Holey Moly!

Look: 7 weird things scientists have found in sinkholes

Beware the (seemingly) bottomless pit!



Off the coast of Belize is a gaping abyss called the Great Blue Hole.

Romona Robbins Photography/Image Source/Getty Images

It’s a massive underwater sinkhole, created naturally by caved-in bedrock. Pits like this one are found across the world, from the Great Barrier Reef to the Great Lakes.

sakchai vongsasiripat/Moment/Getty Images

But what’s in them? Not all sinkholes have been thoroughly explored, but in the ones that have, researchers have found some strange surprises.

Sometimes they even give us clues to what life was like thousands of years ago.

Here are 7 surprising things uncovered from sinkholes:
7. An Ancient Volcano

Volcanologists in New Zealand peered down at a 60,000-year-old volcano that appeared when a sinkhole opened up in the ground near the city of Rotorua in 2018.

Nigel Killeen/Moment Open/Getty Images


The dormant volcano was covered in ash and sediment.

6. Human remains

A skeleton discovered in the submerged Chan Hol cave near Tulum, Mexico, was estimated to be nearly 13,000 years old, giving further evidence to the idea that humans arrived in North American earlier than first assumed.

Nick Poole and Thomas Spamberg


The remains likely belonged to a young man and represent the third human specimen to be uncovered in the sunken caves.

5. Microbe Communities

In Lake Huron, a giant pit called the Middle Island Sinkhole houses thriving communities of bacteria and microbes.

Phil Hartmeyer, NOAA Thunder Bay National Marine Sanctuary

They live in low-oxygen, high-sulfur conditions about 80 feet below the water’s surface — which researchers say is a comparable environment to the ones single-celled organisms inhabited billions of years ago.

4. Fossilized Animals

Tortoises, crocodiles, lizards, snakes, bats, and at least 25 species of birds were uncovered from a blue hole called Sawmill Sink in the Bahamas. Researchers described their findings in a 2007 report in the journal Proceedings of the National Academy of Sciences.

Head Like and Orange via Giphy


The fossils date back from 1,000 to 4,200 years old. Researchers say they can help us piece together what life may have been like when humans first arrived in the region.

3. Stalactites

These massive formations grow from mineral and sediment deposits over thousands of years.

Stephen Frink/Corbis Historical/Getty Images

A research team from Germany analyzed this stalactite sample from the Great Blue Hole for a 2017 paper in the Journal of Sedimentary Research. It was originally gathered in 1970 by famed explorer Jacques Cousteau.

Daniel Parwareschnia


By analyzing its core, they found that climate conditions in the cave were surprisingly dry in the time before it flooded during the Ice Age.

2. Conch tracks

When researchers probed the bottom of the Great Blue Hole in 2018, they saw prints from dead conches — sea snails — that had fallen into the pit.

Barbara Alper/Archive Photos/Getty Images

Germán Vogel/Moment/Getty Images

The bottom of the hole has no oxygen, so the struggling creatures would attempt to crawl back to the top, only to lose their footing and asphyxiate.

Poor sea snails.

1. Trash

Yep, litter has also been found at the bottom of the Great Blue Hole.

Dolphin Discovery via Giphy


Billionaire and Virgin Galactic founder Richard Branson made a trip to the massive pit in 2019, noting that his team had spotted plastic bottles at the bottom.

If that’s not enough of a reason to make sure your trash gets properly disposed of, then perhaps nothing will be.

Rhisang Alfarid/Moment/Getty Images

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