7. Oceanography of an Estuary

Salt Wedge-Draw this in your notes:

Salt Wedge-Description

• Low density FW overrides high density SW• Can extend far upstream• Impacted by tides– Flood (incoming) – wedge is further upstream– Ebb (outgoing) – wedge is less far upstream– Because of it, organisms here must deal with

major salinity fluctuations

Substrate (bottom sediments)• Rivers:– Current is too fast to let sediment drop out– Lots of suspended (floating) material

• Estuaries:– Wider sides, area where water flows opens up (gets

wider) so water is slowed down – Once flow slows suspended sediments drop out– Result: estuaries are usually muddy

• Closer to Oceans:– Currents are stronger– Smaller particles are washed away leaving larger

sediments behind

Read: http://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar05a_wedge.html

View: http://

www.youtube.com/watch?v=eeeIgDs4SdY And

http://www.youtube.com/watch?v=4UyocM9bDL4