468 Works

Particle microenvironments expand the niche of anaerobic metabolism in the ocean, supplement to: Bianchi, Daniele; Weber, Thomas; Kiko, Rainer; Deutsch, Curtis (2018): Global niche of marine anaerobic metabolisms expanded by particle microenvironments. Nature Geoscience, 11(4), 263-268

Daniele Bianchi, Thomas Weber, Rainer Kiko & Curtis Deutsch
In ocean waters, anaerobic microbial respiration should be confined to the anoxic waters found in coastal regions and tropical oxygen minimum zones, where it is energetically favourable. However, recent molecular and geochemical evidence has pointed to a much broader distribution of denitrifying and sulfate-reducing microbes. Anaerobic metabolisms are thought to thrive in microenvironments that develop inside sinking organic aggregates, but the global distribution and geochemical significance of these microenvironments is poorly understood. Here, we develop...

Microsatellite markers and ITS sequences to investigate Usnea antarctica and U. aurantiacoatra species pair

Elisa Lagostina
Lichens are symbiotic associations consisting of a fungal (mycobiont) and one or more photosynthetic (photobionts) partners and are the dominant component, and most important primary producers, of Antarctic terrestrial ecosystems. The most common lichens in the maritime Antarctic are Usnea antarctica and U. aurantiacoatra, a so-called "species pair" in which U. antarctica shows asexual reproduction and propagation via soredia and U. aurantiacoatra forms ascospores in apothecia. Previous molecular analyses were not able to unambiguously distinguish...

Vertical profiles of current velocity, suspended sediment concentration, and salinity during one tidal cycle at Jemgum, Ems estuary, Germany, supplement to: Becker, Marius; Maushake, Christian; Winter, Christian (2018): Observations of mud-induced periodic stratification in a hyperturbid estuary. Geophysical Research Letters, 45(11), 5461-5469

Marius Becker, Christian Maushake & Christian Winter
Stationary ship-based data were collected during a period of 19 h, beginning 2014-19-11 16:20:00 CET (UTC +1), in the tidal river part of the Ems estuary, Germany. The ship was moored next to the navigation channel at Jemgum (N53.271114° E07.397424°). Current velocity data was obtained by an ADCP (acoustic Doppler current profiler, RDI 600 kHz, ping rate 0.5 Hz, cell size 0.2 m, 8 pings per ensemble, mode 1), deployed on a floating platform next...

Magnesium and Strontium compositions of pore fluids and bulk carbonates from Ocean Drilling Project Site 189-1171, supplement to: Chanda, Piyali; Fantle, Matthew S (2017): Quantifying the effect of diagenetic recrystallization on the Mg isotopic composition of marine carbonates. Geochimica et Cosmochimica Acta, 204, 219-239

Piyali Chanda & Matthew S Fantle
The Mg and Sr isotopic compositions (d26Mg and87Sr/86Sr) of pore fluids and bulk carbonates from Ocean Drilling Project Site 1171 is located on the South Tasman Rise (48°29.996000S and 149°06.690100E) at a present-day waterdepth of 2148.2 m on a southwesterly dipping slope.

Biogeochemical investigation of Basiluzzo CO2 vents (Panarea, Italy) during ECO2 cruises from 2011-2013, supplement to: Molari, Massimiliano; Guilini, Katja; Lott, Christian; Weber, Miriam; de Beer, Dirk; Meyer, Stefanie; Ramette, Alban; Wegener, Gunter; Wenzhöfer, Frank; Martin, Daniel; Cibic, Tamara; De Vittor, Cinzia; Vanreusel, Ann; Boetius, Antje (2018): CO2 leakage alters biogeochemical and ecological functions of submarine sands. Science Advances, 4(2), eaao2040

Massimiliano Molari, Katja Guilini, Christian Lott, Miriam Weber, Dirk de Beer, Stefanie Meyer, Alban Ramette, Frank Wenzhöfer, Daniel Martin, Ann Vanreusel, Boris Unger, Matthias Schneider, Hanna Kuhfuss & Antje Boetius
Subseabed CO2 storage is considered a future climate change mitigation technology. We investigated the ecological consequences of CO2 leakage for a marine benthic ecosystem. For the first time with a multidisciplinary integrated study, we tested hypotheses derived from a meta-analysis of previous experimental and in situ high-CO2 impact studies. For this, we compared ecological functions of naturally CO2-vented seafloor off the Mediterranean island Panarea (Tyrrhenian Sea, Italy) to those of nonvented sands, with a focus...

High Resolution Underway Nitrous Oxide Measurements (atmosphere and ocean) during Maria S. Merian cruise MSM18/2 and MSM18/3, supplement to: Arévalo-Martínez, Damian L; Kock, Annette; Steinhoff, T; Brandt, Peter; Dengler, Marcus; Fischer, Tim; Körtzinger, Arne; Bange, Hermann Werner (2017): Nitrous oxide during the onset of the Atlantic cold tongue. Journal of Geophysical Research: Oceans, 122(1), 171-184

Damian L Arévalo-Martínez, Annette Kock, T Steinhoff, Peter Brandt, Marcus Dengler, Tim Fischer, Arne Körtzinger & Hermann Werner Bange
Based on a detailed investigation of the distribution and sea-to-air fluxes of N2O in the eastern equatorial Atlantic (EEA), we show that the onset and seasonal development of the ACT can be clearly observed in surface N2O concentrations, which increase progressively as the cooling in the equatorial region proceeds during spring-summer. We observed a strong influence of the surface currents of the EEA on the N2O distribution, which allowed identifying “high” and “low” concentration regimes...

Dissolved rare earth elements and neodymium isotopes from water samples during METEOR cruise M90, supplement to: Grasse, Patricia; Bosse, Michael; Hathorne, Ed C; Böning, Philipp; Pahnke, Katharina; Frank, Martin (2017): Short-term variability of dissolved rare earth elements and neodymium isotopes in the entire water column of the Panama Basin. Earth and Planetary Science Letters, 475, 242-253

Patricia Grasse & Martin Frank
The distribution of dissolved rare earth elements (REEs) and neodymium isotopes (εNd) in the open ocean traces water mass mixing and provides information on lithogenic inputs to the source regions of the water masses. However, the processes influencing the REE budget at the ocean margins, in particular source and sink mechanisms, are not yet well quantified. In this study the first dissolved REE concentrations and Nd isotope compositions of seawater from the Panama Basin (RV...

A Late Quaternary climate record based on long chain diol proxies from ODP Site 202-1234, supplement to: de Bar, Marijke W; Stolwijk, Dave; McManus, Jerry F; Sinninghe Damsté, Jaap S; Schouten, Stefan (2018): A Late Quaternary climate record based on long-chain diol proxies from the Chilean margin. Climate of the Past, 14(11), 1783-1803

Marijke W de Bar, Dave Stolwijk, Jerry F McManus, Jaap S Sinninghe Damsté & Stefan Schouten
In this study we have applied different indices based on long chain diols, i.e., the Long chain Diol Index (LDI) as proxy for past SST, the Diol Index as indicator of past upwelling conditions and the Nutrient Diol Index (NDI) as proxy for nitrate and phosphate concentrations in seawater. The proxies were analyzed in marine sediments recovered at ODP Site 1234, located within the Peru-Chile upwelling system, with a 2 kyr resolution, covering the last...

Stable oxygen isotopes and Mg/Ca in planktic foraminifera and water column data from the Western Pacific Warm Pool, supplement to: Hollstein, Martina; Mohtadi, Mahyar; Rosenthal, Yair; Moffa-Sanchez, Paola; Oppo, Delia W; Martínez Méndez, Gema; Steinke, Stephan; Hebbeln, Dierk (2017): Stable Oxygen Isotopes and Mg/Ca in Planktic Foraminifera From Modern Surface Sediments of the Western Pacific Warm Pool: Implications for Thermocline Reconstructions. Paleoceanography, 32(11), 1174-1194

Martina Hollstein, Mahyar Mohtadi, Yair Rosenthal, Paola Moffa-Sanchez, Delia W Oppo, Gema Martínez Méndez, Stephan Steinke & Dierk Hebbeln
Mg/Ca and stable oxygen isotope compositions (d18O) of planktic foraminifera tests are commonly used as proxies to reconstruct past ocean conditions including variations in the vertical water column structure. Accurate proxy calibrations require thorough regional studies, since parameters such as calcification depth and temperature of planktic foraminifera depend on local environmental conditions. Here we present radiocarbon-dated, modern surface sediment samples and water column data (temperature, salinity, and seawater d18O) from the Western Pacific Warm Pool....

Astronomical tunings of the Oligocene-Miocene Transition from IODP Site 320-U1334, supplement to: Beddow, Helen M; Liebrand, Diederik; Wilson, Douglas S; Hilgen, Frederik J; Sluijs, Appy; Wade, Bridget S; Lourens, Lucas Joost (2018): Astronomical tunings of the Oligocene-Miocene transition from Pacific Ocean Site U1334 and implications for the carbon cycle. Climate of the Past, 14(3), 255-270

Helen M Beddow, Diederik Liebrand, Douglas S Wilson, Frederik J Hilgen, Appy Sluijs, Bridget S Wade & Lucas Joost Lourens
Astronomical tuning of sediment sequences requires both unambiguous cycle-pattern recognition in climate proxy records and astronomical solutions, and independent information about the phase relationship between these two. Here we present two different astronomically tuned age models for the Oligocene-Miocene Transition (OMT) from Integrated Ocean Drilling Program Site U1334 (equatorial Pacific Ocean) to assess the effect tuning has on astronomically calibrated ages and the geologic time scale. These alternative age models (from ~22 to ~24 Ma)...

Coccolithophore productivity in the North Atlantic during the Middle Pleistocene based on coccolith fraction Sr/Ca ratios from IODP Hole 306-U1313D, supplement to: Cavaleiro, Catarina; Voelker, Antje H L; Stoll, Heather M; Baumann, Karl-Heinz; Kulhanek, Denise K; Naafs, Bernhard David A; Stein, Ruediger; Gruetzner, Jens; Ventura, C; Kucera, Michal (2018): Insolation forcing of coccolithophore productivity in the North Atlantic during the Middle Pleistocene. Quaternary Science Reviews, 191, 318-336

Catarina Cavaleiro, Antje H L Voelker, Heather M Stoll, Karl-Heinz Baumann, Denise K Kulhanek, Bernhard David A Naafs, Ruediger Stein, Jens Gruetzner, C Ventura & Michal Kucera
Coccolithophores play a key role in the oceanic carbon cycle through the biological and carbonate pumps. Understanding controls on coccolithophore productivity is thus fundamental to quantify oceanic carbon cycling. We investigate changes in coccolithophore productivity over several Pleistocene glacial-interglacial cycles using a high-resolution coccolith Sr/Ca ratio record, which is an indicator of growth rate and thus a proxy for coccolithophore productivity. We use Middle Pleistocene sediments from the North Atlantic Integrated Ocean Drilling Program (IODP)...

Middle Miocene benthic oxygen and carbon stable isotopes and Nd isotopes from Pacific ODP sites, supplement to: Holbourn, Ann E; Kuhnt, Wolfgang; Frank, Martin; Haley, Brian A (2013): Changes in Pacific Ocean circulation following the Miocene onset of permanent Antarctic ice cover. Earth and Planetary Science Letters, 365, 38-50

Ann E Holbourn, Wolfgang Kuhnt, Martin Frank & Brian A Haley
We integrate micropaleontological and geochemical records (benthic stable isotopes, neodymium isotopes, benthic foraminiferal abundances and XRF-scanner derived elemental data) from well-dated Pacific Ocean successions(15-12.7Ma) to monitor circulation changes during the middle Miocene transition into a colder climate mode with permanent Antarctic ice cover. Together with previously published records, our results show improvement in deepwater ventilation and strengthening of the meridional overturning circulation following major ice expansion at 13.9 Ma. Neodymium isotope data reveal, however, that...

δ¹⁸Oatm and dO2/N2 records between 100-800 ka from EPICA Dome C ice core on AICC2012 chronology, supplement to: Extier, Thomas; Landais, Amaelle; Bréant, Camille; Prié, F; Bazin, Lucie; Dreyfus, Gabrielle; Roche, Didier M; Leuenberger, Markus Christian (2018): On the use of d18O atm for ice core dating. Quaternary Science Reviews, 185, 244-257

Thomas Extier, Amaelle Landais, Camille Bréant, F Prié, Lucie Bazin, Gabrielle Dreyfus, Didier M Roche & Markus Christian Leuenberger
Deep ice core chronologies have been improved over the past years through the addition of new age constraints. However, dating methods are still associated with large uncertainties for ice cores from the East Antarctic plateau where layer counting is not possible. Indeed, an uncertainty up to 6 ka is associated with AICC2012 chronology of EPICA Dome C (EDC) ice core, which mostly arises from uncertainty on the delay between changes recorded in d18Oatm and in...

Dendrochronological dates of subfossil pines (Pinus sylvestris L.), relative dates of floating chronology, and peat stratigraphy from site \"TOMO_south\" at Totes Moor, northwest Germany, supplement to: Achterberg, Inke E M; Eckstein, Jan; Birkholz, Bernhard; Bauerochse, Andreas; Leuschner, Hanns Hubert (2018): Dendrochronologically dated pine stumps document phase-wise bog expansion at a northwest German site between ca. 6700 and ca. 3400 BC. Climate of the Past, 14(1), 85-100

Inke E M Achterberg, Jan Eckstein, Bernhard Birkholz, Andreas Bauerochse & Hanns Hubert Leuschner
This is a dendrochronological investigation of a mire site densely covered by peat-preserved pine stumps (Pinus sylvestris). The site in the northwest German Tote Moor revealed to feature trees from various Holocene millennia. The dendrochronologically dated site chronology covers 2345 years between 6703 BC and 3403 BC, containing 5 gaps between 6 and 550 years in length. It consists of 477 trees. A floating chronology segment of 309 years, containing 30 trees, was radiocarbon dated...

North Pacific paleotemperature and paleoproductivity reconstructions based on diatom species, supplement to: Lopes, C; Mix, Alan C (2018): North Pacific Paleotemperature and Paleoproductivity Reconstructions Based on Diatom Species. Paleoceanography and Paleoclimatology, 33(7), 703-715

Cristina Lopes & Alan C Mix
The data is comprised of all the modern calibration environmental variables and coretop diatom species as well downcore diatom species for transfer function application

Climate proxies of sea-surface temperature, carbon isotopes, and dust flux for the last 800-kyr and the Mid-Brunhes Transition, supplement to: Barth, Aaron M; Clark, Peter U; Bill, Nicholas S; He, Feng; Pisias, Nicklas G (2018): Climate evolution across the Mid-Brunhes Transition. Climate of the Past, 14(12), 2071-2087

Aaron M Barth, Peter U Clark, Nicholas S Bill, Feng He & Nicklas G Pisias
The Mid-Brunhes Transition (MBT) began ∼430ka with an increase in the amplitude of the 100-kyr climate cycles of the past 800,000 years. The MBT has been identified in ice-core records, which indicate interglaciations became warmer with higher atmospheric CO2 levels after the MBT, and benthic oxygen isotope (δ18O) records, which suggest that post-MBT interglaciations had higher sea levels than pre-MBT interglaciations. It remains unclear, however, whether the MBT was a globally synchronous phenomenon that included...

Nutrient spatial variability in Jepara, Indonesia, on December 2016, supplement to: Adyasari, Dini; Oehler, Till; Afiati, Norma; Moosdorf, Nils (2018): Groundwater nutrient inputs into an urbanized tropical estuary system in Indonesia. Science of the Total Environment, 627, 1066-1079

Dini Adyasari, Till Oehler, Norma Afiati & Nils Moosdorf
Groundwater discharge is known to transport nutrients into estuaries at several locations around the world. However, few studies report groundwater-associated nutrient fluxes from tropical developing regions such as Southeast Asia, even though this area shows the strongest human modifications in the coastal zone worldwide. We investigated groundwater nutrient flux into two streams and estuaries (Awur and Sekumbu Bay) in the urban area of Jepara, Indonesia, and its relation with the land usage surrounding the estuaries.We...

10Be concentrations in Lakes Tiefer and Czechowskie sediments during three grand solar minima, supplement to: Czymzik, Markus; Muscheler, Raimund; Adolphi, Florian; Mekhaldi, Florian; Dräger, Nadine; Ott, Florian; Słowiński, Michał; Blaskiewicz, Mirsolaw; Aldahan, Ala; Possnert, Göran; Brauer, Achim (2018): Synchronizing 10Be in two varved lake sediment records to IntCal13 14C during three grand solar minima. Climate of the Past, 14, 687-696

Markus Czymzik, Raimund Muscheler, Florian Adolphi, Florian Mekhaldi, Nadine Dräger, Florian Ott, Michał Słowiński, Mirsolaw Blaskiewicz, Ala Aldahan, Göran Possnert & Achim Brauer
Time-scale uncertainties between paleoclimate reconstructions often inhibit studying the exact timing, spatial expression and driving mechanisms of climate variations. Detecting and aligning the globally common cosmogenic radionuclide production signal via a curve fitting method provides a tool for the quasi-continuous synchronization of paleoclimate archives. In this study, we apply this approach to synchronize 10Be records from varved sediments of Lakes Tiefer See and Czechowskie covering the Maunder-, Homeric- and 5500 a BP grand solar minima...

Registration Year

  • 2018

Resource Types

  • Collection


  • University of Iowa