scholarly journals First results from radar profiles collected along the US-ITASE traverse from Taylor Dome to South Pole (2006–2008)

2009 ◽  
Vol 50 (51) ◽  
pp. 35-41 ◽  
Author(s):  
Brian C. Welch ◽  
Robert W. Jacobel ◽  
Steven A. Arcone
Keyword(s):  
Flow Regimes ◽  
Radar Data ◽  
East Antarctica ◽  
South Pole ◽  
The West ◽  
Ice Flow ◽  
The Us ◽  
First Results ◽  
Subglacial Lakes ◽  
Deformation Layer

AbstractThe 2006/07 and 2007/08 US-ITASE traverses from Taylor Dome to South Pole in East Antarctica provided opportunities to survey the subglacial and englacial environments using 3 MHz and 200MHz radar. We present first results of these new ground-based radar data. A prominent basal deformation layer indicates different ice-flow regimes for the northern and southern halves of the Byrd Glacier drainage. Buried dune stratigraphy that appears to be related to the megadunes towards the west occurs at depths of up to 1500 m. At least two new water-filled subglacial lakes were discovered, while two recently drained lakes identified from repeat ICESat surface elevation surveys appear to be devoid of water.

scholarly journals A revised inventory of Antarctic subglacial lakes

2005 ◽  
Vol 17 (3) ◽  
pp. 453-460 ◽  
Author(s):  
MARTIN J. SIEGERT ◽  
SASHA CARTER ◽  
IGNAZIO TABACCO ◽  
SERGEY POPOV ◽  
DONALD D. BLANKENSHIP
Keyword(s):  
East Antarctica ◽  
Large Lake ◽  
Dome A ◽  
Lake Vostok ◽  
The Third ◽  
The Us ◽  
Radio Echo Sounding ◽  
Subglacial Lakes ◽  
Lake Type ◽  
Echo Sounding

The locations and details of 145 Antarctic subglacial lakes are presented. The inventory is based on a former catalogue of lake-type features, which has been subsequently reanalysed, and on the results from three additional datasets. The first is from Italian radio-echo sounding (RES) of the Dome C region of East Antarctica, from which 14 new lakes are identified. These data also show that, in a number of occasions, multiple lake-type reflectors thought previously to be individual lakes are in fact reflections from the same relatively large lake. This reduces the former total of lake-type reflectors by six, but also adds a significant level of information to these particular lakes. The second dataset is from a Russian survey of the Dome A and Dome F regions of East Antarctica, which provides evidence of 18 new lakes and extends the coverage of the inventory considerably. The third dataset comprises three airborne RES surveys undertaken by the US in East Antarctica over the last five years, from which forty three new lakes have been identified. Reference to information on Lake Vostok, from Italian and US surveys taken in the last few years, is now included.

scholarly journals A detailed radiostratigraphic data set for the central East Antarctic Plateau spanning from the Holocene to the mid-Pleistocene

2021 ◽  
Vol 13 (10) ◽  
pp. 4759-4777
Author(s):  
Marie G. P. Cavitte ◽  
Duncan A. Young ◽  
Robert Mulvaney ◽  
Catherine Ritz ◽  
Jamin S. Greenbaum ◽  
...  
Keyword(s):  
Ice Core ◽  
Radar Data ◽  
Glacial Cycles ◽  
Data Set ◽  
Ice Flow ◽  
The Holocene ◽  
Antarctic Plateau ◽  
The Us ◽  
Core Site ◽  
Program Data

Abstract. We present an ice-penetrating radar data set which consists of 26 internal reflecting horizons (IRHs) that cover the entire Dome C area of the East Antarctic plateau, the most extensive to date in the region. This data set uses radar surveys collected over the space of 10 years, starting with an airborne international collaboration in 2008 to explore the region, up to the detailed ground-based surveys in support of the Beyond EPICA – Oldest Ice (BE-OI) European Consortium. Through direct correlation with the EPICA-DC ice core, we date 19 IRHs that span the past four glacial cycles, from 10 ka, beginning of the Holocene, to over 350 ka, ranging from 10 % to 83 % of the ice thickness at the EPICA-DC ice core site. We indirectly date and provide stratigraphic information for seven older IRHs using a 1D ice flow inverse model, going back to an estimated 700 ka. Depth and age uncertainties are quantified for all IRHs and provided as part of the data set. The IRH data set presented in this study is available at the US Antarctic Program Data Center (USAP-DC) (https://doi.org/10.15784/601411, Cavitte et al., 2020) and represents a contribution to the SCAR AntArchitecture action group (AntArchitecture, 2017).

Three-dimensional ice sheet structure at Dome C, central East Antarctica: implications for the interpretation of the EPICA ice core

2001 ◽  
Vol 13 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Martin J. Siegert ◽  
Richard D. Eyers ◽  
Ignazio E. Tabacco
Keyword(s):  
Ice Core ◽  
Three Dimensional ◽  
Ice Sheet ◽  
Local Variation ◽  
Radar Data ◽  
East Antarctica ◽  
Airborne Radar ◽  
Internal Layers ◽  
Ice Flow ◽  
Core Site

Airborne radar data acquired in 1995 by the Italian Antarctic Programme over Dome C in central East Antarctica were processed to develop maps of internal isochronous ice sheet layering around the EPICA ice core site. Three internal layers were traced continuously across the radar-survey area at ice depths of 1–2 km. The maps reveal that the ice core site is located where internal layers are near horizontal to depths of at least 2 km. The Italian radar data do not resolve internal layers below 2 km. However, radar data collected over this part of East Antarctica in the 1970s show the internal layers to depths of up to 4 km. These internal layers reveal the regional structure of ice to the west of Dome C. Layers from both surveys are dated through an existing chronostratigraphic link between the Vostok ice core site and Dome C. The pattern of internal layering at Dome C reflects relatively steady conditions of ice flow and accumulation for the last 100 000 years. However, for ice older than this we show that there is significant local variation in the thickness between internal layers and the ice-sheet base. Our maps provide an indication of the structure of the ice sheet from which the EPICA deep ice core will be taken.

Searching for new Sources of growth. Are the Developing Countries Catching up with the Developed ones?

2015 ◽  
pp. 30-53
Author(s):  
V. Popov
Keyword(s):  
Developing Countries ◽  
Western Europe ◽  
Gdp Per Capita ◽  
The West ◽  
Catching Up ◽  
The Us ◽  
The World ◽  
Economic Divergence ◽  
Per Capita ◽  
Relative Standing

This paper examines the trajectory of growth in the Global South. Before the 1500s all countries were roughly at the same level of development, but from the 1500s Western countries started to grow faster than the rest of the world and PPP GDP per capita by 1950 in the US, the richest Western nation, was nearly 5 times higher than the world average and 2 times higher than in Western Europe. Since 1950 this ratio stabilized - not only Western Europe and Japan improved their relative standing in per capita income versus the US, but also East Asia, South Asia and some developing countries in other regions started to bridge the gap with the West. After nearly half of the millennium of growing economic divergence, the world seems to have entered the era of convergence. The factors behind these trends are analyzed; implications for the future and possible scenarios are considered.

First glaciological investigations at Ridge B, central East Antarctica

2021 ◽  
pp. 1-10
Author(s):  
Alexey A. Ekaykin ◽  
Alexey V. Bolshunov ◽  
Vladimir Ya. Lipenkov ◽  
Mirko Scheinert ◽  
Lutz Eberlein ◽  
...  
Keyword(s):  
East Antarctica ◽  
Snow Density ◽  
Deep Drilling ◽  
Surface Mass ◽  
Annual Variations ◽  
First Results ◽  
Vostok Station ◽  
Water Stable Isotope ◽  
Isotope Content ◽  
Firn Core

Abstract The region of Ridge B in central East Antarctica is one of the last unexplored parts of the continent and, at the same time, ranks among the most promising places to search for Earth's oldest ice. In January 2020, we carried out the first scientific traverse from Russia's Vostok Station to the topographical dome of Ridge B (Dome B, 3807 m above sea level, 79.02°S, 93.69°E). The glaciological programme included continuous snow-radar profiling and geodetic positioning along the traverse's route, installation of snow stakes, measurements of snow density, collection of samples for stable water isotope and chemical analyses and drilling of a 20 m firn core. The first results of the traverse show that the surface mass balance at Dome B (2.28 g cm−2 year−1) is among the lowest in Antarctica. The firn temperature below the layer of annual variations is −58.1 ± 0.2°C. A very low value of heavy water stable isotope content (-58.2‰ for oxygen-18) was discovered at a distance of 170 km from Vostok Station. This work is the first step towards a comprehensive reconnaissance study of the Ridge B area aimed at locating the best site for future deep drilling for the oldest Antarctic ice.

scholarly journals Ice flow velocities over Vostok Subglacial Lake, East Antarctica, determined by 10 years of GNSS observations

2013 ◽  
Vol 59 (214) ◽  
pp. 315-326 ◽  
Author(s):  
A. Richter ◽  
D.V. Fedorov ◽  
M. Fritsche ◽  
S.V. Popov ◽  
V.Ya. Lipenkov ◽  
...  
Keyword(s):  
Flow Velocity ◽  
East Antarctica ◽  
Global Navigation Satellite Systems ◽  
Steady Increase ◽  
Lake Area ◽  
Ice Flow ◽  
Satellite Systems ◽  
Subglacial Lake ◽  
Gnss Observations ◽  
Flow Velocities

AbstractRepeated Global Navigation Satellite Systems (GNSS) observations were carried out at 50 surface markers in the Vostok Subglacial Lake (East Antarctica) region between 2001 and 2011. The horizontal ice flow velocity vectors were derived with accuracies of 1 cm a−1 and 0.5°, representing the first reliable information on ice flow kinematics in the northern part of the lake. Within the lake area, ice flow velocities do not exceed 2 m a−1. The ice flow azimuth is southeast in the southern part of the lake and turns gradually to east-northeast in the northern part. In the northern part, as the ice flow enters the lake at the western shore, the velocity decreases towards the central lake axis, then increases slightly past the central axis. In the southern part, a continued acceleration is observed from the central lake axis across the downstream grounding line. Based on the observed flow velocity vectors and ice thickness data, mean surface accumulation rates are inferred for four surface segments between Ridge B and Vostok Subglacial Lake and show a steady increase towards the north.

scholarly journals A wireless subglacial probe for deep ice applications

2012 ◽  
Vol 58 (211) ◽  
pp. 841-848 ◽  
Author(s):  
C.J.P.P. Smeets ◽  
W. Boot ◽  
A. Hubbard ◽  
R. Pettersson ◽  
F. Wilhelms ◽  
...  
Keyword(s):  
Water Pressure ◽  
Greenland Ice Sheet ◽  
Depth Range ◽  
Measured Temperature ◽  
Transmission Power ◽  
The West ◽  
System A ◽  
Antenna Type ◽  
First Results ◽  
Good Agreement

AbstractWe present the design and first results from two experiments using a wireless subglacial sensor system (WiSe) that is able to transmit data through 2500 m thick ice. Energy consumption of the probes is minimized, enabling the transmission of data for at least 10 years. In July 2010 the first prototype of the system was used to measure subglacial pressure at the base and a temperature profile consisting of 23 probes in two 600 m deep holes at Russell Glacier, a land-terminating part of the West Greenland ice sheet near Kangerlussuaq. The time series of subglacial pressure show very good agreement between data from the WiSe system and the wired reference system. The wireless-measured temperature data were validated by comparison with the theoretical decrease of melting point with water pressure inside the water-filled hole directly after installation. To test the depth range of the WiSe system a second experiment using three different probe types and two different surface antennas was performed inside the 2537 m deep hole at NEEM. It is demonstrated that, with the proper combination of transmission power and surface antenna type, the WiSe system transmits data through 2500 m thick ice.

“The Triumph of the West”: American Education and the Narrative of Decolonization, 1930–1965

2018 ◽  
Vol 58 (4) ◽  
pp. 567-594 ◽  
Author(s):  
Stephen Jackson
Keyword(s):  
World War Ii ◽  
World History ◽  
American Education ◽  
World War ◽  
The West ◽  
Global Engagement ◽  
The Us ◽  
Good Government ◽  
Western Values ◽  
European Colonialism

This article examines representations of imperialism, anti-colonial nationalism, and decolonization in US textbooks for American and World History courses between 1930 and 1965. Broadly speaking, 1930s and early 1940s texts lauded imperialism and associated European colonialism with American imperialist activities. Authors extolled the benefits for colonial peoples, including literacy, good government, and peace, and anti-colonial nationalists were caricatured as irrational and ungrateful. US global engagement during and after World War II gradually changed the narrative, particularly following Philippine independence in 1946, as texts subsequently portrayed the US as an enlightened decolonizer. Postwar textbooks tended to argue that nationalism was a product of Western ideas and that anti-colonial nationalism was a triumph for Western civilization. While constructing this narrative of the spread of Western values, textbook authors largely marginalized colonial actors, promoted unflattering and stereotyped views of Africans and Asians, and de-emphasized the extreme violence inherent in the decolonization process.

The Communist Contest for Status

2019 ◽  
pp. 82-133
Author(s):  
Deborah Welch Larson ◽  
Alexei Shevchenko
Keyword(s):  
Soviet Union ◽  
The United States ◽  
Social Competition ◽  
The West ◽  
Republic Of China ◽  
The Soviet Union ◽  
Economic Production ◽  
Communist Ideology ◽  
The Us ◽  
Catch Up

This chapter argues that both the Soviet Union and the People's Republic of China (PRC) pursued social competition with the Western states while at the same time seeking recognition from the states they were trying to subvert. Stalin sought to increase the power and prestige of the Soviet state through coerced industrialization, and Khrushchev made an effort to “catch up and surpass” the West in economic production. The PRC sought to improve its status by allying with the Soviet Union, but the Chinese chafed under their status as “younger brothers” to their senior ally, and eventually Mao challenged the Soviets for leadership of the international communist movement. In the 1970s, China took advantage of the US need to balance Soviet military power by putting aside communist ideology to become a tacit ally of the United States, part of a “strategic triangle.”

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