Sea Ice Melting

An ice sheet is a thick layer of ice that covers a large area for an extended period of time. During the last glacial period, most of the Earth was covered by ice sheets. Today, there are only two ice sheets in the world. One is the Antarctic ice sheet, and the other is the Greenland ice sheet. Ice sheets form as layers of snow accumulate over time. Most of the freshwater available on Earth is trapped in these ice sheets.

The Antarctic ice sheet is up to 3 miles deep. It covers nearly 5.4 million square miles. That’s almost the entire Antarctic continent. If all the water in this ice sheet melted, it would raise the sea level by 200 feet. The Greenland ice sheet is much smaller than the Antarctic one. It covers 656,000 square miles.

These ice sheets are shrinking as they melt more quickly than snow can accumulate. Many scientists believe that global warming is playing a role in the melting of the ice sheets. Global warming is the increase in the world’s average temperature. Most scientists believe that the global warming the Earth is now experiencing is caused in large part by human activity. Humans are releasing gases into the air that trap heat in the atmosphere. One major way they are doing this is by burning fossil fuels.

Scientists are working hard to learn more about how and why these ice sheets are melting. The melting ice sheets can have big effects on the planet. As more water melts and enters the ocean, the sea level rises. The rising water could cover cities that sit near the coast. These cities include New York City and New Orleans, Louisiana. One other effect of the melting ice sheets is that the ocean water will become less salty as it mixes with fresh water. This could disrupt ocean ecosystems that rely on certain levels of seawater to survive.