Caviana
 Satellite picture by Sentinel-2 of Ilha Caviana | |
  Caviana | |
| Geography | |
|---|---|
| Location | Pará State, Brazil |
| Coordinates | 0°10′N 50°0′W / 0.167°N 50.000°W |
| Archipelago | Marajó Archipelago |
| Area | 2,360 km2 (910 sq mi) |
| Length | 98 km (60.9 mi) |
| Width | 45 km (28 mi) |
| Administration | |
| State | Pará |
| Municipality | Chaves |
Caviana (Portuguese: Ilha Caviana, also called Ilha Caviana Meridional or Ilha Caviana de Fora) is a coastal island in the Brazilian state of Pará. The island is part of the Amazon Delta. It is known for a tidal bore called the pororoca, which can be observed here.
Geography
[edit]Caviana is part of the municipality of Chaves. The Equator runs through the island, as well as the 50th meridian west. It is the third-largest island in the Amazon Delta, after Marajó and Ilha Grande de Gurupá, and the 118th largest island in the world.
Caviana was formed in the Tertiary epoch, from river sediments and consolidated terrain. At the beginning of the Holocene 12,000 years ago, it was already separated from the mainland.[1]
The island belongs to the Marajó Archipelago, it is located opposite the north coast of Marajó Island in the delta lowlands at the mouth of the Amazon. It is separated from neighbouring island Mexiana in the south-east by the Canal Perigoso ("Dangerous Channel"). The latter is called such because sandbanks and strong winds make navigation perilous during low tides.[2] To the west are the islands Viçosa and Junipari.
Just off the southern coast, where the South Channel (Canal Sul) of the Amazon meets the Vieira Grande Bay, is a sandbank called Camaleão that is exposed during low tide. It links together some smaller islets, such as Ilha das Pacas, Camaleão, Camaleãozinho and Jacuraru.
The island is an excellent place to observe the tidal bore called the pororoca, where the Amazon river waters meet the incoming Atlantic tides and form a standing wave. In 1850, the pororoca was so strong that it split the island in two at some point.[3]
Nature
[edit]The island forms part of the low-lying Marajó várzea, the inundated land in and around the mouth of the Amazon River. It is flat and marshy, and frequently flooded, especially in the winter months. The shoreline can change due to rapid sedimentation and erosion processes.
The island is mostly covered with different varieties of palm trees.[4] In the eastern part, areas of forest have been cleared for cattle and buffalo farming.
Caviana is a birdwatchers' haven. As many as 145 different species were observed here. The ornithologist Joseph B. Steere observed the birds on the island in 1871, specimens were brought to the University of Michigan Museum of Natural History.[5]
The island is contained in the 59,985 square kilometres (23,160 sq mi) Marajó Archipelago Environmental Protection Area, a sustainable-use conservation unit established in 1989 to protect the environment of the region.[6]
History
[edit]External links
[edit]- "Marajó Várzea". Terrestrial Ecoregions. World Wildlife Fund.
References
[edit]- ^ Henriques, L.P. (1994). Composição e biogeografia da avifauna das ilhas Caviana e Mexiana, foz do Rio Amazonas (Thesis). Belém: Museu Paraense Emílio Goeldi.
- ^ Lisboa, P.L.B. (2012). A Terra dos Aruã: Uma história ecológica do arquipelágo do Marajó (in Portuguese). Belém: Museu Paraense Emílio Goeldi.
- ^ "Marajó and Inner Delta". Amazon Waters Alliance. 26 July 2022.
- ^ "Northern Brazil at the mouth of the Amazon River". World Wildlife Fund. Archived from the original on 2011-09-26.
- ^ Henriques, L.P.; Oren, D (Jan 1997). "The avifauna of Marajo, Caviana and Mexiana Islands, Amazon River Estuary, Brazil". Rev. Brasil. Biol. 57 (3): 357–382.
- ^ APA Arquipélago do Marajó (in Portuguese), ISA: Instituto Socioambiental, retrieved 2016-06-27
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