Recursos de colección

PANGAEA - Publishing Network for Geoscientific & Environmental Data (830.700 recursos)

The information system PANGAEA is operated as an Open Access library aimed at archiving, publishing and distributing georeferenced data from earth system research. The system guarantees long-term availability of its content through a commitment of the operating institutions.

PANGAEA tech-keyword 'supplement' (10352 data sets)

Mostrando recursos 1 - 20 de 11.871

  1. An ocean acidification acclimatised green tide alga is robust to changes of seawater carbon chemistry but vulnerable to light stress

    Gao, Guang; Liu, Yameng; Li, Xinshu; Feng, Zhihua; Xu, Juntian; Lin, Y S
    Ulva is the dominant genus in the green tide events and is considered to have efficient CO2 concentrating mechanisms (CCMs). However, little is understood regarding the impacts of ocean acidification on the CCMs of Ulva and the consequences of thalli's acclimation to ocean acidification in terms of responding to environmental factors. Here, we grew a cosmopolitan green alga, Ulva linza at ambient (LC) and elevated (HC) CO2 levels and investigated the alteration of CCMs in U. linza grown at HC and its responses to the changed seawater carbon chemistry and light intensity. The inhibitors experiment for photosynthetic inorganic carbon utilization...

  2. Two Southern Ocean diatoms are more sensitive to ocean acidification and changes in irradiance than the prymnesiophyte Phaeocystis antarctica

    Trimborn, Scarlett; Thoms, Silke; Brenneis, Tina; Heiden, Jasmin; Beszteri, Sara; Bischof, Kai
    To better understand the impact of ocean acidification (OA) and changes in light availability on Southern Ocean phytoplankton physiology, we investigated the effects of pCO2 (380 and 800 µatm) in combination with low and high irradiance (20 or 50 and 200 µmol photons/m2/s) on growth, particulate organic carbon (POC) fixation and photophysiology in the three ecologically relevant species Chaetoceros debilis, Fragilariopsis kerguelensis and Phaeocystis antarctica. Irrespective of the light scenario, neither growth nor POC per cell was stimulated by OA in any of the tested species and the two diatoms even displayed negative responses in growth (e.g. C. debilis) or...

  3. Functional analysis of a tyrosinase gene involved in early larval shell biogenesis in Crassostrea angulata and its response to ocean acidification

    Yang, Bingye; Pu, F; Li, lingling; You, W; Ke, C; Feng, Danqing
    The formation of the primary shell is a vital process in marine bivalves. Ocean acidification largely influences shell formation. It has been reported that enzymes involved in phenol oxidation, such as tyrosinase and phenoloxidases, participate in the formation of the periostracum. In the present study, we cloned a tyrosinase gene from Crassostrea angulata named Ca-tyrA1, and its potential function in early larval shell biogenesis was investigated. The Ca-tyrA1 gene has a full-length cDNA of 2430 bp in size, with an open reading frame of 1896 bp in size, which encodes a 631-amino acid protein that includes a 24-amino acid putative...

  4. Onshore and offshore apatite fission-track dating from the southern Gulf of California

    Balestrieri, Maria Laura; Ferrari, Luca; Bonini, Marco; Duque-Trujillo, Jose; Cerca, Mariano; Moratti, Giovanna; Corti, Giacomo
    We present the results of an apatite fission-track (AFT) study on intrusive rocks in the southern Gulf of California, sampled along the eastern margin of Baja California Sur (western rift margin), as well as from islands and submerged rifted blocks within the Gulf of California, and from the conjugate Mexican margin (Nayarit state). For most of the samples U-Pb zircon and 40Ar-39Ar mineral ages were already available (Duque-Trujillo et al., 2015). Coupled with the new AFT data these ages provide a more complete information on cooling after emplacement. Our samples span a wide range of ages between 5.5±1.1 and 73.7±5.8...

  5. Tropical SSTs over the past 3.5 million years

    Herbert, Timothy D; Cleaveland Peterson, Laura; Lawrence, Kira T; Liu, Zhonghui
    Determining the timing and amplitude of tropical sea surface temperature (SST) change is an important part of solving the puzzle of the Plio-Pleistocene ice ages. Alkenone-based tropical SST records from the major ocean basins show coherent glacial-interglacial temperature changes of 1° to 3°C that align with (but slightly lead) global changes in ice volume and deep ocean temperature over the past 3.5 million years. Tropical temperatures became tightly coupled with benthic d18O and orbital forcing after 2.7 million years. We interpret the similarity of tropical SST changes, in dynamically dissimilar regions, to reflect "top-down" forcing through the atmosphere. The inception...

  6. Age models and bulk organic isotope geochemistry from Lake Superior sediment cores

    O'Beirne, Molly D; Werne, Josef P; Hecky, Robert E; Johnson, Thomas C; Katsev, Sergei; Reavie, Euan D
    The data contained herein are from eight sediment multicores and three piston sediment cores with accompanying gravity/trigger sediment cores spanning the Lake Superior basin. The multicores were sampled at high resolution encompassing the most recent ca. 200 years and the gravity-piston sediment cores are coarser resolution (ca. every 100 years) and date to ca. 10,000 years cal BP.

  7. Decadal resolution record of sediment core M74/1b_944-6 (SL 163)

    Munz, Philipp; Steinke, Stephan; Böll, Anna; Lückge, Andreas; Groeneveld, Jeroen; Kucera, Michal; Schulz, Hartmut
    The Indian summer monsoon (ISM) is an important conveyor in the ocean-atmosphere coupled system on a transregional scale. Here we present a study of a sediment core from the northern Oman margin, revealing early- to mid Holocene ISM conditions on a near 20-year resolution. We assess multiple independent proxies indicative of sea surface temperatures (SST) during the upwelling season together with bottom water conditions. We use geochemical parameters, transfer functions of planktic foraminiferal assemblages and Mg/Ca paleothermometry and find evidence corroborating previous studies that upwelling intensity varies significantly in coherence to solar sunspot cycles. The dominant ~80-90-year Gleissberg cycle was...

  8. Annotated record of the detailed examination of Mn deposits from the Madcap Volcano in the Madeira-Cape Verde Abyssal plain

    Jones, E J W; Laughton, Anthony S; Hill, M N; Davies, D
    The results are discussed of a geophysical survey undertaken by R.R.S. Discovery II early in 1962 in an area centred on 29° 15'N, 25° 5'W at the western extremity of the Madeira-Cape Verde Abyssal Plain. Seismic investigations show that the sediments are underlain by an intermediate layer about 2 km in thickness of velocity 4·1-5·4 km/sec which overlies a deep layer 5·2-km thick of velocity 6·3-6·8 km/sec. Refracted arrivals on the longest seismic line give a depth of 13·2 km to the M discontinuity. Magnetic results indicate that the topography of the abyssal hills in the western part of the area...

  9. Large-scale ocean connectivity and planktonic body size

    Villarino, Ernesto; Watson, James R; Jönsson, Bror; Gasol, Josep M; Salazar, Guilhem; Acinas, Silvia G; Estrada, Marta; Massana, Ramon; Logares, Ramiro; Giner, Caterina R; Pernice, Massimo C; Olivar, M Pilar; Citores, Leire; Corell, Jon; Rodriguez-Ezpeleta, Naiara; Acuna, José Luis; Molina, Axayacatl; Gonzalez-Gordillo, Ignacio; Cozar, Andrés; Martí, Elisa; Cuesta, Jose A; Agusti, Susana; Fraile-Nuez, Eugenio; Duarte, Carlos M; Irigoien, Xabier; Chust, Guillem
    Global patterns of planktonic species diversity are in large part determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size plays in determining spatial patterns of diversity remains unclear. Here, we quantified the dispersal scale and community structure - ?-diversity - for several planktonic and micro-nektonic organisms spanning a large range of body sizes, from prokaryotes to small mesopelagic fishes, collected during the Malaspina 2010 Circumnavigation Expedition. Global patterns of ?-diversity for these communities were then compared to surface ocean transit times, derived from a global circulation model. Our results reveal that ?-diversity...

  10. Reconstructed Pacific Decadal Oscillation versus Cape Bounty East Lake varve thickness

    Lapointe, François; Francus, Pierre; Lamoureux, Scott; Vuille, Mathias; Jenny, Jean-Philippe; Bradley, Raymond S; Massa, Charly
    Understanding how internal climate variability influences arctic regions is required to better forecast fu- ture global climate variations. This paper investigates an annually-laminated (varved) record from the western Canadian Arctic and finds that the varves are negatively corre- lated with both the instrumental Pacific Decadal Oscillation (PDO) during the past century and also with reconstructed PDO over the past 700 years, suggesting drier Arctic con- ditions during high-PDO phases, and vice versa. These results are in agreement with known regional teleconnections, whereby the PDO is negatively and positively correlated with summer precipitation and mean sea level pressure respec- tively. This...

  11. Soil and water chemistry and mobilization rates for phosphate, dissolved organic matter and methane from soil cores of rewetted peatlands in northeast Germany

    Zak, Dominik; Goldhammer, Tobias; Cabezas, Alvaro; Gelbrecht, Jörg; Gurke, Robert; Wagner, Carola; Reuter, Hendrik; Augustin, Jürgen; Klimkowska, Agata; McInnes, Robert
    Long-term drainage and intensive agricultural use of peatlands make it unlikely that the original sink functions for nutrients and carbon as well as low-nutrient conditions can be re-established within a human time perspective. The data presented here consists of i) soil characteristics, ii) water quality, and iii) mobilization rates for phosphate, dissolved organic matter and methane from soil cores of altogether 12 rewetted inundated peatlands. In addition we included data from a rewetted non-inundated peatland ("Lehstseemoor"). All studied sites are representative of calcareous rich, i.e. groundwater charged peatlands (= fens) found in the lowlands of NE Germany, as well as...

  12. Annotated record of the detailed examination of Mn deposits from the Hirondelle Seamount, Eastern Equatorial Atlantic

    Jones, E J W; BouDagher-Fadel, M K; Thirlwall, Matthew F
    Phosphorites with P2O5 contents up to 33% have been recovered from the eastern Atlantic between 6°N and 9°N. Formed from the replacement of shallow-water reef limestones of Middle Eocene age, the deposits are exposed on the crests of three subsided seamounts, Lighthill, Hirondelle and Carter, at depths of 794-1246, 1161-1176 and 552-1158 m, respectively. Phosphates exposed on the sea floor are associated with high levels of acoustic backscatter recorded using a ship's echo-sounder and a 10-kHz pinger towed ?30 m above the bottom. Seabed scintillometer measurements on Carter Seamount near 9°N, 21°W revealed high ?-ray emission where phosphorites are known...

  13. Analysis of Manganese deposits from the South China Sea

    Zhang, Z G; Du, Y S; Wu, C H; Fang, N Q; Yang, S X; Liu, J; Song, C B
    In the northern South China Sea, the accumulation of enormous quantities of terrigenous sediment during Cenozoic rendered well-developed polymetallic nodules very rare. In this study, we analyzed a polymetallic nodule from the northwestern continental margin of the South China Sea using microscopic mineralogical observation, electron probes, X-ray diffraction (XRD), ICP-MS, and Be isotope dating. We found the nodule's shell layers rich in different types of microstructures, including columnar, laminar, stack-like, petal-like, and porphyritic structures. The major mineral components of the nodule are MnO2. Unlike nodules from the eastern Pacific basin, this nodule has high contents in Fe, Si, Al, and...

  14. Field and simulation data for larches growing in the Taimyr treeline ecotone

    Wieczorek, Mareike; Kruse, Stefan; Epp, Laura Saskia; Kolmogorov, Alexei; Nikolaev, Anatoly N; Heinrich, Ingo; Jeltsch, Florian; Pestryakova, Ludmila A; Zibulski, Romy; Herzschuh, Ulrike
    Arctic and alpine treelines worldwide differ in their reactions to climate change. A northward advance of or densification within the treeline ecotone will likely influence climate-vegetation feedback mechanisms. We present a combined field- and model-based approach to better understand the population processes involved in the responses of the whole treeline ecotone, spanning from closed forest to single-tree tundra, to climate warming. Using information on stand structure, tree age, and seed quality and quantity from seven sites, we investigate effects of intra-specific competition and seed availability on the specific impact of recent climate warming on larch stands. Field data show that...

  15. Mean TerraSAR-X backscatter and in-situ measurements of near surface soil moisture and temperature including vegetation survey in August 2015 on central Yamal (Vaskiny Dachi CALM site)

    Widhalm, Barbara; Bartsch, Annett; Leibman, Marina O; Khomutov, Artem V
    The active layer above the permafrost, which seasonally thaws during summer, is an important parameter for monitoring the state of permafrost. Its thickness is typically measured locally, but a range of methods which utilize information from satellite data exist. Mostly, the normalized difference vegetation index (NDVI) obtained from optical satellite data is used as a proxy. The applicability has been demonstrated mostly for shallow depths of active-layer thickness (ALT) below approximately 70 cm. Some permafrost areas including central Yamal are, however, characterized by larger ALT. Surface properties including vegetation structure are also represented by microwave backscatter intensity. So far, the...

  16. An inventory of active rock glaciers in the northern Tien Shan of China compiled using satellite SAR interferometry

    Wang, Xiaowen; Liu, Lin; Zhao, Lin; Wu, Tonghua; Li, Zhongqin; Liu, Guoxiang
    Rock glaciers are widespread in the Tien Shan. However, rock glaciers in the Chinese part of the Tien Shan have not been systematically investigated for more than two decades. In this study, we propose a new method that combines SAR interferometry and optical images from Google Earth to map active rock glaciers (ARGs) in the Northern Tien Shan (NTS) of China. We compiled an inventory that includes 261 ARGs and quantitative information about their locations, geomorphic parameters, and down-slope velocities. Our inventory shows that most of the ARGs are moraine-derived (69 %) and facing northeast (56 %). The altitude distribution...

  17. Recent changes in glacier mass balance and equilibrium line altitude and the impact of climatic change on King George Island, Antarctic Peninsula

    Falk, Ulrike; López, Damián; Silva-Busso, Adrian A
    The South Shetland Islands are located at the northern tip of the Antarctic Peninsula (AP) which is among the fastest warming regions on Earth. Surface air temperature increases (about 3 K in 50 years) are concurrent with retreating glacier fronts, an increase in melt areas, ice surface lowering and rapid break-up and disintegration of ice shelves. Observed surface air temperature lapse rates show a high variability during winter months (standard deviations up to 1.0 K/100 m), and a distinct spatial heterogeneity reflecting the impact of synoptic weather patterns especially during winter glacial mass accumulation periods. The over the past decades...

  18. Compilation of detailed examination of Mn deposits from the North tip of the Baja peninsula prior to DSDP Leg 64

    Curray, Joseph R; Moore, David G; Kelts, Kerry; Einsele, Gerhard
    he three-site Leg 64 Deep Sea Drilling transect at the tip of the Peninsula of Baja California straddled the transition from continental to oceanic crust. The outer site, 474, penetrated mainly mud turbidites and bottomed in "middle" Pliocene oceanic crust about 3 m.y. old. Two sites on the lower continental slope penetrated hemipelagic muddy sediments, a thin section of low-oxygen, phosphoritic, and glauconitic sediments, and a metamorphic cobble conglomerate; one of the sites, 476, bottomed in deeply weathered granite. The oldest marine sediments at this site are early Pliocene, about 4.5 m.y. old. Depth indicators in these holes suggest that...

  19. (Tables 1-2, page 195) Chemical composition of ferromanganese crusts and associated smectites from the Gulf of Aden

    Cann, Joe R
    Fragments of a hydrothermal deposit, partly moulded on pieces of basalt lava, were dredged from the edge of the median valley in the centre of the Gulf of Aden. The deposit consists of two main components, manganese oxide in the form of spongy brown to hard black lumps and coatings, and friable green massive smectite. There are smaller amounts of an iron-oxide component, and mixed manganese-oxide-smectite material. Contents of the less mobile trace elements in the smectite are too low for it to have formed by alteration of basalt glass, and it is interpreted as a direct precipitate from hydrothermal...

  20. Chemical composition of ferromanganese crusts recovered in the South China Sea during the SO49 Cruise of R/V Sonne

    Bao, G; Li, Q
    Five ferromanganese crusts and 6 ferromanganese nodules samples collected by the Joint Chinese-West Germany Geophysical Investigation Team in May-June, 1987 during the SO49 cruise of the R/V Sonne. They were analyzed for their rare earth element contents by means of X-Ray fluorescent spectrometry. On the basis of study of 15 rare earth elements detected, the relationship among rare earth element concentration, source,, as well as distribution pattern and associated elements was discussed in detail. Results show that 1) The average concentration of rare earth elements in South China Sea ferromanganese crusts and nodules was 1. 625 g/kg and 2. 167...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.