At The Mouth Of The Mighty Amazon River -Belem

Typical scenery cruising down the Amazon river.

Thursday February 23, 2017

The width of the mouth of the river is usually measured from Cabo do Norte to Punto Patijoca, a distance of some 330 km (207 mi); but this includes the ocean outlet, 60 km (40 mi) wide, of the Para river, which should be deducted, as this stream is only the lower reach of the Tocantins. It also includes the ocean frontage of Marajó, an island about the size of Denmark lying in the mouth of the Amazon.

At this forest ecoregion located at the mouth of the Amazon River in eastern Brazil, there are numerous islands throughout the region. Vegetation is noticeably shorter than the surrounding areas, plant diversity is lower, and palms dominate.

The entire area is characterized by an abundance of poorly-drained heavy mottled clay soils. The huge river, having completed its 6,500 km journey, empties into the Atlantic Ocean here. The mouth contains numerous islands. The largest is Ilha Marajó at 48,000 km2. Other islands include Ilha dos Porcos, do Pará, Mututí, and Uituquara. The Amazon estuary is a dynamic lowland consisting of Holocene (less than10,000 years old) sediments surrounded by slightly older Tertiary deposits. There are no protected areas in this ecoregion.

The quantity of fresh water released by the Amazon to the Atlantic Ocean is enormous: up to 300,000 m³ per second in the rainy season. The Amazon is responsible for a fifth of the total volume of fresh water entering the oceans worldwide. It is said that offshore of the mouth of the Amazon potable water can be drawn from the ocean while still out of sight of the coastline, and the salinity of the ocean is notably lower a hundred miles out to sea. This mixture of fresh and salt water is known as brackish water. This quantity of water causes the Amazon to have no clouds above the channel near its mouth,

The region also contains bits of both seasonally inundated floodplain forest and permanently inundated swamp forest. The flora is distinct from that on adjacent uplands. The varzea forest has a lower canopy, less species diversity, and a predominance of palms.

The Marajó várzea, because it lies at the mouth of the Amazon’s "super highway," is a region greatly affected by human activities.

A scene from the widest river in the world.