In 2010, the record-setting largest hailstone fell in the tiny town of Vivian, South Dakota. Weighing almost 2 pounds with an 8-inch diameter, this huge ball of ice set a new record for the largest hailstone in the U.S. This hailstone broke the previous world of 7.5 inches, measured from a hailstone in Texas. This feature will explore the unique properties of ice and how they allow it to form record-setting hailstones to whole floating continents.

Hail

When it comes to hail, most falls in a region of the U.S. referred to as “Hail Alley”. Hail Alley stretches North to South from Texas to the Dakotas. Although it may seem counterintuitive that some of the hottest states such as Texas and Oklahoma receive the most hail, exploring the formation of hail will show how the right geographical characteristics of these states allow the formation of record-breaking hailstones.

The formation of hailstones starts with thunderstorms, formed from unstable updrafts of humid air. In these thunderstorms, updrafts can bring water droplets up to freezing areas of the atmosphere causing them to freeze and form into “seeds” of a hailstone. As these “seeds” collide with other water droplets, the water is supercooled and adds to the growing hailstone. Depending on how fast the water cools, trapped air can form cloudy ice in the hailstone. Kept in the freezing upper atmosphere by the updrafts of the thunderstorms, the hailstones continue to grow through this process until they are too heavy to be held up by the updrafts. Once they have reached this size, they fall to the ground in paths called “hail swaths” following the path of the thunderstorms. Oftentimes, smaller hail can be blown sideways by strong winds and fall sideways, damaging house siding as they fall.

Glaciers and Ice Sheets

Aside from falling from thunderstorms, ice can be found on the Earth today in the form of vast, ancient ice sheets that make up entire continents. One such ice sheet makes up more than 80% of Greenland, the world’s largest island that is much colder than its name suggests.

To be more specific, 80% of Greenland is made up of an ice sheet. By definition, an ice sheet is essentially a glacier that covers more than 50,000 square kilometers of land. To learn more about the Greenland ice sheet, first this story will explore how such glaciers and ice sheets form to begin with.

Glaciers are large accumulations of ice and snow that slowly slide or flow across land. Due to their sheer mass and large size, glaciers can carve large swaths into the land they flow across. These large scars can turn into the formation of fjords, deep, narrow river beds with steep land on both sides. Glaciers also formed the Great Lakes.

  Ice sheets, essentially gigantic glaciers, are masses of ice and snow that can cover entire continents. Today, only two ice sheets exist on Earth: the Antarctic and Greenland.

The two ice sheets in the world contain more than 99% of the land ice and over 68% of the world’s fresh water. Like glaciers, ice sheets are in constant motion. These two ice sheets cover a combined total of nearly 10% of Earth’s surface. The Greenland ice sheet is said to have been around since the Eocene Epoch and contains ancient ice potentially millions of years old. Such ice sheets have been melting and shrinking in size in recent years. According to the Intergovernmental Panel on Climate Change, “the [Greenland] ice sheet had lost 5,390 billion tons (4,890 billion metric tons) of water between 1992 and 2020”. 

Additionally, in recent years, a NASA airborne science mission discovered a ‘mega canyon’ under Greenland ice. According to the data found, this new canyon is, “at least 460 miles long (750 kilometers long)”, comparable to the 277 mile Grand Canyon in Arizona. Although Greenland’s mega canyon is not quite as deep, with depths of 2,600 feet in certain areas, this 2013 discovery is still an incredible find and is still hidden under a mile of Greenland ice.

So the next time you are enjoying a cold drink on a hot summer day or watching the snow fall from your window, remember that there is a lot more to the little ice cubes than you might think. Ice is everywhere, from the smallest snowflake to the greatest glaciers, and it’s always a bit cooler than you’d think.