What is Fjord Region?
Fjords and bays

Fjord is a term originally developed by chemists studying polycyclic aromatic hydrocarbons, along with the term bay.

The descriptions aren't rigidly defined in the same way as stereochemical descriptors, but were designed to be 'self-explanatory', following the real world uses of the words1


Bay: "a broad inlet of the sea where the land curves inwards."
Fjord: "a long, narrow, deep inlet of the sea between high cliffs, as in Norway, typically formed by submergence of a glaciated valley."


In an attempt unify the usage of these terms, IUPAC issued a set of guidelines for their usage in 2014.2 



Some historical context

The earliest publication of these terms was given in the references above by Harry Heaney, Keith Bartle, Denny Jones, and Peter Lees who were working at the now non-existent Institute of Technology (Bradford, UK). They were studying triphenylene, and trying to find descriptions for the various environments present. 




  Circumnavigating triphenylene, the British crew sighted two essentially diffe­rent kinds of H's; and Derry Jones spontaneously called one type "bay" and the other "peninsular." They published these descriptive "self-explanatory" names,40 but not without some apprehension. In fact, Professor Jones confessed to having dreamed that referees rejected their manuscript on account of its "bay" and "peninsular" nomencla­ ture


Reference:

1 Spectrochim. Acta 1966,22,pp941-951; Trans. Farad.  Soc. 1967,63,pp2868-287

2 J. Polycyclic Aromatic Hydrocarbons, 2015, 35, pp 161-176