Pre-LGM open-water conditions south of the Drygalski Ice Tongue, Ross Sea, Antarctica

2007 ◽  
Vol 19 (3) ◽  
pp. 373-377 ◽  
Author(s):  
Furio Finocchiaro ◽  
Carlo Baroni ◽  
Ester Colizza ◽  
Roberta Ivaldi
Keyword(s):  
Ross Sea ◽  
Open Water ◽  
Radiocarbon Dates ◽  
The Core ◽  
Bay Area ◽  
Terra Nova Bay ◽  
Insoluble Organic Matter ◽  
Victoria Land ◽  
Marine Isotope Stage 3 ◽  
Raised Beaches

AbstractA marine sediment core collected from the Nordenskjold Basin, to the south of the Drygalski Ice Tongue, provides new sedimentological and chronological data for reconstructing the Pleistocene glacial history and palaeoenvironmental evolution of Victoria Land. The core consists of an over consolidated biogenic mud covered with glacial diamicton; Holocene diatomaceous mud lies on top of the sequence. Radiocarbon dates of the acid insoluble organic matter indicate a pre-Last Glacial Maximum age (>24kyr) for the biogenic mud at the base of the sequence. From this we can presume that at least this portion of the western Ross Sea was deglaciated during Marine Isotope Stage 3 and enjoyed open marine conditions. Our results are consistent with recent findings of pre-Holocene raised beaches at Cape Ross and in the Terra Nova Bay area.

Significance of selected halocarbons monitoring in air samples collected in the Terra Nova Bay region (northern Victoria Land, Antarctica)

1999 ◽  
Vol 11 (2) ◽  
pp. 261-264 ◽  
Author(s):  
Filippo Mangani ◽  
Michela Maione ◽  
Luciano Lattanzi
Keyword(s):  
Ross Sea ◽  
Atmospheric Concentration ◽  
Air Samples ◽  
Terra Nova Bay ◽  
Victoria Land ◽  
Rate Of Increase ◽  
Terra Nova ◽  
Concentration Levels

CCl3F (or CFC-11) and CCl2F2 (or CFC-12) were determined in air samples collected, during subsequent summer Antarctic campaigns, in different sampling sites in the Ross Sea Region. The samples were analysed by GC-ECD after enrichment. Data obtained since 1988–89 were plotted to observe the trend of CFCs atmospheric concentration levels. A decrease in the rate of increase of CFC-12 concentration was observed, whilst the concentration of CFC-11 was actually seen to be decreasing.

scholarly journals Porifera collection of the Italian National Antarctic Museum (MNA), with an updated checklist from Terra Nova Bay (Ross Sea)

ZooKeys ◽  
2018 ◽  
Vol 758 ◽  
pp. 137-156 ◽  
Author(s):  
Claudio Ghiglione ◽  
Maria Chiara Alvaro ◽  
Matteo Cecchetto ◽  
Simonepietro Canese ◽  
Rachel Downey ◽  
...  
Keyword(s):  
Scientific Community ◽  
3D Model ◽  
Ross Sea ◽  
Species Level ◽  
Genus Level ◽  
Bay Area ◽  
Terra Nova Bay ◽  
Occurrence Data ◽  
Antarctic Research ◽  
Terra Nova

This new dataset presents occurrence data for Porifera collected in the Ross Sea, mainly in the Terra Nova Bay area, and curated at the Italian National Antarctic Museum (MNA, section of Genoa). Specimens were collected in 331 different sampling stations at depths ranging from 17 to 1,100 meters in the framework of 17 different Italian Antarctic expeditions funded by the Italian National Antarctic Research Program (PNRA). A total of 807 specimens, belonging to 144 morphospecies (i.e., 95 taxa identified at species level and 49 classified at least at the genus level) is included in the dataset. Nearly half (45%) of the species reported here correspond to species already known for Terra Nova Bay. Out of the remaining 55% previously unknown records, under a third (~29%) were classified at the species level, while over a quarter (~26%) were ascribed to the genus level only and these would require further study. All vouchers are permanently curated at the MNA and are available for study to the scientific community. A 3D model of an uncommon species from the Ross Sea, i.e. Tethyopsisbrondstedi (Burton, 1929), is also presented and will be made available for outreach purposes.

scholarly journals Polynya Signature Simulation Method polynya area in comparison to AMSR-E 89GHz sea-ice concentrations in the Ross Sea and off the Adélie Coast, Antarctica, for 2002–05: first results

2007 ◽  
Vol 46 ◽  
pp. 409-418 ◽  
Author(s):  
Stefan Kern ◽  
Gunnar Spreen ◽  
Lars Kaleschke ◽  
Sara De La Rosa ◽  
Georg Heygster
Keyword(s):  
Sea Ice ◽  
Ross Sea ◽  
Open Water ◽  
Simulation Method ◽  
Ross Ice Shelf ◽  
Terra Nova Bay ◽  
Defense Meteorological Satellite Program ◽  
First Results ◽  
Daily Scale ◽  
Microwave Imager

AbstractThe Polynya Signature Simulation Method (PSSM) is applied to Special Sensor Microwave/Imager observations from different Defense Meteorological Satellite Program spacecraft for 2002–05 to analyze the polynya area in the Ross Sea (Ross Ice Shelf polynya (RISP) and Terra Nova Bay polynya (TNBP)) and off the Adélie Coast (Mertz Glacier polynya (MGP)), Antarctica, on a sub-daily scale. The RISP and the MGP exhibit similar average total polynya areas. Major area changes (>10000km2; TNPB: >2000km2) occur over a range of 2–3 to 20 days in all regions. Sub-daily area changes are largest for the MGP (5800km2) and smallest for the TNBP (800km2), underlining the persistence of the forcing of the latter. ARTIST sea-ice (ASI) algorithm concentration maps obtained using 89 GHz Advanced Microwave Scanning Radiometer (AMSR-E) data are compared to PSSM maps, yielding convincing agreement in the average, similarly detailed winter polynya distribution. Average ASI algorithm ice concentrations take values of 25–40% and 65–80% for the PSSM open-water and thin-ice class, respectively. The discrepancy with expected values (0% and 100%) can be explained by the different spatial resolution and frequency used by the methods. A new land mask and a mask to flag icebergs are introduced. Comparison of PSSM maps with thermal ice thickness based on AVHRR infrared temperature and ECMWF ERA-40 data suggests an upper thickness limit for the PSSM thin-ice class of 20–25 cm.

Holocene raised beaches at Terra Nova Bay, Victoria Land, Antarctica

1991 ◽  
Vol 36 (2) ◽  
pp. 157-177 ◽  
Author(s):  
Carlo Baroni ◽  
Giuseppe Orombelli
Keyword(s):  
Sea Level ◽  
Level Curve ◽  
Relative Sea Level ◽  
Stratigraphic Sequence ◽  
Large Reservoir ◽  
Terra Nova Bay ◽  
Victoria Land ◽  
Nesting Sites ◽  
Terra Nova ◽  
Raised Beaches

AbstractMore than 40 14C dates for raised beaches at Terra Nova Bay ranging from the present to 7505 ± 230 yr B.P. supply minimum or maximum limiting ages that bracket a relative sea-level curve for this part of Victoria Land. Most samples consist of guano and penguin remains collected from abandoned nesting sites on beach deposits. Up to four 14C dates in stratigraphic sequence have been obtained in two soil profiles. Other samples consist of marine shells collected both within and on the surface of raised beaches. All 14C ages for organisms that lived or fed in circumantarctic waters were corrected for a large reservoir effect. The calibrated ages delimit a first relative sea-level curve for Victoria Land. Rates of uplift ranged from about 10 mm/yr following deglaciation to about 2 mm/yr in the last 3 millennia. Widespread presence of Adélie penguin nesting sites suggests that Terra Nova Bay was deglaciated before 7065 ± 250 yr B.P. (7059/6439 cal yr B.P.), when environmental conditions in the coastal area were similar to the present ones.

Salinity response to atmospheric forcing of the Terra Nova Bay polynya, Antarctica

2021 ◽  
pp. 1-14
Author(s):  
Deborah A. Le Bel ◽  
Christopher J. Zappa ◽  
Giorgio Budillon ◽  
Arnold L. Gordon
Keyword(s):  
Ross Sea ◽  
Open Water ◽  
Heat Fluxes ◽  
Ice Formation ◽  
Atmospheric Forcing ◽  
Surface Heat Fluxes ◽  
Water Fraction ◽  
Salinity Response ◽  
Terra Nova Bay ◽  
Terra Nova

Abstract The density and salinity of High Salinity Shelf Water, a key component of Antarctic Bottom Water emanating from the Ross Sea, are intensified by brine rejection induced by ice formation within the Terra Nova Bay (TNB) polynya. Ocean mooring data from 2007, meteorological observations from automatic weather stations and a satellite-derived history of the opening of TNB polynya delineate variability in water column salinity linked to atmospheric forcing, with a period on the order of 10 days. Lagged correlation analysis indicates that on average salinity response lags the polynya opening by 2 days and the wind forcing by 5 days. We find stronger correlations of salinity with the wind during March through May and with the polynya open-water fraction during June through October, with decreasing lags in the latter period. A one-dimensional mixed-layer model incorporating thermodynamic ice formation captures the oscillations in salinity. A process study shows that the variability in the polynya open-water fraction governs the final salinity attained by the model as well as the salinity cycling. Variability in surface heat fluxes modulates that effect. Our work suggests that there is a more complex relationship between salinity, the polynya open-water fraction, and atmospheric forcing than previously suggested.

scholarly journals Technical procedures for aeromagnetic surveys in Antarctica during the Italian expeditions (1988-1992)

1994 ◽  
Vol 37 (5 Sup.) ◽  
Author(s):  
E. Bozzo ◽  
A. Colla ◽  
G. Caneva ◽  
A. Meloni ◽  
A. Caramelli ◽  
...  
Keyword(s):  
Ross Sea ◽  
Base Stations ◽  
Aeromagnetic Survey ◽  
The North ◽  
Terra Nova Bay ◽  
Victoria Land ◽  
Range Type ◽  
Line Spacing ◽  
Tie Lines ◽  
Shelf Region

For most of Antarctica, the geophysical data now available are those of aeromagnetic surveys performed there from 1950 to 1960. Until 1984, the inaccurate positioning and insufficient monitoring of geomagnetic time variations allowed the investigation of the geomagnetic residual field only along profiles. The Ganovex IV aeromagnetic survey, performed by BGR-USGS over the Ross Sea and the Northern Victoria Land, and the geophysical investigations of BAS on the Southern Antarctic peninsula and the Ronne ice shelf region corresponds to the recent advancement of these techniques in Antarctica. The first experiments of aeromagnetic measurements, during the Italian expeditions in Antarctica were made during the 1988-1989 field season. Some geomagnetic helicopter borne profiles were accomplished with a Proton Precession Magnetometer (PPM) in the Terra Nova Bay-Gerlache Inlet area. In the 1989-1990 ItaliAntartide expedition some profiles were flown over the suture between the Wilson and Bower terranes, in Northern Victoria Land. During the 1991-1992 expedition, in cooperation with researchers of BGR (Bundesanstalt fur Geowissenschaften und Rohstoffe) of Hannover, the GITARA I (German ITalian Aeromagnetic Rescarch Antarctica) program, as part of the LIRA (Litospheric Investigation in the Ross Sea Area) project, was carried out. The investigated area lies between the latitudes 74°18' S and 75°18' S and the longitudes 160°30' E and 164°30'E and it corresponds to a portion of the North Victoria Land, located between the Eisenhower Range and the, DrygaIski Ice Tongue. The survey was made with a Cesium vapour magnetometer. The positioning system was of the “Range-Range” type, it consisted of three transmitters (beacons), installed inside the investigated area and located with GPS measurements. The line spacing was 4.4 km, with tie lines every 22 km. The survey covered an area of 6500 km2 . Four PPM base stations for the determination of the time variation corrections were installed. The aeromagnetic anomalies wilI allow the comparison with the ground geomagnetic surveys performed during the previous Antarctic expeditions, also in connection with the aeromagnetic maps of Ganovex IV, located at the northern and eastern boundaries of the GITARA area.

scholarly journals Late Wisconsin and Early Holocene Glacial History, Inner Ross Embayment, Antarctica

1989 ◽  
Vol 31 (2) ◽  
pp. 151-182 ◽  
Author(s):  
George H. Denton ◽  
James G. Bockheim ◽  
Scott C. Wilson ◽  
Minze Stuiver
Keyword(s):  
Ross Sea ◽  
Ice Sheet ◽  
Drainage System ◽  
Outlet Glacier ◽  
Radiocarbon Dates ◽  
Terra Nova Bay ◽  
Elevation Changes ◽  
Transantarctic Mountains ◽  
Pass Through ◽  
Basal Melting

AbstractLateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore (Beardmore Glacier), Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and “younger” (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000–13,000 yr B.P. Outlet-glacier profiles from these drifts constrain late Wisconsin ice-sheet surface elevations. Within these constraints, we give two extreme late Wisconsin reconstructions of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice-shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment one reconstruction shows floating shelf ice, whereas the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600-6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains. Sea level and basal melting probably controlled the extent of grounded ice in the Ross Embayment. The interplay between the precipitation (low late Wisconsin and high Holocene values) and the influence of grounding on outlet glaciers (late Wisconsin thickening and late Wisconsin/Holocene thinning, with effects dying out inland) probably controlled minor elevation changes of the polar plateau.

Notes on the lichen genus Rhizoplaca from continental Antarctica and on some other species from northern Victoria Land

2010 ◽  
Vol 42 (4) ◽  
pp. 429-437 ◽  
Author(s):  
M. CASTELLO
Keyword(s):  
Type Material ◽  
New Combination ◽  
Additional Species ◽  
Reliable Identification ◽  
Bay Area ◽  
Terra Nova Bay ◽  
Victoria Land ◽  
Continental Antarctica ◽  
Terra Nova

AbstractFive taxa of the genera Omphalodina and Rhizoplaca known from continental Antarctica are reassessed in order to identify a remarkable species collected from northern Victoria Land, for which the new combination Rhizoplaca macleanii (C.W. Dodge) Castello is proposed here. This poorly known species is known only from continental Antarctica. Two synonyms are discussed: Omphalodina exsulans (Th. Fr.) C. W. Dodge and O. siplei (C. W. Dodge & G. E. Baker) C. W. Dodge are synonyms of Rhizoplaca melanophthalma (DC.) Leuckert & Poelt. The correct name of another species is Tephromela priestleyi (C. W. Dodge) Øvstedal. The name O. johnstonii (C. W. Dodge) C. W. Dodge should be abandoned, type material being too scanty for a reliable identification. A contribution to the flora of the Terra Nova Bay area (northern Victoria Land) is provided, with two additional species, including Buellia vilis Th. Fr. new to Antarctic regions, and two nomenclatural corrections.

Ice record of a 13th century explosive volcanic eruption in northern Victoria Land, East Antarctica

2001 ◽  
Vol 13 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Biancamaria Narcisi ◽  
Marco Proposito ◽  
Massimo Frezzotti
Keyword(s):  
Volcanic Eruption ◽  
Ross Sea ◽  
Regional Climate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
13Th Century ◽  
Volcanic Event ◽  
Volcanic Province ◽  
The Core ◽  
Victoria Land

A volcanic event, represented by both coarse ash and a prominent sulphate peak, has been detected at a depth of 85.82 m in a 90 m ice core drilled at Talos Dome, northern Victoria Land. Accurate dating of the core, based on counting annual sulphate and nitrate fluctuations and on comparison with records of major known volcanic eruptions, indicates that the event occurred in 1254 ± 2 AD. The source volcano is most likely to be located within the Ross Sea region. In particular, the glass shards have a trachytic composition similar to rocks from The Pleiades and Mount Rittmann (Melbourne volcanic province), about 200 km from Talos Dome. Sulphate concentration is comparable with that of violent extra-Antarctic explosive events recorded in the same core, but atmospheric perturbation was short-lived and localized, suggesting a negligible impact on regional climate. It is suggested that this eruption may represent the most important volcanic explosion in the Melbourne province during the last eight centuries; thus this event may also represent a valuable chrono-stratigraphical marker on the East Antarctic plateau and in adjoining areas.

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