Vital, Helenice1, Flavo Elano S. Sousa1, Zuleide M.C.
Lima1, Marcelo dos Santos Chaves1, Iracema Miranda
Silveira1, Venerando E. Amaro1
(1) Universidade Federal do Rio Grande do Norte, PRH-ANP 22, Natal, Brazil
ABSTRACT: Shoreline Mobility of Mesotidal Sandy Beaches in the Northeastern Brazil: Implications to Oil and Gas Exploration on the Potiguar Basin (NE Brazil)
One line of sea level evidence is provided by old shoreline features. This paper examines shoreline mobility on a tropical sandy coast located between Galinhos and Ponta do Mel beaches, northeastern Brazil, where Active oil and gas exploration and development are under way. Because critical coastal erosion areas are present on this coast, the goal of this study is to establish a state-of-the-art, shoreline-monitoring and shoreline-change analysis that will help guide coastal-erosion and -mitigation projects along NE Brazil shorelines. The study area is a 80-km-long stretch of mesotidal beach backed by dunes and with a very shallow and narrow shelf seaward. Short-term scale mobility of this shoreline is directly correlated to the integrated performance of waves, coastal currents, tides, and winds, related with the past climates and sea level changes during the Quaternary. Aerial photographs from 1954, satellite multispectral Landsat 5 – Thematic Mapper data, acquired in 2001, and historical documentation, allow us to infer this shoreline back to 1872. Accelerated erosion is accounted mostly to Guamaré, Ponta do Tubarão and Barra do Corta Cachorro areas. From 1872 to 2001 Guamaré and Ponta do Tubarão areas eroded respectively 1200 and 400 m; while Barra do Corta Cachorro eroded 750 m between 1954 and 2001. A comprehensive shoreline evaluation on areas under critical erosion is important for responsible hydrocarbon exploration and development.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.