas, salt water is the most abundant type on Earth, covering about 70% of the planet's surface, but it is not readily consumable without desalination.

Each type is interconnected within the water cycle, with one form transitioning to another, facilitating the diverse climates and habitats on our planet.

Water Distribution Data

The distribution of water on Earth is uneven, and it can be striking to observe the data. As seen from the textbook solution, salt water in the oceans holds the lion's share, making up approximately 97.5% of all water. Freshwater accounts for a mere 2.5%, with the vast majority locked up in glaciers and polar ice caps (1.8%).

Groundwater, which includes soil moisture and swamp water, forms about 0.7%, leaving only a fraction available in lakes and rivers. The atmosphere holds just about 0.001% as water vapor. This distribution highlights the scarcity of accessible fresh water for the billions of organisms, including humans, that rely on it for survival. It is a potent reminder of the importance of conserving and managing our water resources judiciously.