Earth Science
Recent Submissions
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Stable isotope and calcareous nannofossil assemblage record of the late Paleocene and early Eocene (Cicogna section)
(2016)We present records of stable carbon and oxygen isotopes, CaCO3 content, and changes in calcareous nannofossil assemblages across an 81 m thick section of upper Paleocene–lower Eocene marine sedimentary rocks now exposed ... -
Major perturbations in the global carbon cycle and photosymbiont-bearing planktic foraminifera during the early Eocene
(2016)A marked switch in the abundance of the planktic foraminiferal genera Morozovella and Acarinina occurred at low-latitude sites near the start of the Early Eocene Climatic Optimum (EECO), a multi-million-year interval when ... -
Carbon and oxygen isotopes of bulk carbonate in sediment deposited beneath the eastern equatorial Pacific over the last 8 million years
(2015)To improve the understanding and utility of bulk carbonate stable carbon and oxygen isotope measurements, we examine sediment from cores in the eastern equatorial Pacific that span the last 8 Ma. We measured δ13C and δ18O ... -
Forest soil carbon oxidation state and oxidative ratio responses to elevated CO2
(2015)The oxidative ratio (OR) of the biosphere is the stoichiometric ratio (O2/CO2) of gas exchange by photosynthesis and respiration—a key parameter in budgeting calculations of the land and ocean carbon sinks. Carbon cycle-climate ... -
Gas hydrate dissociation prolongs acidification of the Anthropocene oceans
(2015)Anthropogenic warming of the oceans can release methane (CH4) currently stored in sediments as gas hydrates. This CH4 will be oxidized to CO2, thus increasing the acidification of the oceans. We employ a biogeochemical ... -
The efficiency of plate tectonics and nonequilibrium dynamical evolution of planetary mantles
(2015)Consideration of the structure of dynamical equilibria in terrestrial planets using simplified descriptions of the relevant heat transport processes (rigid-lid convection, plate tectonics, and heat pipe volcanism) reveals ... -
Mantle-driven uplift of Hangai Dome: New seismic constraints from adjoint tomography
(2015)The origin of Hangai Dome, an unusual large-scale, high-elevation low-relief landform in central Mongolia, remains enigmatic partly due to lack of constraints on its underlying seismic structure. Using adjoint tomography—a ... -
A window for plate tectonics in terrestrial planet evolution?
(2016)The tectonic regime of a planet depends critically on the contributions of basal and internal heating to the planetary mantle, and how these evolve through time. We use viscoplastic mantle convection simulations, with ... -
Early Paleogene variations in the calcite compensation depth: new constraints using old borehole sediments from across Ninetyeast Ridge, central Indian Ocean
(2015)Major variations in global carbon cycling occurred between 62 and 48 Ma, and these very likely related to changes in the total carbon inventory of the ocean-atmosphere system. Based on carbon cycle theory, variations in ... -
Large-Amplitude Variations in Carbon Cycling and Terrestrial Weathering during the Latest Paleocene and Earliest Eocene: The Record at Mead Stream, New Zealand
(2012)The late Paleocene to early Eocene was marked by major changes in Earth surface temperature and carbon cycling. This included at least two, and probably more, geologically brief (<200-k.yr.) intervals of extreme warming, ... -
Ross Sea paleo-ice sheet drainage and deglacial history during and since the LGM
(2014)Onshore and offshore studies show that an expanded, grounded ice sheet occupied the Ross Sea Embayment during the Last Glacial Maximum (LGM). Results from studies of till provenance and the orientation of geomorphic features ... -
Configuration of the Northern Antarctic Peninsula Ice Sheet at LGM based on a new synthesis of seabed imagery
(2015)We present a new seafloor map for the northern Antarctic Peninsula (AP), including swath multibeam data sets from five national programs. Our map allows for the examination and interpretation of Last Glacial Maximum (LGM) ... -
Understanding long-term carbon cycle trends: The late Paleocene through the early Eocene
(2013)[1] The late Paleocene to the early Eocene (~58–52 Ma) was marked by significant changes in global climate and carbon cycling. The evidence for these changes includes stable isotope records that reveal prominent decreases ... -
Reconstruction of changes in the Amundsen Sea and Bellingshausen Sea sector of the West Antarctic Ice Sheet since the Last Glacial Maximum
(2014)Marine and terrestrial geological and marine geophysical data that constrain deglaciation since the Last Glacial Maximum (LGM) of the sector of the West Antarctic Ice Sheet (WAIS) draining into the Amundsen Sea and ... -
Reconstruction of ice-sheet changes in the Antarctic Peninsula since the Last Glacial Maximum
(2014)This paper compiles and reviews marine and terrestrial data constraining the dimensions and configuration of the Antarctic Peninsula Ice Sheet (APIS) from the Last Glacial Maximum (LGM) through deglaciation to the present ... -
Reconstruction of changes in the Weddell Sea sector of the Antarctic Ice Sheet since the Last Glacial Maximum
(2014)The Weddell Sea sector is one of the main formation sites for Antarctic Bottom Water and an outlet for about one fifth of Antarctica's continental ice volume. Over the last few decades, studies on glacial–geological records ... -
Size, shape and spatial arrangement of mega-scale glacial lineations from a large and diverse dataset
(2014)Mega-scale glacial lineations (MSGLs) are a characteristic landform on ice stream beds. Solving the puzzle of their formation is key to understanding how ice interacts with its bed and how this, in turn, influences the ... -
Rare calcareous microfossils from Middle Miocene strata, Weddell Sea off Antarctic Peninsula
(2012)The calcareousmicrofossil assemblage from Middle Miocene strata of SHALDRIL Site NBP0602A−5D consists of benthic foraminifera, ostracods, bivalves, and gastropods, and is interpreted as shallow−water. It appears to be ... -
A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum
(2014)A robust understanding of Antarctic Ice Sheet deglacial history since the Last Glacial Maximum is important in order to constrain ice sheet and glacial-isostatic adjustment models, and to explore the forcing mechanisms ... -
Assessing offsets between the δ13C of sedimentary components and the global exogenic carbon pool across early Paleogene carbon cycle perturbations
(2012)[1] Negative stable carbon isotope excursions (CIEs) across the Paleocene–Eocene thermal maximum (PETM; ~56 Ma) range between 2‰ and 7‰, even after discounting sections with truncated records. Individual carbon isotope ...
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