Human activity around the Dead Sea could threaten its existence and cause it to dry up, Israeli scientists say.

Although the Dead Sea almost dried up more than 100,000 years ago it recovered, researchers from Tel Aviv and Hebrew universities said, but current drops in its level are more worrisome.

A drilling project revealed water levels have risen and fallen by hundreds of feet in the last 200,000 years during periods of extreme dryness and little rainfall, and during the last interglacial period around 120,000 years ago the sea came close to drying up entirely, they said.

However, despite the historical record that shows climate-driven periods of drying were followed by recovery, there is cause for concern about the current state of the Dead Sea, Zvi Ben-Avraham of TAU's Minerva Dead Sea Research Center said, because the current drop in the sea's water levels is caused by human activity.

Today, the Dead Sea lies 1,400 feet below sea level and is receding rapidly.

"What we see happening in the Middle East is something that mimics a severe dry period, but this is not climate-enforced, this is a man-made phenomenon," he said, caused by increasing amounts of water being taken from rivers for irrigation before it reaches the Dead Sea.

This is preventing the refilling of the sea by the waters of the Jordan River, he said.