Why did Bjarni Herjolfsson explore?

There is no historical evidence to suggest Bjarni Herjolfsson explored on purpose.

Bjarni Herjólfsson was an Icelandic explorer who is credited with being the first European to sight North America. He was sailing from Iceland to Greenland in 986 when he was blown off course by a storm. He sailed for several days until he sighted land. He did not land, but he described the land he saw as being flat and covered with trees. He returned to Greenland and told his story, which inspired Leif Erikson to explore the new land.