The discovery of Australia’s deepest cave

Ciara Smart is a PhD student in history at the University of Tasmania during the week.

On weekends, she joins a caving club that uncovered Australia’s deepest cave during the weekend of July 31.

Smart, along with seven other volunteers from the Southern Tasmanian Caverneers (STC) group, officially mapped and documented the deepest cave in Australia, reaching a depth of 401 meters (1,315 feet).

The cave is located in Mount Field National Park in Tasmania, just northwest of Hobart, the state’s capital.

In the tight-knit caving community, there’s a long-standing tradition: the discoverer of a new cave gets to name it. For the Southern Tasmanian Caverneers, the cave that was revealed during the peak of Australia’s COVID crisis could only be named one thing – Delta Variant.

“With the pandemic, many new terms have emerged, and we embraced the Covid-related theme when naming the cave,” says Smart.

The cave’s entrance, a cramped and narrow opening, is called Test Station Queue. Following that, there’s another tight passage named Close Contact, a vast horizontal section dubbed Superspreader Event, and a wide, stunning area now known as Freedom Day.

While many caves have been stumbled upon by accident, today’s cavers are equipped with advanced scientific tools that help them find new sites and gather crucial data before even stepping foot underground.

To explore the cave that would eventually be named Delta Variant, the STC employed a combination of methods. First, they analyzed satellite imagery to map the area, followed by 3-D laser modeling to create a virtual visualization of the cave system.

Once they pinpointed a potential location, they used dye to track the cave’s hidden water source, which led them to a waterfall deep inside the cave.

Next came the exciting part – the descent into the unknown.

Although high-profile incidents like the 2018 Thai soccer team rescue, where a group was trapped in a cave for weeks, may make caving seem perilous, Smart reassures that it’s not something to fear.

With the right equipment, skilled guides, and prior knowledge of the cave, caving can be a thrilling experience – just like it was for Smart and her team, who made their mark in history.

In fact, Smart points out, the most hazardous part of caving is usually the drive to and from the site, rather than the caving itself.

For Smart, the allure of caving lies in the variety of activities it offers, from exploration to scientific discovery.

Caving can become quite an addictive pursuit, blending thrilling adventure with pure enjoyment, according to Smart.

It’s more than just physical activity; caving is a science too. By mapping and connecting the caves, we're gaining a deeper understanding of how they form and how water flows through them,” she explains.

Venturing into a cave as deep as Delta Variant – where the team spent a total of 14 hours underground – required specialized equipment.

The team relied on bright, powerful headlamps for visibility, and carried extra backup lights to ensure they were well-equipped for the journey.

With the constant presence of the waterfall, Delta Variant remained damp, drenching the cavers in certain sections. To stay warm, they layered up with fleece, flannel shirts, plastic coveralls, rubber boots, and waterproof gloves.

To commemorate their accomplishment, some team members donned playful paper party hats, adding a fun touch to their historic achievement.

While Delta Variant now holds the record as Australia's deepest cave, most of the world’s deepest caves are actually located in Europe and Central Asia.

Georgia is home to four of the world's deepest caves, with the deepest being Veryovkina, reaching an incredible 2,212 vertical meters (7,200 feet).

Other countries renowned for their deep caves include France, Slovenia, Croatia, Uzbekistan, Turkey, and Switzerland.

Prior to the discovery of Delta Variant, Australia's deepest cave was Niggly, which is located just next to it. Niggly is only four meters shallower than Delta Variant and is part of the same expansive cave system.

As if discovering and mapping Australia's deepest cave wasn’t enough, the team received special permission to collect samples from a rare cave shrimp, potentially a new species.

A dissertation and two potentially groundbreaking discoveries? Smart remains unfazed by the unique combination of her academic and adventurous pursuits.

“Yeah, it was an incredibly busy week,” she laughs with a smile.