From 1 - 10 / 28
  • The data are approximately 800 km of airborne electromagnetic survey of coastal sea ice and sub-ice platelet layer (SIPL) thickness distributions in the western Ross Sea, Antarctica, from McMurdo Sound to Cape Adare. Data were collected between 8 and 13 November 2017, within 30 days of the maximum fast ice extent in this region. Approximately 700 km of the transect was over landfast sea ice that had been mechanically attached to the coast for at least 15 days. Most of the ice was first-year sea ice. Unsmoothed in-phase and quadrature components are presented at all locations. Data have been smoothed with an 100 point median filter, and in-phase and quadrature smoothed data are also presented at all locations. Beneath level ice it is possible to identify the thickness of an SIPL and a filter is described (Langhorne et al) to identify level ice. Level ice in-phase, quadrature and SIPL thickness, derived from these, are presented at locations of level ice. For rough ice, the in-phase component is considered the best measure of sea ice thickness. For level ice where there is the possibility of an SIPL, then the quadrature component is considered the best measure of ice thickness, along with SIPL thickness. All data are in meters.

  • The data are approximately 800 km of airborne electromagnetic survey of coastal sea ice and sub-ice platelet layer (SIPL) thickness distributions in the western Ross Sea, Antarctica, from McMurdo Sound to Cape Adare. Data were collected between 8 and 13 November 2017, within 30 days of the maximum fast ice extent in this region. Approximately 700 km of the transect was over landfast sea ice that had been mechanically attached to the coast for at least 15 days. Most of the ice was first-year sea ice. Unsmoothed in-phase and quadrature components are presented at all locations. Data have been smoothed with an 100 point median filter, and in-phase and quadrature smoothed data are also presented at all locations. Beneath level ice it is possible to identify the thickness of an SIPL and a filter is described (Langhorne et al) to identify level ice. Level ice in-phase, quadrature and SIPL thickness, derived from these, are presented at locations of level ice. For rough ice, the in-phase component is considered the best measure of sea ice thickness. For level ice where there is the possibility of an SIPL, then the quadrature component is considered the best measure of ice thickness, along with SIPL thickness. All data are in meters.

  • This Zenodo dataset contain the Common Objects in Context (COCO) files linked to the following publication: Each COCO zip folder contains an "annotations" folder including a json file and an "images" folder containing the annotated images. Verhaegen, G, Cimoli, E, & Lindsay, D (2021). Life beneath the ice: jellyfish and ctenophores from the Ross Sea, Antarctica, with an image-based training set for machine learning. Biodiversity Data Journal. https://doi.org/10.3897/BDJ.9.e69374 GET DATA: https://doi.org/10.5281/zenodo.5118012 GET DATA: http://ipt.pensoft.net/resource?r=life_beneath_the_ice-jellyfish_and_ctenophores_from_the_ross_sea_antarctica&v=1.3

  • Plot data Mc Nemar: To enable comparisons with the 1961 and 2004 survey results, the Lambert Conformal Conic projection from the 2004 survey was used to precisely georeference and trim the RGB image across a 1-m2 grid, generating a total of 3,458 1-m2 grid cells. For each grid cell moss, lichen, or algae/cyanobacteria cover was extracted as one of the four cover classes: Heavy (>40%), Patchy (10–40%), Scattered (less than 10%), and None (0%) for the survey years 1962, 2004 and 2018. Ground truthing: To test the overall accuracy of cover classifications and ensure consistency with 2004 survey methodologies, a ground-truthing approach was performed. Photographs were taken of individual cells along eight transects, running west to east across the plot at 0.5, 1.5, 15.5, 16.5, 28.5, 29.5, 116.5 and 117.5 m distance from the NW corner. Each grid cell could be identified individually with an x/y coordinate in the centre and was surrounded by a rectangular frame parallel to the outer edge of the plot. A total of 174 photographs were taken and archived with Antarctica New Zealand. For each photographed grid cell, the presence of each functional group of vegetation and their cover class was assessed visually. Orthomosaic image: Aerial images were obtained using a DJI Matrice 600 Pro hex-rotor remotely piloted aircraft system equipped with a Canon EOS 5Ds camera (image size: 8688×5792 pixels, focal length: 50 mm, pixel size: 4.14 μm) on November 28, 2018. The flight altitude was 30 m above ground level, and a total of 10 ground-control points were included to provide accurate geo-referencing. An orthomosaic photo and accompanying DEM was generated with the acquired aerial images using Agisoft PhotoScan (now known as Metashape by Agisoft LLC, https://www.agisoft.com/) RELATED PUBLICATION: https://doi.org/10.1029/2022EF002823 GET DATA: https://doi.org/10.7488/ds/3417

  • Here we provide data from the Ross Ice Shelf ocean cavity. The HWD2 Camp was established in October of 2017 at (-80 39.497, 174 27.678) where the ice is moving seaward at around ~600 m a-1 and is sourced from the Transantarctic Mountains. Profiling Instruments - Profiling was primarily conducted with an RBR Concerto CTD (conductivity-temperature depth) profiling instrument, and this was cross-calibrated against irregular profiles with an RBR Duet (pressure and temperature only), a SBE37 MicroCat CTD as well as moored SBE37 MicroCat CTDs. The RBR unit is small and has suitable sensor capability (temperature and conductivity accuracies of ±0.002°C and ±0.003 mS cm-1). Its conductivity cell design is not prone to fouling by ice crystals, making it ideal for work in the sometimes crystal-laden borehole conditions. We were inconsistent in how we mounted the CTD on its protective frame and this appeared to make small difference in the conductivity signal (resulting in an ~0.03 psu variation). This was post-corrected based on the essentially invariant mooring data from the lower water column as well as SBE37 cross-calibration profile data. Because of the potential for sediment contamination of the sensors, the profiles were mostly conservative in their proximity to the sea floor. On several occasions, profiles were conducted all the way to the sea floor. The temperature and salinity are presented in EOS-80 in order to compare with available data. Eighty-three profiles are provided here (ctd_HWD2_*.dat). In addition, limited microstructure profiling was conducted to provide insight into some of the mixing details. The profiles were conducted by lowering the instrument to the ice base then commencing a sequence of three up-down “yo-yos” before returning to the surface and downloading. A data segment is included here (VMP_HWD2.dat). There were some challenges registering the vertical coordinate for the profiles. The melting of the borehole generates a trapped pool of relatively fresh water. The interface between this and the ocean should be near the base of the hole or a little higher – with seawater intrusion. However, there were some instances where the interface was at a higher pressure (i.e. apparently in the open water column). The best explanation for this is that the water in the borehole is not at static equilibrium for some period after initial melting. We use 34.3 psu as a cut-off, in addition to a pressure criterion to identify the top of the useful oceanic profile. It is also not inconceivable that water was being ejected from the hole, but it is unlikely that this would have impacted in the consistent observed pattern. Instrumented Mooring - The mooring instruments at HWD2-A comprised 5 Nortek Aquadopp single point current meters in titanium housings reporting to the surface (30-minute interval, Table SI-Three) via an inductive modem to a Sound-9 data logger and Iridium transmitter. The current meter measurements were corrected to account for the 138° magnetic declination offset (i.e. the south magnetic pole is to the north-west of the field site). Five files are provided here (HWD2_Init_rcm*.dat4). Stevens Craig, Hulbe Christina, Brewer Mike, Stewart Craig, Robinson Natalie, Ohneiser Christian, Jendersie Stefan (2020). Ocean mixing and heat transport processes observed under the Ross Ice Shelf control its basal melting. Proceedings of the National Academy of Sciences, 117 (29), 16799-16804. https://doi.org/10.1073/pnas.1910760117

  • The data are approximately 800 km of airborne electromagnetic survey of coastal sea ice and sub-ice platelet layer (SIPL) thickness distributions in the western Ross Sea, Antarctica, from McMurdo Sound to Cape Adare. Data were collected between 8 and 13 November 2017, within 30 days of the maximum fast ice extent in this region. Approximately 700 km of the transect was over landfast sea ice that had been mechanically attached to the coast for at least 15 days. Most of the ice was first-year sea ice. Unsmoothed in-phase and quadrature components are presented at all locations. Data have been smoothed with an 100 point median filter, and in-phase and quadrature smoothed data are also presented at all locations. Beneath level ice it is possible to identify the thickness of an SIPL and a filter is described (Langhorne et al) to identify level ice. Level ice in-phase, quadrature and SIPL thickness, derived from these, are presented at locations of level ice. For rough ice, the in-phase component is considered the best measure of sea ice thickness. For level ice where there is the possibility of an SIPL, then the quadrature component is considered the best measure of ice thickness, along with SIPL thickness. All data are in meters.

  • This data publication contains biostratigraphic age events for the CIROS-1 drill core, updated age ranges for a suite of samples from the McMurdo erratics sample collection, age-depth tie points for CIROS-1, CRP-2/2A, DSDP 270, DSDP 274, ANDRILL 2A and ANDRILL 1B, and glycerol dialkyl glycerol tetraethers (GDGTs) abundances and indices for samples from the McMurdo erratics, CIROS-1, CRP-2/2A, DSDP 270, DSDP 274, ANDRILL 2A, and ANDRILL 1B. All sample sites are in the Ross Sea region of Antarctica. The McMurdo erratics are glacial erratics collected in the McMurdo Sound region between 1991 and 1996 (Harwood and Levy, 2000). The CIROS-1 drill core was collected from McMurdo sound in 1986 with samples spanning the upper Eocene to lower Miocene. CRP-2/2A drill core was collected in 1999 from offshore Victoria Land with samples for this study from the upper Oligocene-lower Miocene. DSDP Site 270 was recovered from the Eastern Basin of the central Ross Sea in 1973, with samples spanning the upper Oligocene-lower Miocene. DSDP Site 274 was drilled on the lower continental rise in the northwestern Ross Sea in 1973, and samples for this study have been taken from the middle Miocene sections of the drill core. The ANDRILL-2A core was recovered in 2007 from Southern McMurdo Sound, samples span the lower Miocene to middle Miocene and data was originally published in Levy et al. (2016). The ANDRILL-IB core was drilled from the McMurdo Ice Shelf in 2006, samples are compiled from the Plio-Pleistocene section of the core and were originally published in McKay et al. (2012). Biostratigraphic age events are described for CIROS-1, expanding on and updating previously published age models and biostratigraphic ranges. Ages are also revised for the McMurdo erratics by updating the ages of the biostratigraphic markers described by (Harwood and Levy (2000) to more recently published age ranges. Age models for the sample sites are developed using published age datums and the Bayesian age-depth modelling functionality in the R package Bchron (Haslett and Parnell, 2008) to ensure a consistent approach for assigning ages to core depths between datums. GDGT abundances and indices for Ross Sea sites are presented to reconstruct ocean temperatures over the Cenozoic era. Detailed methodology for the processing and analysis of samples for GDGTs is described in the methods section of supplement paper.

  • The data are approximately 800 km of airborne electromagnetic survey of coastal sea ice and sub-ice platelet layer (SIPL) thickness distributions in the western Ross Sea, Antarctica, from McMurdo Sound to Cape Adare. Data were collected between 8 and 13 November 2017, within 30 days of the maximum fast ice extent in this region. Approximately 700 km of the transect was over landfast sea ice that had been mechanically attached to the coast for at least 15 days. Most of the ice was first-year sea ice. Unsmoothed in-phase and quadrature components are presented at all locations. Data have been smoothed with an 100 point median filter, and in-phase and quadrature smoothed data are also presented at all locations. Beneath level ice it is possible to identify the thickness of an SIPL and a filter is described (Langhorne et al) to identify level ice. Level ice in-phase, quadrature and SIPL thickness, derived from these, are presented at locations of level ice. For rough ice, the in-phase component is considered the best measure of sea ice thickness. For level ice where there is the possibility of an SIPL, then the quadrature component is considered the best measure of ice thickness, along with SIPL thickness. All data are in meters.

  • The data set contains sea ice thickness (consolidated ice plus snow) of pack ice in the Western Ross Sea acquired by fixed wing aircraft (BT-67 C-GJKB) between McMurdo Sound (77.68 S / 165.52E) and near Cape Adare (72.01 S / 171.53 E). Two survey profiles are oriented South - North near parallel and about 100km off the Victoria Land coast, and two survey profiles are leading into Terra Nova Bay oriented in East –West direction at around 74.5 S and 75 S. The total length of the survey profiles is about 800 km. The Southern survey was flown from 9 November 2017 22:19 UTC to 10 November 2017 00:25 UTC beginning in McMurdo Sound and went for 300 km to the north, before turning west into Terra Nova Bay for another 100 km. The Northern survey was flown on 11 November 2017 from 1:21 UTC to 3:04 UTC from near the Adare Peninsula in a southerly direction for 215 km before turning southwest towards Cape Washington for another 140 km. The airborne electromagnetic induction (AEM) ice thickness sensor was towed by a Basler BT-67 aircraft sampling thickness every 6m along the flight track. The accuracy of the measured ice thickness is +/-0.1m over level ice. Ice thicknesses are biased up to 50% low for pressure ridges smaller than the signal footprint of about 45 m. Data was collected with the support of Antarctica New Zealand (event K066-1718-A; 25/10/2017-28/11/2017) for the New Zealand National Science Challenge Deep South (Targeted observation and process informed modelling of Antarctic sea ice, PI P. Langhorne). The purpose of data collection was to gain a basic understanding of sea ice thickness close to the areas of the Ross Sea, McMurdo, and Terra Nova Bay Polynyas.

  • Data includes estimates of abundance of seaweed taxa on the seafloor across the Northern Victoria Land coast, Ross Sea, Antarctica. This includes: - Metadata of video transects - Seaweed density across transects - Modelled outputs of light attenuation across sites. Descriptions: - "Antarctic_Seaweed_Metadata_TAN2101_TAN2302_Dryad.xlsx" - Metadata of video transects, date and time, locations, gear, depth, distance covered. - "Antarctic_Seaweeds_TAN2101_TAN2302.csv" - Density of seaweed functional groups across video transects - "Light_transects_TAN2021_TAN2302.csv" - Outputs of light modelling for seafloor regions of the Ross Sea - "Antarctic_Seaweed_RScript_Tait_etal_2024.txt" - R sripts used to plot, analyse and model the above datasets Further details are provided at: Tait, L.W., Chin, C., Nelson, W. et al. Deep-living and diverse Antarctic seaweeds as potentially important contributors to global carbon fixation. Commun Earth Environ 5, 205 (2024). https://doi.org/10.1038/s43247-024-01362-2 GET DATA: https://doi.org/10.5061/dryad.w6m905qwz