A couple weeks ago, scientists were made aware of a massive crater in the permafrost of Yamal, Siberia. They're currently analyzing the crater to understand the origins of the 30-meter-wide hole, but no definitive cause has been identified. Curiouser and curiouser, two new smaller craters have been discovered that seem to have arisen under similarly mysterious conditions. The Siberian Times reports that one of the craters is also located in Yamal and the other is to the east in the Taymyr Peninsula.

The second Yamal crater is about 15 meters wide and has a small icy lake at the bottom. Unlike the original crater, there were witnesses when this was formed on September 27, 2013, although there is some discrepancy about what happened. Some local residents claim the ground began smoking and then a huge flash of light appeared, while others believe it was caused by a meteorite.

Newly discovered second crater in the Yamal Peninsula in Siberia. Image credit: Press service of the Governor YaNAO, via The Siberian Times

The Taymyr crater was accidentally discovered by herders who nearly fell into it, and there are no eyewitness accounts of how it came to be. It is shaped like a slender cone, with the opening at 4 meters in diameter and reaching depths of 60-100 meters. Scientists aren’t sure what would cause this perfect cone shape, as it doesn’t overtly appear to be manmade or naturally occurring.

Cone-shaped crater in the Taymyr Peninsula. Image credit: Local Residents via The Siberian Times

The original crater set the internet on fire with possible explanations of its origins, including weapons testing, meteorites, and even alien activity. One leading hypothesis involves an explosion of gas that had been trapped underground in the permafrost, especially given its proximity to the largest natural gas reserve in Siberia. The thawing ground would have warmed the methane, increasing pressure until it popped like a cork.

As this area has been particularly affected by climate change and is warmer than it has been in 120,000 years. The rampant thawing may have caused a large pingo, in which frozen ground begins to push up to the surface. As the ground thawed, the pingo could have collapsed, forming the deep hole with water at the bottom. While some preliminary analysis has been completed, scientists won’t speculate on a cause until more study has been completed. Unfortunately, the Arctic is so remote that large portions of it have not been well studied.

If climate change really is the driving force behind these mysterious craters, they could very well happen more frequently. Researchers might be able to predict if/when another crater explosion is likely to appear if they are able to determine a definitive cause. This could be important in protecting people and property in the area.

[Hat tip: The Siberian Times]