Pacific walruses spend their winters in the Bering Sea.
As temperatures rise in summer, the edge of the sea ice recedes north.
The phenomenon was first spotted on the US side of the Chukchi Sea in 2007.
Walruses had also been gathering in large groups on the Russian side of the Chukchi Sea.
Once the walruses gather on the beach, the young ones become vulnerable to stampedes.
Stampedes can be triggered by a polar bear, human hunter or low-flying airplane.
Approximately 10,000 walruses were observed hauled out on land slightly north of Point Lay, on 19 August 2011.
Photo credit:Rebecca Shea
Photo credit
viaThe Guardian
