Remember that dramatic 260-foot crater that was discovered in Siberia this past summer? In an effort to learn more about this mysterious hole, a team of Russian geologists has successfully climbed down to the bottom where they managed to perform tests and take some stunning photos.

All images Siberian Times.

Earlier this week, the team descended down the newly-formed crater located on the Yamal Peninsula in northern Siberia. They're hoping to find clues that could explain how this and other similar phenomenon were formed.

One theory is that gas hydrates caused an underground explosion. Gas hydrates are ice-like forms of water containing gas molecules, including methane. They can be found in permafrost regions such as northern Siberia, but also under the oceans in some parts of the world. Gas hydrates are suspected in the area.

Another explanation is that it's a pingo — also known as a hydrolaccolith — which is a block of ice that's grown into a small hill in the frozen arctic ground. When this ice eventually melts away, it leaves an exposed crater. It's quite possible that this and other holes are now appearing on account of global warming, and that more are set to form in the future.

As Siberian Times reports, scientists used climbing equipment to reach the base of the crater — a frozen lake about 35 feet (10.5) meters below the surface. The geologists chose to do it now, in winter, when the ground is hard. The funnel of the crater is about 54 feet (16.5 meters) deep, not including the rampart formed in the blowout. The depth of the mini-lake is estimated at 35 feet, but it could be deeper.

"We took all the probes we planned, and made measurements. Now scientists need time to process all the data and only then can they draw conclusions," noted Vladimir Pushkarev, director of the Russian Centre of Arctic Exploration in the Siberian Times.

The scientists performed radiolocation tests at a depth of 656 feet (200 metres), extracted samples of ice, ground, gases, and air. The next step will be to process the collected data. They're also planning to compare images from space — even those taken in the 1980s — to understand if there are, or were, similar objects.

More at the Siberian Times, including many more images.