Sediments Framing Northern and Eastern Coastlines of Brazil’s Northeast Region7.8S 39.7W
This image shows part of the Northeast Region (Região Nordeste, in Portuguese) of Brazil, which is composed of the following states: Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe and Bahia, and it represents 18.26% of the Brazilian territory.
Geographically, the Northeast consists chiefly of an eroded continental craton with many low hills and small ranges. The highest peaks are around 1,850 metres (6,070 ft) in Bahia, while further north there are no peaks above 1,123 metres (3,684 ft).
On its northern and western side, the plateaus fall steadily to the coast and into the basin of the Tocantins River in Maranhão, but on the eastern side it falls off quite sharply to the coast except in the valley of the São Francisco river. The steep slopes and long cliffs of the eastern coastline are known as “The Great Escarpment”. Here, sediments frame the northern and eastern coastlines.
The escarpment serves an extremely important climatic function. Because for most of the year the Nordeste is out of reach of the Intertropical Convergence Zone, the easterly trade winds blow across the region, giving abundant rainfall to the coast but producing clear, dry conditions inland where the escarpment blocks moisture flow. This gives rise to four distinct regions, the zona da mata on the coast, the agreste on the escarpment, sertão beyond and the Mid north.