How big is just one gigatonne?
Satellite data show that Greenland and Antarctica are losing mass at a rate of and , respectively. So how big is just one gigatonne?
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National Mall dimensions (from OpenStreetMap):
2 km long, 0.2 km wide
ice height = 1.091 km³ / (2 * 0.2) = 2.7275 km = 2,727.5 meters
A fully loaded Nimitz-class aircraft carrier weights 100,000 tonnes, according to the Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet.
Central Park dimensions (from OpenStreetMap):
4 km meters long, 0.8km wide
1 gigatonne of ice = 1.091 km³
4 km * 0.8 km * ice height km = 1.091 km³
ice height = 1.091 km³ / (4 km * 0.8 km)
ice height = 0.3409 km = 340.9 meters
A fully loaded Nimitz-class aircraft carrier weights 100,000 tonnes, according to the Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet.
How much is 5,000 gigatonnes of ice?
This is the amount of ice lost from the polar ice caps that NASA’s original GRACE mission observed from 2002 to 2017.
During the 15-year lifetime of the original Grace mission (2002-2017), 5,641 gigatonnes of ice of were lost in Greenland and Antarctica. Ninety-nine percent of the world’s freshwater ice is located in these ice sheets.
This is enough to cover Texas in a sheet of ice 26 feet high.
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Area of Manhattan: 59.1 km² (U.S. Census)
Ice density = 1.091 km³ / gigatonne
360 gigatonnes * 1.091 km³/gigatonne = ice_height * 59.1 km²
ice_height = (360 gigatonnes * 1.091 km³/gigatonne) / 59.1 km² = 6.64568527919 km = 6,645.68 m = 21,803 feet
New York City’s tallest building is One World Trade Center (WTC).
Height of One World Trade Center: 1,776 feet (about 541 meters)
21,803 / 1776 = 12.276464 times height of WTC
How much is 49,000 gigatonnes of ice?
This is our best estimate of how much Greenland and Antarctic ice has melted into the ocean since the start of the 20th century.
