A ∼43-ka record of paleoenvironmental change in the Central American lowlands inferred from stable isotopes of lacustrine ostracods

Escobar, Jaime; Hodell, David A; Brenner, Mark; Curtis, Jason H.; Gilli, Adrian; Mueller, A.; Anselmetti, Flavio S.; Ariztegui, Daniel; Grzesik, Dustin A.; Pérez, Liseth; Schwalb, Antje; Guilderson, Thomas P.

doi:10.1016/j.quascirev.2012.01.020

Cited by 91 publications

(125 citation statements)

References 82 publications

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“…The following assumptions were made for the comparison between δ 18 O ostr and δ 18 O calcite : (1) changes in the δ 18 O water composition of rivers are induced by changes in the δ 18 O prec composition (Meyers et al, 1993;Sacks and Tihansky, 1996;Sacks, 2002;Wilcox et al, 2004;Price and Swart, 2006;Harvey and McCormick, 2009); (2) evaporation is of minor importance for river water and is seasonally constant (Gremillion and Wanielista, 2000; Dutton et al, 2005); (3) the δ 18 O ostr variation is environmentally induced; (4) if calcification is seasonally restricted, the last molting period for a whole C. ilosvayi population to reach the adult stage lasts 1 month at maximum; (5) and there is a constant positive vital effect for the species of about +1 ‰ (Escobar et al, 2012).…”

Section: Calculation Of Calcification Periodsmentioning

confidence: 99%

“…One vital effect for modern C. ilosvayi of about +1 ‰ is reported from Lake Petén Itzá (Escobar et al, 2012). Recently, it has been shown that the vital effect within a species can differ between sites and the ionic composition of the water may change vital effects (Marco-Barba et al, 2012;Decrouy and Vennemann, 2013).…”

Section: Reconstruction Of C Ilosvayi Calcification Timesmentioning

confidence: 99%

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Modeling calcification periods of <i>Cytheridella ilosvayi</i> from Florida based on isotopic signatures and hydrological data

Meyer

Wrozyna

Leis³

et al. 2017

Biogeosciences

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Abstract. The isotopic signatures of ostracod shells are the result of the temperature and composition of their host water and the phenology and ecology of the target species. Investigations addressing the influence of site-specific environmental variations on the isotopic ranges of ostracod shells are still rare but can provide important information on habitatdependent variations and may signify a seasonally restricted timing of calcification periods. Here we present isotopic signatures (δ 18 O ostr , δ 13 C ostr ) of living Cytheridella ilosvayi (Ostracoda) and physical, chemical, and isotopic (δD, δ 18 O water , δ 13 C DIC ) compositions of 14 freshwater habitats (rivers, lakes, canals, marshes, sinkholes) in South Florida from winter 2013 and summer 2014. We also present instrumental data of river temperatures and δ 18 O of precipitation (δ 18 O prec ) from this region. The physicochemical and isotopic compositions of the selected sites characterize the different habitats and show the influence of the source water, biological activity, and duration of exposure to the surface. Mean δ 18 O ostr and δ 13 C ostr signatures of C. ilosvayi shells correlate well with the isotopic composition of their host waters. Within-sample variabilities in repeated isotopic measurements of single ostracod shells reflect habitat-dependent ranges. The similarly high range of ostracod δ 18 O in rivers and one marsh sample indicates that both temperature and δ 18 O prec are responsible for their variation in the whole study area. Rivers and canals, which are predominantly influenced by the input and mixing of inorganic carbon from the catchment, show smaller δ 13 C ostr ranges than the marsh dominated by local fluctuations in biological activities.Based on these observations, background data of water temperatures and δ 18 O prec were used to calculate monthly δ 18 O variations in a theoretical calcite formed in rivers in Florida assuming a direct reaction on precipitation changes.The calculated values showed a high variation coupled with low mean values during the summer wet season, while during the winter dry season the variation remains small and mean values increased. Inferred configurations were used to approximate possible calcification periods of C. ilosvayi. For a plausible calcification period, mean values and ranges of δ 18 O ostr had to be equal to the theoretical calcite with a slight positive offset (vital effect). The applied model suggests a seasonal calcification period of C. ilosvayi in early spring that is probably coupled to the hydrologic cycle of Florida.

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Section: Calculation Of Calcification Periodsmentioning

confidence: 99%

Section: Reconstruction Of C Ilosvayi Calcification Timesmentioning

confidence: 99%

Modeling calcification periods of <i>Cytheridella ilosvayi</i> from Florida based on isotopic signatures and hydrological data

Meyer

Wrozyna

Leis³

et al. 2017

Biogeosciences

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“…Paleoclimate reconstructions from tropical and subtropical areas have ascribed two distinct hydrologic periods to HS1, which give the event a twofold structure [Broecker et al, 2009;Escobar et al, 2012;Dupont et al, 2010;Zhang et al, 2014]. However, some climate fluctuations observed in tropical climate at the time of HS1 are not fully understood.…”

Section: Introductionmentioning

confidence: 99%

“…[Wang et al, 2001;Zhang et al, 2014]. Furthermore, over the Central American and African monsoon domains [Escobar et al, 2012;Stager et al, 2011] paleoprecipitation reconstructions suggest a double-plunge structure during HS1, with severe droughts peaking at~17 and 16 kyr B.P.. Yet despite the increased number of studies that report abrupt changes in summer monsoon regimes in both hemispheres [Cheng et al, 2012;Chiessi et al, 2009;Dupont et al, 2010], the timing and structure of HS1 over the South American Monsoon System (SAMS) domain are still poorly documented.…”

Section: Introductionmentioning

confidence: 99%

Timing and structure of Mega‐SACZ events during Heinrich Stadial 1

Stríkis

Chiessi

Cruz

et al. 2015

Geophysical Research Letters

115

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A substantial strengthening of the South American monsoon system (SAMS) during Heinrich Stadials (HS) points toward decreased cross‐equatorial heat transport as the main driver of monsoonal hydroclimate variability at millennial time scales. In order to better constrain the exact timing and internal structure of HS1 over tropical South America, we assessed two precisely dated speleothem records from central‐eastern and northeastern Brazil in combination with two marine records of terrestrial organic and inorganic matter input into the western equatorial Atlantic. During HS1, we recognize at least two events of widespread intensification of the SAMS across the entire region influenced by the South Atlantic Convergence Zone (SACZ) at 16.11–14.69 kyr B.P. and 18.1–16.66 kyr B.P. (labeled as HS1a and HS1c, respectively), separated by a dry excursion from 16.66 to 16.11 kyr B.P. (HS1b). In view of the spatial structure of precipitation anomalies, the widespread increase of monsoon precipitation over the SACZ domain was termed “Mega‐SACZ.”

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“…By contrast, at the same time, the discharge of river-borne debris into the Caribbean's Cariaco Basin increased (Fig. 1), and Central America became considerably wetter (17), both attesting to the northward shift of the Amazonian rain belt (18).…”

mentioning

confidence: 98%

Hydrologic impacts of past shifts of Earth’s thermal equator offer insight into those to be produced by fossil fuel CO ₂

Broecker

Putnam

2013

Proc. Natl. Acad. Sci. U.S.A.

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Major changes in global rainfall patterns accompanied a northward shift of Earth’s thermal equator at the onset of an abrupt climate change 14.6 kya. This northward pull of Earth’s wind and rain belts stemmed from disintegration of North Atlantic winter sea ice cover, which steepened the interhemispheric meridional temperature gradient. A southward migration of Earth’s thermal equator may have accompanied the more recent Medieval Warm to Little Ice Age climate transition in the Northern Hemisphere. As fossil fuel CO 2 warms the planet, the continents of the Northern Hemisphere are expected to warm faster than the Southern Hemisphere oceans. Therefore, we predict that a northward shift of Earth’s thermal equator, initiated by an increased interhemispheric temperature contrast, may well produce hydrologic changes similar to those that occurred during past Northern Hemisphere warm periods. If so, the American West, the Middle East, and southern Amazonia will become drier, and monsoonal Asia, Venezuela, and equatorial Africa will become wetter. Additional paleoclimate data should be acquired and model simulations should be conducted to evaluate the reliability of this analog.

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A ∼43-ka record of paleoenvironmental change in the Central American lowlands inferred from stable isotopes of lacustrine ostracods

Cited by 91 publications

References 82 publications

Modeling calcification periods of <i>Cytheridella ilosvayi</i> from Florida based on isotopic signatures and hydrological data

Modeling calcification periods of <i>Cytheridella ilosvayi</i> from Florida based on isotopic signatures and hydrological data

Timing and structure of Mega‐SACZ events during Heinrich Stadial 1

Hydrologic impacts of past shifts of Earth’s thermal equator offer insight into those to be produced by fossil fuel CO ₂

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A ∼43-ka record of paleoenvironmental change in the Central American lowlands inferred from stable isotopes of lacustrine ostracods

Cited by 91 publications

References 82 publications

Modeling calcification periods of &lt;i&gt;Cytheridella ilosvayi&lt;/i&gt; from Florida based on isotopic signatures and hydrological data

Modeling calcification periods of &lt;i&gt;Cytheridella ilosvayi&lt;/i&gt; from Florida based on isotopic signatures and hydrological data

Timing and structure of Mega‐SACZ events during Heinrich Stadial 1

Hydrologic impacts of past shifts of Earth’s thermal equator offer insight into those to be produced by fossil fuel CO 2

Contact Info

Product

Resources

About

Modeling calcification periods of <i>Cytheridella ilosvayi</i> from Florida based on isotopic signatures and hydrological data

Modeling calcification periods of <i>Cytheridella ilosvayi</i> from Florida based on isotopic signatures and hydrological data

Hydrologic impacts of past shifts of Earth’s thermal equator offer insight into those to be produced by fossil fuel CO ₂