INVESTIGADORES
LARA Ruben Jose
artículos
Título:
Palaeolimnological studies confirm secular climate fluctuations in Amazonia inferred from ancient maps
Autor/es:
LARA, RUBÉN JOSÉ; COHEN, MARCELO
Revista:
CLIMATIC CHANGE
Editorial:
Springer
Referencias:
Lugar: Amsterdam; Año: 2009 p. 399 - 408
ISSN:
0165-0009
Resumen:
<!-- /* Font Definitions */ @font-face {font-family:Times; panose-1:2 2 6 3 5 4 5 2 3 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0pt; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-fareast-language:PT;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Secular Amazon discharge oscillations were investigated comparing information from ancient cartography, satellite images, palaeovegetation, sediments, anthropology and climate, focusing on the evolution of Marajó island in the Amazon estuary. Four phases were identified. (I) 800-1200 AD: Amazon discharge increased gradually and east Marajó was a vegetation-free tidal plain with energy oscillations. (II) 1200-1350 AD was a dry period with lower river discharges, lower energy, increasing water salinities and maximum mangrove extension, coinciding with the extinction of chiefdoms in Marajó. (III) 1350-1540 AD: Amazon discharge increased rapidly, inducing a dominance of freshwater vegetation, inundation of east Marajó and likely a regional rise of relative sea-level (RSL). (IV) 1540-1750 AD: RSL decreased, coinciding with an El Niño-related intense drought ca. 1600 AD. Emergence of east Marajó was rapid and completed in the 18th century, under RSL stabilization to current values. The approach used provided evidence of intermittent large changes in Amazon climate, and can facilitate the prediction of future regional dynamics.