Land vs Water Heating

This experiment models how land and water surfaces heat and cool at different rates. By comparing temperature changes in soil (or sand) and water exposed to a heat lamp, students can better understand how the uneven heating of Earth’s surfaces affects weather and climate.

1. Fill one beaker with 200 mL of sand or soil and another with 200 mL of water.
2. Place a thermometer about 1 cm below the surface in each beaker, securing with clips if necessary.
3. Position both beakers 10–15 cm below a heat lamp, making sure they are equally distant from the bulb.
4. Record starting temperatures at 0 minutes.
5. Turn on the lamp and record both temperatures every minute for 10 minutes.
6. At the 10-minute mark, turn off the lamp and move it away.
7. Continue recording temperatures every minute for another 10 minutes while the samples cool.
8. Plot your data on a graph (temperature vs. time) with separate lines for sand/soil and water.

Uneven Heating of Land vs Water - Bill Young:

Heating of Land and Water - Vernier Science Education:

📄 Heating Earth’s Surfaces: Land Versus Water - NASA JXA: https://gpm.nasa.gov/education/sites/default/files/lesson_plan_files/Global%20Energy%20Budget/GPM%20Global%20Energy%20Budget%20-%20Land%20vs%20Water%20Lab.pdf

• Test different materials such as gravel, clay, or dark-colored soil.
• Change the distance from the lamp to see how intensity affects heating.
• Compare results indoors vs. outdoors using real sunlight.
• Extend the cooling period to see longer-term temperature changes.

• The heat lamp and bulb become very hot; avoid touching them during or immediately after the experiment.
• Handle glass beakers carefully to prevent breakage.
• Use caution when working with water and electrical equipment nearby.

• Which material heated up faster, the soil or the water? (Soil heats faster.)
• Which material cooled faster after the lamp was turned off? (Soil cools faster.)
• Why does water heat and cool more slowly than land? (Water has a higher specific heat capacity and circulates to distribute heat.)
• How do these results explain temperature differences between coastal and inland areas? (Coastal areas have smaller day-night temperature ranges, while inland areas have greater extremes.)
• Based on your results, which city would have a greater temperature swing between day and night—Seattle or Bismarck? (Bismarck, because land heats and cools more quickly than water.)