Palaeolimnological studies and ancient maps confirm secular climate fluctuations in Amazonia
Rubén J. Lara
Marcelo C. L. Cohen
Abstract
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. (1) 800–1200 a.d.: Amazon discharge increased gradually and eastern Marajó was a vegetation-free tidal plain with energy oscillations. (2) 1200–1350 a.d. 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. (3) 1350–1540 a.d.: Amazon discharge increased rapidly, inducing a dominance of freshwater vegetation, inundation of east Marajó and likely a regional rise of relative sea-level (RSL). (4) 1540–1750 a.d.: RSL decreased, coinciding with an El Niño-related intense drought ca. 1600 a.d. Emergence of eastern Marajó was rapid and completed in the eighteenth 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.
Lara R.J. and Cohen M.C.L. (2009) Palaeolimnological studies and ancient maps confirm secular climate fluctuations in Amazonia. Climatic Change 94(3-4): 399-408. 10.1007/s10584-008-9507-9
@article{Lara2009,
Title = {Palaeolimnological studies and ancient maps confirm secular climate fluctuations in Amazonia},
Author = {Lara, Rubén J. and Cohen, Marcelo C. L.},
Editor = {},
Journal = {Climatic Change},
Year = {2009},
Pages = {399-408},
Volume = {94},
Doi = {10.1007/s10584-008-9507-9},
Abstract = {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. (1) 800–1200 a.d.: Amazon discharge increased gradually and eastern Marajó was a vegetation-free tidal plain with energy oscillations. (2) 1200–1350 a.d. 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. (3) 1350–1540 a.d.: Amazon discharge increased rapidly, inducing a dominance of freshwater vegetation, inundation of east Marajó and likely a regional rise of relative sea-level (RSL). (4) 1540–1750 a.d.: RSL decreased, coinciding with an El Niño-related intense drought ca. 1600 a.d. Emergence of eastern Marajó was rapid and completed in the eighteenth 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.},
}
TY - JOUR
AU - Lara, Rubén J.
AU - Cohen, Marcelo C. L.
TI - Palaeolimnological studies and ancient maps confirm secular climate fluctuations in Amazonia
T2 - Climatic Change
PY - 2009
SP - 399-408
VL - 94
DO - 10.1007/s10584-008-9507-9
AB - 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. (1) 800–1200 a.d.: Amazon discharge increased gradually and eastern Marajó was a vegetation-free tidal plain with energy oscillations. (2) 1200–1350 a.d. 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. (3) 1350–1540 a.d.: Amazon discharge increased rapidly, inducing a dominance of freshwater vegetation, inundation of east Marajó and likely a regional rise of relative sea-level (RSL). (4) 1540–1750 a.d.: RSL decreased, coinciding with an El Niño-related intense drought ca. 1600 a.d. Emergence of eastern Marajó was rapid and completed in the eighteenth 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.
ER -
