Abstract

O Plano de Levantamento da Plataforma Continental Brasileira (LEPLAC) tem por objetivo estender o limite da Plataforma Continental, no seu enfoque jurídico (PCJ), além do limite das 200 milhas náuticas da Zona Econômica Exclusiva (ZEE), de acordo com o que preceitua a Convenção das Nações Unidas sobre o Direito do Mar (UNCLOS). Na região da PCJ além das 200 milhas, o Brasil exercerá direitos exclusivos de soberania para fins de exploração e aproveitamento dos recursos naturais (vivos e não-vivos) do leito do mar e do subsolo. As atividades do LEPLAC – iniciadas em 1987, com a aquisição de dados de sísmica de reflexão multicanal (46.000 km), batimetria (100.000 km), gravimetria (94.000 km) e magnetometria (88.000 km) – vêm sendo conjuntamente executadas pela PETROBRAS e MARINHA DO BRASIL, apoiadas por pesquisadores do Programa de Geologia e Geofísca Marinha (PGGM) e do Departamento Nacional da Produção Mineral (DNPM), sob a coordenação e diretrizes da Comissão Interministerial para os Recursos do Mar (CIRM). Os resultados do LEPLAC devem ser submetidos à Comissão de Limites da Plataforma Continental, da ONU, até novembro de 2.004.

The Brazilian Continental Shelf Survey Plan – LEPLAC – Plano de Levantamento da Plataforma Continental Brasileira – aims at expanding the outer limits of Brazil’s Legal Continental Shelf (LCS) beyond the 200-nautical mile limit of the Exclusive Economic Zone (EEZ).

In terms of paragraph 1 of article 76 of the United Nations Convention on the Law of the Sea (UNCLOS), "The continental shelf of a coastal State comprises the sea-bed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin, or to a distance of 200 nautical miles from the baselines from which the breadth of the territorial sea is measured where the outer edge of the continental margin does not extend up to that distance".

Wherever the continental margin extends beyond the 200-nautical mile limit, according to the same UNCLOS’ article 76 (paragraph 4) the coastal State shall establish the outer edge of the continental margin by means of the following two criteria: 1) a line defined by "...the outermost fixed points at each of which the thickness of sedimentary rocks is at least 1 per cent of the shortest distance from such point to the foot of the continental slope", or 2) a line defined by "...fixed points not more than 60 nautical miles from the foot of the continental slope".

Once established the outer edge of the continental margin as described before, the outer edge of the LCS "...either shall not exceed 350 nautical miles from the baselines from which the breadth of the territorial sea is measured or shall not exceed 100 nautical miles from the 2,500 metre isobath, which is a line connecting the depth of 2,500 metres" (UNCLOS’ article 76, paragraph 5).

In the offshore area of the LCS beyond the limit of the EEZ, Brazil will exercise exclusive sovereign rights for the exploration and explotation of the living and non-living natural resources in the sea-bed and its subsoil.

The activities of the Brazilian Continental Shelf Survey Plan (Souza et alii, 1992; Souza, 1994 and 1996) – launched in 1987 through the acquisition of data of multichannel 2D seismic reflection (46,000 km), bathymetry (100,000 km), gravimetry (94,000 km) and magnetometry (88,000 km) – are being jointly handled by the Brazilian Navy and PETROBRAS, with the collaboration of researchers from the the National Department on Mineral Production (DNPM) and the Marine Geology and Geophysical Program (PGGM), under the coordination and guidelines of the Interministerial Commission for the Resources of the Sea (CIRM).

As UNCLOS went into effect on 16 November 1994, Brazil must conclude the activities under this Continental Shelf Survey Plan by 15 November 2004. Completion is actually scheduled for late 2001 – well within the ten-year deadline established by UNCLOS –, when Brazil will submit the results of this survey to the United Nations’ Commission on the Limits of the Continental Shelf.

Through this survey (Figure 1), it is estimated that Brazil will be able to incorporate an area of some 700,000 km² of the Legal Continental Shelf beyond the 200 nautical miles allocated to the Exclusive Economic Zone, which totals 3.5 million km². This results in a total offshore area of some 4.2 million km², corresponding to approximately one half of the land mass of Brazil.