Mississippi Delta Flashcards
Background Info
3rd longest river system in world
Width ranges from 6 metres to 17700 metres
31 states and 2 Canadian Provinces
Sediment: 40% silt, 30% clay, 30% fine sand
Birds foot delta
Formation
Delta cycle:
New delta lobe is created over 1000 years
Occurs bc of sediment transported from upper and middle to lower course and deposited at mouth
Plants grow at sediment and transform into thriving plant community
Lobe continues to grow up river path, eventually cuts course to make a shorter route, starts process again
How was the delta formed?
Formed 7500 years ago when sea levels rose
New delta formed 5500 yeas ago when sea levels dropped
St. Bernard Delta formed 4000 years ago when river broke away and relocated
Features on Delta
Huge amounts of sediment deposited
Interconnected habitats including salt marshes
Under threat due to human construction of canals, dams, channels etc.. to make trade easier
Humans drained wetland for urban development
Beaches on the Delta
No different to beaches on coasts
Formed via deposition and transportation of sediment
Long shore drift occurs, more frequent changes in direction
Made of fine sand, easily eroded, vulnerable to stormy conditions
Inter related features
If one feature is eroded, others will be (sediment budget increases -> beaches grow)
Delta environment forms through deposition of material bc of lower course of river causing sediment to be dropped
Characteristics
Present Day Lobe: Balize Delta
Lots of tributaries
High altitude
Steel mountains
