Question

1. how deep are the ice sheets that cover most of antarctica?

a. less than a mile deep on average
b. 1 mile deep on average
c. 1-3 miles deep on average
d. over 3 miles deep on average

Explanation:

Identify the question topic

The question asks about the average thickness (depth) of the ice sheets covering Antarctica.

Analyze geographical data

The Antarctic Ice Sheet contains about 90% of the world's ice. Its average thickness is estimated to be about 1.9 kilometers (approximately 1.2 miles or 6,200 feet).

Evaluate the options

• Option A: "less than a mile deep on average" — Incorrect, as 1.2 miles is greater than 1 mile.
• Option B: "1 mile deep on average" — Incorrect, though close, the average thickness is over 1 mile (about 1.2 miles).
• Option C: "1-3 miles deep on average" — Correct, since the average thickness of 1.2 miles falls directly within this range.
• Option D: "over 3 miles deep on average" — Incorrect, as the maximum thickness reaches nearly 3 miles (4.77 km) in some areas, but the average is much lower.

Formulate the final conclusion

The average depth of the ice sheet is approximately 1.2 miles, which is best represented by the range of 1 to 3 miles.

Answer:

• A. less than a mile deep on average
• B. 1 mile deep on average
• C. 1-3 miles deep on average (Correct answer)
• D. over 3 miles deep on average