During a volcanic eruption, an ash cloud covers a region of 400 km². If the average thickness of the ash deposit is 0.5 m, calculate the total volume of ash deposited in cubic metres. Then discuss how this volume can affect crop yield in the region.

Step-by-step solution

1. Convert the area from km² to m²: $400{\text{km}}^2=400\times 10^6{\text{m}}^2$.
2. Multiply the area by the average thickness: $400\times 10^6{\text{m}}^2\times 0.5\text{m}=200\times 10^6{\text{m}}^3$.
3. Write the result in standard form: $200\times 10^6=2\times 10^8$, i.e. $200,000,000{\text{m}}^3$ of ash.
4. Explain the impact: Such a large ash volume can smother crops, reduce photosynthesis, contaminate soil, and delay planting, leading to significant loss in crop yield in the affected region.

Concept tested: Volcanic ash volume and impact

Published 7 October 2026 · How this solution was prepared and checked