Scientists who lowered a probe into the deepest underwater sinkhole on Earth discovered a world unknown to science – what is hidden there?

Measurements have shown that the Taam Ja’ Blue Hole, located in Chetumal Bay on the southeastern coast of the Yucatan Peninsula, is at least 420 meters below sea level. This is the deepest underwater sinkhole ever discovered. And scientists haven’t yet reached its bottom, which means it could be much deeper.

This sinkhole was measured for the first time in 2021. That time, scientists managed to lower the measuring equipment to a depth of 274 meters.

The next deepest underwater sinkhole is 301 meters deep. This is Sansha Yongle, or Dragon Hole, located in the South China Sea, reports phys.org.

According to a study published April 29 in the scientific journal Frontiers in Marine Science, the latest measurements of the Taam Ja’ Blue Hole were made on December 6, 2023. The purpose of the expedition was to determine the prevailing environmental conditions of the underwater sinkhole.

Conductivity, temperature and depth measurements were made during the research. A probe lowered into the Blue Hole transmitted real-time information to scientists about the properties of water in the depths.

It was during these measurements that it became clear that the Taam Ja’ Blue Hole is “the world’s deepest known blue hole, the bottom of which has not yet been reached.”

Research equipment also showed that there are zones formed at different depths with different water properties.

For example, at a depth of 400 meters, the water temperature and salinity were similar to those of the Caribbean Sea and nearby coastal reef lagoons. Scientists conclude that the Taam Ja’ Blue Hole may be connected to the Caribbean Sea by a network of underwater tunnels and caves, according to Live Science.

Sinkholes are water-filled vertical caves, or underwater sinkholes, found in coastal regions where the bedrock is limestone, marble, or gypsum. Holes form when surface water seeps through the rock, dissolving minerals and widening cracks until the rock eventually disintegrates and collapses.

The initial measurements of the depth of the Blue Hole were made by echo sounder, but this is not the best way to measure the depth of the underwater hole due to some technical nuances of the measurements.

Now the researchers say that their device has not even reached the bottom, as it can only work up to a depth of 500 meters. After reaching a depth of 420 meters, the cable to which the research probe is attached began to drift due to underwater currents, which could interfere with the protruding rocks of the underwater hole.

Therefore, the expedition scientists decided not to send the probe deeper, although neither the bottom nor the limits of the probe’s capabilities had yet been reached.

In the future, the authors of the study plan to explore the depth of the Taam Ja’ Blue Hole by other means and conduct additional research – it is believed that not only underwater cave and tunnel systems exist in the depths, but also a hitherto unexplored biological diversity.