Holocene changes in monsoon precipitation in the Andes of NE Peru based on delta O-18 speleothem records

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Bustamante, M. G. ; Cruz, F. W. ; Vuille, M. ; Apaestegui, J. ; Strikis, N. ; Panizo, G. ; Novello, F. V. ; Deininger, M. ; Sifeddine, A. ; Cheng, H. ; Moquet, J. S. ; Guyot, J. L. ; Santos, R. V. ; Segura, H. ; Edwards, R. L.

• Tipo de documento: Artigo Científico
• Fonte: QUATERNARY SCIENCE REVIEWS; v. 146, p. 274-287, AUG 15 2016.
• Citações Web of Science: 9

Resumo

Two well-dated delta O-18-speleothem records from Shatuca cave, situated on the northeastern flank of the Peruvian Andes (1960 m asl) were used to reconstruct high-resolution changes in precipitation during the Holocene in the South American Summer Monsoon region (SASM). The records show that precipitation increased gradually throughout the Holocene in parallel with the austral summer insolation trend modulated by the precession cycle. Additionally the Shatuca speleothem record shows several hydro climatic changes on both longer- and shorter-term time scales, some of which have not been described in previous paleoclimatic reconstructions from the Andean region. Such climate episodes, marked by negative excursions in the Shatuca delta O-18 record were logged at 9.7-9.5, 9.2, 8.4, 8.1, 5.0, 4.1, 3.5, 3.0, 2.5, 2.1 and 1.5 ka b2k, and related to abrupt multi-decadal events in the SASM. Some of these events were likely associated with changes in sea surface temperatures (SST) during Bond events in the North Atlantic region. On longer time scales, the low delta O-18 values reported between 5.1-5.0, 3.5-3.0 and 1.5 ka b2k were contemporaneous with periods of increased sediment influx at Lake Pallcacocha in the Andes of Ecuador, suggesting that the late Holocene intensification of the monsoon recorded at Shatuca site may also have affected high altitudes of the equatorial Andes further north. Numerous episodes of low SASM intensity (dry events) were recorded by the Shatuca record during the Holocene, in particular at 10.2, 9.8, 9.3, 6.5, 5.1, 4.9, 2.5 and 23 ka b2k, some of them were synchronous with dry periods in previous Andean records. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 12/50260-6 - Estruturação e evolução da biota amazônica e seu ambiente: uma abordagem integrativa
• Beneficiário: Lúcia Garcez Lohmann
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático