Rising Seas

Education Modules > Module 3 > High School > Rising Seas > Science Concepts

Science Concepts—Thermal Expansion

Summary: As the ocean's temperature increases, its volume expands. In this topic guide, students use a model to demonstrate the relationship between water temperature and volume, and then use their findings to describe the impact a warming ocean has on sea level.

Concepts to teach:


  1. Heated water has more volume than cooler water due to a process called thermal expansion.
  2. Thermal expansion is the primary cause of climate induced sea level rise.
  3. A model can demonstrate a scientific concept.

Standards: NGSS Performance Expectations

  • HS-ESS2-5. Plan and conduct an investigation of the properties of water and its effects on Earth materials and surface processes.

Specific Objectives:
Students will be able to:

  1. Demonstrate that heated water has more volume than cooler water due to a process called thermal expansion
  2. Explain how sea level rise results in part from thermal expansion.
  3. Use a model to demonstrate a scientific concept.

Activity Links and Resources:

  • COSEE's Thermal Expansion and Sea Level Rise—In this experiment, students measure the relationship between water volume and water temperature. This activity can be performed as a demonstration, or at the high school level, in student groups.
  • EPA's Sea Level: On the Rise, part I—Another lesson using the same activity.


  • What evidence exists to indicate that sea level is rising?
  • Why is measured and predicted sea level rise less dramatic on the Oregon coast compared to many other places on the globe?
  • How might a large earthquake along the Cascadia subduction zone impact sea level on the Oregon coast?