This document discusses how thermal expansion of water contributes to sea level rise. It explains that as the ocean warms, the density of water decreases which causes the volume of the ocean to increase even if the mass stays the same. Thermal expansion occurs at all ocean temperatures and is a major factor in sea level changes. Additionally, the majority of extra energy in the Earth's climate system is stored in the oceans, with ocean warming dominating the total energy change.

1. This work is supported by the National Science Foundation’s
Directorate for Education and Human Resources TUES-1245025, IUSE-
1612248, IUSE-1725347, and IUSE-1914915. Questions, contact education-AT-unavco.org
THERMAL EXPANSION OF WATER
An Important Contributor to Sea-Level Rise
Version: Jan 16, 2019

2. THERMAL EXPANSION
• Thermal expansion refers to
the tendency of matter to
change shape, area, and
volume in response to a
change in temperature.
• When a substance is heated,
the molecules begin to
vibrate and move more, and
maintain a larger
separation. This results in
the molecules taking up
greater volume.

3. WATER EXPANDS AS IT WARMS

4. THERMAL EXPANSION OF WATER
• As the ocean warms,
the density decreases.
Thus even at constant
mass the volume of the
ocean increases when
warmed.
• Thermal expansion
occurs at all ocean
temperatures and is a
major contributor to
sea-level changes.

5. THE MAJORITY OF ADDITIONAL ENERGY IN THE
EARTH’S CLIMATE SYSTEM IS STORED IN THE OCEANS
• Ocean warming
dominates the total
energy change
inventory.
Plot of energy accumulation in ZJ (1 ZJ =
1021 J) within distinct components of the
Earth’s climate system relative to 1971 and
from 1971 to 2010 unless otherwise
indicated (IPCC 2014).