Shape mixing dynamics in the low-lying states of proton-rich Kr isotopes

We study the oblate-prolate shape mixing in the low-lying states of proton-rich Kr isotopes using the five-dimensional quadrupole collective Hamiltonian. The collective Hamiltonian is derived microscopically by means of the CHFB (constrained Hartree-Fock-Bogoliubov) + Local QRPA (quasiparticle random phase approximation) method, which we have developed recently on the basis of the adiabatic self-consistent collective coordinate method. The results of the numerical calculation show the importance of large-amplitude collective vibrations in the triaxial shape degree of freedom and rotational effects on the oblate-prolate shape mixing dynamics in the low-lying states of these isotopes.Comment: 29 pages, 14 figure

Colonization of the Americas, 'Little Ice Age' climate, and bomb-produced carbon: their role in defining the Anthropocene

A recently published analysis by Lewis and Maslin (Lewis SL and Maslin MA (2015) Defining the Anthropocene. Nature 519: 171–180) has identified two new potential horizons for the Holocene−Anthropocene boundary: 1610 (associated with European colonization of the Americas), or 1964 (the peak of the excess radiocarbon signal arising from atom bomb tests). We discuss both of these novel suggestions, and consider that there is insufficient stratigraphic basis for the former, whereas placing the latter at the peak of the signal rather than at its inception does not follow normal stratigraphical practice. Wherever the boundary is eventually placed, it should be optimized to reflect stratigraphical evidence with the least possible ambiguity

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Global Boundary Stratotype Section and Point (GSSP) for the Anthropocene Series: Where and how to look for potential candidates

International audienc

The noise-lovers: cultures of speech and sound in second-century Rome

This chapter provides an examination of an ideal of the ‘deliberate speaker’, who aims to reflect time, thought, and study in his speech. In the Roman Empire, words became a vital tool for creating and defending in-groups, and orators and authors in both Latin and Greek alleged, by contrast, that their enemies produced babbling noise rather than articulate speech. In this chapter, the ideal of the deliberate speaker is explored through the works of two very different contemporaries: the African-born Roman orator Fronto and the Syrian Christian apologist Tatian. Despite moving in very different circles, Fronto and Tatian both express their identity and authority through an expertise in words, in strikingly similar ways. The chapter ends with a call for scholars of the Roman Empire to create categories of analysis that move across different cultural and linguistic groups. If we do not, we risk merely replicating the parochialism and insularity of our sources.Accepted manuscrip

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Enregistrements sédimentaires des changements environnementaux séculaires à millénaires par la micro- et la macrofaune benthiques littorales

Unraveling the respective influence of human activities and natural processes on recent environmental changes is a critical issue. In this respect, fossil molluscs and foraminifers of the Pertuis Charentais area (western France) as well as the sediments deposited during the Holocene they originate from have been studied. The study is focused on a mud drape that corresponds to the upper, most recent sediment infill of the area. The results show that it is composed of fine grained sediments originating from the adjacent catchments deposited from 1400 AD onwards. This major environmental change was the consequence of an increase in soil erosion promoted by intense deforestation started during the Middle Ages. Mud sedimentation rate increased suddenly in ca. 1760 AD, owing to a short-lived increase of winter rainfall which triggered more intense soil erosion on vulnerable deforested lands. The sharp deposition of fine grained sediments in the Pertuis Charentais has had few consequences on the past benthic mollusc communities, except the local extinction of the bivalve \textit{Lepton squamosum} in the Marennes-Oléron Bay. On the contrary, the increase in mud supply has triggered an ecological succession among benthic foraminifer communities (resistance - disturbance - adaptation). As a whole, the results demonstrate that environments disrupted by human activities become more sensitive to high-frequency climate changes. They also highlight the potential of paleoecology for a better understanding of recent environmental changes occurring within coastal areas at a millennial to centennial scale.Discriminer l'influence des activités humaines de celle des processus naturels sur les changements environnementaux récents est un enjeu scientifique important. Dans ce but, les mollusques et les foraminifères fossiles des Pertuis Charentais (ouest de la France) ainsi que les sédiments déposés pendant l'Holocène dont ils sont issus ont été étudiés. L'objet d'étude central est un drapage vaseux qui constitue une grande partie du comblement sédimentaire terminal des Pertuis. Les résultats obtenus montrent qu'il est composé de sédiments fins d'origine continentale déposés à partir de 1400 AD. Il est la conséquence d'une augmentation de l'érosion des sols, favorisée par la déforestation entreprise au Moyen-Age. Le taux de sédimentation de cette vase a augmenté brutalement, suite à une période d'augmentation des précipitations hivernales à la fin du Petit Age Glaciaire qui a accéléré l'érosion des sols sur ces territoires fragilisés car déforestés. Le dépôt brutal de sédiments fins dans les Pertuis Charentais a eu peu de répercussions sur les communautés de mollusques benthiques, excepté l'extinction locale du bivalve \textit{Lepton squamosum} de la baie de Marennes-Oléron. En revanche, l'augmentation des apports sédimentaires a été à l'origine d'une succession écologique au sein des communautés de foraminifères (résistance - perturbation - adaptation). Les résultats obtenus démontrent comment des milieux perturbés par les activités humaines deviennent plus sensibles aux changements climatiques. Ils soulignent aussi le potentiel de la paléoécologie dans la compréhension des changements environnementaux récents dans les zones côtières à une échelle millénaire à séculaire

Sedimentary records of millennial to centennial environmental changes with coastal benthic micro- and macrofauna

Discriminer l'influence des activités humaines de celle des processus naturels sur les changements environnementaux récents est un enjeu scientifique important. Dans ce but, les mollusques et les foraminifères fossiles des Pertuis Charentais (ouest de la France) ainsi que les sédiments déposés pendant l'Holocène dont ils sont issus ont été étudiés. L'objet d'étude central est un drapage vaseux qui constitue une grande partie du comblement sédimentaire terminal des Pertuis. Les résultats obtenus montrent qu'il est composé de sédiments fins d'origine continentale déposés à partir de 1400 AD. Il est la conséquence d'une augmentation de l'érosion des sols, favorisée par la déforestation entreprise au Moyen-Age. Le taux de sédimentation de cette vase a augmenté brutalement, suite à une période d'augmentation des précipitations hivernales à la fin du Petit Age Glaciaire qui a accéléré l'érosion des sols sur ces territoires fragilisés car déforestés. Le dépôt brutal de sédiments fins dans les Pertuis Charentais a eu peu de répercussions sur les communautés de mollusques benthiques, excepté l'extinction locale du bivalve \textit{Lepton squamosum} de la baie de Marennes-Oléron. En revanche, l'augmentation des apports sédimentaires a été à l'origine d'une succession écologique au sein des communautés de foraminifères (résistance - perturbation - adaptation). Les résultats obtenus démontrent comment des milieux perturbés par les activités humaines deviennent plus sensibles aux changements climatiques. Ils soulignent aussi le potentiel de la paléoécologie dans la compréhension des changements environnementaux récents dans les zones côtières à une échelle millénaire à séculaire.Unraveling the respective influence of human activities and natural processes on recent environmental changes is a critical issue. In this respect, fossil molluscs and foraminifers of the Pertuis Charentais area (western France) as well as the sediments deposited during the Holocene they originate from have been studied. The study is focused on a mud drape that corresponds to the upper, most recent sediment infill of the area. The results show that it is composed of fine grained sediments originating from the adjacent catchments deposited from 1400 AD onwards. This major environmental change was the consequence of an increase in soil erosion promoted by intense deforestation started during the Middle Ages. Mud sedimentation rate increased suddenly in ca. 1760 AD, owing to a short-lived increase of winter rainfall which triggered more intense soil erosion on vulnerable deforested lands. The sharp deposition of fine grained sediments in the Pertuis Charentais has had few consequences on the past benthic mollusc communities, except the local extinction of the bivalve \textit{Lepton squamosum} in the Marennes-Oléron Bay. On the contrary, the increase in mud supply has triggered an ecological succession among benthic foraminifer communities (resistance - disturbance - adaptation). As a whole, the results demonstrate that environments disrupted by human activities become more sensitive to high-frequency climate changes. They also highlight the potential of paleoecology for a better understanding of recent environmental changes occurring within coastal areas at a millennial to centennial scale