Antarctic Environmental Change and Ice Sheet Evolution through the Miocene to Pliocene ¿ A perspective from the Ross Sea and George V to Wilkes Land Coasts

We wish to acknowledge the support of National Antarctic Programmes and the International Scientific Drilling Programmes and Projects that have allowed our community to acquire the critical records of environmental change that have been discussed in this review. We thank Jenny Black, GNS Science, for her assistance with Fig. 9.2. R.L., T.N., R.M., C.O. and N.G. acknowledge funding support from the New Zealand Ministry of Business and Innovation and Employment through the Antarctic Science Platform contract (ANTA1801) Antarctic Ice Dynamics Project (ASP-021-01). C.E. acknowledges funding by the Spanish Ministry of Economy, Industry and Competitivity (grant CTM2017-89711-C2-1/2-P), co-funded by the European Union through FEDER funds. L.F.P. was funded through the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement number 792773 for the West Antarctic Margin Signatures of Ice Sheet Evolution (WAMSISE) Project

Past Antarctic ice sheet dynamics (PAIS) and implications for future sea-level change

Coauthors from the PAIS community Aisling M. Dolan, University of Leeds, Leeds, UK Alan K. Cooper, U.S. Geological Survey Emeritus, Menlo Park, USA Alessandra Venuti, Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy Amy Leventer, Colgate University, Hamilton, NY, USA Andrea Bergamasco, C.N.R. (National Research Council) ISMAR, Venice, Italy Carolina Acosta Hospitaleche, CONICET, División Paleontología Vertebrados, Museo de La Plata (Facultad de Ciencias Naturales y Museo, UNLP) La Plata, Argentina Carolina Acosta Hospitaleche, CONICET – División Paleontología Vertebrados, Museo de La Plata, Facultad de Ciencias Naturales y Museo, UNLP; La Plata, Argentina Catalina Gebhardt, Alfred Wegener Institute Helmholtz Centre of Polar and Marine Research, Bremerhaven, Germany Christine S. Siddoway, Colorado College, Colorado Springs, USA Christopher C. Sorlien, Earth Research Institute, University of California, Santa Barbara, Santa Barbara, California, USA David Harwood, University of Nebraska-Lincoln, Lincoln, Nebraska, USA David Pollard, Pennsylvania State University, University Park, Pennsylvania, USA David J. Wilson, Department of Earth Sciences, University College London, London, UK Denise K. Kulhanek, Texas A&M University, College Station, TX, United States Dominic A. Hodgson, British Antarctic Survey, Cambridge, UK Edward G.W. Gasson, University of Bristol, UK Fausto Ferraccioli, NERC/British Antarctic Survey, Cambridge, UK Fernando Bohoyo, Instituto Geológico y Minero de España, Madrid, Spain Francesca Battaglia, University of Venice Cá Foscari, Italy Frank O. Nitsche, Lamont-Doherty Earth Observatory of Columbia University, Palisades, USA Georgia R. Grant, GNS Science Wellington, New Zealand Gerhard Kuhn, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany Guy J.G. Paxman, Lamont-Doherty Earth Observatory, Columbia University, New York, USA Ian D. Goodwin, Climate Change Research Centre, University of New South Wales, Sydney, Australia Isabel Sauermilch, University of Tasmania, Institute for Marine and Antarctic Studies, Australia Jamey Stutz, Antarctic Research Centre at Victoria University of Wellington, New Zealand Jan Sverre Laberg, Department of Geosciences, UiT The Arctic University of Norway, NO-9037 Tromsø, Norway Javier N. Gelfo, CONICET – UNLP, División Paleontología Vertebrados, Museo de La Plata, Argentina Johann P. Klages, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany Julia S. Wellner, University of Houston, Houston, USA Karsten Gohl, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany Laura Crispini, University of Genova (DISTAV, Genova, Italy) Leanne K. Armand, Australian National University, Canberra, Australia. Marcelo A. Reguero, Instituto Antártico Argentino, B1650HMK, San Martín, Buenos Aires, Argentina Marcelo A. Reguero, Instituto Antártico Argentino, Buenos Aires, Argentina Marco Taviani, Institute of Marine Sciences (ISMAR), National Research Council (CNR), 40129, Bologna, Italy and Biology Department, Woods Hole Oceanographic Institution, 02543, Woods Hole, USA Martin J. Siegert, Imperial College London, London, UK Marvin A. Speece, Montana Technological University, Butte, USA Mathieu Casado, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany Michele Rebesco, OGS, Trieste, Italy Mike Weber, University of Bonn, Institute for Geosciences, Department of Geochemistry and Petrology, 53115 Bonn, Germany Minoru Ikehara, Kochi University, Japan Nicholas R. Golledge, Antarctic Research Centre Victoria University of Wellington, Wellington 6140, New Zealand Nigel Wardell, OGS, Trieste, Italy Paolo Montagna, Institute of Polar Sciences, National Research Council, Bologna, Italy Peter J. Barrett, Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand. Peter K. Bijl, Utrecht University, Utrecht, The Netherlands Philip E. O’Brien, Macquarie University, Sydney, Australia Philip J. Bart, Louisiana State University, Baton Rouge, USA Raffaella Tolotti, University of Genoa, Genoa, Italy Reed P. Scherer, Northern Illinois University, DeKalb, IL, USA Renata G. Lucchi, National Institute of Oceanography and Applied Geophysics (OGS), Sgonico-Trieste, Italy Riccardo Geletti, National Institute of Oceanography and Applied Geophysics – OGS, Trieste, Italy Richard C.A. Hindmarsh, British Antarctic Survey & Durham University, Cambridge & Durham, United Kingdom Richard H. Levy, GNS Science and Victoria University of Wellington, Lower Hutt and Wellington, New Zealand Robert B. Dunbar, Stanford University, Stanford, California, USA Robert D. Larter, British Antarctic Survey, Cambridge, UK Robert M. Mckay, Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand R. Selwyn Jones, Monash University (Melbourne, Australia) Sandra Passchier, Montclair State University, Montclair, USA Sean P.S. Gulick, University of Texas at Austin, Austin, Texas Sidney R. Hemming, Columbia University, New York, USA Stefanie Brachfeld, Montclair State University, New Jersey, USA Suzanne OConnell, Wesleyan University, Middletown, CT, USA Trevor Williams, International Ocean Discovery Program, Texas A&M University, College Station, USA Ursula Röhl, MARUM, University of Bremen, Bremen, Germany Yasmina M. Martos, NASA Goddard Space Flight Center, Greenbelt, MD, USA & University of Maryland College Park, MD, USAThe legacy of the Scientific Committee on Antarctic Research’s (SCAR) PAIS strategic research programme includes not only breakthrough scientific discoveries, but it is also the story of a long-standing deep collaboration amongst different multi-disciplinary researchers from many nations, to share scientific infrastructure and data, facilities, and numerical models, in order to address high priority questions regarding the evolution and behaviour of the Antarctic ice sheets (AIS). The PAIS research philosophy is based on data-data and data-model integration and intercomparison, and the development of ‘ice-to-abyss’ data transects and paleo-environmental, extending from the ice sheet interior to the deep sea. PAIS strives to improve understanding of AIS dynamics and to reduce uncertainty in model simulations of future ice loss and global sea level change, by studying warm periods of the geological past that are relevant to future climate scenarios. The multi-disciplinary approach fostered by PAIS represents its greatest strength. Eight years after the start of this programme, PAIS achievements have been high-profile and impactful, both in terms of field campaigns that collected unique data sets and samples, and in terms of scientific advances concerning past AIS dynamics, that have measurably improved understanding of ice sheet sensitivity in response to global warming. Here we provide an overview and synthesis of the new knowledge generated by the PAIS Programme and its implications for anticipating and managing the impacts of global sea-level rise.TN acknowledges support from MBIE Antarctic Science Platform contract ANTA1801

Cenozoic history of Antarctic glaciation and climate from onshore and offshore studies

The past three decades have seen a sustained and coordinated effort to refine the seismic stratigraphic framework of the Antarctic margin that has underpinned the development of numerous geological drilling expeditions from the continental shelf and beyond. Integration of these offshore drilling datasets covering the Cenozoic era with Antarctic inland datasets, provides important constraints that allow us to understand the role of Antarctic tectonics, the Southern Ocean biosphere, and Cenozoic ice sheet dynamics and ice sheet–ocean interactions on global climate as a whole. These constraints are critical for improving the accuracy and precision of future projections of Antarctic ice sheet behaviour and changes in Southern Ocean circulation. Many of the recent advances in this field can be attributed to the community-driven approach of the Scientific Committee on Antarctic Research (SCAR) Past Antarctic Ice Sheet Dynamics (PAIS) research programme and its two key subcommittees: Paleoclimate Records from the Antarctic Margin and Southern Ocean (PRAMSO) and Palaeotopographic-Palaeobathymetric Reconstructions. Since 2012, these two PAIS subcommittees provided the forum to initiate, promote, coordinate and study scientific research drilling around the Antarctic margin and the Southern Ocean. Here we review the seismic stratigraphic margin architecture, climatic and glacial history of the Antarctic continent following the break-up of Gondwanaland in the Cretaceous, with a focus on records obtained since the implementation of PRAMSO. We also provide a forward-looking approach for future drilling proposals in frontier locations critically relevant for assessing future Antarctic ice sheet, climatic and oceanic change.We thank many people who collaborated, by sharing data and ideas, on geoscience research projects under the umbrella of the highly successful Paleoclimate Records from the Antarctic Margin and Southern Ocean (PRAMSO) and Palaeotopographic-Palaeobathymetric Reconstructions subcommittees of the Scientific Committee on Antarctic Research (SCAR) Past Antarctic Ice Sheet scientific program. This synthesis, which reflects our views, would not have been possible without the efforts of these many investigators, most of whom continue their collaborative Antarctic studies, now under the successor SCAR INSTANT programme. Chris Sorlien is thanked for drafting Fig. 3.6. We thank John Anderson, Peter Barrett, Giuliano Brancolini and Alan Cooper for their useful comments and for their continuous dedication to the past Antarctic Ice Sheet evolution reconstructions. We thank Nigel Wardell, Frank Nitsche and Paolo Diviacco for maintaining the Seismic Data Library System and the National Antarctic funding agencies of many countries (Australia, China, Germany, Italy, Japan, Korea, New Zealand, Russia, Spain, the UK, the United States) for supporting geophysical and geological surveys essential for Paleotopographic and Paleobathymetric reconstructions. We thank the International Ocean Discovery Program (IODP) for its support of recent expeditions that arose out of PRAMSO discussions. R.M. was funded by the Royal Society Te Apārangi NZ Marsden Fund (grant 18-VUW-089). C.E. acknowledges funding by the Spanish Ministry of Economy, Industry and Competitivity (grants CTM2017-89711-C2-1/2-P), cofunded by the European Union through FEDER funds. L.D.S. and F.D. were funded by the Programma Nazionale delle Ricerche in Antartide (PNRA16_00016 project and PNRA 14_00119). R.Larter and C.D.H. were funded by the BAS Polar Science for Planet Earth Programme and NERC UK IODP grant NE/J006548/1. S.K. was supported by the KOPRI Grant (PE21050). L.P. was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 792773 WAMSISE. A.S. and S.G. were funded by NSF Office of Polar Programs (Grants OPP-1744970 (A.S.), -1143836 (A.S.), and -1143843 (S.G.). This is University of Texas Institute for Geophysics Contribution #3784. B.D. acknowledges funding from a Rutherford Foundation Postdoctoral Fellowship (RFT-VUW1804-PD). K.G. and G.K. were funded by AWI research programme Polar Regions and Coasts in the changing Earth System (PACES II) and the Sub-EIS-Obs programme by the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR). RL, RM, TN acknowledge support from MBIE Antarctic Science Platform contract ANTA1801

Contourite features distribution and water masses circulation in the Eastern Bransfield Basin (Antarctic Peninsula)

ISAES 2019: XIII International Symposium on Antarctic Earth Sciences, Songdo Convensia, Incheon, Republic of Korea, 22-26 july (2019

Reconstruction of intermediate and deep water circulation patterns in the Eastern Bransfield Basin (Antarctic Peninsula) from high-resolution acoustic data

4th Deep Water Circulation Research Conference. Edinhburgh, 24-26 May 2023This work aims to understand the link between the seafloor morphology and sub-seafloor stratigraphy of the Eastern Bransfield Basin (EBB; Antarctic Peninsula) with the water masses circulation established since the opening of the basin at around 3.3 Ma. Bottom currents (contourite) features identified from swath bathymetry data and parametric echo-sounder profiles acquired in the DRAKE2018 and POWELL2020 cruises are correlated with published information about water masses circulation and hydrological data. The EBB is the easternmost sector of the Bransfield Strait, oriented SW-NE and bounded by the Antarctic Peninsula to the southeast and the South Shetland and Elephant islands to the north and northwest. Contourite features are identified based on their sedimentary stacking pattern and morphological characteristics. They locate at distinctive depth levels in the EBB. A large mounded drift has been identified in an intra-slope platform in the SE margin, at water depths of 1000-1500 m. It is 35 km long and 20 km wide and is bounded by erosional contourite moats. These features are interpreted to result from the southwestward flow of the East Basin Deep Water (EBDW) at intermediate depths, formed by a mix of water masses from the Weddell Sea. Plastered drifts topped by contourite terraces occupy depths of 1100-1200 m along the SE margin of the basin, and are related to the high-energy oceanographic regime formed at the transitional boundary between the EBDW and the East Bransfield Bottom Water (EBBW). Contourite features on the deep, flat seafloor of the EBB at 2000-2300 m water depth are also formed by the EBBW. Mounded contourite drifts prograde and thin towards the outer limits of the basin, where contourite moats are interbedded with mass transport deposits. These contourite features have been generated by the episodic entrance of bottom water masses from the Central Basin and their mix with deep water masses flowing from the NE. This work reveals the highly dynamic oceanographic circulation in the Bransfield Strait, which has been established as tectonic processes led to the opening and deepening of gateways in the narrow basins at the tip of the Antarctic Peninsula and South Scotia Sea. Understanding the onset and temporal variability of the oceanographic pattern is of key importance to study the impact of deep-sea gateways in global oceanographic and climatic models

Experiencia clínica con los cannabinoides en la terapia de la espasticidad en la esclerosis múltiple

Resumen: Introducción: La espasticidad es un síntoma muy frecuente entre los pacientes con esclerosis múltiple (EM). El objetivo del presente estudio es evaluar la efectividad y la seguridad de la combinación de delta-9-tetrahidrocannabinol (THC) y cannabidiol (CBD) en la práctica clínica del tratamiento de la espasticidad en EM. Métodos: Estudio observacional retrospectivo con los pacientes tratados con THC/CBD inhalado de abril del 2008 a marzo del 2012. Se recogieron variables descriptivas de paciente y tratamiento. La respuesta se evaluó mediante impresión global de respuesta terapéutica analizada por el médico. Resultados: Cincuenta y seis pacientes iniciaron tratamiento, 6 fueron excluidos por falta de datos. Se evaluó a 50 pacientes (42% hombres), mediana de edad 47,8 años, el 38% de ellos diagnosticados de EM primaria progresiva, el 44% de EM secundaria progresiva y el 18% de EM remitente recurrente. El motivo de prescripción fue espasticidad (44%), dolor (10%) o ambos (46%). Se suspendió tratamiento en 16 pacientes por inefectividad (7 pacientes), abandono (4) y efectos adversos (5). La mediana de tiempo de exposición de los pacientes que suspendieron tratamiento fue 30 días y 174 días para los que continuaban tratamiento al final del estudio. THC/CBD fue efectivo en un 80% de pacientes, con dosis mediana de 5 (2-10) pulverizaciones/día. El perfil de efectos adversos fue: mareo (11 pacientes), somnolencia (6), debilidad muscular (7), molestias bucales (2), diarrea (3), sequedad de boca (2), visión borrosa (2), agitación (1), náuseas (1), ideas paranoides (1). Conclusiones: THC/CBD se muestra como una buena alternativa al tratamiento habitual mejorando la espasticidad refractaria en la EM con perfil de toxicidad aceptable. Abstract: Introduction: Spasticity is a common symptom among patients with multiple sclerosis (MS).This study aims to assess the effectiveness and safety of the combination of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in clinical practice for the treatment of spasticity in MS. Methods: Retrospective observational study with patients treated with inhaled THC/CBD between April 2008 and March 2012. Descriptive patient and treatment variables were collected. Therapeutic response was evaluated based on the doctor's analysis and overall impression. Results: Of the 56 patients who started treatment with THC/CBD, 6 were excluded because of missing data. We evaluated 50 patients (42% male) with a median age 47.8 years (25.6-76.8); 38% were diagnosed with primary progressive MS, 44% with secondary progressive MS, and 18% with relapsing-remitting MS. The reason for prescribing the drug was spasticity (44%), pain (10%), or both (46%). Treatment was discontinued in 16 patients because of ineffectiveness (7 patients), withdrawal (4), and adverse effects (5). The median exposure time in patients whose treatment was discontinued was 30 days vs 174 days in those whose treatment continued at the end of the study. THC/CBD was effective in 80% of patients at a median dose of 5 (2-10) inhalations/day. The adverse event profile consisted of dizziness (11 patients), somnolence (6), muscle weakness (7), oral discomfort (2), diarrhoea (3), dry mouth (2), blurred vision (2), agitation (1), nausea (1), and paranoid ideation (1). Conclusions: THC/CBD appears to be a good alternative to standard treatment as it improves refractory spasticity in MS and has an acceptable toxicity profile. Palabras clave: Cannabidiol, Cannabinoides, Delta-9-tetrahidrocannabinol, Efectividad, Esclerosis múltiple, Espasticidad, Keywords: Cannabidiol, Cannabinoids, Delta-9-tetrahydrocannabinol, Effectiveness, Multiple sclerosis, Spasticit