Bites of Mouths of Rivers
Tuesday, November 23, 2010 9:11:12 PM
River-mouths range from deltas that protrude into the sea, over rivers that just enter into the sea without any significant influence on the coastline to estuaries, where the sea intrude into the river-mouth.
Deltas are named after the Greek character capital delta (Δ). The Greek historian Herodotus coined this term when he observed the triangular form of the Nile delta around 450 B.C.). A delta forms where there is no tidal or current action capable of removing the sediments from the river as fast as they are deposited.
Estuaries are situated at the other end of the energy spectrum. The word itself in fact alludes to that. The word “estuary” is derived from the Latin word aestuarium meaning tidal inlet of the sea, which in itself is derived from the term aestus, meaning tide. In an estuary sea water (upstream) and fresh water (downstream) are mixed to become brackish. The power of the tide (or currents) not only transports any silt away from the river-mouth, but may also cause erosion in the sides of the estuary. To be honest, however, many modern estuaries are a result of the sea level rise that has been taking place over the latest 10 thousand years or so, due to the melting of ice age ice and global warming. This has drowned many river valleys. An estuary occupying a former river valley is known as a ria. The word ría comes from the Galician language, as rias are present all along the Galician coast. It is related to the word río (river). A coast with many such drowned river valleys is known as a rias coast or rias coastline. Much of the south coast of the English county of Devon (with the drowned valleys of the Dart, Avon, Yealm, and Erme rivers, and the Salcombe–Kingsbridge Estuary) is such a rias coast.
A former glaciated valley when drowned becomes a fjord, a word that I featured in my post on Fjord, Firth, Förde - Fare, Ferry, Port.
And now back to the word mouth. The most common use of the word mouth is of course for the opening in your face between the lips. In the sense of "outfall of a river" it is attested from early 12th century. The word can be traced back to Indo-European. The modern form in other Germanic languages is mund (German, Danish, and Swedish), mond (Dutch), munn (Norwegian - i.e. both bokmål and nynorsk). This has lead to place names like Warnemünde (mouth of the river Warnow) in Germany, Roermond (mouth of the river Roer) in the Netherlands and Dendermonde (mouth of the river Dender) in the Dutch-speaking part of Belgium.
A funny thing is that Bournemouth translates into Århus (the name of a Danish city). Bourne is a word from the Anglo-Saxon language of England. It means a stream, flowing from a spring, and is commonly used in southern England, (particularly Dorset) as a name for a small river. So Bournemouth means river-mouth - and so does Århus, which in Old Danish was called Ārōs. Å still means a stream. Os is a very old Scandinavian word for mouth, in fact it is still used in Icelandic. There are quite a few placed in Norway ending on -os like Glåmos - the mouth of the river Glomma/Glåma. Århus is not the only city in Scandinavia originally called Aros, this was also the case for Västerås in Sweden. Later it became Västra Aros (western Aros), and finally Västerås. I suppose that os can be traced back to Indo-European, although I haven’t checked that, but in Latin os also means mouth. We recognise that root in oral - by word of mouth or related to the mouth - from late Latin oralis, from Latin os, or- ‘mouth.’
I have only covered a few languages here, but I suppose that mouths of rivers are also called an equivalent of ‘mouth’ in a multitude of languages. Like in French ‘bouche de la riviere’ or’ bouche du fleuve’. Or like in Spanish “boca del río” (Boca del Rio is in fact the name of a city in Mexico, where the Jamapa River flows into the Gulf of Mexico).
But now it is probably about time I keep my mouth shot, before you all fall asleep (I assure you that I could have gone on for quite a while). Back to more geology in my next post!