The Mystery of the Centuries-Old Seal Mummies of Antarctica

SEAL MUMMY: Mummified remains of seals can be found scattered throughout Antarctica's Dry Valleys (Photo: Kristan Hutchison/National Science Foundation).

Antarctica's Dry Valleys, located within Victoria Land west of McMurdo Sound, is one of the coldest, driest places on Earth. The harsh landscape is frequented by katabatic winds that can reach 200 mph, which strip the land of whatever moisture it may have otherwise retained and transform it into the largest ice-free region on the continent.

Though this remote, barren desert is mostly lifeless, there are clues that point to a deeper story — a mystery — which has been unfolding here for centuries and which has left many scientists perplexed. Scattered haphazardly amongst the Valleys' loose, colorless gravel lay something you'd usually expect to find in an ancient Egyptian desert instead: mummies. Hundreds of them. But these mummies are not of human origin. These are seal mummies.

Finding mummified seals in the Dry Valleys isn't so unexpected. Seals frequent the coastline here as part of their seasonal migration, and the dry conditions are ideal for natural mummification should any seal become wounded and die. But what makes these mummified seals so mysterious is the fact that some of them have been found up to 41 miles inland and as high as 5,900 feet above sea level.

How could these seals have gotten so far from the ocean? What could possibly have driven them to roam so far and so high?

Carbon dating has revealed that many of these seal mummies are hundreds of years old, with the oldest dating as far back as 2,600 years. Something strange has been happening here for millennia, and so far scientists can only guess at what.

One theory suggests that seals may occasionally become disoriented after waddling ashore for a nap. Since many of the mummies appear to be juveniles, it's also possible that an undeveloped sense of direction is to blame. After mistakenly heading inland, the lost seals may make a bad situation worse by climbing toward the glaciers that sit atop the surrounding mountains, mistaking them for a frozen ocean.

If this theory is correct, then the heroing journey many of these seals have taken is a horrifying thing to imagine. Remember that many seals are clumsy on land, having to waddle by undulating their abdominal muscles and wringgling their front flippers. A 41 mile journey into the mountains, on loose and sharp gravel, is therefore almost unbelievable.

Many of the mummies display injuries characteristic of such a journey, showing significant blood loss. It's also common for them to appear completely depleted of blubber and with stomachs empty of food. Some of them actually have stomachs filled instead with appreciable amounts of sand, gravel and rocks, as if to suggest the animals were trying to eat whatever was available to them. A few of the seals showcase mortal wounds and broken bones that likely came after they fell off a cliff.

Analysis has thankfully shown that such journeys are rare, with an average of only one seal becoming lost in the Dry Valleys every 4 to 8 years. After hundreds, even thousands of years, those carcasses can nevertheless add up. Interestingly, there are actually places where several mummies can be found in the same vicinity, likely funneled by the landscape to arrive at the same spot again and again over hundreds of years.

One can only imagine a terrified lost seal crawling through the valleys, ominously passing by so many other carcasses along the way.

Though scientists can't say for sure that this theory is correct, the tale does have one redeeming theme. If such incredible journeys prove anything, it's the remarkable resiliency of these seals to strive onwards against all odds, refusing to give up on life no matter how far lost they become.