Institution
Australian National University
Education•Canberra, Australian Capital Territory, Australia•
About: Australian National University is a education organization based out in Canberra, Australian Capital Territory, Australia. It is known for research contribution in the topics: Population & Galaxy. The organization has 34419 authors who have published 109261 publications receiving 4315448 citations. The organization is also known as: The Australian National University & ANU.
Topics: Population, Galaxy, Context (language use), Politics, Stars
Papers published on a yearly basis
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TL;DR: In this article, the authors show that observations from certain regions in the Mediterranean are particularly important in effecting the separation and demonstrate that a small observation data set from sites that exhibit some of the desirable features of an ideal data set.
470 citations
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TL;DR: It is found that deep-sea temperature and sea level generally decreased through time, but distinctly out of synchrony, which is remarkable given the importance of ice-albedo feedbacks on the radiative forcing of climate.
Abstract: Ice volume (and hence sea level) and deep-sea temperature are key measures of global climate change. Sea level has been documented using several independent methods over the past 0.5 million years (Myr). Older periods, however, lack such independent validation; all existing records are related to deep-sea oxygen isotope (δ18O) data that are influenced by processes unrelated to sea level. For deep-sea temperature, only one continuous high-resolution (Mg/Ca-based) record exists, with related sea-level estimates, spanning the past 1.5 Myr. Here we present a novel sea-level reconstruction, with associated estimates of deep-sea temperature, which independently validates the previous 0–1.5 Myr reconstruction and extends it back to 5.3 Myr ago. We find that deep-sea temperature and sea level generally decreased through time, but distinctly out of synchrony, which is remarkable given the importance of ice-albedo feedbacks on the radiative forcing of climate. In particular, we observe a large temporal offset during the onset of Plio-Pleistocene ice ages, between a marked cooling step at 2.73 Myr ago and the first major glaciation at 2.15 Myr ago. Last, we tentatively infer that ice sheets may have grown largest during glacials with more modest reductions in deep-sea temperature. A novel approach to the estimation of sea level and deep-sea temperature has been used to determine these quantities over the past 5.3 million years; this approach, based on oxygen isotope records from the eastern Mediterranean, shows that temperature and sea-level histories are broadly correlated but also show intriguing temporal offsets. Most records of past sea-level variation and associated changes in ocean temperature rely on variations in oxygen isotopes recorded in deep-sea marine microorganisms. These signals, unfortunately, are confounded by other influences, making it difficult to extract a clear climate-related signal. Eelco Rohling and colleagues now present a novel approach to estimating sea-level and deep-sea temperature variations for the past 5.3 million years. The record, based on oxygen isotope variations from the eastern Mediterranean, avoids the issues of the deep-sea approach and generally corresponds to an independent record of the past 1.6 million years. As expected, temperature and sea level are broadly correlated but also show intriguing temporal discontinuities, as at the initiation of Plio–Pleistocene ice ages, when a major sea-level drop lagged a sharp temperature decline by several hundred thousand years.
470 citations
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TL;DR: The bulk chemical composition of pyrolite is derived from experimental and petrological studies of the complementary relationships between basaltic magmas and refractory peridotites as discussed by the authors.
470 citations
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Günter Blöschl1, Marc F. P. Bierkens2, António Chambel3, Christophe Cudennec4 +209 more•Institutions (124)
TL;DR: In this article, a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts is described. But despite the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work.
Abstract: This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.
469 citations
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TL;DR: These measurements satisfy one of the conditions required by the hypothesis that the diversion of meltwater from the Mississippi to the St. Lawrence River triggered the Younger Dryas event, and show that globally averaged rates of melting were relatively high at the beginning of the YD.
Abstract: Paired carbon-14 ((14)C) and thorium-230((230)Th) ages were determined on fossil corals from the Huon Peninsula, Papua New Guinea. The ages were used to calibrate part of the (14)C time scale and to estimate rates of sea-level rise during the last deglaciation. An abrupt offset between the (14)C and (230)Th ages suggests that the atmospheric (14)C/(12)C ratio dropped by 15 percent during the latter part of and after the Younger Dryas (YD). This prominent drop coincides with greatly reduced rates of sea-level rise. Reduction of melting because of cooler conditions during the YD may have caused an increase in the rate of ocean ventilation, which caused the atmospheric (14)C/(12)C ratio to fall. The record of sea-level rise also shows that globally averaged rates of melting were relatively high at the beginning of the YD. Thus, these measurements satisfy one of the conditions required by the hypothesis that the diversion of meltwater from the Mississippi to the St. Lawrence River triggered the YD event.
469 citations
Authors
Showing all 34925 results
Name | H-index | Papers | Citations |
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Cyrus Cooper | 204 | 1869 | 206782 |
Nicholas G. Martin | 192 | 1770 | 161952 |
David R. Williams | 178 | 2034 | 138789 |
Krzysztof Matyjaszewski | 169 | 1431 | 128585 |
Anton M. Koekemoer | 168 | 1127 | 106796 |
Robert G. Webster | 158 | 843 | 90776 |
Ashok Kumar | 151 | 5654 | 164086 |
Andrew White | 149 | 1494 | 113874 |
Bernhard Schölkopf | 148 | 1092 | 149492 |
Paul Mitchell | 146 | 1378 | 95659 |
Liming Dai | 141 | 781 | 82937 |
Thomas J. Smith | 140 | 1775 | 113919 |
Michael J. Keating | 140 | 1169 | 76353 |
Joss Bland-Hawthorn | 136 | 1114 | 77593 |
Harold A. Mooney | 135 | 450 | 100404 |