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Please show source where you found it at. Thank you.

2006-11-30 23:59:05 · 4 answers · asked by HolyDovePraise 2 in Science & Mathematics Geography

4 answers

Hello Holy Dove,

I think this is called a delta.
Here's the quote from "The American Heritage® Dictionary of the English Language, Fourth Edition.
Copyright © 2000 by Houghton Mifflin Company. "

http://education.yahoo.com/reference/dictionary/entry/delta;_ylt=AkjhTfV4xSzHKnXL8xqD9qQZvskF

Here's the complete quote from the above URL

"NOUN:

The fourth letter of the Greek alphabet. See Table at alphabet.
An object shaped like a triangle.

A usually triangular alluvial deposit at the mouth of a river.
A similar deposit at the mouth of a tidal inlet, caused by tidal currents.
Mathematics A finite increment in a variable.

--------------------------------------------------------------------------------
ETYMOLOGY:
Middle English, from Latin, from Greek, of Phoenician origin; see dl in Semitic roots

OTHER FORMS:
del·taic (-tk) KEY or deltic (-tk) KEY (Adjective)

WORD HISTORY:
A Greek letter sits at the mouth of many rivers. Noticing the resemblance between the island formed by sediment at the mouth of a river such as the Nile and the triangular shape of their letter delta (), the Greeks gave the name delta to such an island. English borrowed this sense from Greek, although the word delta appeared first in English as the name of the letter, in a work written possibly around 1200. The sense "alluvial deposit" is not recorded until 1555, when delta is used with reference to the Nile River delta."

Encyclopedia of Britannica online
http://www.britannica.com/ebc/article-9029856
[brief summary of article available to nonmembers]

!!Please note third paragraph for the names of three
kinds of deltas!!

Full quote here from the above web page
"Some 2,500 years ago, Herodotus recognized that the land bounded by the seaward-diverging distributary branches of the Nile and the sea was deltoid in shape and so used the Greek letter D (delta) to describe it. Although many of the world's deltas are deltoid, or triangular, in shape, notable exceptions exist. In most cases, the delta shape is controlled by the outline of the water body being filled by sediments. For this reason, the term delta is now normally applied, without reference to shape, to the exposed and submerged plain formed by a river at its mouth.

Deltas have been important to humankind since prehistoric times. Sands, silts, and clays deposited by floodwaters were extremely productive agriculturally; and major civilizations flourished in the deltaic plains of the Nile and Tigris-Euphrates rivers. In recent years geologists have discovered that much of the world's petroleum resources are found in ancient deltaic rocks.

Deltas display much variation in size, structure, composition, and origin. These differences result from sediment deposition taking place in a wide range of settings. Numerous factors influence the character of a delta, the most important of which are: climatic conditions, geologic setting and sediment sources in the drainage basin, tectonic stability, river slope and flooding characteristics, intensities of depositional and erosional processes, and tidal range and offshore energy conditions. Combinations of these factors and time give rise to the wide variety of modern deltas. The presence of a delta represents the continuing ability of rivers to deposit stream-borne sediments more rapidly than they can be removed by waves and ocean currents. Deltas typically consist of three components. The most landward section is called the upper delta plain, the middle one the lower delta plain, and the third the subaqueous delta, which lies seaward of the shoreline and forms below sea level.

That part of the river confined by valley walls, termed the alluvial plain, serves as a conduit through which sediment and water derived from the drainage basin are brought to the sea. At some point downstream the plain broadens out, and most river channels break up into more than one course. This is the apex of the delta and the beginning of the upper delta plain. All of this land lies at an elevation above the effective intrusion of tidal water and is formed entirely by riverine processes. Areas between channels usually support broad freshwater marshes, swamps, or shallow lakes. The lower delta plain is periodically flooded by tidal waters, and landforms result from the interaction of both riverine and marine processes. Areas between the channels show a variety of landforms, ranging from brackish water bays and mangrove swamps to saline tidal flats and beach ridges. The subaqueous delta forms entirely below the level of the sea and commonly constitutes the obvious bulge on the continental shelf seen seaward of many deltas. It serves as the submarine platform across which the exposed delta eventually builds. Variations in the proportions of each deltaic component give rise to the different sizes and slopes of the world's deltas."

Hoping this helps!
Janice

2006-12-01 00:15:35 · answer #1 · answered by jmflahiff 3 · 1 0

It's called an alluvial plain. Although there is some overlap in the meanings, a delta refers to the case in which sediments are deposited in the ocean, or other large body of water.

2016-05-23 07:24:56 · answer #2 · answered by Anonymous · 0 0

A Delta or as Captain Nemo called them, "A freekin' hazard to navigation"!

2006-12-01 00:08:10 · answer #3 · answered by Anonymous · 1 0

Delta.

Geography, forever ago.

2006-12-01 00:02:17 · answer #4 · answered by timc_fla 5 · 0 1

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