@article {543, title = {Late Holocene precipitation variability recorded in the sediments of Reloncav{\'\i} Fjord (41{\textdegree}S, 72{\textdegree}W), Chile}, journal = {Quaternary Research}, volume = {84}, year = {2015}, note = {Co0ceTimes Cited:1Cited References Count:93}, month = {Jul}, pages = {21-36}, abstract = {We present reconstructions of late Holocene changes in the source of organic matter and siliceous export production in the Relocanv{\'\i} Fjord (41{\textdegree}S, 72{\textdegree}W), Northern Chilean Patagonia, based on organic carbon content, δ13Corg, N/C ratio, diatom assemblages and biogenic silica contents from three sediment cores. The age models are based on a combination of 210Pb profiles, AMS 14C dating, and on the first occurrence of the diatom Rhizosolenia setigera f. pungens, as a stratigraphic marker in the fjords. The cores span the last 300 to 700 yr. Diatoms dominate the siliceous assemblages in the three cores (98\% on average). Our results suggest that precipitation seasonality in the region of Reloncav{\'\i} was high in CE 1300{\textendash}1400 and CE 1700{\textendash}1850, with a clear decreasing trend since CE 1850. The latter trend is in agreement with instrumental records and tree-ring reconstructions. These fluctuations seem to be associated with the Southern Annular Mode (SAM).}, issn = {0033-5894}, doi = {10.1016/j.yqres.2015.05.006}, author = {Rebolledo, Lorena and Lange, Carina B. and Bertrand, S{\'e}bastien and Mu{\~n}oz, Praxedes and Salamanca, Marco and Lazo, Pablo and Iriarte, Jos{\'e} L. and Vargas, Gabriel and Pantoja, Silvio and Dezileau, Laurent} } @article {185, title = {Siliceous productivity changes in Gulf of Ancud sediments (42{\textdegree}S, 72{\textdegree}W), southern Chile, over the last \~{}150 years}, journal = {Fjord Oceanography of the Chilean Patagonia}, volume = {31}, year = {2011}, note = {id: 2191}, pages = {356-365}, abstract = {We evaluated changes in siliceous export production and the source of organic matter preserved in sediment core MD07-3109H recovered from the Gulf of Ancud, Chilo{\'e} Inner Sea (42{\textdegree}S, 72{\textdegree}W, water column depth: 328 m), southern Chile. We analyzed the abundance of siliceous microfossils (diatoms, silicoflagellates, sponge spicules, Chrysophyte cysts, phytoliths), geochemical proxies (weight percent silicon \%SiOPAL, organic carbon, total nitrogen, C/N molar), and sediment stable isotopes (δ13Corg, δ15N). Chronology based on 210Pb and 14C provided an accumulated age of 144 years at the base of the core. Sediments of core MD07-3109H are predominantly marine in origin, averaging δ13Corg={\textendash}20.75{\textperthousand}{\textpm}0.82, δ15N=8.7{\textpm}0.35{\textperthousand}, and C/N=8.76{\textpm}0.36. Marine diatoms compose 94\% of the total assemblage of siliceous microfossils. Our record of productivity based on the mass accumulation rates of organic carbon, total nitrogen, SiOPAL, and total diatoms showed high values between 1863 and 1869 AD followed by a declining trend until 1921 AD, a transition period from 1921 to 1959 AD with fluctuating values, and a clear decreasing pattern from 1960 AD to the present. This marked reduction in productivity was associated with decreased precipitation and Puelo River streamflow (41{\textdegree}S), as well as a warmer and more stratified water column, especially since the 1980s.}, issn = {0278-4343}, doi = {10.1016/j.csr.2010.06.015}, url = {http://www.sciencedirect.com/science/article/pii/S0278434310002177}, author = {Rebolledo, Lorena and Gonz{\'a}lez, Humberto E. and Mu{\~n}oz, Praxedes and Iriarte, Jos{\'e} L. and Lange, Carina B. and Pantoja, Silvio and Salamanca, Marco} } @article {503, title = {Late Holocene marine productivity changes in Northern Patagonia-Chile inferred from a multi-proxy analysis of Jacaf channel sediments}, journal = {Estuarine Coastal and Shelf Science}, volume = {80}, year = {2008}, note = {id: 2117; PT: J; TC: 5; J9: ESTUAR COAST SHELF S; UT: WOS:000261562600002}, pages = {314-322}, abstract = {A multi-proxy approach based on organic (organic carbon, alkenones, and C/N) and inorganic geochemical proxies (biogenic opal, inorganic carbon, Fe, Ti, and Ca) preserved in the sediments of the Jacaf channel (CF7-PC33; 44 degrees 21{\textquoteright}S, 72 degrees 58{\textquoteright}W, 510 m water depth), Chilean fjords, yields evidence of major past productivity fluctuations in accordance with climatic changes over the last similar to 1800 years. The downcore record clearly shows two productivity/climate modes. The first period, prior to 900 cal yr BP, is characterized by decreased marine productivity and a reduced continental signal, pointing to diminished precipitation and runoff. In contrast, the second period between similar to 750 cal yr BP and the late 1800s (top of core) is illustrated by elevated productivity and an increased continental signal, suggesting higher precipitation and runoff. Both time intervals are separated by a relatively abrupt transition of similar to 150 years which roughly coincides with the beginning of the Little Ice Age. The increased content of freshwater diatoms and Chrysophyte cysts that characterize the last 200 years of the latter mode coincides with a significant decrease in the carbonate content of the sediment; together they further indicate increased terrigenous contributions and decreased marine carbonate productivity at the end of the Little Ice Age. The correspondence between our record and other paleoclimate studies carried out in South America and Antarctica demonstrates that the Chilean fjord area of Northern Patagonia is not just sensitive to local climatic variability but also to regional and possibly global variability. (C) 2008 Elsevier Ltd. All rights reserved.}, issn = {0272-7714}, doi = {10.1016/j.ecss.2008.08.016}, author = {Rebolledo, Lorena and Sepulveda, Julio and Lange, Carina B. and Pantoja, Silvio and Bertrand, Sbastien and Hughen, Konrad and Figueroae, Dante} }