Wave and tide processes on Rocas Atoll: geomorphological implications and future projections

• Grant number: 11/22661-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2012
• End date: July 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Eduardo Siegle
• Grantee: Mirella Borba Santos Ferreira Costa
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The interactions between waves and tides induced processes and sediment dynamics have been studied worldwide, especially at the Indo-Pacific atolls. However, at Rocas Atoll, the only atoll in the South Atlantic (located 145 km from the Fernando de Noronha Island and 260 km from Natal city - RN) these studies have still been limited. Futhermore, Rocas Atoll houses, since 1993, one of the few Brazilian's research bases in the open ocean and has been undergoing intense erosion forced by atmospheric and oceanographic processes. The aim of this research is to describe the processes induced by waves and tides at Rocas Atoll and its implications for sediment dynamics, in particular, the morphological responses of the sedimentary islands. The methodological approach involved the analysis of wave climate time series (global model NWW3), field experiments to collect in situ data (waves, currents, tides and sediment morphology of the atoll) and numerical model (Delft 3D) simulations of sediment transport in two different conditions (actual and according to future projections). The results will contribute to understanding the dynamics of Rocas Atoll on a multi-temporal scale which comprises tidal cycle variations, seasonal changes and long-term evolution. Furthermore, they can be used to support the Biological Reserve Rocas Atoll managers and futures projections concerning human occupation at the atoll.

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COSTA, MIRELLA B.; MACEDO, EDUARDO C.; VALLE-LEVINSON, ARNOLDO; SIEGLE, EDUARDO. Wave and tidal flushing in a near-equatorial mesotidal atoll. CORAL REEFS, v. 36, n. 1, p. 277-291, MAR 2017. (11/22661-3)

SIEGLE, EDUARDO; COSTA, MIRELLA B.. Nearshore Wave Power Increase on Reef-Shaped Coasts Due to Sea-Level Rise. EARTHS FUTURE, v. 5, n. 10, p. 1054-1065, OCT 2017. (11/22661-3)

COSTA, MIRELLA B.; SIEGLE, EDUARDO. Wave climate and extremes on a mesotidal atoll lagoon. Ocean and Coastal Research, v. 70, p. 22-pg., 2022-01-01. (11/22661-3)

COSTA, MIRELLA B.; MACEDO, EDUARDO C.; SIEGLE, EDUARDO. Planimetric and volumetric changes of reef islands in response to wave conditions. EARTH SURFACE PROCESSES AND LANDFORMS, v. 42, n. 15, p. 2663-2678, DEC 2017. (11/22661-3)

COSTA, MIRELLA B.; MACEDO, EDUARDO C.; SIEGLE, EDUARDO. Wave refraction and reef island stability under rising sea level. GLOBAL AND PLANETARY CHANGE, v. 172, p. 256-267, JAN 2019. (11/22661-3)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

COSTA, Mirella Borba Santos Ferreira. Wave and tidally induced processes on Rocas Atoll: geomorphological implications and future projections. 2015. Doctoral Thesis - Universidade de São Paulo (USP). Instituto Oceanográfico (IO/DIDC) São Paulo.