how does alluvial fan differ from a delta?

Question

geography

Answer 1

A delta is where a river empties into the sea and dumps its load of silt. Some famous deltas include the Mississippi, the Amazon, and the Nile. Usually there are many different channels of the river going through the delta.

An alluvial fan occurs at the base of mountains. Flash floods, snow melt, and the like create torrents of rushing water coming off the mountain. This water finds its way to gullies heading down the mountain, carrying rocks and pebbles with it. (TGhis is erosion). When the rushing stream gets near the bottom, it slows down because the terrain is no longer as steep as it was higher up.

When the stream slows down like that, it begins to drop its load of pebbles and rocks, creating an alluvial fan that, incidentally, is often shaped like a delta.

Alluvial fans are often found at the base of mountain ranges, at the base of the gorge between two adjacent moluntains. In the Basin and Range section of the American west, they're common sights -- in the Owens Valley or Death Valley, at the base of the Panamints, and so on.

Answer 2

Alluvial Fan Vs Delta

Answer 3

This Site Might Help You.

RE:
how does alluvial fan differ from a delta?
geography

Answer 4

an alluvial fan is found at the base of a mountain or steep slope and is not underwater. It forms as rocks erode and fall down the slope. It does not even require water to transport the material, but rivers, streams, snowmelt, etc. do play a big role in sorting the materials and moving the finer materials farther away from the slope.

a delta is predominantly an underwater feature. It is formed where sediment from a river discharges into a larger body of water such as a lake or ocean.

Answer 5

DELTA - depositional plain formed by a river at its mouth where sedimentation processes irregularly prograde the shoreline

- first named 2500 yr ago by Herodotus when he noted that the mouth of Nile River resembled greek letter D (delta)

- modern deltas vary greatly in size and shape

- from apex, trunk river divides into distributaries

distributaries - distribute water and sediment on alluvial fan (i.e. glacial fan)



delta studies vary according to subdiscpline of investigator:

sedimentologist - more interested in submarine forms and sediments

geomorphologist - more interested in fluvial processes forming delta - subaerial



Fan Delta

- alluvial fan emptying into body of water

- stream comes out of hills, runs into water, spreads out


e.g., braid delta - coarse subaerial component of braided river or braidplain facies

- differ from normal fan deltas which have fine grained seds



Fans vs. Deltas

1) deposition on deltas due to reduced river V when enters water

2) limited vertical growth of deltas - determined by base-level of water

3) delta gradient noticeably shallower than most fans

Answer 6

I think a delta has to have water and a river whereas an alluvial fan is dry...

Could be wrong as it's from memory...

;^)

Answer 7

Leonard Lee and David Lewis asked the same question. You should see the answers side by side.