# Melting of Floating Ice Will Raise Sea Level

##### August 4, 2005

When ice on land slides into the ocean, it displaces ocean water and causes sea level to rise. People believe that when this floating ice melts, water level doesn’t rise an additional amount because the freshwater ice displaces the same volume of water as it would contribute once it melts. Similarly, people also think that when ocean water freezes to form sea ice and then melts, the water is merely going through a change of state, so it won’t affect sea level. However, in a visit to NSIDC in May, Dr. Peter Noerdlinger, a professor at St. Mary’s University in Nova Scotia, Canada, suggested otherwise.

In a paper titled "The Melting of Floating Ice will Raise the Ocean Level" submitted to Geophysical Journal International, Noerdlinger demonstrates that melt water from sea ice and floating ice shelves could add 2.6% more water to the ocean than the water displaced by the ice, or the equivalent of approximately 4 centimeters (1.57 inches) of sea-level rise.

The common misconception that floating ice won’t increase sea level when it melts occurs because the difference in density between fresh water and salt water is not taken into consideration. Archimedes’ Principle states that an object immersed in a fluid is buoyed up by a force equal to the weight of the fluid it displaces. However, Noerdlinger notes that because freshwater is not as dense as saltwater, freshwater actually has greater volume than an equivalent weight of saltwater. Thus, when freshwater ice melts in the ocean, it contributes a greater volume of melt water than it originally displaced.

Figure 1: A freshwater ice cube floats in a beaker of concentrated saltwater. Note that the ice cube floats much higher in the saltwater than it would in a glass of freshwater because saltwater has a greater density.

Figure 2: When the freshwater ice melts, it raises the water level. Freshwater is not as dense as saltwater; so the floating ice cube displaced less volume than it contributed once it melted.

Noerdlinger's collaborator, Professor Kay R. Brower, of the New Mexico Institute of Technology, Socorro, validated the effect experimentally as seen in Figures 1 and 2.

## Related Stories

#### Scientists show polar 'polynya' supported marine life during last Ice Age

September 27, 2018

However, there was a small ice-free 'polynya' between the frozen continents and the open ocean where microscopic marine life prevailed, which would have provided otherwise unavailable food for fish and mammals.

#### The circular economy – a solution to the world's water crises?

August 7, 2018

Now in their third year of drought, Cape Town citizens narrowly avoided running out of water altogether this summer. The authorities threatened to shut off water altogether and refer residents to communal water taps if the ...

#### Atlantic circulation is not collapsing—but as it shifts gears, warming will reaccelerate

July 18, 2018

A huge circulation pattern in the Atlantic Ocean took a starring role in the 2004 movie "The Day After Tomorrow." In that fictional tale the global oceanic current suddenly stops and New York City freezes over.

#### How changing the world's food systems can help to protect the planet

August 1, 2018

Going into debt with nature is a dangerous thing. When our stocks of water, land and clean air are spent – we don't have a second planet to borrow from. But that's exactly the way that Earth is heading. 1 August 2018 marks ...

#### Climate change poses uncertain future for Indiana's aquatic habitats

September 13, 2018

Indiana's average air temperatures are expected to rise by as much as 6 degrees Fahrenheit by mid-century, warming and reducing wintertime ice cover on the state's lakes, streams, and rivers. At the same time, increases in ...

#### Britain's rarest freshwater fish found in Bassenthwaite Lake

October 2, 2014

Two adult vendace, Britain's rarest freshwater fish and a relic of the last ice age, were found in Bassenthwaite Lake in north-West England last month, more than a decade after being declared 'locally extinct'. Last year, ...

## Recommended for you

#### World Heritage sites threatened by sea level rise

October 16, 2018

From Venice and the tower of Pisa to the medieval city of Rhodes, dozens of UNESCO World Heritage sites in the Mediterranean basin are deeply threatened by rising sea levels, researchers warned Tuesday.

#### New memristor boosts accuracy and efficiency for neural networks on an atomic scale

October 16, 2018

Just like their biological counterparts, hardware that mimics the neural circuitry of the brain requires building blocks that can adjust how they synapse, with some connections strengthening at the expense of others. One ...

#### Toward unhackable communication: Single particles of light could bring the 'quantum internet'

October 16, 2018

Hacker attacks on everything from social media accounts to government files could be largely prevented by the advent of quantum communication, which would use particles of light called "photons" to secure information rather ...

#### Algorithmic innovation may help reduce invasive heart procedures

October 16, 2018

Doctors use invasive procedures to map the hearts of patients suffering from atrial fibrillation, an abnormal heart rhythm, to decide whether an ablation procedure to remove heart tissue is likely to have a positive outcome. ...

#### New, durable catalyst for key fuel cell reaction may prove useful in eco-friendly vehicles

October 16, 2018

One factor holding back the widespread use of eco-friendly hydrogen fuel cells in cars, trucks and other vehicles is the cost of the platinum catalysts that make the cells work. One approach to using less precious platinum ...

#### New reservoir computer marks first-ever microelectromechanical neural network application

October 16, 2018

As artificial intelligence has become increasingly sophisticated, it has inspired renewed efforts to develop computers whose physical architecture mimics the human brain. One approach, called reservoir computing, allows hardware ...