Bjarne Groennov killed the animal after it threw fellow expert Jens Fog Jensen to the ground in the incident on Saturday, said the National Museum of Denmark.
“It was a shocking experience but in such a situation we are just glad to get out alive and more or less unharmed,” Jensen was quoted by the museum as saying on his return to Denmark after treatment in Iceland.
Jensen was taking notes on Clavering island in northeast Greenland when “suddenly the polar bear came out from behind the rocks, just 10 or 15 metres away from him,” the museum said.
Groennov shouted out to warn him and Jensen tried to run away, but “the bear chased him and threw him to the ground before biting him and clawing his arms and legs.”
Groennov grabbed a gun but when he shot toward the animal it began heading in his direction. The archeologist then shot dead the bear.
The pair were carrying out digs on disused meteorological stations built by the Nazis in the Second World War to improve their weather forecasts in western Europe.