The Last 41.000 Years Fluctuation in Atmosperic CO2 Concentration Inferred From the Changes in Oxygen and Carbon Stable Isotopes Ratios of the Marine Sediment

The past atmospheric CO2 concentrations were reconstructed based on the results of measurements of stable oxygen and carbon isotopic ratios of fossil foraminifer and total organic carbon contained in marine sediment taken from the Okinawa Trough, East China Sea. In this study, we utilized two models of Popp et al and Rau et al. for the reconstruction. The results show that the whole trends of the changes in CO2 concentrations are very similar, even when it is compared to the atmospheric CO2 concentration of air trapped in ice core from southern pole. Changes in atmospheric CO2 concentrations are interpreted as a consequence of fluctuation in ocean surface water utilization of CO2 by marine organism and those are closely related to glacial-interglacial (cold-warm) fluctuations between maximum and minimum values through most Quaternary. Rekonstruksi terhadap Perubahan konsentrasi CO2 yang terkandung dalam udara telah dilakukan berdasarkan hasil pengukuran rasio isotop stabil oksigen dan karbon dalam fosil foraminifera dan total karbon organik yang terkandung dalam sedimen dasar laut dari Okinawa Trough, Laut Cina Timur. Dalam studi ini, dipakai model dari Popp et al. dan Rau et al. untuk rekonstruksi. Hasil studi menunjukkan bahwa kedua tren dari Perubahan kandungan CO2 udara sangat mirip, bahkan bila dibandingkan dengan kandungan CO2 udara yang terperangkap dalam inti es di Kutup Selatan sekalipun. Perubahan kandungan CO2 udara diinterpretrasikan sebagai akibat fluktuasi konsumsi CO2 di permukaan air laut oleh mikro-organisme yang juga sangat erat hubungannya dengan fluktuasi glasial-interglasial (dingin-panas) antara suhu udara bumi maksimum dan minimum sepanjang masa Kuarter

The Last 41.000 Years Fluctuation in Atmosperic CO2 Concentration Inferred from The Changes in Oxygen and Carbon Stable Isotopes Ratios of The Marine Sediment

The past atmospheric CO2 concentrations were reconstructed based on the results of measurements of stable oxygen and carbon isotopic ratios of fossil foraminifer and total organic carbon contained in marine sediment taken from the Okinawa Trough, East China Sea. In this study, we utilized two models of Popp et al and Rau et al. for the reconstruction. The results show that the whole trends of the changes in CO2 concentrations are very similar, even when it is compared to the atmospheric CO2 concentration of air trapped in ice core from southern pole. Changes in atmospheric CO2 concentrations are interpreted as a consequence of fluctuation in ocean surface water utilization of CO2 by marine organism and those are closely related to glacial-interglacial (cold-warm) fluctuations between maximum and minimum values through most Quaternary. Rekonstruksi terhadap perubahan konsentrasi CO2 yang terkandung dalam udara telah dilakukan berdasarkan hasil pengukuran rasio isotop stabil oksigen dan karbon dalam fosil foraminifera dan total karbon organik yang terkandung dalam sedimen dasar laut dari Okinawa Trough, Laut Cina Timur. Dalam studi ini, dipakai model dari Popp et al. dan Rau et al. untuk rekonstruksi. Hasil studi menunjukkan bahwa kedua tren dari perubahan kandungan CO2 udara sangat mirip, bahkan bila dibandingkan dengan kandungan CO2 udara yang terperangkap dalam inti es di Kutup Selatan sekalipun. Perubahan kandungan CO2 udara diinterpretrasikan sebagai akibat fluktuasi konsumsi CO2 di permukaan air laut oleh mikro-organisme yang juga sangat erat hubungannya dengan fluktuasi glasial-interglasial (dingin-panas) antara suhu udara bumi maksimum dan minimum sepanjang masa Kuarter

Preservation in 70% ethanol solution does not affect δ13C and δ15N values of reindeer blood samples – relevance for stable isotope studies of diet

We compared duplicate samples of whole blood samples from 18 reindeer that were preserved either by immediate freezing or by immersion in 70 % ethanol. All samples were dried at 60 °C, powdered, treated with 1:1 chloroform: methanol, and dried again before isotope analysis. There were no differences in the values of δ13C and δ15N between the methods of preservation. Isotopic differences were absolutely small (δ13C = 0.1±0.10/00; δ15N=0.2±0.20/00), random in direction, and within the limits of analytical precision for the mass spectrometer. Preservation in ethanol thus appears to be an effective and efficient method for preserving blood samples for stable isotope analysis under field conditions. Abstract in Norwegian / Sammendrag:Konservering av blodprøver fra rein i 70% etanolløsning påvirker ikke verdiene av δ13C and δ15N–verdiene og er en fullgod metode for analyse av stabile isotoperVi sammenlignet to og to prøver av blodprøver fra 18 reinsdyr. Prøvene var enten konservert ved umiddelbar frysing eller ved bruk av 70% etanol. Alle prøver ble tørket ved 60 °C, pulverisert og behandlet med kloroform:metanol i forholdet 1:1. Til slutt ble de tørket på nytt før gjennomføring av isotopanalysen. Vi fant ingen forskjell i verdiene av δ13C and δ15N mellom de to konserveringsmetodene. I absolutte verdier var isotopforskjellene små (δ13C = 0.1±0.1 0/00; δ15N=0.2±0.2 0/00). Forskjellene var tilfeldige og innenfor grensene for massespektrometerets presisjon. Bruk av etanol framstår som en effektiv og fullgod metode til konservering av blodprøver for analyse av stabile isotoper under feltforhold

Pretreatment of coral aragonite for Mg and Sr analysis: Implications for coral thermometers

Trace elements (e.g., Sr, Mg, and U) in coral skeletons are widely used as a potential robust paleothermometers. However, there is little consensus among workers on the chemical pretreatment of skeletal samples, which contain small amounts of organic material and inorganic detritus enriched in many metals compared to the skeleton. We tested the analytical effects of chemical treatment on coral aragonite by comparing several chemical treatments for Mg/Ca and Sr/Ca ratios as well as oxygen and carbon isotopic ratios. Our results suggested that the Sr/Ca ratio and stable isotopic ratios are resistant to chemical treatments. However, organic matter or crystal surfaces in corals could absorb more than 40% of magnesium although 60% of magnesium in coral aragonite substitutes for calcium. Our results suggest that it is expedient to remove impurities by the method outlined here, especially before determining Mg/Ca ratios in corals for paleoenvironmental reconstruction

Spatial and temporal sea-surface temperatures in the eastern equatorial Pacific over the past 150 kyr

We present the new alkenone-based sea-surface temperature (SST) records from the eastern equatorial Pacific over the past 150 kyr. Core HY04 (4°N) at the North Equatorial Countercurrent (NECC) registered the invariant SSTs (25.8–27.2°C), whereas core HY06 (0°N) registered cyclic glacial-interglacial SST variations (22.4–26.1°C). Although HY06 alkenone-based SST evolution was almost consistent with the previously published SST records from around the equator, at site HY04 alkenone- and foraminiferal Mg/Ca-based SSTs showed a large difference in the magnitude of LGM SST cooling. We hypothesize that alkenone-based SSTs might not fully express the true magnitude of glacial SST cooling in the NECC, as suggested by the coincidence of higher glacial productivity and unchanged glacial SSTs at site HY04. However, further SST data in the NECC are needed before this can be accepted with any degree of confidence

Biomarker flux in surface sediments corrected from 230Th flux in the middle latitude of North Pacific

13th Annual V. M. Goldschmidt Conferenc