Stable oxygen isotope record and Sr/Ca ratios of corals from IODP Holes M0009D and M0023A

We present monthly resolved records of strontium/calcium (Sr/Ca) and oxygen isotope (d18O) ratios from well-preserved fossil corals drilled during the Integrated Ocean Drilling Program (IODP) Expedition 310 'Tahiti Sea Level' and reconstruct sea surface conditions in the central tropical South Pacific Ocean during two time windows of the last deglaciation. The two Tahiti corals examined here are uranium/thorium (U/Th)-dated at 12.4 and 14.2 ka, which correspond to the Younger Dryas (YD) cold reversal and the Bølling-Allerød (B-A) warming of the Northern Hemisphere, respectively. The coral Sr/Ca records indicate that annual average sea surface temperature (SST) was 2.6-3.1 °C lower at 12.4 ka and 1.0-1.6 °C lower at 14.2 ka relative to the present, with no significant changes in the amplitude of the seasonal SST cycle. These cooler conditions were accompanied by seawater d18O (d18Osw) values higher by ~0.8 per mill and ~0.6 per mill relative to the present at 12.4 and 14.2 ka, respectively, implying more saline conditions in the surface waters. Along with previously published coral Sr/Ca records from the island [Cohen and Hart (2004), Deglacial sea surface temperatures of the western tropical Pacific: A new look at old coral. Paleoceanography 19, PA4031, doi:10.1029/2004PA001084], our new Tahiti coral records suggest that a shift toward lower SST by ~1.5 °C occurred from 13.1 to 12.4 ka, which was probably associated with a shift toward higher d18Osw by ~0.2 per mill. Along with a previously published coral Sr/Ca record from Vanuatu [Corrège et al. (2004), Interdecadal variation in the extent of South Pacific tropical waters during the Younger Dyras event. Nature 428, 927-929], the Tahiti coral records provide new evidence for a pronounced cooling of the western to central tropical South Pacific during the Northern Hemisphere YD event.

Monthly Tahiti coral Sr/Ca and oxygen isotope data from IODP Hole 310-M0024A

The early last glacial termination was characterized by intense North Atlantic cooling and weak overturning circulation. This interval between ~18,000 and 14,600 years ago, known as Heinrich Stadial 1, was accompanied by a disruption of global climate and has been suggested as a key factor for the termination. However, the response of interannual climate variability in the tropical Pacific (El Niño-Southern Oscillation) to Heinrich Stadial 1 is poorly understood. Here we use Sr/Ca in a fossil Tahiti coral to reconstruct tropical South Pacific sea surface temperature around 15,000 years ago at monthly resolution. Unlike today, interannual South Pacific sea surface temperature variability at typical El Niño-Southern Oscillation periods was pronounced at Tahiti. Our results indicate that the El Niño-Southern Oscillation was active during Heinrich Stadial 1, consistent with climate model simulations of enhanced El Niño-Southern Oscillation variability at that time. Furthermore, a greater El Niño-Southern Oscillation influence in the South Pacific during Heinrich Stadial 1 is suggested, resulting from a southward expansion or shift of El Niño-Southern Oscillation sea surface temperature anomalies.

Element ratio (Sr/Ca, Ba/Ca, B/Ca, and Mg/Ca) profiles throughout the larval life stage of Mytilus edulis, 2011

Rising anthropogenic CO2 in the surface ocean has raised serious concerns for the ability of calcifying organisms to secrete their shells and skeletons. Previous mollusc carbonate perturbation experiments report deleterious effects at lowered pH (7.8-7.4 pH units), including reduced shell length and thickness and deformed shell morphology. It is not clear whether the reduced shell growth results from a decrease in calcification rate due to lowered aragonite saturation or from an indirect effect on mollusc metabolism. We take a novel approach to discerning between these two processes by examining the impact of lowered pH on the 'vital-effect' associated with element ratios. Reported herein are the first element ratio (Sr/Ca, Ba/Ca, B/Ca, Mg/Ca and Mn/Ca) profiles throughout the larval life stage of Mytilus edulis. Element ratio data for individuals reared in ambient conditions provide new insights into biomineralization during larval development. Sr/Ca ratios are consistent with Sr incorporation in the mineral phase. Mg and Mn are likely hosted in an organic phase. The Ba partition coefficient of early larval shells is one of the highest reported in biogenic aragonite. The reason for the high Ba concentrations is unknown, but may reflect the assimilation of Ba from food and/or Ba concentration in an organic or amorphous carbonate phase. There is no observable difference in the way the studied elements are incorporated into the shells of individuals reared in ambient and lowered pH conditions. The reduced growth rate at lower pH may be a consequence of a disruption to the larval mollusc metabolism.

The influence of seawater pH on U/ Ca ratios in the scleractinian cold-water coral Lophelia pertusa

The increasing pCO2 in seawater is a serious threat for marine calcifiers and alters the biogeochemistry of the ocean. Therefore, the reconstruction of past-seawater properties and their impact on marine ecosystems is an important way to investigate the underlying mechanisms and to better constrain the effects of possible changes in the future ocean. Cold-water coral (CWC) ecosystems are biodiversity hotspots. Living close to aragonite undersaturation, these corals serve as living laboratories as well as archives to reconstruct the boundary conditions of their calcification under the carbonate system of the ocean. We investigated the reef-building CWC Lophelia pertusa as a recorder of intermediate ocean seawater pH. This species-specific field calibration is based on a unique sample set of live in situ collected L. pertusa and corresponding seawater samples. These data demonstrate that uranium speciation and skeletal incorporation for azooxanthellate scleractinian CWCs is pH dependent and can be reconstructed with an uncertainty of ±0.15. Our Lophelia U / Ca-pH calibration appears to be controlled by the high pH values and thus highlighting the need for future coral and seawater sampling to refine this relationship. However, this study recommends L. pertusa as a new archive for the reconstruction of intermediate water mass pH and hence may help to constrain tipping points for ecosystem dynamics and evolutionary characteristics in a changing ocean.

Scandanavia, ca. 1690 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: La Scandinavie où sont les royaumes de Suede, Danemark et Norwege, presenté ... par ... H. Iaillot. It was published by chez Pierre Mortier ca. 1690. Scale [ca 1:4,000,000]. Covers Scandinavia including Norway, Sweden, Finland, Estonia, Latvia, and portions of Denmark, Lithuania, Belarus, and Russia. Map in French.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Europe Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, roads, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown pictorially.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Quebec, Canada, ca. 1690 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Plan de Quebec en la nouvelle France assiegé par les Anglois : le 16 d'octobre 1690, jusqu'au 22 dudit mois qu'ils furent obligés de se retirer chez eux apprés avoir ésté bien battus, par mr. le comte de Frontenac, gouverneur general du pays, par le Sr. de Villeneuve, ingénieur du Roy. Scale [ca. 1:16,000]. Map in French. Manuscript copy of a manuscript map. Copied by Pierre-Louis Morin, ca. 1855? Made in Paris for Francis Parkman. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator (UTM) Zone 19N NAD 1983 coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, selected buildings with names of landowners, fortification, English ships and lines-of-fire, ground cover, and more. Relief is shown by hachures. Includes index. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

Arabian Peninsula, ca. 1747-1767 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Carte de la coste d'Arabie, Mer Rouge et Golfe de Perse : tir�e de la Carte de l'Oc�an Oriental publi�e en 1740 par Ordre de Mgr le Comte de Maurepas augment�e sur des remarques particuli�res et dress�e sur des observations astronomiques = Kaart van de Kust van Arabi�, de Roode-Zee en de Gulf van Persi� Gemaakt na de Fransse-Kaart van den Ooster-Ocean uitgegeven A. 1740 op Bevel van den Hre Grave de Maurepas Vermeederd op byzondere Aanmerkingen, en geschikt volgens Sterrekundige-Waarnemingen, J. V. Schley. It was published by Pierre de Hondt between 1747 and 1767. Scale [ca. 1:14,000,000]. Covers the Arabian Peninsula. Map in French and Dutch. The image inside the map neatline is georeferenced to the surface of the earth and fit to the World Gall Stereographic projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, shoreline features, and more. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection as part of the Open Collections Program at Harvard University project: Islamic Heritage Project. Maps selected for the project represent a range of regions, originators, ground condition dates, scales, and purposes. The Islamic Heritage Project consists of over 100,000 digitized pages from Harvard's collections of Islamic manuscripts and published materials. Supported by Prince Alwaleed Bin Talal and developed in association with the Prince Alwaleed Bin Talal Islamic Studies Program at Harvard University.

Paris, France, ca. 4th Century (Time Series Map 1 of 8) (Raster Image)

This layer is a georeferenced raster image from the historic paper map series entitled: Lutece ... plan de la ville de Paris ..., par M.L.C.D.L.M. ; A. Coquart, delineavit et sculp. It was published by Jean & Pierre Cot in 1705. Scale [ca. 1:10,000]. This image is of map 1 entitled: Lutece, ou, premier plan de la ville de Paris: tiré de Cesar, de Strabon, de l'empereur Iulien, et d'Ammian Marcellin. The map represents Paris ca. 4th Century. Map in French.The image inside the map neatline is georeferenced to the surface of the earth and fit to the European Datum 1950, Universal Transverse Mercator (UTM) Zone 31N projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, towns and villages, roads, selected buildings, ground cover, and more. Relief shown by hachures. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.