Story highlights Water seeps roughly 15 meters in to a tunnel at the entrance of the seed vault

Preventive measures will include building waterproof walls inside the tunnel entrance

(CNN) Unseasonably warm temperatures last fall caused water to breach the entrance to the Arctic's so-called "Doomsday" seed vault, one of humanity's last hopes after a global catastrophe, the company that manages the vault said last week.

The Global Seed Vault is beneath the icy permafrost of Svalbard, midway between Norway and the North Pole. Carved into the side of a mountain, the vault holds more than 500 million seeds from around the globe that could be used to recreate food supplies.

The seeds were unharmed by the water breach. Hege Njaa Aschim, a spokeswoman for the management company, Statsbygg, said water seeped only about 15 meters in to part of an access tunnel during the "very unusual warm and rainy October."

"We have seen changes; the ground is looser and the permafrost has not settled as planned," Aschim said Friday.

She said the management team, along with climate scientists from University Centre in Svalbard, don't know if the event was part of a long-term cycle or if it will escalate. But "we will not take any chances," Aschim said.

Read More