Estuary without a River

[TiggerToo]

I suspect mother nature didn't apeciate that it had to be classified into discrete pigeonholes

true. But Mother Nature generated Old Fogies like you and me, who delight in pedantic classifications and debates about terminology.

So, all is well and legitimate.

(By the way, pigeonholes are useful to know what you mean when you say something)

 

[Yealm]

Funny to think that the English Channel was once an estuary , a marsh, and you could walk over from Le Continent
About 5 hours would do it I imagine

Priti would have kittens

 

[Wansworth]

Priti would have kittens

Don’t start?

 

[michael_w]

Deleted

 

[LadyInBed]

The French call them Calanques
Don't the Scot's call them Loch's?

 

[AntarcticPilot]

The French call them Calanques
Don't the Scot's call them Loch's?

A loch is not (generally) a Ria. A loch is usually a flooded glacial valley; a Ria is a flooded river valley. The former does not require a relative change in sea level (glaciers can cut valleys below sea level), but a Ria does.

 

[Lodestone]

If you go to the Baltic you have rivers without estuaries . The Narva and the Luga emptying into the Gulf of Finland spring to mind.

 

[AntarcticPilot]

If you go to the Baltic you have rivers without estuaries . The Narva and the Luga emptying into the Gulf of Finland spring to mind.

Typical of a very young landscape. All that are was planed flat by glaciers not too long ago, so there hasn't been time for valleys etc. to be cut by rivers.

 

[mrming]

I had thought our home waters of the Swale was a Ria for sure but after reading this thread I think I’m going to switch to calling it a “tidal channel”.

 

[johnalison]

If you go to the Baltic you have rivers without estuaries . The Narva and the Luga emptying into the Gulf of Finland spring to mind.

There are some strange waterways in the Baltic. At Swinoujscie there is a reverse delta. Because the sea level changes non-tidally, Baltic seawater sometimes flows back into the Swin and where the river meets an inland lake, or bodden in German, there is a substantial delta, though this is more evident on the charts than from ground level. It was around here that they set off a WW2 Tallboy a few years ago.

 

[Adios]

If you go to the Baltic you have rivers without estuaries . The Narva and the Luga emptying into the Gulf of Finland spring to mind.

Since this thread I wonder if what you mean is they don't have estuaries as we generally call them, which now we might have to start calling rias. They must have estuaries because thats what the river opening to the sea is called even if small. but because they don't have much tidal action in the baltic to wash out estuaries much wider than the river they don't have rias.

 

[Graham376]

A loch is not (generally) a Ria. A loch is usually a flooded glacial valley; a Ria is a flooded river valley. The former does not require a relative change in sea level (glaciers can cut valleys below sea level), but a Ria does.

It depends where you are, we're based in the Ria Formosa which is certainly not a flooded valley and alternative name would be lagoon.

 

[johnalison]

Since this thread I wonder if what you mean is they don't have estuaries as we generally call them, which now we might have to start calling rias. They must have estuaries because thats what the river opening to the sea is called even if small. but because they don't have much tidal action in the baltic to wash out estuaries much wider than the river they don't have rias.

It's not something I had thought about, but it appears that the essential part of an estuary's definition is the mixing of seawater with the river water, as in :
"An estuary is a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean. Estuaries, and their surrounding lands, are places of transition from land to sea."
In that sense, Lodestone is correct, although non-tidal mixing may occur in varying degrees, such as in my example. I think that what he possibly means is that rivers in the Baltic often flow into the sea without widening at their mouths or change in the land form, which would match my naive notion of an estuary.

 

[LittleSister]

It depends where you are, we're based in the Ria Formosa which is certainly not a flooded valley and alternative name would be lagoon.

But isn't that because it's the Spanish word for river estuary, rather than the English geographical term that ultimately derives from the same word?

 

[Adios]

But isn't that because it's the Spanish word for river, rather than the English geographical term that ultimately derives from the same word?

river is rio in spanish

 

[LittleSister]

river is rio in spanish

My apologies - ria is Spanish for estuary.

(. . . and Portuguese for 'laugh'! )

 

[Graham376]

But isn't that because it's the Spanish word for river estuary, rather than the English geographical term that ultimately derives from the same word?

No, the Ria Formosa isn't in Spain, Portuguese is a different language although also Latin based.

 

[LittleSister]

No, the Ria Formosa isn't in Spain, Portuguese is a different language although also Latin based.

I know the Ria Formosa isn't in Spain, but languages are neither entirely discrete entities, nor great respecters of political/administrative boundaries.

 

[Adios]

It's not something I had thought about, but it appears that the essential part of an estuary's definition is the mixing of seawater with the river water, as in :
"An estuary is a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean. Estuaries, and their surrounding lands, are places of transition from land to sea."
In that sense, Lodestone is correct, although non-tidal mixing may occur in varying degrees, such as in my example. I think that what he possibly means is that rivers in the Baltic often flow into the sea without widening at their mouths or change in the land form, which would match my naive notion of an estuary.

Unless the river ends with a fall into the sea from a cliff there will always be some mixing.

Estuary - Wikipedia has estuary as the term for the broad category "A more comprehensive definition of an estuary is "a semi-enclosed body of water connected to the sea as far as the tidal limit or the salt intrusion limit and receiving freshwater runoff; however the freshwater inflow may not be perennial, the connection to the sea may be closed for part of the year and tidal influence may be negligible".[3] This broad definition also includes fjords, lagoons, river mouths, and tidal creeks. "

and then Rias as a subcategory of estuary:

Drowned river valleys
Main article: Ria
Drowned river valleys are also known as coastal plain estuaries. In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley. This is the most common type of estuary in temperate climates. Well-studied estuaries include the Severn Estuary in the United Kingdom and the Ems Dollard along the Dutch-German border.

The width-to-depth ratio of these estuaries is typically large, appearing wedge-shaped (in cross-section) in the inner part and broadening and deepening seaward. Water depths rarely exceed 30 m (100 ft). Examples of this type of estuary in the U.S. are the Hudson River, Chesapeake Bay, and Delaware Bay along the Mid-Atlantic coast, and Galveston Bay and Tampa Bay along the Gulf Coast.[5]"

The next category mentions bars and lagoons and eventually I'm still unsure of the classification of rivers with a bar, widening behind, but where there is always an outflow such as Deben or Teign.

Wikipedia seems to be pretty definitive these days on benign topics like this so I'm happy to go with it (but its utterly untrustworthy on politically charged issues.) I'm happy with calling all of them estuaries then and leaving the rest uncertain.

 

[LittleSister]

. . . I'm still unsure of the classification of rivers with a bar, widening behind, but where there is always an outflow such as Deben or Teign.

To my mind a bar is a shallowing at the entrance (exit?) of a river, ria etc. , rather than (necessarily) a narrowing. This is typically caused by a slowing of the flow of the river as it widens and/or meets the sea, leading to the depositing of some of the sediment that is carried by the flow at higher speeds. Salcome bar is a (relatively wide) example of this.

Such a bar does sometimes lead to the build up of a drying, or above sea level, spit from one or both sides of the mouth, presumably where the 'bar' of sediment is added to by wave-carried sediment from seaward. Orford Ness being an extreme example of this.

p.s. I've just learnt that Orford Ness is described as a 'cuspate foreland', and the latter is defined as being primarily the result of longshore drift of material along the coast.