To determine which city's rocks are likeliest to experience frost wedging, we need to understand the conditions that facilitate this process. Frost wedging occurs when water enters cracks in rocks, freezes, and then expands, causing the rocks to break apart. The key conditions that promote frost wedging are:
1. A climate with substantial rainfall (wet climate) to ensure there is sufficient water available to enter the cracks in the rocks.
2. Temperatures that frequently fluctuate around the freezing point (0°C), so water can freeze and thaw repeatedly within the rocks.
Let’s inspect each city based on these criteria:
- City A:
- Climate: Dry
- Day Temperature: -11°C
- Night Temperature: -30°C
- Analysis: City A has consistently subzero temperatures and a dry climate. The lack of rain and consistently below-freezing temperatures make it unlikely for water to enter the cracks and freeze-thaw cycles to occur.
- City B:
- Climate: Wet
- Day Temperature: 5°C
- Night Temperature: -4°C
- Analysis: City B has a wet climate, ensuring sufficient rainfall. Additionally, the temperatures fluctuate around the freezing point (with positive temperatures during the day and negative temperatures at night), which makes it ideal for freeze-thaw cycles that can lead to frost wedging.
- City C:
- Climate: Wet
- Day Temperature: 14°C
- Night Temperature: 6°C
- Analysis: City C has a wet climate but the temperatures are too high (both positive) for frost wedging since they don’t reach freezing point, thus water won’t freeze and expand within the rocks.
- City D:
- Climate: Dry
- Day Temperature: 26°C
- Night Temperature: 17°C
- Analysis: City D has a dry climate and consistently warm temperatures, making frost wedging unlikely due to the absence of sufficient water and freezing conditions.
Given this analysis, the correct answer is:
B. City B because it is a wet region and the temperature fluctuates around the freezing point.
