Earth Snapshot RSS Feed Twitter

Posts tagged Estuary

Cape Fear River Spilling Sediments off North Carolina Coast, USA

October 21st, 2009 Category: Lakes, Rivers

USA - September 29th, 2009

USA - September 29th, 2009

The Cape Fear River is a 202 mile (325 km) long blackwater river in east central North Carolina in the United States. It flows into the Atlantic Ocean near Cape Fear, from which it takes its name. Here, greenish sediments flow from the rivermouth into the Atlantic.

The river has its source at Haywood, by the confluence of the Deep and Haw rivers just below Jordan Lake. It flows southeast, then receives the Black River approximately 10 miles (16 km) northwest of the city of Wilmington, which appears as a greyish-brown area north of the rivermouth.

At Wilmington, it receives the Northeast Cape Fear River and turns south, widening as an estuary and entering the Atlantic approximately 3 miles (5 km) west of Cape Fear.

Another body of water visible west of the estuary is Lake Waccamaw, an oval-shaped freshwater lake measuring roughly 5 miles by 7 miles with an average depth of 7.5 feet.

The Penner River and Pulicat Lake, India

13.5N 80.1E

October 18th, 2009 Category: Lakes, Rivers

India - September 24th, 2009

India - September 24th, 2009

Greenish sediments line the east coast of India near the estuary of the Penner River (above) and Pulicat Lake (below). Here, the tan-colored Penner flows eastward across the plain of Coastal Andhra, where it empties into the Bay of Bengal 15 km east of Nellore at a place called Utukuru. The estuary of the Penner River extends 7km upstream from the Bay of Bengal.

Pulicat Lake, straddling the border of Tamil Nadu and Andhra Pradesh states on the Coromandal Coast, is the second largest brackish-water lake or lagoon in India. The lake is separated from the Bay of Bengal by the barrier island of Sriharikota, which is home to the Satish Dhawan Space Centre.

Mobile and Perdido Bays, USA

30.7N 88.2W

June 8th, 2009 Category: Rivers

Mobile Bay, Alabama, USA - June 2nd, 2009

Mobile Bay, Alabama, USA - June 2nd, 2009

Two bays can be seen draining into the Gulf of Mexico: Mobile Bay, in the center, and Perdido Bay, on the right. Here, the former is spilling a greater quantity of brown sediments into the gulf. On the left side of the image, several condensation trails are visible over land.

Mobile Bay is an inlet lying within the state of Alabama in the USA. Its mouth is formed by the Fort Morgan Peninsula on the eastern side and Dauphin Island, a barrier island, on the western side.

Mobile Bay is 413 square miles (1,070 km2) in area. It is 31 miles (50 km) long by a maximum width of 24 miles (39 km).

It is the fourth largest estuary in the United States, with a discharge of 62,000 cubic feet (1,800 m3) of water per second.

The deepest areas of the bay are located within the shipping channel, sometimes in excess of 75 feet (23 m) deep, but the average depth of the bay is 10 feet (3 m).

The Mobile River and Tensaw River empty into the northern end of the bay, making it an estuary. Several smaller rivers also empty into the bay: Dog River, Deer River, and Fowl River on the western side of the bay, and Fish River on the eastern side.

Perdido Bay is a bay draining the Perdido River that lies on the borders of Baldwin County, Alabama and Escambia County, Florida. It lies west of the Florida communities of Pensacola and Perdido Key and east of the Alabama communities of Orange Beach and Lillian.

Ono Island and the mouth of the bay are within Alabama territory, as the Florida border crosses the barrier islands just east of Perdido Pass and Alabama Point, where the bay empties into the Gulf of Mexico.

Contours of Chesapeake Bay Coastline, USA – May 30th, 2009

37.5N 76.1W

May 30th, 2009 Category: Fires, Image of the day, Rivers

Chesapeake Bay, USA - May 21st, 2009

Chesapeake Bay, USA - May 21st, 2009

The Chesapeake Bay (middle) is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland (above) and Virginia (below). Parts of the states of Delaware and New Jersey are also visible in the upper right quadrant. Also of note is a plume of smoke at the lower left, from a fire in Virginia.

The Chesapeake Bay stretches about 200 miles (300 km) from the Susquehanna River in the north to the Atlantic Ocean in the south. The Chesapeake Bay is the ria, or drowned valley, of the Susquehanna, meaning that it was where the river flowed when the sea level was lower.

Much of the bay is quite shallow. At the point where the Susquehanna River flows into the bay, the average depth is 30 feet (9 m), although this soon diminishes to an average of 10 feet (3 m) from the city of Havre de Grace for about 35 miles (56 km), to just north of Annapolis.

In this image, sun glint makes the water of the bay appear whitish, and thus highlights the contours of the coastline. However, despite the glint it is still possible to observe some greenish sediments flowing into the bay.

Since the bay is an estuary, it has fresh water and brackish water. Brackish water has three salinity zones — oligohaline (little salt, freshwater species able to survive), mesohaline (medium amount of salt), and polyhaline (very salty, sometimes as much as sea water).

In the Chesapeake Bay, the fresh water zone runs from the mouth of the Susquehanna River to north Baltimore.  The mesohaline zone reaches from the Bay Bridge to the mouth of the Rapahannock River, and the salty polyhaline zone runs from the mouth of the Rappahannock River to the mouth of the bay.

Confluence of the Paraná and Uruguay Rivers – April 20th, 2009

April 20th, 2009 Category: Rivers

Argentina - April 5th, 2009

Argentina - April 5th, 2009

Close-up of Paraná River

Close-up of Paraná River

Close-up of confluence

Close-up of confluence

The Paraná  River snakes southward then curves to the East, after which it merges with the Uruguay River. At this convergence, it becomes the Río de la Plata, the world’s widest estuary.

An estimated 57 million cubic metres (2 billion cubic feet) of silt is carried into the estuary each year, where the muddy waters are stirred up by winds and the tides. Here, such sediments differ in color: the Paraná carries light tan sediments, while those in the Uruguay appear dark brown.

Argentina’s capital city, Buenos Aires, can be seen on the southern banks of the estuary.