Now showing items 1-20 of 210

  • Abiotic ozone and oxygen in atmospheres similar to prebiotic earth 

    Domagal-Goldman, S.D.; Segura, A.; Claire, M.W.; Robinson, T.D.; Meadows, V.S. (2014-09-10) - Journal article
    The search for life on planets outside our solar system will use spectroscopic identification of atmospheric biosignatures. The most robust remotely detectable potential biosignature is considered to be the detection of ...
  • Absence of molybdenum isotope fractionation during magmatic differentiation at Hekla volcano, Iceland 

    Yang, J.; Siebert, C.; Barling, J.; Savage, P.; Liang, Y.-H.; Halliday, A.N. (2015-08-01) - Journal article
    This study investigates the behaviour of molybdenum (Mo) isotopes during magmatic differentiation. Molybdenum isotope compositions, as well as concentrations of rare earth elements and a selection of trace elements, have ...
  • Andean grasslands are as productive as tropical cloud forests 

    Oliveras, I.; Girardin, C.; Doughty, C. E.; Cahuana, N.; Arenas, C. E.; Oliver, V.; Huasco, W. Huaraca; Malhi, Y. (2014-11) - Journal article
    We aim to assess net primary productivity (NPP) and carbon cycling in Andean tropical alpine grasslands (puna) and compare it with NPP of tropical montane cloud forests. We ask the following questions: (1) how do NPP and ...
  • Antarctic sea ice control on ocean circulation in present and glacial climates 

    Ferrari, Raffaele; Jansen, Malte F.; Adkins, Jess F.; Burke, Andrea; Stewart, Andrew L.; Thompson, Andrew F. (2014-06-17) - Journal article
    In the modern climate, the ocean below 2 km is mainly filled by waters sinking into the abyss around Antarctica and in the North Atlantic. Paleoproxies indicate that waters of North Atlantic origin were instead absent below ...
  • Anticlockwise P-T evolution at ∼280 Ma recorded from ultrahigh-temperature metapelitic granulite in the Chinese Altai orogenic belt, a possible link with the Tarim mantle plume? 

    Tong, Laixi; Xu, Yi-Gang; Cawood, Peter A.; Zhou, Xin; Chen, Yibing; Liu, Zhao (2014-11) - Journal article
    An ultrahigh-temperature (UHT) metapelitic granulite assemblage consisting of garnet(g)–spinel(sp)–orthopyroxene(opx)-sillimanite(sil)–cordierite(cd)–ilmenite(ilm)–biotite(bi)–plagioclase(pl)–quartz(q) occurs within ...
  • Apparent OSL ages of modern deposits from Fåbergstølsdalen, Norway : implications for sampling glacial sediments 

    King, Georgina; Robinson, Ruth Alison Joyce; Finch, Adrian Anthony (2013-10-16) - Journal article
    The application of optically stimulated luminescence (OSL) dating within glacial settings can be limited where sediments have not had their OSL signal fully reset by sunlight exposure. Heterogeneous bleaching can result ...
  • Ardnamurchan 3D cone-sheet architecture explained by a single elongate magma chamber 

    Burchardt, Steffi; Troll, Valentin R.; Mathieu, Lucie; Emeleus, Henry C.; Donaldson, Colin Henry (2013-10-08) - Journal article
    The Palaeogene Ardnamurchan central igneous complex, NW Scotland, was a defining place for the development of the classic concepts of cone-sheet and ring-dyke emplacement and has thus fundamentally influenced our thinking ...
  • Are inventory based and remotely sensed above-ground biomass estimates consistent? 

    Hill, Timothy Charles; Williams, Mathew; Bloom, A. Anthony; Mitchard, Edward; Ryan, Casey (2013-09-19) - Journal article
    Carbon emissions resulting from deforestation and forest degradation are poorly known at local, national and global scales. In part, this lack of knowledge results from uncertain above-ground biomass estimates. It is ...
  • Are thermophilic microorganisms active in cold environments? 

    Cockell, Charles S.; Cousins, Claire Rachel; Wilkinson, Paul T.; Olsson-Francis, Karen; Rozitis, Ben (2015-07) - Journal article
    The mean air temperature of the Icelandic interior is below 10 °C. However, we have previously observed 16S rDNA sequences associated with thermophilic lineages in Icelandic basalts. Measurements of the temperatures of ...
  • Assembly of the Lhasa and Qiangtang terranes in central Tibet by divergent double subduction 

    Zhu, Di-Cheng; Li, Shi-Min; Cawood, Peter A.; Wang, Qing; Zhao, Zhi-Dan; Liu, Sheng-Ao; Wang, Li-Quan (2015) - Journal article
    Integration of lithostratigraphic, magmatic, and metamorphic data from the Lhasa-Qiangtang collision zone in central Tibet (including the Bangong suture zone and adjacent regions of the Lhasa and Qiangtang terranes) indicates ...
  • The Astrobiology Primer v2.0 

    Domagal-Goldman, Shawn D.; Wright, Katherine E.; Adamala, Katarzyna; De La Rubia, Leigh Arina; Bond, Jade; Dartnell, Lewis R.; Goldman, Aaron D.; Lynch, Kennda; Naud, Marie Eve; Paulino-Lima, Ivan G.; Singer, Kelsi; Walter-Antonio, Marina; Abrevaya, Ximena C.; Anderson, Rika; Arney, Giada; Atri, Dimitra; Azuá-Bustos, Armando; Bowman, Jeff S.; Brazelton, William J.; Brennecka, Gregory A.; Carns, Regina; Chopra, Aditya; Colangelo-Lillis, Jesse; Crockett, Christopher J.; De Marines, Julia; Frank, Elizabeth A.; Frantz, Carie; De La Fuente, Eduardo; Galante, Douglas; Glass, Jennifer; Gleeson, Damhnait; Glein, Christopher R.; Goldblatt, Colin; Horak, Rachel; Horodyskyj, Lev; Kaçar, Betül; Kereszturi, Akos; Knowles, Emily; Mayeur, Paul; McGlynn, Shawn; Miguel, Yamila; Montgomery, Michelle; Neish, Catherine; Noack, Lena; Rugheimer, Sarah; Stüeken, Eva E.; Tamez-Hidalgo, Paulina; Walker, Sara Imari; Wong, Teresa (2016-08-01) - Journal article
  • Atmospheric drying as the main driver of dramatic glacier wastage in the southern Indian Ocean 

    Favier, V.; Verfaillie, D.; Berthier, E.; Menegoz, M.; Jomelli, V.; Kay, J. E.; Ducret, L.; Malbéteau, Y.; Brunstein, D.; Gallée, H.; Park, Y. -H.; Rinterknecht, V. (2016-09-01) - Journal article
    The ongoing retreat of glaciers at southern sub-polar latitudes is particularly rapid and widespread. Akin to northern sub-polar latitudes, this retreat is generally assumed to be linked to warming. However, no long-term ...
  • Atmospheric origins of perchlorate on Mars and in the Atacama 

    Catling, D. C.; Claire, Mark; Zahnle, K. J.; Quinn, R. C.; Clark, B. C.; Hecht, M. H.; Kounaves, S. (2010) - Journal article
    Isotopic studies indicate that natural perchlorate is produced on Earth in arid environments by the oxidation of chlorine species through pathways involving ozone or its photochemical products. With this analogy, we propose ...
  • Biogeochemical significance of pelagic ecosystem function : an end-Cretaceous case study 

    Henehan, Michael; Hull, Pincelli; Penman, Donald; Rae, James William Buchanan; Schmidt, Daniela (2016-05) - Journal article
    Pelagic ecosystem function is integral to global biogeochemical cycling, and plays a major role in modulating atmospheric CO2 concentrations (pCO2). Uncertainty as to the effects of human activities on marine ecosystem ...
  • Biological regulation of atmospheric chemistry en route to planetary oxygenation 

    Izon, Gareth; Zerkle, Aubrey L.; Williford, Kenneth; Farquhar, James; Poulton, Simon; Claire, Mark W. (2017-03-28) - Journal article
    Emerging evidence suggests that atmospheric oxygen may have varied before rising irreversibly ∼2.4 billion years ago, during the Great Oxidation Event (GOE). Significantly, however, pre-GOE atmospheric aberrations toward ...
  • Boron isotope evidence for oceanic carbon dioxide leakage during the last deglaciation 

    Martínez-Botí, M A; Marino, G; Foster, G L; Ziveri, P; Henehan, M J; Rae, J W B; Mortyn, P G; Vance, D (2015-02-12) - Journal article
    Atmospheric CO2 fluctuations over glacial-interglacial cycles remain a major challenge to our understanding of the carbon cycle and the climate system. Leading hypotheses put forward to explain glacial-interglacial atmospheric ...
  • Causes of unrest at silicic calderas in the East African Rift: new constraints from InSAR and soil-gas chemistry at Aluto volcano, Ethiopia 

    Hutchison, William; Biggs, Juliet; Mather, Tamsin A.; Pyle, David M.; Lewi, Elias; Yirgu, Gezahegn; Caliro, Stefano; Chiodini, Giovanni; Clor, Laura E.; Fischer, Tobias P. (2016-08-06) - Journal article
    Restless silicic calderas present major geological hazards, and yet many also host significant untapped geothermal resources. In East Africa this poses a major challenge, although the calderas are largely unmonitored their ...
  • Challenging the sensitivity limits of paleomagnetism : magnetostratigraphy of weakly magnetized Guadalupian-Lopingian (Permian) limestone from Kyushu, Japan 

    Kirschvink, J.L.; Isozaki, Y.; Shibuya, H.; Otofuji, Y.-I.; Raub, T.D.; Hilburn, I.A.; Kasuya, T.; Yokoyama, M.; Bonifacie, M. (2015-01-15) - Journal article
    Despite their utility for bio- and chemostratigraphy, many carbonate platform sequences have been difficult to analyze using paleomagnetic techniques due to their extraordinarily weak natural remanent magnetizations (NRMs). ...
  • Changes in Timor Strait hydrology and thermocline structure during the past 130 ka 

    Lo Giudice Cappelli, Elena; Holbourn, Ann; Kuhnt, Wolfgang; Regenberg, Marcus (2016-11-15) - Journal article
    Paleostudies of the Indonesian Throughflow (ITF) are largely based on temperature and salinity reconstructions of its near surface component, whereas the variability of its lower thermocline flow has rarely been investigated. ...
  • Channel and floodplain change analysis over a 100-year period : Lower Yuba River, California 

    Ghoshal, S.; James, L.A.; Singer, Michael B.; Aalto, R. (2010-07-19) - Journal article
    Hydraulic gold mining in the Sierra Nevada, California (1853–1884) displaced ~1.1 billion m3 of sediment from upland placer gravels that were deposited along piedmont rivers below dams where floods can remobilize them. ...