This topic contains a solution. Click here to go to the answer

Author Question: Define and describe the formation of an alluvial fan. How does it differ from a delta? What will ... (Read 46 times)

TFauchery

  • Hero Member
  • *****
  • Posts: 500
Define and describe the formation of an alluvial fan. How does it differ from a delta?
 
  What will be an ideal response?

Question 2

Define base level. What processes cause base level to change?
 
  What will be an ideal response?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

ndhahbi

  • Sr. Member
  • ****
  • Posts: 390
Answer to Question 1

When a stream flows out of a narrow bedrock channel in a mountain range, it forms a fan-shaped mass of alluvium called an alluvial fan because the water enters a broad valley where there are no hard-rock valley walls to confine the flow. Alluvial fans form when the discharge of the stream does not change, but the flow is deeper in the upstream channel than it is where the water spreads out downstream as a shallow sheet. The shallower flow exerts less shear stress, and this means the stream power drops, so sediment abruptly deposits to form the fan. A delta is the landform produced by deposition of sediment where a stream enters a lake, reservoir, or sea. Deltas form when there is a drop in stream velocity as it reaches the standing body of water and this causes a drop in stream power which leads to deposition.

Answer to Question 2

The point at which a stream is no longer eroding or depositing sediment. Streams seek to erode to this point. Ultimate base level is sea level. Base level can change when the system changes. Sea level can impact baseline such that when sea level falls, base level falls and the stream must adjust to the new lower shoreline through incision. During sea- level rise, the stream adjusts to a higher shoreline position with deposition occurring in the lower part of the stream.




TFauchery

  • Member
  • Posts: 500
Reply 2 on: Jul 16, 2018
Gracias!


sailorcrescent

  • Member
  • Posts: 334
Reply 3 on: Yesterday
Excellent

 

Did you know?

Elderly adults are at greatest risk of stroke and myocardial infarction and have the most to gain from prophylaxis. Patients ages 60 to 80 years with blood pressures above 160/90 mm Hg should benefit from antihypertensive treatment.

Did you know?

When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.

Did you know?

Acetaminophen (Tylenol) in overdose can seriously damage the liver. It should never be taken by people who use alcohol heavily; it can result in severe liver damage and even a condition requiring a liver transplant.

Did you know?

In 1844, Charles Goodyear obtained the first patent for a rubber condom.

Did you know?

Signs of depression include feeling sad most of the time for 2 weeks or longer; loss of interest in things normally enjoyed; lack of energy; sleep and appetite disturbances; weight changes; feelings of hopelessness, helplessness, or worthlessness; an inability to make decisions; and thoughts of death and suicide.

For a complete list of videos, visit our video library