Drowned River Valleys
Many drowned river valley estuaries were formed between about 15,000 and 6000 years ago following the end of the Wisconsin (or 'Devensian') glaciation when a eustatic rise in sea level of 100 to 130 m (330 to 430 ft) flooded river valleys that were cut into the landscape when sea level was lower, creating the estuarine systems. Additionally, the general subsidence of coastal regions contributed to the development. Well-developed drowned river valleys are generally found on coastlines with low, wide coastal plains. Their width-to-depth ratio is typically large, appearing wedge-shaped in the inner part and broadening and deepening seaward. Water depths rarely exceed 30 m (98 ft). Examples of this type of estuary include the Hudson River, Chesapeake Bay, and Delaware Bay along the U.S. Mid-Atlantic coast; and along the U.S. Gulf coast, Galveston Bay and Tampa Bay.
Read more about this topic: Estuary, Classification Based On Geomorphology
Famous quotes containing the words drowned, river and/or valleys:
“the thing I came for:
the wreck and not the story of the wreck
the thing itself and not the myth
the drowned face always staring
toward the sun”
—Adrienne Rich (b. 1929)
“The river’s tent is broken; the last fingers of leaf
Clutch and sink into the wet bank. The wind
Crosses the brown land, unheard. The nymphs are departed.
Sweet Thames, run softly, till I end my song.
The river bears no empty bottles, sandwich papers,
Silk handkerchiefs, cardboard boxes, cigarette ends
Or other testimony of summer nights.”
—T.S. (Thomas Stearns)
“I do like a little romance ... just a sniff, as I call it, of the rocks and valleys.... Of course, bread-and-cheese is the real thing. The rocks and valleys are no good at all, if you haven’t got that.”
—Anthony Trollope (1815–1882)