A fjard (Swedish: fjärd, IPA: [ˈfjæːɖ]) is a large open space of water between groups of islands or mainland in archipelagos. Fjards can be found along sea coasts, in freshwater lakes or rivers. Fjard and fjord were originally the same word with the general meaning of sailable waterway. In Scandinavia, fjords dominate along the North Sea coast while fjards dominate the Baltic Sea coast.
Although fjards and fjords are similar in that they are a glacially-formed topography, they still differ in some key ways:
Fjords are characterized by steep high relief cliffs carved by glacial activity and often have split or branching channels.
Fjards are a glacial depression or valley that has much lower relief than a fjord. Fjards fill with eroded local materials which assists "filling" along with rising sea level since the last ice age contributing as well. Other low relief landforms that are only associated with fjards such as mud flats, salt marshes, and flood plains further characterize the difference between fjords and fjards.
"Förden" of the German coast and the fjords of Danish eastern Jutland together form a third type of glacial inlets. They tend to occur along older 'beheaded' river channels and open into the tideless Baltic sea.
Rias are drowned valleys, such as the estuaries of Thames, Severn and Humber, firths of Tay and Forth.
^ABPmer and HR Wallingford. 2007. Understanding and Managing Morphological Change in Estuaries, Ch. 3 of The Estuary-Guide: A website based overview of how to identify and predict morphological change within estuaries., Joint Defra/EA Flood and Coastal Erosion Risk Management R&D Programme. UK Department for Environment, Food, and Public Affairs.
^Bird, E.C.F., 2008, Coastal Geomorphology: An Introduction, 2nd ed. John Wiley and Sons Ltd. West Sussex, England. ISBN 978-0-470-51729-1
^Cooper, J. A. G. (2006). "Geomorphology of Irish estuaries: inherited and dynamic controls". Journal of Coastal Research: 176–180. JSTOR 25741557.
^Jackson, J.A., 1997, Glossary of Geology. American Geological Institute. Alexandria, Virginia. ISBN 0-922152-34-9
^Goudie, A., 2004, Encyclopedia of Geomorphology. Routledge. London, England. ISBN 0-415-27298-X