Storfjorden was historically known as Wybe Jans Water, named after the Frisian whaler Wybe Jansz van Stavoren. The fjord was first labelled as such in 1620.
References
Conway, W. M. 1906. No Man's Land: A History of Spitsbergen from Its Discovery in 1596 to the Beginning of the Scientific Exploration of the Country. Cambridge: At the University Press.