Israeli researchers have just determined that a cave located on the southern point of the Dead Sea is the worlds longest salt cave.

Mulham Cave, located on Mount Sodom in Israel, has been discovered to span about 10 total kilometres, beating the earlier record agreed upon by scientists by almost half.

Boaz Langford, a masters student from the Hebrew University of Jerusalem at the Institute of Earth Sciences was part of the team responsible for surveying the salt cave.

The geological phenomenon is special for two reasons. First, says Langford, is because of the cave's unique salt composition.

"It's unusual. Most of the caves on Earth are limestone, it's the usual showcase that people [are used to visiting], but this case, it's made [of]... salt growth."

These layers of salt growth that make up the Dead Sea and Mount Sodom where the Mulham Cave is located can be attributed to the shifting of tectonic plates and flooding over the course of millions of years. In most places in the world, the high solubility of salt caves has resulted in them existing primarily underground.

"It just dissolves by the rain and by the water," explained Langford. "The unique conditions of Mount Sodom in Israel is when the salt meets a hyper-dry climate with very low rain, the salt can exist above surface... with enough rain to dissolve it and create a cave. It's a balance."

The second reason for the fascination with Mulham Cave is its length. "There are more than 150 caves on the mountain and this cave is the longest one," said Langford, "and not just the longest in the mountain... it's the longest salt cave in the world."

Long salt caves: a history

According to Langford, the determination of Mulham Cave's length can be traced back to 1981 when a professor at the Hebrew University in the course of his PhD studies on the creation of slat caves first discovered the cave. According to his measurements, the cave spanned five-and-a-half kilometres, which at that time was the longest in the world.

In 2006, a team from the Czech Republic began work on Iran's salt caves, also known as salt diapirs. One of these caves was found to be a kilometre longer than the Israeli cave.

The quest to re-determine the length of the cave on Mount Sodom stemmed from this finding, said Langford.

"We understood the cave was surveyed and mapped during the 1980s with the best technology that was available back then, and now the skills, the abilities, the technology are much better," Langford explained.

No official world record for the longest cave exists, but rather scientists determine these findings through careful exploration and data comparison.

"We decided to go back to the cave and to resurvey and to do it more precisely by using the new technology and to be sensitive to every corridor [and] level."

Caving clubs from a number of countries, including Bulgaria, took part in the surveying of Mulham Cave.

"It was very new for them," said Langford, as Mulham Cave is unusual for having a temperature inside of around 20 degrees, compared to typical cave temperatures in Europe that hover at or just below freezing.

A discovery as young as yesterday morning

From the studies of Professor Amos Frumkin of Hebrew University, the Sodom salt cave has been determined to be only around the age of 7,000 years.

"In the geology field, [that] is considered like yesterday morning," Langford said. "7,000, it's nothing."

To make the cave even more interesting, it is located underground as a cavern that is often prone to flash flooding.

Two 10-day expeditions have been completed thus far by the team, totalling about 1,500 work days with distributed amongst 80 cavers according to Langford.

Most of the cave so far has been surveyed and the length has been recorded, but Langford says caverns and corridors still remain unexamined.

"We know there are still extra hidden passages that we still need to explore... this is the most difficult part to find and survey," reported Langford. The team is currently planning their third expedition of the cave, to be carried out next winter.

Biblical ties

The long Sodom salt cave resides only a few hundred metres from another salty geological occurrence.

A pillar of salt, called "Lot's Wife" in reference to the Bible story of Sodom and Gomorrah found in the book of Genesis, is more closely related to a smaller salt cave on its other side than Mulham Cave. The pillar, however, stands tall, visible from a distance away and a draw for many tourists.

For Langford, the cave and its exploration has been an incredible experience. "It's part of our lives now."

While the "attractive" part of the excursions in identifying the cave as the longest in the world may be behind them, Langford is looking forward to the cave for its simple grandeur.

"To walk on those edges is super attractive and I am looking forward to that."