Set in Dviete, Latvia, near the banks of the Daugava River, the video depicts a mysterious whirlpool churning — and destroying — all that enters.
Huge chunks of ice? Gone. Floating islands of debris? Annihilated.
“Swallowing everything dragged towards its direction,” reads the description by Jānis Astičs, “this monstrous whirlpool looks as if a plug has been pulled from the ground beneath.”
Here is the video:
Upon first look at this, I immediately suspected what it might be. Then, other articles noted that comments in the Huffington Post piece may have hit on the same – it’s possible a result of the karstic bedrock underneath. Openings exist in the solutioned bedrock underground. Connected passageways can drain water or loose surface material above. It appears that there has been significant rainfall or ice melt here. Spring is the prime time for sinkholes to form – the ground thaws, water washes surface materials down into openings in the rock below. But why is this water disappearing? Well, the groundwater level would be BELOW the level of the stream in this particular location. There could be many reasons why that happens including low rainfall previously, groundwater pumping from wells or industry, etc. Abundant limestone deposits of the area lend evidence that this may be the case.
I have observed the same feature, swirling water even forming a depression such as this, in streams in Pennsylvania. It occurs where there is active sinkhole development in the stream. The groundwater table was depressed so when an opening in the ‘perched’ stream bed was breached, down the water went. In some places, karstic conditions underground can accomodate the ENTIRE stream flow. The stream reappears most often as springs in a (hydrologically) lower area. This is not unusual but it can be disruptive and damaging to wildlife and property, not to mention the stream bed. I have heard colleagues tell of fish being sucked into a swallet hole like this and you can certainly imagine that could have happened here.
Here is an example in shallower water where you can see the hole draining the water.