The competing teams have been watching the Russians and sharing notes over the past few days, Dr Pearce said, yet no one knows what has happened.

"We're all waiting with bated breath," he said.

Antarctic scientists carry Iridium satellite phones for communication, he said, but there are spots without coverage. The scientists may have encountered a technical issue, he speculated, or perhaps they have simply packed up and are traveling home - keeping their discoveries to themselves.

"I don't think there's anything sinister or ominous," Dr Pearce said.