Thetis Mound facts for kids

Thetis Mound is a small hill located in the very northern part of Alaska, in an area called the North Slope Borough. It's a special kind of hill known as a pingo, which means it has a core of ice inside.

What is Thetis Mound?

Thetis Mound is a small, natural rise in the ground. It stands only about 3 feet (less than 1 meter) tall. Even though it's not very high, it's an interesting feature in the flat, icy landscape of northern Alaska.

Where is Thetis Mound Located?

This unique hill is found in the North Slope Borough. This is a large, very cold region in the far north of the United States. Thetis Mound is about 4 miles (6.4 kilometers) southeast of a place called Oliktok Point. It's also about 13 miles (21 kilometers) west of Beechey Point. These areas are all near the Arctic Ocean.

How Did Thetis Mound Get Its Name?

The name "Thetis Mound" was first officially written down in 1911. This was done by the United States Geological Survey (USGS). The USGS is a government group that studies the Earth. A person named Ernest de Koven Leffingwell used the hill as a "triangulation station." This means he used it as a fixed point to help measure distances and create maps of the area. The name "Thetis Mound" was officially added to the Geographic Names Information System on March 31, 1981. This system keeps track of all the names of places in the United States.

What is a Pingo?

Thetis Mound is a type of hill called a pingo. Pingos are very special hills that only form in extremely cold places. These places have "permafrost," which is ground that stays frozen all year round.

• How they form: Pingos are created when water under the ground gets trapped and freezes. As the water turns into ice, it expands. This expanding ice pushes up the ground above it, forming a dome-shaped hill.
• Where they are found: You can find pingos mostly in the Arctic regions of the world. They are a clear sign of permafrost.
• Appearance: Pingos often look like small, rounded mounds sticking out of the flat tundra. They can range in size from very small, like Thetis Mound, to much larger hills.

The fact that Thetis Mound is a pingo makes it a cool example of how natural forces shape the land in cold environments.