Estuaries

Question 1

Estuary.

Answer 1

• A body of water partially surrounded by land, where fresh and salta water mix.
• Origins: drowned river mouth, fjord, bar-built, or tectonic.
• Circulation Patterns: salt wedge, well-mixed, partially mixed, fjord, or revers.

Question 2

Drowned river mouth estuary.

Answer 2

• As sea level has risen, it has invaded the mouth of a river.
• Ex: Chesapeake Bay.

Question 3

Fjord Estuary.

Answer 3

• Where the sill is sunk deeper, ocean water passes over and occupies the bottom of the trough.
• River water passes over the top and slow mixing occurs.
• Ex: Strait of Juan de Fuca.

Question 4

Bar-Built estuary.

Answer 4

• A barrier island/spit parallel to the coast shelters smaller inlets coming from mainland, protecting them from most wave action.
• Ex: common in North Carolina, Maryland.

Question 5

Tectonic Estuary.

Answer 5

• Coastal indentation formed by faulting and local subsidence.
• Fresh and salt water, both flow in.
• Ex: San Francisco Bay.

Question 6

Salta Wedge Estuary.

Answer 6

• Powerful river enters area of low tidal action, pushing back the “wedge” of salt water.
• Ex: Mississippi River.

Question 7

Well-Mixed Estuary.

Answer 7

• Different mixtures of fresh and salt water throughout the length, due to tidal turbulence.
• Ex: Columbia River.

Question 8

Partially Mixed Estuary.

Answer 8

• Strong tidal turbulence and powerful river flow.

- Ex: Chesapeake Bay.

Question 9

Reverse Estuary.

Answer 9

• When a river ceases to flow, seawater flows up the estuary, so salinity increases moving toward the mouth of the river.
• Ex: common along Gulf Coast.