Palaeomagnetic results from the middle Tertiary Meander Intrusives of northern Victoria Land, East Antarctica

1996 ◽  
Vol 8 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Elena Belluso ◽  
Roberto Lanza
Keyword(s):  
Remanent Magnetization ◽  
Ross Sea ◽  
East Antarctica ◽  
Magnetic Mineralogy ◽  
Tilt Correction ◽  
Palaeomagnetic Data ◽  
Victoria Land ◽  
Geological Models ◽  
Laboratory Investigations ◽  
The Antarctic

The Tertiary stocks (Meander Intrusives) cropping out along the coasts of the Ross Sea were sampled for a palaeomagnetic study during the sixth Italian expedition to northern Victoria Land. Laboratory investigations concerned magnetic mineralogy and remanent magnetization. Minerals of the magnetiteulvöspinel series occur in the rocks from all stocks, with low-Ti titanomagnetite usually prevalent. Haematite and goethite occur in small amounts as alteration products. Large secondary components commonly screen the characteristic remanent magnetization and were removed by thermal or AF demagnetization at temperatures or peak-fields higher than 360°C and 20 mT respectively. A total of 10 VGPs were obtained from radiometrically dated rocks (42–22 Ma); the averaged position (69°S, 334°E; α95=9.9°) is the first middle Tertiary palaeomagnetic pole for East Antarctica, and gives evidence for a reversal in the course of the APW path. This evidence is not substantially altered by a supposed tilt-correction consistent with geophysical and geological models for the uplift of the Transantarctic Mountains. No definite conclusion about relative movements between East Antarctica and the Antarctic Peninsula can be drawn from the existing palaeomagnetic data.

scholarly journals Sub-decadal variations in outlet glacier terminus positions in Victoria Land, Oates Land and George V Land, East Antarctica (1972–2013)

2017 ◽  
Vol 29 (5) ◽  
pp. 468-483 ◽  
Author(s):  
A.M. Lovell ◽  
C.R. Stokes ◽  
S.S.R. Jamieson
Keyword(s):  
Antarctic Peninsula ◽  
East Antarctica ◽  
West Antarctica ◽  
Position Change ◽  
Outlet Glacier ◽  
Glacier Terminus ◽  
Victoria Land ◽  
Decadal Scale ◽  
Decadal Variations ◽  
The Antarctic

AbstractRecent work has highlighted the sensitivity of marine-terminating glaciers to decadal-scale changes in the ocean–climate system in parts of East Antarctica. However, compared to Greenland, West Antarctica and the Antarctic Peninsula, little is known about recent glacier change and potential cause(s), with several regions yet to be studied in detail. In this paper, we map the terminus positions of 135 glaciers along the coastline of Victoria Land, Oates Land and George V Land from 1972–2013 at a higher temporal resolution (sub-decadal intervals) than in previous research. These three regions span a range of climatic and oceanic conditions and contain a variety of glacier types. Overall, from 1972–2013, 36% of glaciers advanced, 25% retreated and the remainder showed no discernible change. On sub-decadal timescales, there were no clear trends in glacier terminus position change. However, marine-terminating glaciers experienced larger terminus position changes compared with terrestrial glaciers, and those with an unconstrained floating tongue exhibited the largest variations. We conclude that, unlike in Greenland, West Antarctica and the Antarctic Peninsula, there is no clear glacier retreat in the study area and that most of the variations are more closely linked to glacier size and terminus type.

scholarly journals Additions to the lichen flora of Victoria Land, Antarctica

2011 ◽  
Vol 32 (2) ◽  
pp. 123-138 ◽  
Author(s):  
Jerzy Smykla ◽  
Beata Krzewicka ◽  
Karina Wilk ◽  
Steven Emslie ◽  
Lucyna Śliwa
Keyword(s):  
Ross Sea ◽  
Land Area ◽  
Victoria Land ◽  
Continental Antarctica ◽  
The Antarctic ◽  
Lichen Flora

Additions to the lichen flora of Victoria Land, Antarctica Lichens of relict penguin colonies and sites affected by active penguin colonies were investigated in Victoria Land, Ross Sea sector, continental Antarctica. A total of 17 coastal sites, seven in northern and ten in southern Victoria Land, have been investigated across 7° of latitude from 71° to 78°S. Altogether 40 taxa of lichens have been identified. Four of the recorded species are new to the Antarctic - Caloplaca erecta, C. soropelta, C. tominii and Physcia tenella; two species are new to the Victoria Land area - Lecania nylanderiana and Lecanora polytropa. The first lichen records from Beaufort Island are also provided. Data presented here expand the knowledge on the occurrence, diversity and distribution of Victoria Land lichens.

scholarly journals Victoria Land, Antarctica: An Improved Geodynamic Interpretation Based on the Strain Rate Field of the Current Crustal Motion and Moho Depth Model

2020 ◽  
Vol 13 (1) ◽  
pp. 87
Author(s):  
Antonio Zanutta ◽  
Monia Negusini ◽  
Luca Vittuari ◽  
Leonardo Martelli ◽  
Paola Cianfarra ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Ross Sea ◽  
East Antarctica ◽  
Gravity Potential ◽  
Moho Depth ◽  
Airborne Gravity ◽  
Narrow Strip ◽  
Continental Scale ◽  
Victoria Land ◽  
Marine Gravity

In Antarctica, the severe climatic conditions and the thick ice sheet that covers the largest and most internal part of the continent make it particularly difficult to systematically carry out geophysical and geodetic observations on a continental scale. It prevents the comprehensive understanding of both the onshore and offshore geology as well as the relationship between the inner part of East Antarctica (EA) and the coastal sector of Victoria Land (VL). With the aim to reduce this gap, in this paper multiple geophysical dataset collected since the 1980s in Antarctica by Programma Nazionale di Ricerche in Antartide (PNRA) were integrated with geodetic observations. In particular, the analyzed data includes: (i) Geodetic time series from Trans Antarctic Mountains DEFormation (TAMDEF), and Victoria Land Network for DEFormation control (VLNDEF) GNSS stations installed in Victoria Land; (ii) the integration of on-shore (ground points data and airborne) gravity measurements in Victoria Land and marine gravity surveys performed in the Ross Sea and the narrow strip of Southern Ocean facing the coasts of northern Victoria Land. Gravity data modelling has improved the knowledge of the Moho depth of VL and surrounding the offshore areas. By the integration of geodetic and gravitational (or gravity) potential results it was possible to better constrain/identify four geodynamic blocks characterized by homogeneous geophysical signature: the Southern Ocean to the N, the Ross Sea to the E, the Wilkes Basin to the W, and VL in between. The last block is characterized by a small but significant clockwise rotation relative to East Antarctica. The presence of a N-S to NNW-SSE 1-km step in the Moho in correspondence of the Rennick Geodynamic Belt confirms the existence of this crustal scale discontinuity, possibly representing the tectonic boundary between East Antarctica and the northern part of VL block, as previously proposed by some geological studies.

scholarly journals Antarctic Interglacial Features

1965 ◽  
Vol 5 (40) ◽  
pp. 433-449
Author(s):  
Robert L. Nichols
Keyword(s):  
Sea Water ◽  
Ross Sea ◽  
Core Sample ◽  
Alluvial Fan ◽  
Ocean Bottom ◽  
Mcmurdo Sound ◽  
Cinder Cones ◽  
Fluvial Deposits ◽  
Victoria Land ◽  
The Antarctic

AbstractThe upper 180 ft. (55 m.) of Lake Vanda in Wright Valley, south Victoria Land, is essentially potable, whereas that part below 200 ft. (61 m.) is more than three times as saline as sea-water. The salinity below 200 ft. (61 in.) resulted from the evaporation and freezing, mainly during interglacial (Loop-Trilogy) time, of a larger, less saline body of water.An alluvial fan in Wright Valley has been dated as interglacial on the basis of (1) ice-marginal channels formed in Loop time that cut across it, and (2) the fjord-like longitudinal cross-section of the valley formed by the ice of the oldest glaciation or glaciations.Fossils found in till and glacio-fluvial deposits in the McMurdo Sound region, south Victoria Land, date from both early and late Pleistocene interglacial time.An ocean-bottom core sample obtained in the Ross Sea contained interglacial material. The presence in the sample of glacial marine sediments deposited in interglacial time suggests that the Antarctic Ice Sheet maintained itself throughout the Pleistocene.Sub-surface efflorescences consisting of a layer of pure salts as much as 3 in, (7.6 cm.) thick are found 2−5 in. (5−13 cm.) below the surface in Loop deposits in Wright Valley. The absence of similar thick occurrences in Trilogy deposits indicates that the efflorescences are, in part at least, interglacial.Interglacial cinder cones and lava flows are found in the McMurdo Sound area, and some of the widespread scoria present in moraines, glacio-fluvial deposits and beaches dates from interglacial time.

Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica)

Zootaxa ◽  
2021 ◽  
Vol 4966 (3) ◽  
pp. 321-336
Author(s):  
ÁLVARO L. PEÑA CANTERO
Keyword(s):  
New Zealand ◽  
Continental Shelf ◽  
New Records ◽  
East Antarctica ◽  
Atmospheric Research ◽  
Antarctic Continental Shelf ◽  
Victoria Land ◽  
Small Collection ◽  
The Antarctic

The Balleny Islands, an isolated archipelago located 240 km off the coast of Victoria Land (East Antarctica), are separated from the Antarctic continental shelf by waters more than 2000 m deep. The benthic hydroid fauna of these islands is little known, with only 25 species reported so far. The present study contributes to a better knowledge of the benthic hydrozoans inhabiting this archipelago by studying a small collection held at the National Institute of Water and Atmospheric Research Invertebrate Collection at Wellington, New Zealand. Sixteen species of benthic hydroids were found in the collection, belonging to nine families and 12 genera of Leptothecata. Kirchenpaueriidae and Oswaldella, with three species each, are the most speciose family and genus. Ten species represent new records for the region. The total number of benthic hydroid species known from the islands is raised to 34. 

Air and permafrost temperatures at Mount Melbourne (1989–98)

2005 ◽  
Vol 17 (1) ◽  
pp. 151-152 ◽  
Author(s):  
SALVATORE GAMBINO
Keyword(s):  
Ross Sea ◽  
Volcanic Belt ◽  
Temperature Sensors ◽  
Continuous Recording ◽  
Wide Spread ◽  
The Past ◽  
Victoria Land ◽  
General Cooling ◽  
Mixed Pattern ◽  
The Antarctic

Recent meteorological studies suggest a mixed pattern of climate change in Antarctica: a general cooling of the interior continent and warming in the Antarctic Peninsula over the past several decades (e.g. Comiso 2000, Doran et al. 2002, Vaughan et al. 2003). This note presents 10 years of continuous recording of air and permafrost temperature at Mount Melbourne (74°21′S, 164°42′E) in Northern Victoria Land. Mount Melbourne is a quiescent volcano belonging to a wide-spread volcanic belt which has developed since the Oligocene along the western margin of the Ross Sea, parallel to the Transantarctic Mountains (Fig. 1a). In 1988 a tilt network composed of five continuous recording sensors each equipped with four temperature sensors (Fig. 1b) was installed within the framework of Italian PRNA between the end of 1988 and the beginning of 1989 (Bonaccorso et al. 1995).

Downslope flow observations near Cape Adare shelf-break

2004 ◽  
Vol 16 (2) ◽  
pp. 199-204 ◽  
Author(s):  
A. BERGAMASCO ◽  
V. DEFENDI ◽  
G. BUDILLON ◽  
G. SPEZIE
Keyword(s):  
Ross Sea ◽  
Spatial Scales ◽  
Shelf Break ◽  
Investigation Area ◽  
Shelf Slope ◽  
Antarctic Continental Shelf ◽  
Victoria Land ◽  
Downslope Flow ◽  
The Antarctic ◽  
Continental Shelf Break

The analysis of two high resolution hydrological datasets acquired during the 1997 and 2001 summers across the Antarctic continental shelf-break near Cape Adare (Ross Sea) is presented. The main focus of these cruises was the investigation of the overflow of the High Salinity Shelf Water (HSSW). This dense and salty water mass forms along Victoria Land and flows northward, descending the slope near Cape Adare. Water types characterizing the study area are detected through vertical salinity profiles and by the horizontal distributions of the temperature and salinity. Temperature and salinity hydrological sections obtained by means of objective analysis method well describe the water masses interactions at the shelf/slope edge. The 1997 dataset shows evidence of a strong HSSW signature on the slope, but it is difficult to quantify the spatial scales involved in the spreading mechanism, because the overflow takes place at the edge of the investigation area. The 2001 data, collected at the same position with improved spatial and temporal resolution, clearly indicates the absence of a “true” HSSW downslope process. Even though no estimation of the amount of downslope flow can be given at present due to the resolution of the available dataset, it is possible to get a better phenomenological picture of the process by comparing the two years.

Genesis, properties and sensitivity of Antarctic Gelisols

1999 ◽  
Vol 11 (4) ◽  
pp. 387-398 ◽  
Author(s):  
L. Beyer ◽  
J.G. Bockheim ◽  
I.B. Campbell ◽  
G.G.C. Claridge
Keyword(s):  
Organic Matter ◽  
Antarctic Peninsula ◽  
Ross Sea ◽  
Mineral Weathering ◽  
East Antarctica ◽  
Soil Taxonomy ◽  
Nitrogen And Phosphorus ◽  
Human Disturbances ◽  
The Antarctic ◽  
Water Contents

According to the newest version of the US Soil Taxonomy permafrost-affected soils are Gelisols. Antarctic Gelisols in the cold deserts of the Ross Sea sector are formed under extreme conditions of low temperature and aridity. The main soil forming processes are oxidation and salinization, with almost complete absence of organic matter. The oldest soils date from around 13 Ma. The origin of most soil salts is atmospheric, linking these soils to those in other parts of the world through atmospheric processes. The soils have water contents in the active layer of the most arid areas <1%. With decreasing latitude or proximity to the coast in East Antarctica and the Antarctic Peninsula, soil water contents increase and the soils support a range of soil organisms and plant species. At latitudes ≤66°S organic matter accumulation and several other pedogenic processes such as cryoturbation, mineral weathering, brunification, acidification, podzolization and redoximorphism occur. In addition, these soils receive nitrogen and phosphorus from seabirds. In most places summer thaw lasts little more than six weeks; thaw depths range from around 10–100 cm. A critical factor in the soil development is the albedo of the soil surface, since the absorbed energy controls weathering processes. The extreme fragility of the soils in the arid Ross Sea sector is largely due to the absence of structure, cohesion, moisture and organic materials. Recovery from physical human disturbances is in the order of hundreds to thousands of years. In East Antarctica and the Antarctic Peninsula plant and organisms growth is similarly slow and ecosystems are susceptible to human impact. The occurrence of many old soils at high inland elevation indicates that little response to global climatic change would be expected there. For the much younger soils in East Antarctica and the Antarctic Peninsula, when mean annual summer temperatures are higher, responses to global change and change in sea level may be significant.

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