TIMS measurements of full range of natural Ca isotopes with internally consistent fractionation correction

This study presents static measurements of the Ca isotopic composition of standard reference materials SRM 915 a/b on a Triton Plus™ thermal ionization mass spectrometer with a specially developed Faraday cup array allowing simultaneous measurement of 40Ca and 48Ca. The total amount of Ca in all analyses was kept < 1 µg. With this setup the measurement uncertainties were 0.06 ‰ for 40Ca/44Ca and 0.12 ‰ for 48Ca/40Ca. Measuring all isotopes simultaneously better allows to test the internal consistency of different Ca isotope abundances reported in the literature. The exponential law was observed to correct incompletely instrumental mass fractionation. An improved fractionation correction based on the exponential law is proposed. It changes the 40Ca/44Ca ratio of SRM 915a (corrected relative to 42Ca/44Ca = 0.31221; 48Ca/44Ca = 0.08871) from 47.1635 ± 0.0028 to 47.1649 ± 0.0047. The measurements of SRM 915b were performed with different analytical conditions (runs were prolonged till complete filament load depletion). Even if the 40Ca/44Ca ratio of SRM 915b, when corrected with the simple exponential law, appears different (47.1532 ± 0.0038) from that of SRM 915a, it becomes coincident (47.1613 ± 0.0028) when corrected with a second-order refinement. This supports the use of the improved exponential law to obtain internally consistent Ca isotope ratio for natural samples.

Adam und Eva [Illustration] : Ölgemälde, ca. 1530

Jan Gossaert

Freshening of the Alaska Coastal Current Recorded By Coralline Algal Ba/Ca Ratios

Arctic Ocean freshening can exert a controlling influence on global climate, triggering strong feedbacks on ocean-atmospheric processes and affecting the global cycling of the world's oceans. Glacier-fed ocean currents such as the Alaska Coastal Current are important sources of freshwater for the Bering Sea shelf, and may also influence the Arctic Ocean freshwater budget. Instrumental data indicate a multiyear freshening episode of the Alaska Coastal Current in the early 21st century. It is uncertain whether this freshening is part of natural multidecadal climate variability or a unique feature of anthropogenically induced warming. In order to answer this, a better understanding of past variations in the Alaska Coastal Current is needed. However, continuous long-term high-resolution observations of the Alaska Coastal Current have only been available for the last 2 decades. In this study, specimens of the long-lived crustose coralline alga Clathromorphum nereostratum were collected within the pathway of the Alaska Coastal Current and utilized as archives of past temperature and salinity. Results indicate that coralline algal Mg/Ca ratios provide a 60 year record of sea surface temperatures and track changes of the Pacific Decadal Oscillation, a pattern of decadal-to-multidecadal ocean-atmosphere climate variability centered over the North Pacific. Algal Ba/Ca ratios (used as indicators of coastal freshwater runoff) are inversely correlated to instrumentally measured Alaska Coastal Current salinity and record the period of freshening from 2001 to 2006. Similar multiyear freshening events are not evident in the earlier portion of the 60 year Ba/Ca record. This suggests that the 21st century freshening of the Alaska Coastal Current is a unique feature related to increasing glacial melt and precipitation on mainland Alaska.

Beiträge zur Entwicklungsgeschichte des Judentums, von ca. 400 v. Chr. bis ca. 1000 n. Chr.

von D. Chwolson

Josef Kainz als Hamlet, Statue, Denkmal, in: William Shakespeare: Hamlet, Wien: Sternwartepark, ca. 1910

Signatur des Originals: S 36/F04850

Ausstellung "Das Theater im Freien", Frankfurt a. M. - Die Stadt des deutschen Handwerks in Verbindung mit dem Reichsbund der deutschen Freilicht- und Volksschauspiele E. V. : Frederick van Valckenborch (ca. 1570-1623): Trionfo und Bühne. Museum Wallraf-Richartz Köln

Signatur des Originals: S 36/F07994

W. A. Mozart nach dem Originale seines Schwagers Hofschauspieler Lange im Juli 1791 [ca 5 Monate vor Beginn der Zauberflöte]

Signatur des Originals: S 36/F09329

Aloys Altmayer, Brustbild, Profil, ca. 1939

Signatur des Originals: S 36/F10577

Aloys Altmayer, Brustbild, ca. 1939

Signatur des Originals: S 36/F10578

Opernhaus, Frankfurt a. M., ca. 1890

Signatur des Originals: S 36/F10551

{[N.N.], Szenenfoto, Gruppenbildnis, in: Gustav Lazarus: Mandainka, Frankfurt a. M.: Opernhaus, ca. 1901

Signatur des Originals: S 36/F11977

{[N.N.], Szenenfoto, Gruppenbildnis, in: Gustav Lazarus: Mandainka, Frankfurt a. M.: Opernhaus, ca. 1901

Signatur des Originals: S 36/F11978

{[N.N.], Szenenfoto, Gruppenbildnis, in: Pe͏̈tr Il Čajkowskij: Jolanthe, Frankfurt a. M.: Opernhaus, ca. 1901

Signatur des Originals: S 36/F11996

Kaiserlich-Osmanische Palast-Kapelle, Gruppenbildnis, Benefizkonzert zugunsten des Roten Kreuzes, Berlin, ca. 1918

Signatur des Originals: S 36/F12190