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1

Hydraulic performance of a permeable reactive barrier at Casey Station, Antarctica.  

PubMed

A permeable bio-reactive barrier (PRB) was installed at Casey Station, Antarctica in 2005/06 to intercept, capture and degrade petroleum hydrocarbons from a decade old fuel spill. A funnel and gate configuration was selected and implemented. The reactive gate was split into five separate cells to enable the testing of five different treatment combinations. Although different treatment materials were used in each cell, each treatment combination contained the following reactive zones: a zone for the controlled release of nutrients to enhance degradation, a zone for hydrocarbon capture and enhanced degradation, and a zone to capture excess nutrients. The materials selected for each of these zones had other requirements, these included; not having any adverse impact on the environment, being permeable enough to capture the entire catchment flow, and having sufficient residence time to fully capture migrating hydrocarbons. Over a five year period the performance of the PRB was extensively monitored and evaluated for nutrient concentration, fuel retention and permeability. At the end of the five year test period the material located within the reactive gate was excavated, total petroleum hydrocarbon concentrations present on the material determined and particle size analysis conducted. This work found that although maintaining media reactivity is obviously important, the most critical aspect of PRB performance is preserving the permeability of the barrier itself, in this case by maintaining appropriate particle size distribution. This is particularly important when PRBs are installed in regions that are subject to freeze thaw processes that may result in particle disintegration over time. PMID:25078614

Mumford, K A; Rayner, J L; Snape, I; Stevens, G W

2014-12-01

2

Cost-efficient methods for marine pollution monitoring at Casey Station, East Antarctica: the choice of sieve mesh-size and taxonomic resolution  

Microsoft Academic Search

Contaminants from sewage discharge and abandoned waste tips enter the marine environment adjacent to Australia’s Casey Station, East Antarctica. To establish cost-efficient methods for benthic pollution monitoring the effects of sieve mesh-size (0.5 and 1.0 mm) and taxonomic aggregation (family, order and class) on the description of infaunal assemblages were determined. The abundance and taxonomy of fauna retained on a

Belinda W Thompson; Martin J Riddle; Jonathan S Stark

2003-01-01

3

Cost-efficient methods for marine pollution monitoring at Casey Station, East Antarctica: the choice of sieve mesh-size and taxonomic resolution.  

PubMed

Contaminants from sewage discharge and abandoned waste tips enter the marine environment adjacent to Australia's Casey Station, East Antarctica. To establish cost-efficient methods for benthic pollution monitoring the effects of sieve mesh-size (0.5 and 1.0 mm) and taxonomic aggregation (family, order and class) on the description of infaunal assemblages were determined. The abundance and taxonomy of fauna retained on a 0.5 mm sieve after passing through a 1.0 mm sieve were examined in this study. The 1.0 mm sieve fraction [Human impacts and assemblages in marine soft-sediments at Casey Station, Antarctica, Ph.D. thesis, University of New England, 2001] contained 70% of individuals and 94% of taxa when compared to combined abundances on the 1.0 and 0.5 mm sieves. Furthermore, the addition of 0.5 mm data did not increase sampling precision or the statistical power to detect differences between locations. Differences between locations were detected when species were aggregated to the family level however, further aggregation to order and class levels altered the perceived pattern of differences. Marine pollution monitoring of the soft-bottom benthos at Casey Station is most cost-effective when using a 1.0 mm sieve and identifying fauna to the family level. This is the first reported comparison of sampling techniques using Antarctic benthos. PMID:12586119

Thompson, Belinda W; Riddle, Martin J; Stark, Jonathan S

2003-02-01

4

Investigation of evaporation and biodegradation of fuel spills in Antarctica: II-extent of natural attenuation at Casey Station.  

PubMed

In many temperate regions, fuel and oil spills are sometimes managed simply by allowing natural degradation to occur, while monitoring soils and groundwater to ensure that there is no off-site migration or on-site impact. To critically assess whether this approach is suitable for coastal Antarctic sites, we investigated the extent of evaporation and biodegradation at three old fuel spills at Casey Station. Where the contaminants migrated across frozen ground, probably beneath snow, approximately half the fuel evaporated in the first few months prior to infiltration at the beginning of summer. Once in the ground, however, evaporation rates were negligible. In contrast, minor spills from fuel drums buried in an abandoned waste disposal site did not evaporate to the same extent. Biodegradation within all three spill sites is generally very minor. We conclude that natural attenuation is not a suitable management strategy for fuel-contaminated soils in Antarctic coastal regions. PMID:16169050

Snape, Ian; Ferguson, Susan H; Harvey, Paul McA; Riddle, Martin J

2006-03-01

5

Benthic diatom community response to environmental variables and metal concentrations in a contaminated bay adjacent to Casey Station, Antarctica.  

PubMed

This study examined the effects of anthropogenic contaminants and environmental variables on the composition of benthic diatom communities within a contaminated bay adjacent to an abandoned waste disposal site in Antarctica. The combination of geographical, environmental and chemical data included in the study explained all of the variation observed within the diatom communities. The chemical data, particularly metal concentrations, explained 45.9% of variation in the diatom communities, once the effects of grain-size and spatial structure had been excluded. Of the metals, tin explained the greatest proportion of variation in the diatom communities (28%). Tin was very highly correlated (R2>0.95) with several other variables (copper, iron, lead, and sum of metals), all of which explained similarly high proportions of total variation. Grain-size data explained 23% of variation once the effects of spatial structure and the chemical data had been excluded. The pure spatial component explained only 1.8% of the total variance. The study demonstrates that much of the compositional variability observed in the bay can be explained by concentrations of metal contaminants. PMID:15757690

Cunningham, Laura; Snape, Ian; Stark, Jonathan S; Riddle, Martin J

2005-03-01

6

Ionospheric convection at Casey, a southern polar cap station  

NASA Astrophysics Data System (ADS)

A digital ionosonde (Digisonde Portable Sounder 4) located at Casey, Antarctica (66.3°S, 110.5°E, -80.8° corrected geomagnetic latitude) has been operational since early 1993 and has accumulated 3 years of plasma drift measurements, providing an excellent data set for studying the characteristics of ionospheric convection flow at a southern polar cap station. The purpose of this study is to investigate the influence of the IMF on the F region ionospheric convection over Casey and to compare it to the Heppner-Maynard satellite-derived electric field models. We find clear dependencies in the drift on the sign and strength of the IMF By and Bz components and with Kp. Antisunward flow dominates during Bz south conditions, turning to have a sunward component around noon when Bz is northward. The By component causes the entire convection system to rotate and distorts the dayside flow in the proximity of the throat, with a dawnward (duskward) component for By negative (positive). Comparison with the Bz south Heppner-Maynard BC, DE, and A patterns is favorable at most times, although we predict a rounder, more dominant dusk (dawn) cell and a smaller crescent-shaped dawn (dusk) cell for By<0 (By>0). There is a dependence on Kp when Bz is south in both the model and the drifts, flow directions becoming more antisunward and velocities becoming higher on the dayside as Kp increases. This implies the polar cap is expanding under conditions of enhanced reconnection. When Bz is north, the F region drift agreement with the BCP(P) and DEP(P) models is excellent on the dawn (dusk) side for By<0 (By>0) but diverges on the opposite side as the pattern flow lines twist sunward. Separation of the drifts into Bz weakly (<3nT) and strongly (>3nT) northward cases did not reveal any appreciable difference in the observed drift velocities.

Smith, P. R.; Dyson, P. L.; Monselesan, D. P.; Morris, R. J.

1998-02-01

7

Blowing snow at Mizuho station, Antarctica  

Microsoft Academic Search

Blowing snow observations were carried out at Mizuho station, Antarctica, from October to November 2000. A blowing snow observation system including snow particle counters, which can sense not only the number of snow particles, but also their diameters, was situated on a 30 m tower. All instruments worked correctly and the data obtained revealed profiles of mass flux and particle

Kouichi Nishimura; Masaki Nemoto

2005-01-01

8

Blowing snow at Mizuho station, Antarctica.  

PubMed

Blowing snow observations were carried out at Mizuho station, Antarctica, from October to November 2000. A blowing snow observation system including snow particle counters, which can sense not only the number of snow particles, but also their diameters, was situated on a 30 m tower. All instruments worked correctly and the data obtained revealed profiles of mass flux and particle size distributions as a function of the friction velocity. Measurements were compared with a blowing snow model that accounted for most physical processes including aerodynamic entrainment, grain/bed collisions, wind modification, particle size distribution and turbulent fluctuations on the particle trajectories. Simulated and measured results showed close agreement, and the validity of the model was demonstrated. Vertical profiles of horizontal mass flux from saltation to suspension, as well as the particle size distributions were expressed precisely, which could not be achieved using the previous models. PMID:16011937

Nishimura, Kouichi; Nemoto, Masaki

2005-07-15

9

Ozone profiles above Palmer Station, Antarctica  

NASA Technical Reports Server (NTRS)

NASA's Goddard Space Flight Center/Wallops Flight Facility conducted a series of 52 balloon-borne measurements of vertical ozone profiles over the National Science Foundation (NSF) research facility at Palmer Station, Antarctica (64 deg 46 S, 64 deg 3 W) between August 9 and October 24, 1987. High resolution measurements were made from ground level to an average of 10 mb. While much variation was seen in the profile amounts of ozone, it is clear that a progressive depletion of ozone occurred during the measurement period, with maximum depletion taking place in the 17 to 19 km altitude region. Ozone partial pressures dropped by about 95 percent in this region. Shown here are plotted time dependences of ozone amounts observed at 17 km and at arbitrarily selected altitudes below (13 km) and above (24 km) the region of maximum depletion. Ozone partial pressure at 17 km is about 150nb in early August, and has decreased to less than 10nb in the minimums in October. The loss rate is of the order of 1.5 percent/day. In summary, a progressive depletion in stratospheric ozone over Palmer Station was observed from August to October, 1987. Maximum depletion occurred in the 17 to 19 km range, and amounted to 95 percent. Total ozone overburden decreased by up to 50 percent during the same period.

Torres, Arnold L.; Brothers, George

1988-01-01

10

Antarctica: A Southern Hemisphere Windpower Station?  

E-print Network

The International Polar Year commences in 2007. We offer a macroproject plan to generate a large amount of electricity on the continent of Antarctica by using sail-like wind dams incorporating air turbines. Electricity can be used to make exploration and exploitation efforts on Antarctica easier. We offer the technical specifications for the Fabric Aerial Dam and indicate some of the geographical facts underpinning our macro-engineering proposal.

Alexander A. Bolonkin; Richard B. Cathcart

2007-01-04

11

VLF wave-injection experiments from Siple Station, Antarctica  

NASA Astrophysics Data System (ADS)

Experiments in which VLF waves are injected into the magnetosphere from Siple Station, Antarctica, are described. Emphasis is placed on the growth, saturation, and triggering of VLF waves due to the interaction between coherent input waves and energetic charge particles. Consideration is also given to wave-induced precipitation and its effects on the ionosphere.

Helliwell, R. A.

12

Measurements of enhanced springtime ultraviolet radiation at Palmer Station, Antarctica  

Microsoft Academic Search

Measurements of ultraviolet solar spectra from Palmer Station, Antarctica have defined the surface radiation environment of the region during the Austral spring of 1988. At wavelengths where absorption by ozone is negligible, 335-345 nm, the noontime irradiances show the expected gradual increase from the first day of measurements, September 19 through December 21. Large variations related to cloudiness are imposed

Dan Lubin; John E. Frederick; C. Rocky Booth; Timothy Lucas; David Neuschuler

1989-01-01

13

Atmospheric CO2 record from continuous measurements at Jubany Station, Antarctica  

E-print Network

Atmospheric CO2 record from continuous measurements at Jubany Station, Antarctica Graphics Location The Italian PNRA (National Research Program in Antarctica) began continuous atmospheric carbon Jubany Station, Antarctica 62°14' S, 58°40' W 15 m right MSL #12;Period of Record March 1994 - December

14

Concordia CCD - A Geoscope station in continental Antarctica  

NASA Astrophysics Data System (ADS)

Concordia (Dome C, Antarctica) has had a permanent seismic station since 2005. It is run by EOST and INGV in collaboration with the French and Italian polar institutes (IPEV and PNRA). It is installed in an ice-vault, at 12m depth, distant 1km from the permanent scientific base at Concordia. The temperature in the vault is a constant -55°C. The data quality at the station has improved continuously since its installation. In 2007, the station was declared at ISC as an open station with station code CCD (ConCorDia), with data available upon request. It is only the second permanent station in the Antarctic continent, after South Pole. In 2010, CCD was included in the Geoscope network. Data from CCD starting in 2007 are now freely available from the Geoscope Data Center and IRIS. We present an analysis of the data quality at CCD, and describe the technical difficulties of operating an observatory-quality seismic station in the extreme environmental conditons present in continental Antarctica.

Maggi, A.; Lévêque, J.; Thoré, J.; Bes de Berc, M.; Bernard, A.; Danesi, S.; Morelli, A.; Delladio, A.; Sorrentino, D.; Stutzmann, E.; Geoscope Team

2010-12-01

15

VLF wave injection into the magnetosphere from Siple Station, Antarctica  

Microsoft Academic Search

Radio signals in the 1.5- to 16-kHz range transmitted from Siple Station, Antarctica (L = 4), are used to control wave-particle interactions in the magnetosphere. Observations at the conjugate point show signal growth and triggered emissions including risers, failers, and hooks. Growth rates of the order of 100 dB\\/s and total gains up to 30 dB are observed. Triggered emissions

R. A. Helliwell; J. P. Katsufrakis

1974-01-01

16

Chemical composition of fresh snowfalls at Palmer Station, Antarctica  

Microsoft Academic Search

A first time investigation was performed to establish a chemical baseline for snowfall at Palmer Station Antarctica (64°46?S, 64°05?W) since there was no such record. A chemical baseline for snow could be use to validate climate change studies based on ice core analyses. The snow samples contained (from high to low mass concentration) total organic carbon, chloride, inorganic carbon, sodium,

T. P. DeFelice

1998-01-01

17

Chemical composition of fresh snowfalls at Palmer Station, Antarctica  

NASA Astrophysics Data System (ADS)

A first time investigation was performed to establish a chemical baseline for snowfall at Palmer Station Antarctica (64°46'S, 64°05'W) since there was no such record. A chemical baseline for snow could be use to validate climate change studies based on ice core analyses. The snow samples contained (from high to low mass concentration) total organic carbon, chloride, inorganic carbon, sodium, sulfate, magnesium, calcium, potassium, fluoride, ammonium, and nitrate, excluding hydrogen and hydroxide. The pH of these samples ranged between 4.0-6.2. The relatively low nitrate and relatively high sulfate concentrations found in our samples are consistent with the results of other studies for this region of Antarctica. The ions and pH do not appear to favor a particular wind direction during this period. The total deposition of sulfate and flouride via snowfall between 10 January and 10 February is conservatively estimated to be 4.78 and 1.3 kg km -2, respectively.

DeFelice, T. P.

18

Record low ozone measured at McMurdo Station, Antarctica, during the austral spring of 1993  

SciTech Connect

The annual springtime ozone hole over Antarctica has been studied extensively since it was first reported. The University of Wyoming has participated in monitoring the development of the ozone hole over Antarctica since 1986 using balloonborne instruments to measure vertical profiles of ozone and particles at McMurdo Station, Antarctica. During austral spring 1993, record minimums in total column ozone were observed along with a record low within the main ozone layer at 12-20 kilometers (km). 6 refs., 2 figs.

Johnson, B.J.; Deshler, T. [Univ. of Wyoming, Laramie, WY (United States)

1994-12-31

19

Antarctica  

article title:  Twilight in Antarctica     View larger JPEG image  (51 kb) Twilight in Antarctica, February 24, 2000 . Nearly 15 times every 24 hours, the Terra ... - The Ross Ice Shelf and the Transantarctic Mountains of Antarctica at twilight. project:  MISR category:  ...

2013-04-16

20

Temporal and spatial variability of geochemical backgrounds in the Windmill Islands, East Antarctica: Implications for climatic changes and human impacts  

Microsoft Academic Search

To establish a natural background and its temporal and spatial variability for the area around Casey Station in the Windmill Islands, East Antarctica, the authors studied major and trace element concentrations and the distribution of organic matter in marine and lacustrine sediments. A wide range of natural variability in trace metal concentrations was identified between sites and within a time

Massimo Gasparon; Katharina Ehrler; Jörg Matschullat; Martin Melles

2007-01-01

21

Sulphate profile in EPICA-DML ice core (Kohnen Station East Antarctica) by Fast Ion Chromatography  

Microsoft Academic Search

Kohnen Station (Dronning Maud Land - Atlantic sector of Antarctica) is one of the two drilling sites, the other being located at Dome C, chosen in the framework of EPICA project. Unlike Dome C ice core (EDC), where the low accumulation rate allowed recovering climatic and environmental data covering more than 800.000 years, the Kohnen Station ice core (EDML) is

M. Severi; S. Becagli; S. Benassai; E. Castellano; A. Migliori; R. Udisti

2003-01-01

22

Kory Hanley Casey Peters  

E-print Network

Arduino Kory Hanley Casey Peters Brandon Cox #12;Overview Arduino is an open-source single development environment #12;The History Arduino means "Brave Friend" in Italian Created in 2005 in Ivrea, Italy Arduino team: Massimo Banzi, David Cuartielles, Tom Igoe, Gianluca Martino and David Mellis #12

Valtorta, Marco

23

A study of the surface mass balance in Dronning Maud Land, Antarctica, using automatic weather stations  

Microsoft Academic Search

We use data from four automatic weather stations (AWSs) in Dronning Maud Land, East Antarctica, to study the surface mass balance and its components. Distinct differences were found between the moisture climates of the high plateau, the katabatic wind zone and the coastal ice shelves: significant undersaturation occurs year-round in the katabatic wind zone, while on the high plateau and

Michiel R. van den Broeke; Carleen H. Reijmer

2004-01-01

24

Surface radiation balance in Antarctica as measured with automatic weather stations  

Microsoft Academic Search

We present 4 years of near-surface radiation balance observations of four Antarctic automatic weather stations (AWS). The AWS are situated along a traverse line in Dronning Maud Land, connecting the coastal ice shelf and the inland plateau via the katabatic wind zone, covering the three major climate regimes of East Antarctica. Important differences in the radiation balance of the three

Michiel van den Broeke; Carleen Reijmer; Roderik van de Wal

2004-01-01

25

Temporal and spatial patterns of anthropogenic disturbance at McMurdo Station, Antarctica  

NASA Astrophysics Data System (ADS)

Human visitations to Antarctica have increased in recent decades, raising concerns about preserving the continent's environmental quality. To understand the spatial and temporal patterns of anthropogenic disturbances at the largest scientific station in Antarctica, McMurdo Station, a long-term monitoring program has been implemented. Results from the first nine years (1999-2007) of monitoring are reported. Most physical disturbance of land surfaces occurred prior to 1970 during initial establishment of the station. Hydrocarbons from fuel and anthropogenic metals occur in patches of tens to hundreds of square meters in areas of fuel usage and storage. Most soil contaminant concentrations are not expected to elicit biological responses. Past disposal practices have contaminated marine sediments with polychlorinated biphenyls (PCBs), petroleum hydrocarbons, and metals in close proximity to the station that often exceed concentrations expected to elicit biological responses. Chemical contamination and organic enrichment reduced marine benthic ecological integrity within a few hundred meters offshore of the station. Contaminants were detected in marine benthic organisms confirming bioavailability and uptake. PCBs in sediments are similar to suspected source materials, indicating minimal microbial degradation decades after release. Anthropogenic disturbance of the marine environment is likely to persist for decades. A number of monitoring design elements, indicators and methodologies used in temperate climates were effective and provide guidance for monitoring programs elsewhere in Antarctica.

Kennicutt, Mahlon C., II; Klein, Andrew; Montagna, Paul; Sweet, Stephen; Wade, Terry; Palmer, Terence; Sericano, Jose; Denoux, Guy

2010-07-01

26

Addition to the Greenhouse at McMurdo Station, Antarctica  

NSF Publications Database

... McMurdo Station while using less imported fossil fuels. III. Alternatives Alternative A. In this ... lights at the existing greenhouse, no on-site fuel storage is required. The new structure will ...

27

Absolute-gravity stations in Western Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

Absolute-gravity stations are an important part of the geodetic infrastructure of the Antarctic. They provide accurate starting values for gravity surveys performed e.g. for the determination of the geoid, for geological studies and for geophysical investigations. The time variation in gravity determined from repeated absolute-gravity measurements provides insights into the Glacial Isostatic Adjustment (GIA) and into solid Earth deformation due to variation in contemporary ice load. Given sufficient joint coverage with International Terrestrial Reference Frame (ITRF) sites, gravity rates in high latitudes could in principle provide an independent check of the geocentricity of the z-dot (velocities in the direction of the rotation axis of the Earth) of the ITRF. We review the absolute gravity stations in Western and Central Dronning Maud Land. The oldest station is at the Finnish base Aboa, with 5 measurements by the Finnish Geodetic Institute (FGI) starting with the FINNARP 1993 expedition. Measurements at Maitri (India) and Novolazarevskaya (Russia) were first performed in 2004 by the National Geophysical Research Institute (NGRI) of India, and by the FGI, respectively. In the season 2010/11 a new station was constructed at Troll (Norway). In the season 2011/12 the aforementioned four sites were occupied by the FG5-221 absolute gravimeter of the FGI. At Sanae IV (South Africa) there are previous occupations by the FG5-221, in 2003/4 and 2005/6. All these bases have continuous GNSS stations. Numerous supporting measurements have been made at the sites: microgravity networks, levelling and GNSS ties to excentres etc., for controlling the stability of the stations. At some sites, nearby glacier elevations were surveyed to monitor the attraction of the variable close-field snow and ice masses. We give a description of the sites and the measurements performed at them. The work has benefited from the co-operation in the COST Action ES0701 "Improved Constraints on Models of GIA".

Mäkinen, Jaakko; Rasindra, Ravik; Chand, Uttam; Tiwari, Virendra; Lukin, Valery; Anisimov, Michail; Melvaer, Yngve; Melland, Gudmund; Koivula, Hannu; Näränen, Jyri; Poutanen, Markku

2013-04-01

28

Snowpack Chemistry of Reactive Gases at Station Concordia, Antarctica  

NASA Astrophysics Data System (ADS)

During December 2012 a new experiment for the study of snow photochemical processes and surface gas exchange was installed at Dome Concordia, Antarctica. The experiment consists of two sampling manifolds ('snow tower') which facilitate the withdrawal of interstitial firn air from four depths in the snowpack and from above the surface. One of these snow towers can be shaded for investigation of the dependency of snow chemistry on solar radiation. A nearby 12 m meteorological tower facilitates above surface turbulence and trace gas gradient measurements. Temperature profiles and UV and IR light penetration are monitored in the snowpack. Air samples are directed through sampling lines to a nearby underground laboratory that houses the experiment control system and gas monitors. The system is fully automated, sampling gases from the array of inlet ports sequentially, and is intended to be operated continuously for a full annual cycle. The computerized control system can be accessed remotely for data retrieval and quality control and for configuring experimental details. Continuous gas measurements include ozone, nitrogen oxides, methane, carbon monoxide, and gaseous elemental mercury. Whole air samples were sampled on four occasions for volatile organic compound analysis. The objective of this research is the study of the year-round snowpack gas chemistry and its dependency on snowpack and above surface physical and environmental conditions. A particular emphasis will be the investigation of the effects of increased UV radiation during the occurrence of the stratospheric ozone hole. We will present the conceptual design of the experiment and data examples from the first three months of the experiment.

Helmig, Detlev; Mass, Alex; Hueber, Jacques; Fain, Xavier; Dommergue, Aurelien; Barbero, Albane; Savarino, Joel

2013-04-01

29

A theoretical study of the ionosphere over Zhongshan Station, Antarctica  

Microsoft Academic Search

A three-dimensional, time-dependent model for the polar ionosphere has been developed. The simulation results are applied to the interpretation of the ionospheric F region over Zhongshan Station. The daily variation is obtained for the high-latitude global polar ionosphere NmF2, mainly taking into account the interaction between the solar EUV ionization and the ionospheric convection processes in the polar region. It

B. Zhang; R. Liu; H. Yang; Z. Chen

2005-01-01

30

Dome Fuji Station in East Antarctica and the Japanese Antarctic Research Expedition  

NASA Astrophysics Data System (ADS)

Japanese Antarctic Research Expedition (JARE) commenced on the occasion of International Geophysical Year in 1957-1958. Syowa Station, the primary station for JARE operations, is located along the northeastern coastal region of Lützow-Holm Bay, East Antarctica (69° 00'S, 39° 35'E), and was opened on 29 January 1957. Since then, JARE have been carrying out research in various fields of earth and planetary sciences and life science. Astronomical science, however, has not been popular in Antarctica. In 1995, JARE established a new inland station, Dome Fuji Station (77° 19'S, 39° 42'E), which, at 3,810 m a.s.l., is located on one of major domes of the Antarctic ice sheet, some 1,000 km south of Syowa. The climatic conditions at Dome Fuji are harsh, with an annual average air temperature of -54°C, and a recorded minimum of -79°C. In 2007, JARE completed scientific drilling to obtain ice core samples of the Antarctic ice sheet reaching 3,050 m in depth. These ice cores record environmental conditions of the earth extending back some 720,000 B.P. In recent years, it is widely known that the high-altitude environment of inland Antarctica is suitable for astronomical observations and the Japanese astronomy community identified Dome Fuji Station as a potential candidate for a future astronomical observatory. In this article, the history of Japanese Antarctic activities are described in terms of access to the inland plateau of the Antarctic continent. The general scheme and future plans of science objectives and logistics of JARE will also be introduced.

Shiraishi, Kazuyuki

2013-01-01

31

Application of ground-penetrating radar at McMurdo Station, Antarctica  

SciTech Connect

Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

Stefano, J.E.

1992-05-01

32

Ground-based measurements of column amounts of NO{sub 2} over Syowa Station, Antarctica  

SciTech Connect

The authors interpret column measurements of NO{sub 2} made from Syowa Station, Antarctica since March, 1990. It is lowest in midwinter, and peaks in midsummer. The fall rate of decrease is considerably greater than the spring increase rate. Temperature trends indicate that late winter polar stratospheric clouds could form, providing an explanation for low NO{sub 2} abundances. They have used a box model to simulate the observed density variations. Increasing amounts of aerosols from the eruption of Pinatubo probably account for lower NO{sub 2} densities in late spring of 1991. Effects due to the atmospheric aerosol loading are seen to extend into 1992, and also during 1992 the vortex boundary was located differently with respect to the observation station.

Kondo, Y.; Hayashi, M.; Nakajima, H.; Tsukui, K. [Nagoya Univ., Toyokawa (Japan)] [Nagoya Univ., Toyokawa (Japan); Matthews, W.A. [National Institute of Water and Atmospheric Research, Lauder (New Zealand)] [National Institute of Water and Atmospheric Research, Lauder (New Zealand); Solomon, S. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)] [National Oceanic and Atmospheric Administration, Boulder, CO (United States); Yamazaki, K. [Meteorological Research Institute, Tsukuba (Japan)] [Meteorological Research Institute, Tsukuba (Japan)

1994-07-20

33

Year Round Operation of Autonomous, Low Power Geophysical Stations in Antarctica  

NASA Astrophysics Data System (ADS)

Year round operation of autonomous, low power geophysical stations in Antarctica presents both technical and logistical challenges. Prior to 2005, few if any autonomous seismic or GPS stations operated continuously throughout the austral winter. There are two basic environmental challenges in Antarctica beyond the logistical challenge: the margins with relatively mild temperatures but extreme winds and the Polar Plateau with extreme temperatures but relatively little wind. Large caches of lead-acid batteries can operate stations on the Antarctic margins where temperatures are relatively high, but are logistically expensive and will not survive the extreme temperatures of the Polar Plateau. Primary lithium thionyl chloride batteries have been proven to be successful and economical for use in the extreme plateau environment. These technical and logistical challenges were the focus of an IRIS/PASSCAL-UNAVCO collaboration to design power and communications for a < 5W system capable of continuous operation without intervention for two years. This collaboration has resulted in the successful operation of close to 100 GPS and seismic stations on several IPY projects with better than 80% data return. Our systems were designed to challenging logistical constrains for increased efficiency in polar operations. These year-round systems can now be deployed in a single twin otter flight. The IRIS/PASSCAL-UNAVCO collaboration has resulted in deployable systems backed by facilities with proven track records of longevity of technical field support. Our expertise and sustained engineering has resulted in a robust community product. We have significantly lowered the barriers of entry to scientists who desire year-round autonomous data collection in the Polar regions. A transparent development process with broad community support and input has resulted in a new generation of GPS and seismic systems fielded on several major IPY projects. The challenge now is how to keep the development and testing effort sustained to take advantage of the evolving renewable energy research.

Beaudoin, B. C.; White, S.; Bonnett, B.; Parker, T.; Johns, B.; Anderson, K. R.

2009-12-01

34

Christine Casey Department of Entomology  

E-print Network

pesticide use Photo Rollin Coville #12;Water Bees drink water, while most insects derive moisture indirectlyChristine Casey Department of Entomology UC Davis Gardening to Conserve Bees, Beneficials and logs #12;Shelter­ above ground · Bee houses · Bird houses · Grasses · Dead trees, if you have the space

Ishida, Yuko

35

Casey Doyle: Artist at Play  

ERIC Educational Resources Information Center

The article discusses the work of Casey Doyle, and the narrative metaphors and personal explorations that inform his sculptures and how, for his undergraduate thesis, he selected a body of work whose central theme explores his identity as a gay man, informing his relationships with family, friends and society. (Contains 5 figures.)

Sanders, James H., III; Doyle, Casey

2008-01-01

36

FY 1994 ambient air monitoring report for McMurdo Station, Antarctica  

SciTech Connect

This report presents the results of ambient air monitoring performed during the 1994 fiscal year (FY 1994) in the vicinity of McMurdo Station, Antarctica. Routine monitoring was performed during the 1993-1994 austral summer at three locations for airborne particulate matter less than 10 micrometers (PM-10) and at two locations for carbon monoxide (CO), sulfur dioxide (SO{sub 2}), and nitrogen oxides (NO, NO{sub 2}, and NO{sub x}). Selected PM-10 filters were analyzed for arsenic, beryllium, cadmium, chromium, lead, mercury, and nickel. Additional air samples were collected at three McMurdo area locations and at Black Island for determination of the airborne concentration of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with US Environmental Protection Agency guidance for local ambient air quality networks.

Lugar, R.M.

1994-12-01

37

Bursts of cloud condensation nuclei (CCN) by dissipating clouds at Palmer Station, Antarctica  

SciTech Connect

The authors present here a case study of cloud-mediated production of cloud condensation nuclei (CCN) recorded at Palmer Station (64{degrees}46`S, 64{degrees}05`W), Antarctica on 20 Jan 1994. Four instances of CCN bursts occured on January 17, 19, 20 and February 7, 1994 when cloud base descended to the surface and dissipated under prevailing meteorlogical conditions. The most spectacular event ocurred on January 20 when the CCN concentration was enhanced by a factor of four at 0.025% supersaturation (with respect to water) compared to the prevent concentration. At 1.25% supersaturation, the corresponding enhancement was by a factor of seven. This indicated a larger production of aerosol particles in smaller size ranges. The elevated CCN concentrations were measured for over fifteen hours. The CCN activity spectrum during the event resembled the ones that are typical of previous measurements in the urban plumes of St. Louis and Denver. 30 refs., 3 figs.

Saxena, V.K. [North Carolina State Univ., Raleigh, NC (United States)] [North Carolina State Univ., Raleigh, NC (United States)

1996-01-01

38

Results of monitoring for PCDDs and PCDFs in ambient air at McMurdo Station, Antarctica  

SciTech Connect

This report presents the results of ambient air monitoring for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) performed during the 1992-1993 austral summer in the vicinity of McMurdo Station, Antarctica. Fifteen air samples were collected from four different locations for determination of the presence and concentration of PCDD/PCDF compounds. General Metal Works Inc. PS-1 air samplers equipped with polyurethane foam (PUF) with a sample flow rate of approximately 0.27 m{sup 3}/min. were used to collect air samples. Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with U.S. Environmental Protection Agency guidance for local ambient air quality networks. PCDD/PCDF compounds were not detected at the predominantly upwind location and at a more remote site on Black Island. Trace levels of only a few PCDD/PCDF congeners were detected sporadically at a location approximately 500 meters downwind of the station. The most frequent, most varied, and highest levels of PCDDs/PCDFs were measured at a {open_quotes}downtown{close_quotes} location, where concentrations of total PCDDs ranged from 0.27 to 1.80 pg/m{sup 3} and total PCDFs from less than 0.1 to 2.77 pg/m{sup 3}. Results from the remote Black Island site indicate that the background Antarctic air is still {open_quotes}free{close_quotes} of PCDD/PCDF compounds (not detectable at current method detection limits). The initial baseline effort demonstrated that site selection and sampling equipment performance were satisfactory, provided useful data for assessing the impact of McMurdo operations on the local ambient air quality, and provided baseline data for assessing the Antarctica continental air quality.

Lugar, R.M.

1993-09-01

39

Column ozone measurements from Palmer Station, Antarctica: Variations during the Austral Springs of 1988 and 1989  

SciTech Connect

The National Science Foundation scanning spectroradiometer at Palmer Station, Antarctica (64{degree}-46{prime}S, 64{degree}04{prime}W), provides hourly ground-based measurements of solar ultraviolet (UV) irradiance. In addition to defining the UV radiation environment of the region, these measurements allow the derivation of the column density of atmospheric ozone above the station nearly every daylight hour. This hourly time resolution, not generally available from other methods of monitoring Antarctic ozone abundances, enables the detection of large and rapid changes in total column ozone and UV surface irradiance associated with the dynamics of the polar vortex. Column ozone abundance is derived from a ratio of measured irradiances at 300 and 313.5 nanometers (nm) by means of theoretical calculation of this ratio as a function of total ozone amount. Noontime ozone abundances over Palmer Station obtained from this method agree with those obtained by the Total Ozone Mapping Spectrometer (TOMS) instrument aboard Nimbus 7 to within about 10% throughout the austral spring of 1988. Ozone recovery at Palmer Station, associated with the breakup of the polar vortex as indicated by TOMS satellite ozone observations, occurred rapidly within a 24-hour period beginning in midafternoon on November 15. Over the Antarctic Peninsula, the 1989 ozone depletion was slightly greater than in 1988, the minimum noontime ozone abundances over Palmer Station as measured by the spectroradiometer being 194 and 166 Dobson units for October 14, 1988, and October 14, 1989, respectively. The 1989 ozone depletion however ended by November 5 over the Antarctic Peninsula, 10 days earlier than the 1988 event.

Lubin, D. (Univ. of California, San Diego, La Jolla (USA)); Frederick, J.E. (Univ. of Chicago, IL (USA))

1990-08-20

40

Comprehensive characterization report on Winter Quarters Bay, McMurdo Station, Antarctica  

SciTech Connect

Winter Quarters Bay is a small embayment located adjacent to the United States largest base in Antarctica, McMurdo Station. McMurdo Station, which is managed by the National Science Foundation`s Office of Polar Programs, was constructed in 1955, has been in constant use since that time, and has a population of about 1,000 persons during the summer and about 250 people for the winter. The bay offers shelter for ships and an ice dock is used during January and February to off load fuel and cargo. During earlier times, trash from the McMurdo Station was piled on the steep shoreline of the bay, doused with several thousand gallons of fuel and ignited. That practice has ceased and the site has been regraded to cover the waste. The bottom of the bay is littered with drums, equipment, tanks, tires, all sorts of metal objects, cables, etc., especially the southeastern side where dumping took place. The sediments are gravel in some places yet fine and fluid at other sites with coarse particles intermixed. The original benthic community is not well recorded but significant ecological changes have occurred. Sediments are contaminated with PCBs, metals, and hydrocarbon fuels. This report summarizes available information on Winter Quarters Bay and was originally intended to be used by workshop participants to become familiar with the bay prior to becoming updated with unpublished data by various Antarctic investigators. The proposed workshop was to assist the National Science Foundation in determining whether and how the bay should be remediated and to develop an integrated research plan if additional data were needed. However, plans changed, the workshop was never conducted, but the briefing report was prepared. Most of this report reviews and summarizes other published data. The only new data are those from the Idaho National Engineering and Environmental Laboratory`s investigation into the distribution of organic contaminants in the bay and sediment toxicity testing.

Crockett, A.B.; White, G.J.

1997-01-01

41

Simultaneous aerosol measurements of unusual aerosol enhancement in the troposphere over Syowa Station, Antarctica  

NASA Astrophysics Data System (ADS)

Unusual aerosol enhancement is often observed at Syowa Station, Antarctica, during winter and spring. Simultaneous aerosol measurements near the surface and in the upper atmosphere were conducted twice using a ground-based optical particle counter, a balloon-borne optical particle counter, and micropulse lidar (MPL) in August and September 2012. During 13-15 August, aerosol enhancement occurred immediately after a storm condition. A high backscatter ratio and high aerosol concentrations were observed from the surface to ca. 2.5 km over Syowa Station. Clouds appeared occasionally at the top of the aerosol-enhanced layer during the episode. Aerosol enhancement was terminated on 15 August by strong winds from a cyclone's approach. In the second case, on 5-7 September, aerosol number concentrations in Dp > 0.3 ?m near the surface reached > 104 L-1 at about 15:00 UT (Universal Time) on 5 September despite calm wind conditions, whereas MPL measurement exhibited aerosols were enhanced at about 04:00 UT at 1000-1500 m above Syowa Station. The aerosol enhancement occurred near the surface to ca. 4 km. In both cases, air masses with high aerosol enhancement below 2.5-3 km were transported mostly from the boundary layer over the sea-ice area. In addition, air masses at 3-4 km in the second case came from the boundary layer over the open-sea area. This air mass history strongly suggests that dispersion of sea-salt particles from the sea-ice surface contributes considerably to aerosol enhancement in the lower free troposphere (about 3 km) and that the release of sea-salt particles from the ocean surface engenders high aerosol concentrations in the free troposphere (3-4 km). Continuous MPL measurements indicate that high aerosol enhancement occurred mostly in surface-lower free troposphere (3 km) during the period July-September.

Hara, K.; Hayashi, M.; Yabuki, M.; Shiobara, M.; Nishita-Hara, C.

2014-04-01

42

Measurement of black carbon at Syowa station, Antarctica: seasonal variation, transport processes and pathways  

NASA Astrophysics Data System (ADS)

Measurement of black carbon (BC) was carried out at Syowa station Antarctica (69° S, 39° E) from February 2004 until January 2007. The BC concentration at Syowa ranged from below detection to 176 ng m-3 during the measurements. Higher BC concentrations were observed mostly under strong wind (blizzard) conditions due to the approach of a cyclone and blocking event. The BC-rich air masses traveled from the lower troposphere of the Atlantic and Indian Oceans to Syowa (Antarctic coast). During the summer (November-February), the BC concentration showed a diurnal variation together with surface wind speed and increased in the katabatic wind from the Antarctic continent. Considering the low BC source strength in the Antarctic continent, the higher BC concentration in the continental air (katabatic wind) might be caused by long range transport of BC via the free troposphere from mid- and low- latitudes. The seasonal variation of BC at Syowa had a maximum in August, while at the other coastal stations (Halley, Neumayer, and Ferraz) and the continental station (Amundsen-Scott), the maximum occurred in October. This difference may result from different transport pathways and scavenging of BC by precipitation during the transport from the source regions. During the austral summer, long-range transport of BC via the free troposphere is likely to make an important contribution to the ambient BC concentration. The BC transport flux indicated that BC injection into the Antarctic region strongly depended on the frequency of storm (blizzard) conditions. The seasonal variation of BC transport flux increased by 290 mg m-2 month-1 in winter-spring when blizzards frequently occurred, whereas the flux decreased to lower than 50 mg m-2 month-1 in the summer with infrequent blizzards.

Hara, K.; Osada, K.; Yabuki, M.; Hayashi, M.; Yamanouchi, T.; Shiobara, M.; Wada, M.

2008-05-01

43

Sources of PM10 and sulfate aerosol at McMurdo Station, Antarctica.  

PubMed

Source contributions to PM10 and sulfate aerosol at McMurdo Station, Antarctica during the austral summers of 1995-1996 and 1996-1997 were estimated using Chemical Mass Balance (CMB) receptor modeling. The average PM10 (particles with aerodynamic diameters less than 10 microm) concentration at Hut Point, located less than 1 km downwind of downtown McMurdo, was 3.4 microg/m3. Emissions profiles were determined for potentially important aerosol source types in McMurdo: exposed soil, power generation, space heating, and surface vehicles. Soil dust, sea salt, combustion emissions, sulfates, marine biogenic emissions as methanesulfonate, and nitrates contributed 57%, 15%, 14%, 10%, 3%, and 1%, respectively, of average estimated PM10 at Hut Point (3.2 microg/m3). Soil dust, sea salt, and combustion sources contributed 12%, 8%, and 20%, respectively, of the average PM10 sulfate concentration of 0.46 microg/m3. Marine biogenic sources contributed 0.17 microg/m3 (37%). The remaining sulfate is thought to have come from emissions from Mt. Erebus or hemispheric pollution sources. PMID:11592425

Mazzera, D M; Lowenthal, D H; Chow, J C; Watson, J G

2001-10-01

44

Ozone profiles at McMurdo Station, Antarctica during the austral spring of 1992  

SciTech Connect

Thirty-seven vertical profiles of ozone and temperature were measured at McMurdo Station, Antarctica (78[degrees]S) from 23 August to 31 October 1992. Total column ozone dropped from an initial 223 Dobson Units (DU) on 24 August to 158 DU on 27 September. The 12-20 km column reached a record low of 17 DU on 9 October, an 84% loss compared to the initial value of 106 DU. The most severely depleted layer was between 12 and 15 km which coincided with the volcanic aerosol layer (11-16 km) observed by aerosol counter flights and the Italian Lidar at McMurdo. By the end of September the polar vortex elongated and shifted away from McMurdo. Subsequent profiles, above 20 km altitude, were typically 15-20[degrees]C warmer and ozone concentrations were 50-100% higher for the remainder of the measurement period. The 12-16 km layer, however, remained 80 to 97% depleted compared to the initial profile. 9 refs., 5 figs.

Johnson, B.J.; Deshler, T.; Rozier, W.R. (Univ. of Wyoming, Laramie, WY (United States))

1994-02-15

45

Ozone profiles over McMurdo Station, Antarctica, during August, September, and October of 1986 - 1991  

NASA Technical Reports Server (NTRS)

Vertical profiles of ozone and temperature have been measured at McMurdo Station, Antarctica, during the springs of 1986 to 1991, roughly every two days from 25 August to 31 October. Comparisons of temporal histories and average vertical structure for these years reveals some striking consistency in the ozone depletion process. Ozone depletion generally begins in early September, and with a half-life of 20-30 days, reaches its maximum in mid-October. The depletion occurs almost exclusively between 12 and 20 km. At the time of maximum depletion total ozone has been decreased roughly 40 percent while ozone between 12 and 20 km has been reduced 80 percent. Recovery generally begins in late October with the influx, above 20 km, of ozone rich air from the lower latitudes. From this record the worst years for ozone depletion were 1987, 1989, and 1990. A new region of ozone depletion, below 12 km, was observed in 1991, coinciding with the entrainment of a volcanic cloud into the polar vortex.

Deshler, Terry; Hofmann, David J.

1994-01-01

46

Stratospheric ClO profiles from McMurdo Station, Antarctica, spring 1992  

SciTech Connect

The authors describe ground-based measurements of ClO made at McMurdo Station, Antarctica, during September and October 1992. Vertical profiles were retrieved from molecular rotational emission spectra at 278 GHz. Peak mixing ratios of 1.6{+-}0.3 ppbv were seen in mid-September at approximately 18 km altitude, suggestive of somewhat larger quantities than were measured at the same site and season in 1987. As the core of the polar vortex moved away from McMurdo by early October, the ClO mixing ratio at this altitude dropped to less than 0.2 ppbv, coincident with increasing temperature, ozone, and NO{sub 2}. The diurnal variation of ClO was also observed. The lower stratospheric layer from 15 to 27 km was found to reach approximately midday abundance by 2-3 hours after sunrise. The column abundance in this layer began to decrease by the period 4-2 hours before sunset and had declined to approximately one quarter of its midday value by 2-0 hours before sunset. In contrast, the ClO column in the upper stratosphere, from 28 to 50 km, built up slowly until midday and remained large while sunlight persisted. 20 refs., 7 figs., 2 tabs.

Emmons, L.K.; Shindell, D.T.; Reeves, J.M. [State Univ. of New York, Stony Brook, NY (United States)] [and others] [State Univ. of New York, Stony Brook, NY (United States); and others

1995-02-20

47

Detection of crevasses near McMurdo station, Antarctica with airborne short-pulse radar  

NASA Astrophysics Data System (ADS)

Airborne short-pulse radar is evaluated experimentally as a rapid reconnaissance tool for locating snow-bridged crevasses. An immediate need for a crevasse detector is present within the U.S. Antarctic Program, which is planning a major surface traverse from McMurdo to deliver construction materials to South Pole Station. This feasibility study of a crevasse detection system was performed near McMurdo Station, Antarctica, in Jan. 1994. The radar utilized pulses centered near 200 and 500 MHz and was operated from a low flying helicopter with altitude and speed as variables. A global positioning system (GPS) was used for survey control. Results are presented over glacial ice on Ross Island and at various locations on the Ross Ice Shelf near White and Black Islands and near the Aurora Glacier terminus. These studies include a control line along which crevasse width and snow-bridge thickness were measured, transects along which crevasses were apparent, and also where crevasses were expected, but were not apparent. Strong evidence of crevassing was recorded at flight speeds near 20 m 5-1 (45 mph), at altitudes near 15 m, and at a data acquisition rate of 51 scans/second. Crevasses are detected by the reflections and diffractions from distorted layering in snow bridges, and by the strong diffractions from within the crevasses. The strongest diffractions apparently emanated from within the crevasse and not from the base of the snow bridge. Along the control line, a crevasse with no surface expression was detected by radar and verified by probing and digging. Transects devoid of crevasses show layering without the small scale distortion seen over snow bridges. Future plans are to use data acquisition rates of 160 scans/second, available with commercial equipment, to allow a survey speed of about 64 ms-1 (140 mph).

Delaney, Allan J.; Arcone, Steven A.

1995-03-01

48

Ocean current observations near McMurdo Station, Antarctica, 1993 to 1994: Relation to wastewater discharge dispersal  

SciTech Connect

This report presents analyses of current measurements from McMurdo Sound, Antarctica during December, 1993 to November, 1994, in relation to dispersal of the McMurdo Station wastewater plume. Data collected from 1991 to 1993 are also discussed here. Six current meters were deployed near McMurdo Station, Antarctica, from December 1993 to November 1994. Five functioned properly throughout the observation period, and one failed. Analyses of 5 data series include: (1) summaries of current speed and direction, (2) directional analyses of flow, (3) time series current vectors averaged over 1, 3, 6, 12, and 24 h, (4) principal axes of flow, (5) maps of mean seasonal flow, (6) progressive vector plots, (7) spectral analyses, and (8) low-pass filtered (30h) time series of currents at McMurdo Station. Observations of flow near McMurdo Station during 1994 were generally similar to 1993. Short term variation in flow was related principally to diurnal tidal motions. Longer period oscillations in flow such as seasonal shifts, and non-periodic changes in current speed and direction were likely related to changes in ice cover and wind stress in the vicinity of McMurdo Station or over much larger scales or both. Three distinct oceanographic {open_quote}seasons{close_quote} were apparent in time series from 1992 to 1994, from stations furthest offshore, where the effects of local topography are minimal. The spring-summer (Oct.-Jan.) period of both years was dominated by regional southward flow, which generates a counter-clockwise eddy (McMurdo Gyre) adjacent to McMurdo Station. With regard to dispersal of the wastewater plume from McMurdo Station, observations of currents during 1994 generally corroborate those from 1993, and the recommendation that the outfall pipe should be repositioned offshore of the McMurdo Gyre is supported.

Barry, J.P. [J.P. Barry Consulting, Monterey, CA (United States)

1995-09-01

49

Weather in Antarctica  

NSDL National Science Digital Library

This homepage includes information about the weather in Antarctica and links to pages on the climate, wind chill, clouds, snow and ice, and pressure and storms of Antarctica. The current weather conditions updated automatically at various stations are also provided.

Hutchings, Thomas

1998-01-01

50

Direct evidence of histopathological impacts of wastewater discharge on resident Antarctic fish (Trematomus bernacchii) at Davis Station, East Antarctica.  

PubMed

During the 2009/2010 summer, a comprehensive environmental impact assessment (EIA) of the wastewater discharge at Davis Station, East Antarctica was completed. As part of this, histological alteration of gill and liver tissue in Antarctic Rock-cod (Trematomus bernacchii) from four sites along a spatial gradient from the wastewater outfall were assessed. All fish within 800m of the outfall exhibited significant histological changes in both tissues. Common pathologies observed in fish closest to the outfall include proliferation of epithelial cells with associated secondary lamellar fusion in the gills and multifocal granulomata with inflammation and necrosis as well as cysts in the liver. Fish from sites >800m from the outfall also exhibited alterations but to a lesser degree, with prevalence and severity decreasing with increasing distance from the outfall. This study highlights the value of histopathological investigations as part of EIAs and provides the first evidence of sub-lethal alteration associated with wastewater discharge in East Antarctica. PMID:25173596

Corbett, Patricia A; King, Catherine K; Stark, Jonathan S; Mondon, Julie A

2014-10-15

51

Impact of human activities on the geomagnetic field of Antarctica: a high resolution aeromagnetic survey over Mario Zucchelli Station.  

PubMed

Environmental protection of Antarctica is a fundamental principle of the Antarctic Treaty. Impact assessment and significance evaluation are due for every human activity on the remote continent. While chemical and biological contaminations are widely studied, very little is known about the electromagnetic pollution levels. In this frame, we have evaluated the significance of the impact of Mario Zucchelli Antarctic Station (Northern Victoria Land) on the local geomagnetic field. We have flown a high resolution aeromagnetic survey in drape mode at 320m over the Station, covering an area of 2km(2). The regional and the local field have been separated by a third order polynomial fitting. After the identification of the anthropic magnetic anomaly due to the Station, we have estimated the magnetic field at the ground level by downward continuation with an original inversion scheme regularized by a minimum gradient support functional to avoid high frequency noise effects. The resulting anthropic static magnetic field at ground extends up to 650m far from the Station and reaches a maximum peak to peak value of about 2800nT. This anthropic magnetic anomaly may interact with biological systems, raising the necessity to evaluate the significance of the static magnetic impact of human installations in order to protect the electromagnetic environment and the biota of Antarctica. PMID:22706521

Armadillo, E; Bozzo, E; Gambetta, M; Rizzello, D

2012-10-15

52

Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica: a regional comparison.  

PubMed

The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are some generalizations regarding responses which will aid future management of stations. PMID:24919053

Stark, Jonathan S; Kim, Stacy L; Oliver, John S

2014-01-01

53

Sea-ice thickness and mass at Ice Station Belgica, Bellingshausen Sea, Antarctica  

NASA Astrophysics Data System (ADS)

Ice Station Belgica was commenced in late winter 2007 in the Bellingshausen Sea as part of Sea Ice Mass Balance in Antarctica (SIMBA), an IPY 2007 cruise on the research vessel N.B. Palmer. A primary objective was to build on the work of previous Antarctic drift station experiments to geophysically characterize sea ice in terms of thickness, surface and ice bottom morphology, and ultimately area-unitized mass. A 24 day drift station was established at approximately 70°S and 93°W in mixed first-year and multi-year ice with three geophysical study sites selected on a 5 km 2 floe. A comprehensive time series assessment of elevation-surveyed transects ranging from 100 m to 300 m in length included snow surface elevation, snow depth, electromagnetic (EM) profiling, and direct drilling for ice draft and ice freeboard. Additional work included a snow surface morphology characterization of a 100 m×300 m area between the primary time series EM transects. Correlation of EM ice thicknesses with collocated drilled ice thickness yielded equations for the correction of EM underestimation of thick deformed ice, particularly at pressure ridges. Mean ice thickness from corrected EM was compared to isostatic ice thickness calculated from surface elevation, snow depth, ice freeboard and respective snow, slush, ice, and sea water densities. Results were consistent, with mean ice thicknesses for multi-year ice of 2.35 m, 2.34 m, and 2.41 m, with similar variance, for corrected EM, drilling, and buoyancy methods respectively. Additionally, a mean ice thickness of 2.31 m was calculated from ASPeCt observations of the ice field associated with the floe, using the method incorporating mean sail heights and fractional coverage of surface deformities or ridging. Temporal series assessment of ice freeboard indicated a slightly negative mean ice freeboard (<0.04 m), with clear evidence of new snow-ice formation from the freezing of slush. The three distinct snow and ice regions assessed on the Belgica floe had mean corrected EM ice thickness of 0.52±0.04 m (±1 std. deviation), 0.92±0.17 m, and 2.35±1.37 m, and mean snow depths of 0.08±0.03 m, 0.36±0.09 m, and 0.68±0.31 m respectively. Each ice type represented a sizable fraction of the floe's total area (˜20%, 40%, and 40% respectively from visual estimates) reflecting a complex dynamic and thermodynamic history of formation, as well as the difficulty in characterizing even a single floe by a single class or mean value for thickness and snow depth. Implications of these results are discussed with regards to the resolution of satellite-based altimetry and snow depth products and efforts to generate and validate satellite sea ice and snow thickness products.

Weissling, B. P.; Lewis, M. J.; Ackley, S. F.

2011-05-01

54

Meteorological profiles comparison from global models and experimental radiosoundings at the Antarctica station of Belgrano  

NASA Astrophysics Data System (ADS)

Ozonesoundings are launched from Antarctic Belgrano station (77.87S, 34.62W) since 1999 in the framework of an extensive stratospheric trace-gas measurement program. In the frame of VIOLIN (Extended Vertical Investigation of the Ozone Layer In ANtarctica) project and as a previous step in the application of meteorological models, a comparison-validation exercise has been carried out using simulations and experimental profiles. The aim is to assess the reliability of the meteorological files obtained from global models which could be used as input data in models of higher spatial resolution. Meteorological profiles (potential temperature, relative humidity, wind speed and direction) have been obtained from ECMWF and NCEP-GDAS models with a spatial resolution of 1°x1° and 14 vertical levels from 950 to 500 mb. The simulated profiles have been compared with in situ soundings at Belgrano. A total of 83 soundings covering the period from 2009 to 2010 have been used. Data have been grouped in three period's: diurnal, nocturnal and transition diurnal-nocturnal or vice versa. The comparison has been performed with the statistical root mean square deviation (RMSD) and BIAS for the four meteorological variables. Results show that potential temperature using both models and wind speed with NCEP-GDAS are underestimated while the rest of parameters are overestimated. The RMSD of the potential temperature ranges between 1.7 and 3.2 °C with a BIAS of -0.18 to -0.74 °C. No differences were found according to the time of the year. The relative humidity analysis shows a RMSD between 21.4 and 30.2 % while the BIAS was ranging from 9.9 to 14.8 %. Best results have been obtained in the transition period. For the wind speed the RMSD oscillate between 2.9 and 4.9 m/s with a BIAS from -0.35 to 0.31 m/s. The wind direction is the parameter with the highest differences, RMSD between 68 and 104°, with a BIAS from 34 to 62°. The highest differences have been found for the diurnal period. According to the results obtained with these simulated and experimental profiles of Belgrano and applying RMSD and BIAS, the profiles obtained with ECMWF model show lower differences than NCEP-GDAS.

Adame, J. A.; Yela, M.; Parrondo, M. C.; Ochoa, H.; Gil, M.

2012-04-01

55

Benthic changes at McMurdo Station, Antarctica following local sewage treatment and regional iceberg-mediated productivity decline.  

PubMed

McMurdo Station, the largest research station in Antarctica, ceased on-site garbage dumping in 1988 and initiated sewage treatment in 2003. In 2003-2004 its sea-ice regime was altered by the massive B-15A and C-19 iceberg groundings in the Ross Sea, approximately 100km distant. Here we follow macrofaunal response to these changes relative to a baseline sampled since 1988. In the submarine garbage dump, surface contaminants levels have declined but associated macrofaunal recolonization is not yet evident. Although sewage-associated macrofauna were still abundant around the outfall nearly 2yr after initiation of treatment, small changes downcurrent as far as 434m from the outfall suggest some community recovery. Widespread community changes in 2003-2004, not seen in the decade previously, suggests that the benthos collectively responded to major changes in sea-ice regime and phytoplankton production caused by the iceberg groundings. PMID:19945127

Conlan, K E; Kim, S L; Thurber, A R; Hendrycks, E

2010-03-01

56

Ocean current observations near McMurdo Station, Antarctica from 1991 to 1993: Relation to wastewater discharge dispersal  

SciTech Connect

Analyses of ocean currents in the vicinity of McMurdo Station, Antarctica, are relevant to the transport and dispersal of wastewater from the McMurdo Station sewage outfall pipe. Observations of ocean currents during the initial phases of this study have been presented by Howington and McFeters. These studies, using coliform bacterial counts as an indicator of dispersion of the wastewater plume and current meters to measure flow patterns, indicated that dispersal of the plume by local currents does not effectively remove the plume from the vicinity of McMurdo Sound, under the present outfall pipe location. Moreover, these studies suggest that, although the flow pattern is generally consistent with transport of the plume away from McMurdo Station, episodes of current reversal are sufficient to transport the wastewater plume along the shore toward the southeast, eventually overlapping the seawater intake area near the McMurdo jetty. Several concerns included (a) impacts of wastewater inputs to nearshore benthic and pelagic habitats adjacent to McMurdo Station, (b) effects of wastewater input to the McMurdo Station fresh water intake source, and (c) reduction in human impacts on the McMurdo Sound ecosystem. These concerns motivated studies to characterize nearshore currents more extensively in relation to dispersal of the wastewater plume. This report discusses analysis results of current observations from November 1992 to November 1993.

Barry, J.P. [J. P. Consulting, Monterey, CA (United States)

1994-08-01

57

[Polycyclic aromatic hydrocarbons content in Antarctica soils as exemplified by the Russian polar stations].  

PubMed

The comprehensive study of the qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) in soils of Antarctica (reference landscapes--mountains Hudson, Haswell Archipelago contaminated soil--Mirny, Druznaya-4, Bellingshausen--and imported soils) was performed with the use of HPLC in a gradient mode. A characteristic feature of the studied PAHs content of soils is the predominance of low-molecular polyarenes in them. Due to anthropogenic pollution the quantitative accumulation of both light and heavy PAHs occurs under the qualitative increase in the proportion of heavy polyarenes. Polyarenes pool in the studied soils is represented mainly by light PAHs: naphthalene, phenanthrene, fluoranthene, pyrene, etc. The content of benzo(a)pyrene does not exceed the MCL (adopted in the Russian Federation) for this ecotoxicant. Performed primary factual and statistical analysis of data permitted to reveal that heavy PAH pollution of Antarctica soils is in the most initial stage, there is no sustained and statistically significant accumulation of PAHs in soils of maritime as well as continental Antarctica. There are established the levels of the actual content of various PAHs in soils of different regions of the Antarctica, which is the basic data for further comparative analysis of data of geochemical studies. PMID:24749277

Abakumov, E V; Lodygin, E D; Gabov, D A; Krylenkov, V A

2014-01-01

58

Daily variation at Concordia station (Antarctica) and its dependence on IMF conditions  

Microsoft Academic Search

After some short test surveys, during the 2004-2005 summer expedition in Antarctica, a geomagnetic French-Italian observatory was installed on the plateau (geographic coordinates: 75.1° S, 123.4° E; corrected geomagnetic coordinates: 88.9° S, 54.3° E; UT=LT-8) very close to the geomagnetic pole. In this paper we present some peculiarities of the daily variation as observed at this polar cap observatory during

L. Cafarella; D. di Mauro; S. Lepidi; A. Meloni; M. Pietrolungo; L. Santarelli; J. J. Schott

2007-01-01

59

Balloon-borne measurements of aerosol, condensation nuclei, and cloud particles in the stratosphere at McMurdo Station, Antarctica, during the spring of 1987  

Microsoft Academic Search

Measurements of the vertical profile of particles with condensation nuclei counters and eight channel aerosol detectors at McMurdo Station, Antarctica, in 1987 verified observations made in 1986 concerning the absence of upwelling in the polar vortex and the presence of a condensation nuclei layer in conjunction with the ozone hole region. New observations of a bimodal aerosol size distribution, consisting

D. J. Hofmann; J. M. Rosen; J. W. Harder; J. V. Hereford

1989-01-01

60

Health and safety plan for the preliminary site investigation for McMurdo Station, Ross Island, Antarctica  

SciTech Connect

The primary purpose of this health and safety plan is to provide the Argonne National Laboratory (ANL) field team with important procedures, regulations, and requirements necessary for performing work at McMurdo Station, Antarctica, with a minimum hazard to its health and safety. Field workers will be required to conduct their operations in a safe environment through specific safety and occupational health procedures. The plan assigns responsibilities and provides for contingencies that may arise at the site. The health and safety plan will also demonstrate to the National Science Foundation (NSF), the US Department of Energy (DOE), the US Environmental Protection Agency (EPA), the US Occupational Safety and Health Administration (OSHA), environmental interest groups, and other countries represented in Antarctica that the health and safety of ANL personnel have been given the utmost consideration in planning the work operations, applicable rules and regulations of the area have been met, and the health and safety of the public and the environment have been given significant consideration during field sampling activities. This document represents the final health and safety plan for the preliminary site investigation. A draft version of this report was presented to NSF in January 1991. 16 refs., 3 figs., 8 tabs.

Wozny, M.C.

1991-05-01

61

Visible and near-ultraviolet spectroscopy at McMurdo Station, Antarctica. 6. Observations of BrO  

SciTech Connect

Observations of the evening twilight BrO abundance over McMurdo Station, Antarctica during austral spring, 1987, are described. The observed variation of the slant column abundance with increasing solar zenith angles suggests that most of the BrO is located near 15 km. The total vertical column abundance observed during 1 week of measurements yielded an average value of 2.5 {times} 10{sup 13} cm{sup {minus}2}, assuming the room temperature absorption cross sections measured by Cox et al. (1982). These values are consistent with BrO mixing ratios of about 5-15 parts per trillion by volume distributed from 150 to 20 mbar. If the differential absorption cross section of BrO increases by 30% at temperatures characteristic of the Antarctic lower stratosphere, as indicated by Sander and Watson (1981), then the BrO measurements reported in this paper should be decreased by 30%.

Carroll, M.A.; Solomon, S.; Schmeltekopf, A.L. (NOAA, Boulder, CO (United States)); Sanders, R.W. (Univ. of Colorado, Boulder (United States))

1989-11-30

62

Measurement of atmospheric opacity at 278 GHz at McMurdo Station, Antarctica in austral spring seasons, 1986 and 1987  

NASA Technical Reports Server (NTRS)

A quasi-continuous record is presented of atmospheric opacity measured at 278 GHz (1.1 mm wavelength) from the McMurdo Station (Antarctica) during austral spring seasons of 1986 (August 30 - October 30) and 1987 (September 4 - October 13) with measurements taken every 20 minutes (except during storms or other periods of high opacity). All data are reduced to represent opacity in the zenith direction. It was found that, during much of September, the two successive years differed considerably in tropospheric opacity. In 1986, water vapor and attendant opacity were generally lower, due to low tropospheric temperatures. Measured opacities were found to be higher than would be expected from the empirical relationships representing opacity as a function of water vapor column density at mm-wavelengths, as proposed by Rice and Ade (1979), Zammit and Ade (1981), and Liebe (1985).

De Zafra, R. L.; Jaramillo, M.; Barrett, J.; Emmons, L. K.; Parrish, A.

1990-01-01

63

The controlled ecological life support system Antarctic analog project: Analysis of wastewater from the South Pole Station, Antarctica, volume 1  

NASA Technical Reports Server (NTRS)

The Controlled Ecological Life Support system (CELSS) Antarctic Analog Project (CAAP) is a joint National Science Foundation (NSF) and NASA project for the development, deployment and operation of CELSS technologies at the Amundsen-Scott South Pole Station. NASA goals are operational testing of CELSS technologies and the conduct of scientific studies to facilitate technology selection and system design. The NSF goals are that the food production, water purification, and waste treatment capabilities which will be provided by CAAP will improve the quality of life for the South Pole inhabitants, reduce logistics dependence, and minimize environmental impacts associated with human presence on the polar plateau. This report presents an analysis of wastewater samples taken from the Amundsen-Scott South Pole Station, Antarctica. The purpose of the work is to develop a quantitative understanding of the characteristics of domestic sewage streams at the South Pole Station. This information will contribute to the design of a proposed plant growth/waste treatment system which is part of the CELSS Antarctic Analog Project (CAAP).

Flynn, Michael T.; Bubenheim, David L.; Straight, Christian L.; Belisle, Warren

1994-01-01

64

Atmospheric ozone above Troll station, Antarctica observed by a ground based microwave radiometer  

NASA Astrophysics Data System (ADS)

This paper describes the stratospheric and mesospheric ozone profiles retrieved from spectral measurements of the 249.96 GHz O3 line, using the British Antarctic Survey's ground-based Microwave Radiometer at Troll (BAS-MRT), Antarctica (72°01' S, 02°32' E, 62° Mlat). The instrument operated at Troll from February 2008 through January 2010, and hourly averaged spectra were used to retrieve approximately 20 ozone profiles per day. The ozone profiles cover the pressure range from 3 hPa to 0.02 hPa (approximately 38 to 72 km) which includes the topside of the stratospheric ozone layer and the peak of the tertiary maximum. Comparing the retrieved ozone volume mixing ratio (vmr) values to Aura/MLS and SD-WACCM shows no significant bias to within the instrumental uncertainties. The long-term variations (>20 days) between MLS and SD-WACCM agree well with BAS-MRT at all altitudes with significant correlation coefficients of at least 0.9 (0.7 with SD-WACCM) in the upper stratosphere and middle mesosphere. A weaker correlation is found for the long-term variations in summer when most of the vmr values are below the random noise level of Aura/MLS. The correlation of short-term variations (<20 days) between MLS and BAS-MRT agree well at all altitudes with significant correlation coefficients of at least 0.7 in the upper stratosphere and middle mesosphere. The ozone profiles retrieved at Troll, Antarctica extend the sparse data coverage of middle atmospheric ozone above Antarctica, where, due to the dynamic nature of the ozone concentrations, systematic observations with a high temporal resolution are desirable. The O3 profiles presented here are stored at the UK's Polar Data Centre (http://doi.org/nc3) and are available for public scientific use.

Daae, M.; Straub, C.; Espy, P. J.; Newnham, D. A.

2014-03-01

65

Sounding rockets in Antarctica  

NASA Technical Reports Server (NTRS)

Sounding rockets are versatile tools for scientists studying the atmospheric region which is located above balloon altitudes but below orbital satellite altitudes. Three NASA Nike-Tomahawk sounding rockets were launched from Siple Station in Antarctica in an upper atmosphere physics experiment in the austral summer of 1980-81. The 110 kg payloads were carried to 200 km apogee altitudes in a coordinated project with Arcas rocket payloads and instrumented balloons. This Siple Station Expedition demonstrated the feasibility of launching large, near 1,000 kg, rocket systems from research stations in Antarctica. The remoteness of research stations in Antarctica and the severe environment are major considerations in planning rocket launching expeditions.

Alford, G. C.; Cooper, G. W.; Peterson, N. E.

1982-01-01

66

A former teacher, 2013 graduate Casey  

E-print Network

K-8 technology at a Catholic school for a few years. She also spent a summer teaching English-resourced elementary school in Mississippi. "It was probably the hardest thing I've ever done," she said. "I learnedWhat cancer teaches A former teacher, 2013 graduate Casey McCluskey overcame cancer, applied

Alvarez, Francisco J.

67

WBUR Journeys to Antarctica  

NSDL National Science Digital Library

This is the record of an environmental reporter's expedition to Antarctica. During his time in Antarctica, the author wrote reports and captured photos, video and audio of the animals, the environment and the people who live there. Topics include wildlife and how it has been affected by climate change, equipment needed for working in Antarctica, and life at Palmer Station. A series of journal entries by the author give an account of what it was like to travel, work, and live in Antarctica. An extensive collection of multimedia materials includes photos, videos, and an interactive tour of Palmer Station.

68

Results of monitoring for polychlorinated dibenzo-p-dioxins and dibenzofurans in ambient air at McMurdo station, Antarctica  

SciTech Connect

This paper presents the results of ambient air monitoring for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) performed during the 1992-1993 and 1993-1994 austral summers in the vicinity of McMurdo Station, Antarctica. Twenty-eight air samples were collected from four different locations to determine the identity and concentration of PCDD/PCDF compounds. PCDD/PCDF compounds were not detected at either the predominantly upwind location or a more remote site on Black Island. Trace levels of only a few PCDD/PCDF congeners were detected sporadically at a location approximately 500 m downwind of the station. The most frequent, most varied, and highest levels of PCDDs/PCDFs were measured at a `downtown` location, where concentrations of total PCDDs ranged from 0.12 to 1.80 pg/m{sup 3} and total PCDDs ranged from less than 0.02 to 2.77 pg/m{sup 3}. The data indicate that there are combustion sources at McMurdo other than the solid waste incinerator (power plants, vehicles, heating furnaces, etc.) that contribute PCDD/PCDF compounds to the ambient air. The greatest variety and highest concentration of PCDD/PCDF congeners measured in 1992-1993 during incineration of selected solid wastes implicates the interim incinerator as the likely source of the increased presence of these compounds in air. 18 refs., 2 figs., 3 tabs.

Lugar, R.M. [ERM-Program Management Co., Idaho Falls, ID (United States)] [ERM-Program Management Co., Idaho Falls, ID (United States); Harles, R.L. [EPA/AREAL, Research Triangle Park, NC (United States)] [EPA/AREAL, Research Triangle Park, NC (United States); Dupuy, A.E.; McDaniel, D.D. [EPA/OPPTS/OPP/BEAD/ACB, Stennis Space Center, MS (United States)] [EPA/OPPTS/OPP/BEAD/ACB, Stennis Space Center, MS (United States)

1996-02-01

69

Exposure and nutrients as delimiters of lichen communities in continental Antarctica  

Microsoft Academic Search

Lichens dominate the terrestrial vegetation of the ice-free regions of continental Antarctica. Vegetation patterns were studied in the Windmill Islands Oasis, Wilkes Land, continental Antarctica, in relation to edaphic features to elucidate the factors that govern lichen distribution and abundance. Vegetation was studied on a low rounded knoll on Clark Peninsula some 3 km North East of the present Casey

M. J. Hovenden; R. D. Seppelt

1995-01-01

70

Propagation of low frequency geomagnetic field fluctuations in Antarctica: comparison between two polar cap stations  

Microsoft Academic Search

We conduct a statistical analysis of the coherence and phase difference of low frequency geomagnetic fluctuations between two Antarctic stations, Mario Zucchelli Station (geographic coordinates: 74.7° S, 164.1° E; corrected geomagnetic coordinates: 80.0° S, 307.7° E) and Scott Base (geographic coordinates: 77.8° S 166.8° E; corrected geomagnetic coordinates: 80.0° S 326.5° E), both located in the polar cap. Due to

L. Santarelli; S. Lepidi; L. Cafarella

2007-01-01

71

A methodology study to define pathways and heights to calculate backtrajectories at near coastal Continental Antarctica station (Belgrano)  

NASA Astrophysics Data System (ADS)

Within the framework of the VIOLIN (Extended Vertical Investigation of the Ozone Layer In ANtarctica) project, different atmospheric components are measured in the Antarctica station of Belgrano (77.87S, 34.62W) such as surface ozone. In order to investigate the origin of the observed chemical species, a study to identify the features and variability of air masses impacting the area has been carried out. The pathways of the air masses are determined through back trajectories calculated with the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model. As a first step of this study it is necessary to define duration and heights for which the back trajectories will be obtained. The NCEP-GDAS meteorological data with a 1°x1° spatial resolution and 14 vertical levels from surface to 500 mb have been used as input. The years 2009 and 2010 have been used to perform this study which will be expanded in the future. To determinate the optimal duration of the back trajectories daily back trajectories starting at 12:00 UTC for starting altitudes of 500 and 1500 m, with durations of 120, 168, 240 and 360 hours. A cluster methodology has been used to group the back trajectories. An optimal cluster number between 4 and 6 has been obtained. The back trajectories corresponding to 120 and 168 hours show pathways covering half of the Antarctic continent while the ones obtained with 240 and 360 hours travel across all continent. The back trajectories lasting168 hours have been selected as optimal. To study optimum heights and using duration of 168 hours we calculated daily back trajectories starting at 100, 500, 1000, 1500, 2000, 2500, 3000, 3500, and 4000 m. The typologies and path of air masses increase with height. The results obtained in this work identify five groups that represent the lowest 4000 m which are the back trajectories of 100, 500, 1000-1500, 2000-2500 and 3500-4000 m. As conclusion, to perform a study of air masses origin in Belgrano which will help to the interpretation of chemical species collected in this station, the back trajectories will be calculated with duration of 168 hours and five heights.

Adame, J. A.; Yela, M.; Navarro, M.; Parrondo, M. C.; Gil, M.

2012-04-01

72

Daily variation at Concordia station (Antarctica) and its dependence on IMF conditions  

NASA Astrophysics Data System (ADS)

After some short test surveys, during the 2004-2005 summer expedition in Antarctica, a geomagnetic French-Italian observatory was installed on the plateau (geographic coordinates: 75.1° S, 123.4° E; corrected geomagnetic coordinates: 88.9° S, 54.3° E; UT=LT-8) very close to the geomagnetic pole. In this paper we present some peculiarities of the daily variation as observed at this polar cap observatory during the years 2005 and 2006, taking into account the different Loyd seasons and different interplanetary magnetic field conditions. Some interesting results emerge from the analysis, confirming the dependence of the daily variation (and of the associated polar current systems) on the IMF Bz and By components. In particular the analysis showed that different Bz conditions correspond to different contribution to daily variation of ionospheric and field aligned currents, while particular By conditions lead to a time shift of the diurnal variation, indicating an asymmetry with respect to the noon meridian.

Cafarella, L.; di Mauro, D.; Lepidi, S.; Meloni, A.; Pietrolungo, M.; Santarelli, L.; Schott, J. J.

2007-10-01

73

Observations of Earth space by self-powered stations in Antarctica S. B. Mende,1  

E-print Network

of operation in spite of the relative unpredictability of the Antarctic environment. Sample data are shown of these regions with a network of ground-based observatories over other techniques. The Antarctic continent on the Antarctic plateau. Each station housed a suite of science instruments including a dual wavelength

California at Berkeley, University of

74

Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

A first long-term monitoring of selected persistent organic pollutants (POPs) in Antarctic air has been conducted at the Norwegian research station Troll (Dronning Maud Land). As target contaminants 32 PCB congeners, ?- and ?-hexachlorocyclohexane (HCH), trans- and cis-chlordane, trans- and cis-nonachlor, p,p'- and o,p-DDT, DDD, DDE as well as hexachlorobenzene (HCB) were selected. The monitoring program with weekly samples taken during the period 2007-2010 was coordinated with the parallel program at the Norwegian Arctic monitoring site (Zeppelin mountain, Ny-Ålesund, Svalbard) in terms of priority compounds, sampling schedule as well as analytical methods. The POP concentration levels found in Antarctica were considerably lower than Arctic atmospheric background concentrations. Similar to observations for Arctic samples, HCB is the predominant POP compound, with levels of around 22 pg m-3 throughout the entire monitoring period. In general, the following concentration distribution was found for the Troll samples analyzed: HCB > Sum HCH > Sum PCB > Sum DDT > Sum chlordanes. Atmospheric long-range transport was identified as a major contamination source for POPs in Antarctic environments. Several long-range transport events with elevated levels of pesticides and/or compounds with industrial sources were identified based on retroplume calculations with a Lagrangian particle dispersion model (FLEXPART).

Kallenborn, R.; Breivik, K.; Eckhardt, S.; Lunder, C. R.; Manø, S.; Schlabach, M.; Stohl, A.

2013-07-01

75

Observations of Earth space by self-powered stations in Antarctica  

NASA Astrophysics Data System (ADS)

Coupling of the solar wind to the Earth magnetosphere/ionosphere is primarily through the high latitude regions, and there are distinct advantages in making remote sensing observations of these regions with a network of ground-based observatories over other techniques. The Antarctic continent is ideally situated for such a network, especially for optical studies, because the larger offset between geographic and geomagnetic poles in the south enables optical observations at a larger range of magnetic latitudes during the winter darkness. The greatest challenge for such ground-based observations is the generation of power and heat for a sizable ground station that can accommodate an optical imaging instrument. Under the sponsorship of the National Science Foundation, we have developed suitable automatic observing platforms, the Automatic Geophysical Observatories (AGOs) for a network of six autonomous stations on the Antarctic plateau. Each station housed a suite of science instruments including a dual wavelength intensified all-sky camera that records the auroral activity, an imaging riometer, fluxgate and search-coil magnetometers, and ELF/VLF and LM/MF/HF receivers. Originally these stations were powered by propane fuelled thermoelectric generators with the fuel delivered to the site each Antarctic summer. A by-product of this power generation was a large amount of useful heat, which was applied to maintain the operating temperature of the electronics in the stations. Although a reasonable degree of reliability was achieved with these stations, the high cost of the fuel air lift and some remaining technical issues necessitated the development of a different type of power unit. In the second phase of the project we have developed a power generation system using renewable energy that can operate automatically in the Antarctic winter. The most reliable power system consists of a type of wind turbine using a simple permanent magnet rotor and a new type of power control system with variable resistor shunts to regulate the power and dissipate the excess energy and at the same time provide heat for a temperature controlled environment for the instrument electronics and data system. We deployed such systems and demonstrated a high degree of reliability in several years of operation in spite of the relative unpredictability of the Antarctic environment. Sample data are shown to demonstrate that the AGOs provide key measurements, which would be impossible without the special technology developed for this type of observing platform.

Mende, S. B.; Rachelson, W.; Sterling, R.; Frey, H. U.; Harris, S. E.; McBride, S.; Rosenberg, T. J.; Detrick, D.; Doolittle, J. L.; Engebretson, M.; Inan, U.; Labelle, J. W.; Lanzerotti, L. J.; Weatherwax, A. T.

2009-12-01

76

Observations of Earth space by self-powered stations in Antarctica.  

PubMed

Coupling of the solar wind to the Earth magnetosphere/ionosphere is primarily through the high latitude regions, and there are distinct advantages in making remote sensing observations of these regions with a network of ground-based observatories over other techniques. The Antarctic continent is ideally situated for such a network, especially for optical studies, because the larger offset between geographic and geomagnetic poles in the south enables optical observations at a larger range of magnetic latitudes during the winter darkness. The greatest challenge for such ground-based observations is the generation of power and heat for a sizable ground station that can accommodate an optical imaging instrument. Under the sponsorship of the National Science Foundation, we have developed suitable automatic observing platforms, the Automatic Geophysical Observatories (AGOs) for a network of six autonomous stations on the Antarctic plateau. Each station housed a suite of science instruments including a dual wavelength intensified all-sky camera that records the auroral activity, an imaging riometer, fluxgate and search-coil magnetometers, and ELF/VLF and LM/MF/HF receivers. Originally these stations were powered by propane fuelled thermoelectric generators with the fuel delivered to the site each Antarctic summer. A by-product of this power generation was a large amount of useful heat, which was applied to maintain the operating temperature of the electronics in the stations. Although a reasonable degree of reliability was achieved with these stations, the high cost of the fuel air lift and some remaining technical issues necessitated the development of a different type of power unit. In the second phase of the project we have developed a power generation system using renewable energy that can operate automatically in the Antarctic winter. The most reliable power system consists of a type of wind turbine using a simple permanent magnet rotor and a new type of power control system with variable resistor shunts to regulate the power and dissipate the excess energy and at the same time provide heat for a temperature controlled environment for the instrument electronics and data system. We deployed such systems and demonstrated a high degree of reliability in several years of operation in spite of the relative unpredictability of the Antarctic environment. Sample data are shown to demonstrate that the AGOs provide key measurements, which would be impossible without the special technology developed for this type of observing platform. PMID:20059157

Mende, S B; Rachelson, W; Sterling, R; Frey, H U; Harris, S E; McBride, S; Rosenberg, T J; Detrick, D; Doolittle, J L; Engebretson, M; Inan, U; Labelle, J W; Lanzerotti, L J; Weatherwax, A T

2009-12-01

77

Applied Research Staff: Casey DiCocco  

Cancer.gov

Casey DiCocco, MPH is a Presidential Management Fellow designated to the National Cancer Institute. He received his Master of Public Health from Columbia University's Mailman School of Public Health in May 2013. During his graduate education, his focus was on health promotion and social science research. He received his BA from Boston University in 2009. Since joining NCI's PMF program in July 2013, Mr.

78

Welcome New Staff: Casey DiCocco  

Cancer.gov

Casey DiCocco, MPH is a Presidential Management Fellow designated to the National Cancer Institute. He received his Master of Public Health from Columbia University's Mailman School of Public Health in May 2013. During his graduate education, his focus was on health promotion and social science research. He received his BA from Boston University in 2009. Since joining NCI's PMF program in July 2013, Mr.

79

Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

A first long-term monitoring of selected persistent organic pollutants (POPs) in Antarctic air has been conducted at the Norwegian Research station Troll (Dronning Maud Land). As target contaminants 32 PCB congeners, a- and g-hexachlorocyclohexane (HCH), trans- and cis-chlordane, trans- and cis-nonachlor, p,p'- and o,p-DDT, DDD, DDE as well as hexachlorobenzene (HCB) were selected. The monitoring program with weekly samples taken during the period 2007-2010 was coordinated with the parallel program at the Norwegian Arctic monitoring site (Zeppelin mountain, Ny-Ålesund, Svalbard) in terms of priority compounds, sampling schedule as well as analytical methods. The POP concentration levels found in Antarctica were considerably lower than Arctic atmospheric background concentrations. Similar as observed for Arctic samples, HCB is the predominant POP compound with levels of around 22 pg m-3 throughout the entire monitoring period. In general, the following concentration distribution was found for the Troll samples analyzed: HCB > Sum HCH > Sum PCB > Sum DDT > Sum chlordanes. Atmospheric long-range transport was identified as a major contamination source for POPs in Antarctic environments. Several long-range transport events with elevated levels of pesticides and/or compounds with industrial sources were identified based on retroplume calculations with a Lagrangian particle dispersion model (FLEXPART). The POP levels determined in Troll air were compared with 1 concentrations found in earlier measurement campaigns at other Antarctic research stations from the past 18 yr. Except for HCB for which similar concentration distributions were observed in all sampling campaigns, concentrations in the recent Troll samples were lower than in samples collected during the early 1990s. These concentration reductions are obviously a direct consequence of international regulations restricting the usage of POP-like chemicals on a worldwide scale.

Kallenborn, R.; Breivik, K.; Eckhardt, S.; Lunder, C. R.; Manø, S.; Schlabach, M.; Stohl, A.

2013-03-01

80

Propagation of low frequency geomagnetic field fluctuations in Antarctica: comparison between two polar cap stations  

NASA Astrophysics Data System (ADS)

We conduct a statistical analysis of the coherence and phase difference of low frequency geomagnetic fluctuations between two Antarctic stations, Mario Zucchelli Station (geographic coordinates: 74.7° S, 164.1° E; corrected geomagnetic coordinates: 80.0° S, 307.7° E) and Scott Base (geographic coordinates: 77.8° S 166.8° E; corrected geomagnetic coordinates: 80.0° S 326.5° E), both located in the polar cap. Due to the relative position of the stations, whose displacement is essentially along a geomagnetic parallel, the phase difference analysis allows to determine the direction of azimuthal propagation of geomagnetic fluctuations. The results show that coherent fluctuations are essentially detectable around local geomagnetic midnight and, in a minor extent, around noon; moreover, the phase difference reverses in the night time hours, indicating a propagation direction away from midnight, and also around local geomagnetic noon, indicating a propagation direction away from the subsolar point. The nigh time phase reversal is more clear for southward interplanetary magnetic field conditions, suggesting a relation with substorm activity. The introduction, in this analysis, of the Interplanetary Magnetic Field conditions, gave interesting results, indicating a relation with substorm activity during nighttime hours. We also conducted a study of three individual pulsation events in order to find a correspondence with the statistical behaviour. In particular, a peculiar event, characterized by quiet magnetospheric and northward interplanetary magnetic field conditions, shows a clear example of waves propagating away from the local geomagnetic noon; two more events, occurring during southward interplanetary magnetic field conditions, in one case even during a moderate storm, show waves propagating away from the local geomagnetic midnight.

Santarelli, L.; Lepidi, S.; Cafarella, L.

2007-11-01

81

Spatial-temporal dynamics of chemical composition of surface snow in East Antarctica along the Progress station-Vostok station transect  

NASA Astrophysics Data System (ADS)

In January of 2008, during the 53rd Russian Antarctic Expedition, surface snow samples were taken from 13 shallow (0.7 to 1.5 m depth) snow pits along the first tractor traverse from Progress to Vostok stations, East Antarctica. Sub-surface snow/firn layers are dated from 2.1 to 18 yr. The total length of the coast to inland traverse is more than 1280 km. Here we analysed spatial variability of concentrations of sulphate ions and elements and their fluxes in the snow deposited within the 2006-2008 time interval. Anions were analysed by high-performance liquid chromatography (HPLC), and the determination of selected metals, including Na, K, Mg, Ca and Al, was carried out by mass spectroscopy with atomization by induced coupled plasma (ICP-MS). Surface snow concentration records were examined for trends versus distance inland, elevation, accumulation rate and slope gradient. Na shows a significant positive correlation with accumulation rate, which decreases as distance from the sea and altitude increase. K, Ca and Mg concentrations do not show any significant relationship either with distance inland or with elevation. Maximal concentrations of these elements with a prominent Al peak are revealed in the middle part of the traverse (500-600 km from the coast). Analysis of element correlations and atmospheric circulation patterns allow us to suggest their terrestrial origin (e.g. aluminosilicates carried as a continental dust) from the Antarctic nunatak areas. Sulphate concentrations show no significant relationship with distance inland, elevation, slope gradient and accumulation rate. Non-sea salt secondary sulphate is the most important contribution to the total sulphate budget along the traverse. Sulphate of volcanic origin attributed to the Pinatubo eruption (1991) was revealed in the snow pit at 1276 km (depth 120-130 cm).

Khodzher, T. V.; Golobokova, L. P.; Osipov, E. Yu.; Shibaev, Yu. A.; Lipenkov, V. Ya.; Osipova, O. P.; Petit, J. R.

2014-05-01

82

Results of SO{sub 2}, NO{sub x}, and CO monitoring at McMurdo Station, Antarctica  

SciTech Connect

This report presents the results of ambient air monitoring of carbon monoxide (CO), sulfur dioxide (SO{sub 2}), nitric oxide (NO), nitrogen dioxide (NO{sub 2}), and total oxides of nitrogen (NO{sub x}) performed during the final weeks of the 1992-1993 austral summer in the vicinity of McMurdo Station, Antarctica. Commercially available, high sensitivity ambient air gas analyzers were used to continuously measure gas concentrations at two locations over a two and a three week time period respectively. Sampling site selection, sampling procedures and quality assurance procedures used for this effort were consistent with U.S. Environmental Protection Agency guidelines for local ambient air quality networks. CO, SO{sub 2}, and NO{sub 2} concentrations measured were below the associated U.S. National Ambient Air Quality Standards. Carbon monoxide levels measured at both locations were near or below the instrument detection limit of 0.1 part per million (ppm). Hourly average SO{sub 2} concentrations ranged from below the detection limit of 1 part per billion (ppb) to a single maximum hourly average value of 60 ppb. Hourly average NO{sub 2} concentrations ranged from below the detection limit of 1 ppb to a single maximum hourly average value of 26 ppb. The impact on local air quality of ships docked at an ice pier was observed and quantified. The initial baseline effort demonstrated that site selection and sampling equipment performance were satisfactory, and provided useful data for assessing the impact of McMurdo operations on the local ambient air quality.

Lugar, R.M.

1993-05-01

83

Stratosphere aerosol and cloud measurements at McMurdo Station Antarctica during the spring of 1987  

NASA Technical Reports Server (NTRS)

Measurements of stratospheric aerosols with balloonborne optical particle counters on 6 occasions at McMurdo Station (78 deg S) in the spring of 1986 indicated subsidence of the stratospheric sulfate layer during the time that the ozone hole was forming (Hofmann et al., 1988). Since dynamic models of ozone depletion involving upwelling in the spring polar vortex would suggest the opposite, we repeated the measurements with an increased frequency (about one sounding per week) in 1987. During 3 of the aerosol soundings in 1986, temperatures in the 15 to 20 km range were low enough (less than 80 C) for HNO3 to co-condense with water according to several theories of polar stratospheric cloud formation. However, particles were not observed with the characteristic size suggested by theory (approx. 0.5 microns). For this reason, it was proposed that polar stratospheric clouds may predominantly consist of large (approx. 5 to 50 microns) ice crystals at very low (approx. 10 sup 4- 10 sup 3 cm cubed) concentrations (Rosen et al., 1988). The particle counter employed would be relatively insensitive to these low concentrations. With the increased frequency of soundings in 1987, and adding additional size discrimination in the 1 to 2 micron region, this hypothesis could be verified if suitably low temperatures were encountered.

Hofmann, D. J.; Rosen, J. M.; Harder, J. W.

1988-01-01

84

Ozone profile measurements at McMurdo Station Antarctica during the spring of 1987  

NASA Technical Reports Server (NTRS)

During the Antarctic spring of 1986, 33 ozone soundings were conducted from McMurdo Station. These data indicated that the springtime decrease in ozone occurred rapidly between the altitudes of 12 and 20 km. During 1987, these measurements were repeated with 50 soundings between 29 August and 9 November. Digital conversions of standard electrochemical cell ozonesondes were again employed. The ozonesonde pumps were individually calibrated for flow rate as the high altitude performance of these pumps have been in question. While these uncertainties are not large in the region of the ozone hole, they are significant at high altitude and apparently resulted in an underestimate of total ozone of about 7 percent (average) as compared to the Total Ozone Mapping Spectrometer (TOMS) in 1986, when the flow rate recommended by the manufacturer was used. At the upper altitudes (approx. 30 km) the flow rate may be overestimated by as much as 15 percent using recommended values (see Harder et al., The UW Digital Ozonesonde: Characteristics and Flow Rate Calibration, poster paper, this workshop). These upper level values are used in the extrapolation, at constant mixing ratio, required to complete the sounding for total ozone. The first sounding was on 29 August, prior to major ozone depletion, when 274 DU total ozone (25 DU extrapolated) was observed. By early October total ozone had decreased to the 150 DU range; it then increased during mid-October owing to motion of the vortex and returned to a value of 148 DU (29 DU extrapolated) on 27 October.

Hofmann, D. J.; Harder, J. W.; Rosen, J. M.; Hereford, J.; Carpenter, J. R.

1988-01-01

85

Ozone profile measurements of McMurdo Station, Antarctica, during the spring of 1987  

NASA Technical Reports Server (NTRS)

Ozone and temperature profiles were measured in 50 balloon flights at McMurdo Station (78 deg S) during the spring of 1987. Compared to similar data obtained in 1986, stratospheric temperatures were lower and the spring time Antarctic ozone reduction was greater in magnitude, extended to higher altitude, and proceeded at a higher rate in 1987. Ozone partial pressures reached values as low as 3 nbar (as compared to about 10 nbar in 1986) in the 16- to 18-km region in early and late October, down from about 150 nbar in late August. These low values suggest essentially complete removal of ozone in this region. The upper boundary of the depletion region was observed to be 2-3 km higher than in 1986, extending to altitudes as high as 24 km in mid-September. When averaged over September, the ozone mixing ratio at 18 km decayed with a half-life of only 12.4 days, as compared to about 28 days in 1986. Adiabatic vertical motions over 1- to 2-km intervals between 12 and 20 km with consequent ozone reductions were observed in association with the formation of nacreous clouds, indicating these to be rare events on a local scale probably associated with mountain lee waves.

Hofmann, D. J.; Harder, J. W.; Rosen, J. M.; Hereford, J. V.; Carpenter, J. R.

1989-01-01

86

Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations  

Microsoft Academic Search

Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987—1991 by means of a network of nine AWS (auto- matic weather stations). Spatial configurations of temper- ature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell

E. Cogliani; G. Abbate; S. Racalbuto

1996-01-01

87

Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations  

Microsoft Academic Search

Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987–1991 by means of a network of nine AWS (automatic weather stations). Spatial configurations of temperature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell ice tongues,

E. Cogliani; G. Abbate; S. Racalbuto

1997-01-01

88

General sound classification and similarity in MICHAEL CASEY  

E-print Network

General sound classification and similarity in MPEG-7 MICHAEL CASEY MERL Cambridge Research Laboratory, Cambridge, USA E-mail: casey@merl.com We introduce a system for generalised sound classification of environmental sounds, musical instruments, music genre and human speakers. In addition to classification

Casey, Michael

89

Proposed Casey`s Pond Improvement Project, Fermi National Accelerator Laboratory  

SciTech Connect

The U.S. Department of Energy (DOE) has prepared an Environmental Assessment (EA), evaluating the impacts associated with the proposed Casey`s Pond Improvement Project at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois. The improvement project would maximize the efficiency of the Fermilab Industrial Cooling Water (ICW) distribution system, which removes (via evaporation) the thermal load from experimental and other support equipment supporting the high energy physics program at Fermilab. The project would eliminate the risk of overheating during fixed target experiments, ensure that the Illinois Water Quality Standards are consistently achieved and provide needed additional water storage for fire protection. Based on the analysis in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required.

NONE

1995-05-01

90

Balloonborne measurements of ozone and aerosol profiles at McMurdo Station, Antarctica, during the austral spring of 1992  

SciTech Connect

This paper reports some of the findings of an overall study of the ozone hole over Antarctica. Vertical profiles of ozone and aerosols were measured, and the inclusion of aerosols from the June 1991 eruption of Mount Pinatubo was of particular interest. 4 refs., 2 figs.

Johnson, B.J.; Deshler, T. (Univ. of Wyoming, Laramie, WY (United States))

1993-01-01

91

Visible and near-ultraviolet spectroscopy at McMurdo Station, Antarctica 9. Observations of OClO from April to October 1991  

SciTech Connect

This paper presents results from a series of measurements of atmospheric OClO covering the period April to October 1991, made at McMurdo Station, Antarctica. These measurements were made to extend the knowledge of the general role of atmospheric chlorine dioxide in the general problem of ozone depletion. It is now recognized that atmospheric depletion of ozone occurs in regions other than near the poles, and is mediated by processes beyond polar stratospheric clouds and accompanying photochemistry. This paper reports on a seasonal study of chlorine dioxide abundances using visible and near-ultraviolet absorption spectroscopy. Scattered light is the light source used for many of the observations. The observed abundances are combined with other measurements of NO[sub 2] and NO[sub 3], and a simple box type circulation model to infer that these species can be transported to lower latitudes, and exposed to sunlight, resulting in atmospheric ozone depletion.

Sanders, R.W.; Solomon, S.; Mount, G.H. (National Oceanic and Atmospheric Administration, Boulder, CO (United States)); Smith, J.P.; Perliski, L.; Miller, H.L. (Univ. of Colorado, Boulder (United States)); Keys, J.G. (Department of Scientific and Industrial Research, Lauder, Central Otago (New Zealand)); Schmeltekopf, A.L. (A.L. Schmeltekopf, Marshall, NC (United States))

1993-04-20

92

Detection of Seismic Sources Associated with Ice Movement in Antarctica using POLENET Seismic Array, AGAP Seismic Array, and GSN Seismic Stations  

NASA Astrophysics Data System (ADS)

Antarctica has the fewest reported seismic events of all the continents. In 2009 and 2010 only four Antarctic events were located by the ISC bulletin. The lack of seismicity is partly due to limited station coverage (only 9 permanent stations). Over 40 temporary stations have been installed beginning in 2007 as part of the IPY POLENET and AGAP projects. These stations greatly increase coverage, especially in the Antarctic interior, and allow us to locate events too small to be recorded at coastal stations. Recent interest in long period glacial sources (due to calving or ice movement) has led to the development and implementation of new detection algorithms. Traditional detections rely on high frequency impulsive signals typical of fast slipping earthquakes. These detectors miss 'slow' events (often associated with ice motion such as calving or slip events such as the tidally controlled periodic slip of the Whillans Ice Stream) that do not generate high frequency P phases and thus are absent from global catalogs. This study analyzes seismic data from 2009-2011 filtered in both long period (33-75s) and short period (0.1-2s) bands from over 50 stations. We detect, associate, and locate events in short period bands by identifying first arriving P and S phases using both automated STA/LTA detection and visual inspection. We also use a modified time reversal to identify 'slow' events. Long period envelopes are shifted by Rayleigh wave propagation times and stacked at equidistantly spaced source locations. The source is the location displaying the greatest amplitude stack. We find the Vanderford glacier region is highly seismic in both bands (one high frequency event being large enough to be included in the ISC bulletin). The David and Mullock glacier regions of the Transantarctic Mountains frequently produce magnitude 3-4 events (detected in the high frequency band) associated with ice movements. Several tectonic earthquakes have been detected in the interior of the continent near the center of East Antarctica (depths between 20-40 km). We have also detected a new type of cryospheric source characterized by ~ 1 s Rayleigh waves traveling in the ice layer (1.5-1.7 km/s propagation velocity) over distances of up to 1000 km. These sources are located within the upper part of the ice sheet and are distributed around the interior of East Antarctica, and may correspond to large crevassing or snow collapse events. We continue to analyze both long and short period bands of data collected starting in IPY. When completed the catalog will give great insight into both the tectonic and glacial processes capable of producing seismic waves (such as calving or sudden ice stream motion) active in unobserved regions of the the Antarctic continent.

Lough, A. C.; Barcheck, C. G.; Wiens, D. A.; Barklage, M. E.; Nyblade, A.; Aster, R. C.; Anandakrishnan, S.; Huerta, A. D.; Wilson, T. J.

2011-12-01

93

Contrasts between the summertime surface energy balance and boundary layer structure at Dome C and Halley stations, Antarctica  

Microsoft Academic Search

The Antarctic research stations of Dome C and Halley lie at similar latitudes (?75°S) and are thus subject to similar diurnal variation of solar radiation at the top of the atmosphere. However, the response of the atmospheric boundary layer to this diurnally varying forcing differs greatly at the two stations. At Dome C during summer there is a strong diurnal

J. C. King; S. A. Argentini; P. S. Anderson

2006-01-01

94

Occurrence of microbial indicators and Clostridium perfringens in wastewater, water column samples, sediments, drinking water, and Weddell seal feces collected at McMurdo Station, Antarctica  

USGS Publications Warehouse

McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered.

Lisle, J.T.; Smith, J.J.; Edwards, D.D.; McFeters, G.A.

2004-01-01

95

Occurrence of Microbial Indicators and Clostridium perfringens in Wastewater, Water Column Samples, Sediments, Drinking Water, and Weddell Seal Feces Collected at McMurdo Station, Antarctica  

PubMed Central

McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered. PMID:15574926

Lisle, John T.; Smith, James J.; Edwards, Diane D.; McFeters, Gordon A.

2004-01-01

96

Linking the Annual Variation of Snow Radar-derived Accumulation in West Antarctica to Long-term Automatic Weather Station Measurements  

NASA Astrophysics Data System (ADS)

Understanding the snow accumulation rate on polar ice sheets is important in assessing mass balance and ice sheet contribution to sea level rise. Measuring annual accumulation on a regional scale and extending back in time several decades has been accomplished using the Center for Remote Sensing of Ice Sheets (CReSIS) Snow Radar on the NASA DC-8 that is part of NASA's Ice-Bridge project. The Snow Radar detects and maps near-surface internal layers in polar firn, operating from 2- 6 GHz and providing a depth resolution of ~4 cm. During November 2011, Snow Radar data were obtained for large areas of West Antarctica, including a flight segment that passed within ~70 km of Byrd Station (80°S, 119°W). Byrd Station has a very long automatic weather station (AWS) record, extending from present to 1980, with 3 relatively brief gaps in the record. The AWS data for Byrd Station were obtained from the Antarctic Meteorological Research Center (AMRC) at the University of Wisconsin. The L1B Snow Radar data products, available from the National Snow and Ice Data Center (NSIDC), were analyzed using layer picking software to obtain the depth of reflectors in the firn that are detected by the radar. These reflectors correspond to annual markers in the firn, and allow annual accumulation to be determined. Using the distance between the reflectors and available density profiles from ice cores, water equivalent accumulation for each annual layer back to 1980 is obtained. We are analyzing spatial variations of accumulation along flight lines, as well as variations in the time series of annual accumulation. We are also analyzing links between annual accumulation and surface weather observations from the Byrd Station AWS. Our analyses of surface weather observations have focused on annual temperature, atmospheric pressure and wind extremes (e.g. 5th and 95th percentiles) and links to annual snow accumulation. We are also examining satellite-derived sea ice extent records for the Bellingshausen and Amundsen seas sector (60°W-120°W) over the same 31-year time period and comparing results to annual snow accumulation. Results from this work will be presented at the meeting.

Feng, B.; Braaten, D. A.; Gogineni, P.; Paden, J. D.; Leuschen, C.; Purdon, K.

2013-12-01

97

Curriculum Vitae Casey J. Law Radio Astronomy Lab  

E-print Network

Curriculum Vitae ­ Casey J. Law Radio Astronomy Lab University of California Hearst Field Annex ­ B://astro.berkeley.edu/claw 1 Education Northwestern University, Ph.D., Astrophysics (2007) Boston University, M.A., Astronomy: Radio Astronomy Lab Postdoctoral Fellow at UC Berkeley. Worked with Geoff Bower, Don Backer, and Carl

Militzer, Burkhard

98

Analysis of the Use of Wind Energy to Supplement the Power Needs at McMurdo Station and Amundsen-Scott South Pole Station, Antarctica  

SciTech Connect

This report summarizes an analysis of the inclusion of wind-driven power generation technology into the existing diesel power plants at two U.S. Antarctic research stations, McMurdo and Amundsen-Scott South Pole Station. Staff at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) conducted the analysis. Raytheon Polar Services, which currently holds the private sector support contract for the two research stations, was a major contributor to this report. To conduct the analysis, available data were obtained on the wind resources, power plant conditions, load, and component cost. Whenever possible, we validated the information. We then used NREL's Hybrid2 power system modeling software to analyze the potential and cost of using wind turbine generators at the two aforementioned facilities. Unfortunately, the power systems and energy allocations at McMurdo and South Pole Station are being redeveloped, so it is not possible to validate future fuel use. This report is an initial assessment of the potential use of wind energy and should be followed by further, more detailed analysis if this option is to be considered further.

Baring-Gould, I.; Robichaud, R.; McLain, K.

2005-05-01

99

Astronomy in Antarctica  

E-print Network

Antarctica provides a unique environment for astronomy. The cold, dry and stable air found above the high plateau, as well as the pure ice below, offers new opportunities across the photon & particle spectrum. The summits of the plateau provide the best seeing conditions, the darkest skies and the most transparent atmosphere of any earth-based observing site. Astronomical activities are now underway at four plateau sites: the Amundsen-Scott South Pole Station, Concordia Station at Dome C, Kunlun Station at Dome A and Fuji Station at Dome F, in addition to long duration ballooning from the coastal station of McMurdo. Astronomy conducted includes optical, IR, THz & sub-mm, measurements of the CMBR, solar, as well as high energy astrophysics involving measurement of cosmic rays, gamma rays and neutrinos. Antarctica is also the richest source of meteorites on our planet. An extensive range of site testing measurements have been made over the high plateau. We summarise the facets of Antarctica that are dri...

Burton, Michael G

2010-01-01

100

The role of sublimation and condensation in the formation of ice sheet surface at Mizuho Station, Antarctica  

Microsoft Academic Search

Three methods were used to determine the sublimation and condensation at Mizuho Station in 1977-1978, that is, direct observations with an evaporimeter filled with ice and repeated measurements of offset stakes and indirect estimation using an empirical formula derived from meteorological parameters. A comparison of three methods shows satisfactory agreement, especially in the weekly average of sublimation in the 1977-1978

Yoshiyuki Fujii; Kou Kusunoki

1982-01-01

101

Balloon-borne measurements of aerosol, condensation nuclei, and cloud particles in the stratosphere at McMurdo Station, Antarctica, during the spring of 1987  

NASA Technical Reports Server (NTRS)

Measurements of the vertical profile of particles with condensation nuclei counters and eight channel aerosol detectors at McMurdo Station, Antarctica, in 1987 verified observations made in 1986 concerning the absence of upwelling in the polar vortex and the presence of a condensation nuclei layer in conjunction with the ozone hole region. New observations of a bimodal aerosol size distribution, consisting of a large-particle mode mixed in with the small-particle sulfate mode, at temperatures below -79 C are consistent with the presence of nitric acid-water particles at low concentrations. Higher concentrations of large particles were observed in association with nacreous clouds. An unusual particle layer which contained enhanced concentrations of both the small-particle (sulfate) mode and the large-particle (nitric acid) mode was detected at temperatures below -85 C, suggesting simultaneous nucleation and growth phenomena. The vortex condensation nuclei layer was observed to form at the same time as the ozone hole, indicating that formation of the layer is triggered by photochemical processes and may be important in controlling ozone depletion above 22 km.

Hofmann, D. J.; Rosen, J. M.; Harder, J. W.; Hereford, J. V.

1989-01-01

102

Ground-based monitoring of nitric oxide (NO) in the mesosphere and the lower thermosphere from Syowa Station in Antarctica  

NASA Astrophysics Data System (ADS)

Ion-molecule chemistry triggered by energetic particle precipitation (EPP) due to large solar proton events or geomagnetic storms influences the atmospheric minor constituents such as HOx, NOx and ozone from the upper stratosphere to the lower thermosphere. To understand the effect of the EPP on the middle atmosphere in the polar region, we installed a new spectroscopic radiometer at Syowa Station (69.00S, 39.85E) in the 52nd Japanese Antarctic Research Expedition. We have carried out ground-based continuous observations of spectral line of nitric oxide (NO) at 250.796 GHz since January 2012. We obtained 197 and 172 daily averaged NO spectra in 2012 and 2013 (until 30 September; DOY 273), respectively. The NO spectra are characterized by narrow line width of about 0.5MHz at FWHM, suggesting that the NO emitting region is between 75 and 100 km based on the relationship between the pressure broadening line width and the altitude. We derived partial column density of NO from the spectral intensity. We found two temporal variation patterns of the NO column density, i.e., long-term and short-term variations. The long-term variation is a seasonal one with a maximum in the winter and a minimum in the summer. The column density of NO during the winter was about 4 times larger than that during the summer. This seasonal variation is considered to be related to the atmospheric transport and the photo-dissociation of NO by solar radiation. The other short-term variation is associated with EPP events such as solar proton events and geomagnetic storms. Typical duration of the short-term variation is 5-10 days. At Syowa Station, we have found that the short-term variations were caused mainly by the precipitation of electrons rather than protons based on the comparison with the precipitating fluxes of protons and electrons obtained by the POES and METOP-02 satellites. We studied more detailed behavior of NO within a day by using high time resolution (˜ 3-hour) data for one of the short-term NO enhancement events in April 2012, which is the most prominent NO short-term event observed at Syowa Station since January 2012. We revealed a diurnal tendency that NO column density increased about twice at UT 0 during 3 days around the peak of the NO enhancement. Based on the comparison between the NO column density and the electron fluxes obtained by the POES and METOP-02, we interpret that this diurnal tendency resulted from the dawn-dusk asymmetry of the precipitated electrons with energies 30-300 keV.

Mizuno, Akira; Nakamura, Takuji; Miyoshi, Yoshizumi; Fujiwara, Hitoshi; Tsutsumi, Masaki; Ejiri, Mitsumu K.; Nagahama, Tomoo; Isono, Yasuko; Kataoka, Ryuho; Hiroyuki, Maezawa; Uemura, Miku

103

Visible and near-ultraviolet spectroscopy at McMurdo Station, Antarctica. 7. OClO diurnal photochemistry and implications for ozone destruction  

SciTech Connect

Observations of the ratio between the change in slant column abundance of OClO and that of ozone as a function of solar zenith are used to deduce the diurnal cycle of the daytime OClO column abundance above Antarctica during September 1987. This approach effectively normalizes other factors such as air mass factor changes and allows study of the photochemical variations of OClO during twilight. The data exhibits a marked increase in OClO at large solar zenith angles in the evening twilight (near 90{degree}-93{degree}), in agreement with model predictions. The increase is likely caused primarily by the attenuation of the OClO photolysis rate in the twilight. Knowledge of both the full diurnal and daily variations of OClO deduced from the data can be used to evaluate the destruction of the ozone column due to coupled chlorine-bromine chemistry. The inferred ozone loss above McMurdo Station assuming presently accepted photochemistry is 19.5 {plus minus} 10 Dobson units over the entire month of September, or about 20 {plus minus} 10% of the observed total column decline. This value is in general agreement with inferences drawn from in-situ measurements of ClO and BrO. In mid-September, available OClO and HOCl column measurement suggest that the chlorine-bromine and chlorine-hydrogen cycles respectively contribute about 22-28% and 3-4% of the observed rate of column ozone decrease at that time of the month. Model calculations constrained by ClO, BrO, and OClO measurements suggest that these mechanisms combined with photolysis of the ClO dimer can account for much, and possibly all, of the total ozone destruction rate observed in mid-September 1987.

Solomon, S.; Sanders, R.W. (NOAA, Boulder, CO (USA)); Miller, H.L. Jr. (Univ. of Colorado, Boulder (USA))

1990-08-20

104

Characteristics of highprecipitation events in Dronning Maud Land, Antarctica  

E-print Network

, Antarctica E. Schlosser,1 K. W. Manning,2 J. G. Powers,2 M. G. Duda,2 G. Birnbaum,3 and K. Fujita4 Received events at the deep ice core drilling site Kohnen Station, Dronning Maud Land, Antarctica, during precipitation events in Dronning Maud Land, Antarctica, J. Geophys. Res., 115, D14107, doi:10.1029/2009JD013410

Schlosser, Elisabeth

105

SIAMOIS: Asteroseismology in Antarctica Beno^it MOSSER1  

E-print Network

SIAMOIS: Asteroseismology in Antarctica Beno^it MOSSER1 & the SIAMOIS team2 1 LESIA, Observatoire-based asteroseismology project, to pursue velocity measurements from the Dome C Concordia station in Antarctica. Dome C conditions in Antarctica. The instrument will be fully automatic, with no moving parts, and it will require

Demoulin, Pascal

106

Geoenvironments from the vicinity of Arctowski Station, Admiralty Bay, King George Island, Antarctica: vulnerability and valuation assessment  

USGS Publications Warehouse

The use of a geographic information system (GIS) allows the mapping and quantification of biotic and physical features of importance to the environmental planning of Antarctic areas. In this paper we examined the main aspects of the geoenvironments of Arctowski Station vicinity (Admiralty bay, Maritime Antartica), by means of a photointerpretation of an orthomosaic at 1:6000 scale, produced by non-conventional aerial photographs obtained by the Brazilian Cryosols project. We carried out a preliminary environmental valuation and vulnerability assessment of the area. Hence, geoenvironments were classified and ranked according with their biological valuation and vulnerability (fragility), mapping 20 units covering approximately 150 ha. The most fragile geoenvironmental units were former and present penguin rookeries with different vegetation covers, all very prone to degradation by over-trampling and human perturbations. The relationships between each geoenvironment were also explored, emphasizing the ecological aspects and their valuation. In quantitative terms, the most vulnerable and fragile units (classes 4 and 5) occupy nearly 22 % of the total area, being highly concentrated near the coastal areas. There, ornithogenic input is an important factor favoring the vegetation development.

Schaefer, Carlos Ernesto G.R; Santana, Rogério Mercandelle; Simas, Felipe Nogueira Bello; Francelino, Márcio R.; Filho, Elpídio Inácio Fernandes; Albuquerque, Miriam Abreu; Calijuri, Maria Lúcia

2007-01-01

107

The CELSS Antarctic Analog Project: an advanced life support testbed at the Amundsen-Scott South Pole Station, Antarctica.  

PubMed

The Controlled Ecological Life Support System (CELSS) Antarctic Analog Project (CAAP) is a joint endeavor between the National Science Foundation, Office of Polar Programs (NSF-OPP) and the National Aeronautics and Space Administration (NASA). Its fundamental objective is to develop, deploy and operate a testbed of NASA CELSS technologies and life support approaches at the Amundsen-Scott South Pole Station, located at latitude 90 degrees S, longitude 0 degrees. The goal of NASA's CELSS Program is to develop technologies and systems that will allow spacefaring scientists and explorers to carry out long duration extraterrestrial missions, leading ultimately to permanent habitation of the Solar System, without total dependence on a costly resupply system. A CELSS would do this by providing regenerated life support materials (air, food and water) and by processing "waste" materials into useful resources. This will be accomplished using biological and physical/chemical techniques in a nearly closed environmental habitation system. CELSS technologies also have great implications for application to terrestrial systems with intrinsic transferability to society at large. The CELSS Program intends to provide opportunities for the transfer of these systems and technologies outside the US Space Program, to applications within the American economy as space technology spin-offs. PMID:11538582

Straight, C L; Bubenheim, D L; Bates, M E; Flynn, M T

1994-01-01

108

Variation of NO in lower thermosphere associated with a magnetic storm on April 2012 detected at Syowa station in Antarctica  

NASA Astrophysics Data System (ADS)

In the polar regions, it is known that energetic particle precipitation (EPP) induces ion-molecule chemistry and changes abundances of some minor molecules in the upper- and sometimes in the middle-atmosphere. Energetic solar protons directly enter the middle atmosphere, causing increase of HOx and NOx radicals and decrease of ozone (e.g., Jackman et al. 2001). Energetic electrons also increase NOx in the thermosphere, and the NOx-rich air is transported downward in the polar vortex during the polar winter (e.g., Seppälä et al. 2007). To understand the relationship between the EPP induced NOx variation and the solar activities in more detail, we newly installed a millimeter-wave spectroscopic radiometer at Syowa Station (69.00S, 39.85E) in the 52nd Japanese Antarctic Research Expedition. We have been carried out ground-based continuous monitoring of millimeter-wave ozone (235.709 GHz) and NO (250.796 GHz) spectral lines with a 70 kHz resolution and a 1 GHz bandwidth since March 2011. Based on the NO spectra integrated over 24 hours (UT 0-24), we found enhancement of the NO emission in 25-29 April, 2012. During this period, there was no significant solar proton increase. The peak intensity of the NO emission increased up to 4.1 K on 28th, while an average of the NO intensities from 18 to 23 April was estimated to be 1.4 K. After the enhancement, the intensity decreased below 2.5 K on 30th. In this period, a large magnetic storm occurred and its main phase was on April 23. The minimum value of Dst index reached -100 nT on April 24, and the electron flux with an energy less than 30 keV became a maximum of ~104 cm-2 s-1 str-1 on April 25 observed by POES. These results suggest that the remarkable enhancement of NO emission is associated with the energetic electron precipitation from radiation belts, although there is a 5-day delay between at the peak of the NO intensity and the main phase of the magnetic storm. In addition, from the NO data integrated every 12 hours (MLT 0-12 and 12-24), we clearly found that the NO intensity observed in MLT 0-12 is about 50 % stronger than that in MLT 12-24 on average during a period from 26 to 29 April. This suggests that the NO intensity is modulated in connection with the dawn-dusk asymmetry of the electron distribution in the magnetopause. In this presentation, we will discuss a possible mechanism for the two different kind of NO intensity variations, i.e. persistent enhancement for a few days and daily variation, observed related with EPP at Syowa Station.

Isono, Y.; Mizuno, A.; Nagahama, T.; Ejiri, M. K.; Kataoka, R.; Kuwahara, T.; Maezawa, H.; Miyoshi, Y.; Nakamura, T.; Tsutsumi, M.

2012-12-01

109

Physico-Chemical Properties and CO2 fluxes at a frost-flower station in the Bellingshausen Sea, Antarctica (SIMBA)  

NASA Astrophysics Data System (ADS)

This study documents the physico-chemical properties of newly formed sea ice at a frost flower site of the Ice Station ‘Belgica’. in the Bellingshausen Sea, (Sept-Oct 2007). Frost flower formation on sea ice is of interest, both for paleoclimatic reconstructions in deep ice cores and for potential impacts on atmospheric chemistry. The site has been surveyed for thickness at 3 occasions and samples were collected for multiparametric analyses on days 277 and 290 of 2007. CO2 fluxes were measured on day 290 along a 15 meters transect across the rim of the recently ice covered lead (8-27 cm). Ice samples were collected at 5 regularly spaced locations. Snow cover regularly decreased from the rim (10 cm) to the inner part of the lead (0 cm) We will present texture, temperature, bulk salinity, brine volume, ?18O, chl a, major cations and anions data and accumulation chamber-type CO2 fluxes and discuss the effect of the varying snow cover on salt fractionation and CO2 fluxes. The large contrasts in the snow cover along the transect resulted in contrasting snow-ice interface temperatures and therefore permeability, which in turn was clearly driving the gas fluxes and processes of salt concentration at the ice surface. This study provides the first field evidence that newly forming ice temporarily acts as a source for CO2 to the atmosphere, thereby confirming recent results from experimental work. It also brings new insights to the role of ice texture in controlling CO2 fluxes and suggests the potential need for revisiting the validity domain of the “law of fives”. Finally, it demonstrates that the processes responsible for frost flower formation are clearly inhibited by the snow cover build up.

Tison, J.; Geilfus, N.; Brabant, F.; Ackley, S. F.; Golden, K. M.; Worby, A. P.; Fritsen, C. H.; Delille, B.

2009-12-01

110

The Geography of Antarctica.  

National Technical Information Service (NTIS)

Contents: Development of geographic theories on Antarctica; The theory of a southern continent; Temperate and high latitudes in the Southern Hemisphere; Morphometric parameters of Antarctica; Rock surface of Antarctica; Ice Antarctica (climate and glaciat...

K. K. Markov, V. I. Bardin, V. L. Lebedev, A. I. Orlov, I. A. Suetova

1970-01-01

111

The Geology of Antarctica.  

National Technical Information Service (NTIS)

Contents: Tectonic setting of Antarctica; Basic tectonic divisions of Antarctica; The bedrock topography of Antarctica; The crystalline basement rock surface; Crustal structure in Antarctica; Seismic refraction studies of the upper crust; Crustal structur...

G. P. Woollard

1970-01-01

112

Antarctica Ice  

NSDL National Science Digital Library

This short video examines the recent melting ice shelves in the Antarctica Peninsula; the potential collapse of West Antarctic ice shelf; and how global sea levels, coastal cities, and beaches would be affected.

Geographic, National

113

Cool Antarctica  

NSDL National Science Digital Library

Paul Ward, the designer of this site, spent over two years in Antarctica as a marine biologist with the British Antarctic Survey. Currently a teacher at a community college in Britain, Ward decided to develop this site to provide information about Antarctica's history, wildlife, and the various explorers who have traveled across the continent. The section featuring Ward's photographs is quite compelling, featuring hundreds of pictures of wildlife, the area's mountains, and icebergs. The historical pages are quite detailed, particularly those about the legendary Ernest Shackleton and his amazing Trans-Antarctica Expedition of 1914 to 1917. Persons looking for material about visiting Antarctica will find a section dedicated to helping people prepare for a visit to the area, including information about various cruise operators and what type of clothing is most suitable.

114

Tardigrades of the Australian Antarctic Territories: the Windmill Islands, East Antarctica  

Microsoft Academic Search

Six species of tardigrades,Pseudechiniscus suillus, Macrobiotussp.,Hypsibius antarcticus, Ramajendas frigidus, Diphascon chilenenseandDiphascon pinguewere extracted from mosses and lichens from the ice-free regions of the Windmill Islands near Casey Base, East Antarctica. Significant positive associations were found between the three common species (Pseudechiniscus suillus, Hypsibius antarcticus, Diphascon chilenense) and bryophytes, whereas strong negative associations were found between these species and algae and

W. R. MILLER; J. D. MILLER; H. HEATWOLE

1996-01-01

115

SPRILIB Antarctica  

NSDL National Science Digital Library

The Scott Polar Research Institute at the University of Cambridge has recently made available online the database, SPRILIB Antarctica. SPRILIB Antarctica, a subset of SPRILIB, a polar and glaciological bibliographic database, contains 33,000 records from 1602 to 1996. The database offers comprehensive coverage of Antarctic literature on all subjects in all available languages for the period before 1962. However, it only includes some periodical articles and conference papers for the period after 1962. This database is intended to complement the Antarctic Bibliography at the Cold Regions Bibliography page of the Library of Congress site, and for the period after 1962, the Antarctic Bibliography contains comprehensive coverage of Antarctic literature. The SPRILIB Antarctica database is searchable by keyword, author, time period, place, expedition, or date of publication.

116

Antarctica Geology  

NSDL National Science Digital Library

This site contains information about the continent of Antarctica. There is a classroom practice and instructional module. The students will be able to describe the general geology of the land under the Antarctic ice and to explain from where the rocks may have come.

117

Undermining Antarctica  

SciTech Connect

Antarctica is not a global footnote. Its seas contain one of the world's richest concentrations of marine life. And the continent and adjacent shelf may harbor quantities of oil, gas, and other minerals. Many nations want to cash in on these resources. So in 1980 the member countries of the Antarctic Treaty - the agreement that sets the continent aside as a peaceful scientific reserve - signed a pact to regulate the harvesting of fish and other Antarctic life. Now the group, consisting today of 37 nations, is trying to finish a legal framework for exploiting minerals in the region. Antarctica plays a vital role in global atmospheric and oceanic systems. Its vast frozen crust, which accounts for more than 90 percent of the world's ice, greatly affects weather and sea levels and contains an invaluable record of the earth's climatic history. The continent provides precious information on increases in atmospheric carbon dioxide and global pollutants such as DDT. In other words, what happens to Antarctica is of vital importance to us all. It is essential, then, that the minerals pact now being devised heed the concerns of the many nations that don't have a say in Antarctica today, and that it does not endanger this precious continent.

Mitchell, B.

1988-02-01

118

Antarctica. Commission Reports 1962.  

National Technical Information Service (NTIS)

Contents: Geological structure of the central Queen Maud Land mountains in east Antarctica; Morphometric parameters of Antarctica; Blank areas on maps of the Antarctic; The geomorphological map of Antarctica; Physiographic zoning map of the Antarctic; Pal...

V. A. Bugaev

1969-01-01

119

Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations  

NASA Astrophysics Data System (ADS)

Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987-1991 by means of a network of nine AWS (automatic weather stations). Spatial configurations of temperature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell ice tongues, throughout the year. A second warm island is present to the north along the coast, between Aviator and Mariner ice tongues, for most of the year. From February to March a rapid drop in temperature is observed at all stations. A strong thermal gradient develops during February, March, April and October, November, December, between the coastal region and inner highlands. The baric configuration follows the elevation of the area. Annual average pressure and temperature as functions of stations altitude show linear trends. Severe katabatic wind episodes are recorded at all stations, with wind speed exceeding 25 m s-1 and direction following the orographic features of the inner areas. Co-occurrences of these episodes were observed for stations located along stream lines of cold air drainage. The autocorrelation function of maximum wind speed time series shows wind persistence of 2-3 days and wind periodicity of about one week. Acknowledgements. We gratefully appreciate the on-line DMSP database facility at APL (Newell et al., 1991) from which this study has benefited greatly. We wish to thank E. Friis-Christensen for his encouragement and useful discussions. A. Y. would like to thank the Danish Meteorological Institute, where this work was done, for its hospitality during his stay there and the Nordic Baltic Scholarship Scheme for its financial support of this stay. Topical Editor K.-H. Glassmeier thanks M. J. Engebretson and H. Lühr for their help in evaluating this paper.--> Correspondence to: A. Yahnin-->

Cogliani, E.; Abbate, G.; Racalbuto, S.

1996-10-01

120

Discover Antarctica  

NSDL National Science Digital Library

Antarctica is arguably the continent that most people know the least about, so it is nice to find out that the Royal Geographical Society (in partnership with the British Antarctic Survey) has created this website which explores all aspects of life on this landmass. The "Imagining Antarctica" area is a fine place to start, and visitors can watch a short video clip about the continent, test their existing knowledge with a short quiz, and then participate in a "being there" activity. Other engaging sections include "A Changing Climate", "Living There Today" and "What Future?" The site also lists all of the resources by format, including audio files, video clips, Word documents, and images. Finally, the site also includes a "Teachers' Area", which offers a number of learning activities for students and teacher notes that are correlated to each of the main sections of the site.

121

Cosmology from Antarctica  

E-print Network

Observation of the CMB is central to observational cosmology, and the Antarctic Plateau is an exceptionally good site for this work. The first attempt at CMB observations from the Plateau was an expedition to the South Pole in December 1986 by the Radio Physics Research group at Bell Laboratories. Sky noise and opacity were measured. The results were sufficiently encouraging that in the Austral summer of 1988-1989, three CMB groups participated in the "Cucumber" campaign, where a temporary site dedicated to CMB anisotropy measurements was set up 2 km from South Pole Station. Winter-time observations became possible with the establishment in 1990 of the Center for Astrophysical Research in Antarctica (CARA), a National Science Foundation Science and Technology Center. CARA developed year-round observing facilities in the "Dark Sector", a section of Amundsen-Scott South Pole Station dedicated to astronomical observations. CARA scientists fielded several astronomical instruments: AST/RO, SPIREX, White Dish, Python, Viper, ACBAR, and DASI. By 2001, data from CARA, together with BOOMERANG, a CMB experiment on a long-duration balloon launched from McMurdo Station on the coast of Antarctica, showed clear evidence that the overall geometry of the Universe is flat, as opposed to being positively or negatively curved. In 2002, the DASI group reported the detection of polarization in the CMB. These observations strongly support the concordance model of cosmology, where the dynamics of a flat Universe are dominated by forces exerted by the Dark Energy and Dark Matter. The South Pole Telescope (SPT) is a newly-operational 10 m diameter offset telescope designed to rapidly measure anisotropies on scales much smaller than 1 degree.

Robert W. Wilson; Antony A. Stark

2008-10-04

122

SIAMOIS : AN ASTEROSEISMIC NETWORK WITH 1 SITE... IN ANTARCTICA Mosser Beno^it1  

E-print Network

SIAMOIS : AN ASTEROSEISMIC NETWORK WITH 1 SITE... IN ANTARCTICA Mosser Beno^it1 and the SIAMOIS- seismology, involving an instrument to be installed at the Dome C Concordia station in Antarctica. Dome C ap with a dedicated small 40-cm telescope. Key words: Instrumentation, Antarctica, Stars: oscilla- tions. 1

Demoulin, Pascal

123

The role of synoptic-scale features and advection in prolonged warming and generation of different forms of precipitation at Dome Fuji station, Antarctica, following a prominent blocking event  

NASA Astrophysics Data System (ADS)

A blocking event over the East Antarctic ice sheet during June 1997 generated the highest surface air temperature (which increased from around -70°C to around -30°C) and pressure of that year at the Dome Fuji station (77.5°S, 40°E). Following the blocking event, the anomalously high air temperature (around -50°C to -60°C) and pressure were maintained at the surface for about 1 week. This study investigates how these warm conditions were maintained and documents the sequential occurrence of two forms of synoptic-scale high-pressure systems with conditions that produced precipitation by different processes in each case. In the first half of the warm period, a solitary high-pressure system (the Solitary High) formed over the Dome Fuji station and traveled west over East Antarctica after being cut off from the tip of the preceding blocking ridge. During this phase, tropospheric temperatures were higher, and surface-based temperature inversions were more intense than during the following period. While a dry-out developed in the troposphere below about 300 hPa, the precipitation of ice crystals in the surface-based temperature inversion layer was generated by deposition of moisture that had become trapped in the boundary layer after being transported onto the continent by the previous blocking ridge. This mechanism has not been previously reported elsewhere. During the second half of the warm period, a ridge of high pressure (the Transcontinental Ridge) traversed East Antarctica almost completely, and its western section was amplified by the merging of the Solitary High with a preceding quasi-stationary Rossby wave train propagating along the Southern Ocean. This ridge allowed an intrusion of warm, moist air from the Weddell Sea toward the station, which generated precipitation throughout the whole troposphere by orographic uplift once again, and ended the dry-out. This represents the typical mechanism of both moisture transportation and the generation of precipitation, and this mechanism was the same as that associated with the preceding blocking ridge.

Hirasawa, Naohiko; Nakamura, Hisashi; Motoyama, Hideaki; Hayashi, Masahiko; Yamanouchi, Takashi

2013-07-01

124

Bouvet Island near Antarctica  

... Lozier. Bouvet was convinced it was the northernmost tip of Antarctica but could not circumnavigate or land upon the island due to severe ... Bouvet Island location:  Antarctica Atlantic Ocean thumbnail:  ...

2013-04-16

125

Gateway to Antarctica  

NSDL National Science Digital Library

The International Centre for Antarctic Information and Research is produces the Gateway Antarctica. This Web server has been set up to provide the international community with information about Antarctica.

1969-12-31

126

This article was downloaded by: [University of Nebraska Kearney], [Casey W. Schoenebeck] On: 03 February 2012, At: 12:44  

E-print Network

in Yellow Perch Populations? Casey W. Schoenebeck a b & Michael L. Brown a a Department of Wildlife Anaerobic Activity Differ Seasonally or between Sexes in Yellow Perch Populations?, Transactions Seasonally or between Sexes in Yellow Perch Populations? Casey W. Schoenebeck*1 and Michael L. Brown

127

Antarctica and Continental Drift.  

National Technical Information Service (NTIS)

Continental drift reconstructions by computerized matching of the 1,000 fm isobaths are presented for Africa/Antarctica, Australia/Antarctica and India/Antarctica. Sufficiently good congruency is obtained for the first two to suggest that they are probabl...

R. S. Dietz, J. C. Holden, W. P. Sproll

1972-01-01

128

Vertical profiles of atmospheric temperature between upper troposphere and mesosphere obtained from Rayleigh/Raman lidar installed at Syowa station in Antarctica  

NASA Astrophysics Data System (ADS)

Atmospheric gravity waves (AGWs) propagating upward from lower atmospheric sources play a dominant role in transporting and depositing energy and momentum from upper troposphere (UT) to lower mesosphere (LM). Particularly, in polar region, these effects of AGWs are well-known to strongly decelerate the polar night jet and drive large scale meridional circulation from the summer pole towards the winter pole. In addition, polar stratospheric clouds (PSCs) described in relation to ozone depletion are effectively induced by orographic AGWs. Therefore, investigation of the activity of AGWs between UT and LM based on continuous observational studies can be regarded as one of important subjects in the middle atmosphere dynamics. The National Institute of Polar Research (NIPR) is leading a six year prioritized project of the Antarctic research observations since 2010. One of the sub-projects is entitled 'the global environmental change revealed through the Antarctic middle and upper atmosphere'. As a part of the sub-project, a Rayleigh/Raman lidar (RR lidar) was installed at Syowa, Antarctica (69S, 39E) in January, 2011. The operation has been conducted since February 2011 and the RR lidar has kept measuring temperature profiles continuously between approximately 10 and 80 km for almost 3 years. The RR lidar system in Syowa can obtain photon count data for 4 channels simultaneously, and each data is recorded separately in binnary format. We used the data from 3 channels, i.e., Raman (10-30km), Rayleigh-Low (20-65km), Rayleigh-High (30-80km), for estimations of temperature profiles from UT to LM. In order to estimate height continuous profiles of atmospheric temperature based on the 3 different channels, we are examining the following analysis methods. (1) The temperature for Rayleigh-High and Rayleigh-Low channels estimated by solving the lidar equation can be assigned to temperature at an initial height for the lidar equation in Rayleigh-Low and Raman channels, respectively. (2) The initial heights for the lidar equation can be determined automatically taking into account time and height dependent shot noises due to background luminosity. (3) The error propagations from the initial height to lower heights are evaluated by assigning artificial temperature offset ranging from -50 to 50 K. The height continuous temperature profiles between UT and LM obtained from improved analysis methods would allows us to investigate important scientific issues such as temporal and height variabilities of potential energy per unit mass of AGWs and the relationship between occurrence of PSCs and background atmospheric temperature.

Nishiyama, Takanori; Nakamura, Takuji; Tsutsumi, Masaki; Kawahara, Takuya D.; Tomikawa, Yoshihiro; Suzuki, Hidehiko; Ejiri, Mitsumu K.; Abo, Makoto; Tsuda, Takuo T.

129

Getting Results: Outcomes Management and the Annie E. Casey Foundations Jobs Initiative.  

ERIC Educational Resources Information Center

The Anne E. Casey Foundation (AECF) funded replications of effective jobs projects to achieve better job placement and retention for low-income, young adults. The six projects funded, collectively called the Jobs Initiative (JI), in Denver, Milwaukee, New Orleans, Philadelphia, Seattle, and St. Louis, used an outcomes framework developed by The…

Giloth, Robert; Phillips, William

130

AdvoCasey: Documenting Programs That Work for Kids and Families, 2000.  

ERIC Educational Resources Information Center

This publication includes five articles on health care and health promotion within impoverished communities. "The Health of Families and Communities" (Douglas W. Nelson) introduces the issue, discussing the work of the Annie E. Casey Foundation in communities. "Inconspicuous Consumption: Treating Latent TB Infection in Seattle" (Bill Rust) reports…

Nelson, Douglas W.; Rust, Bill; Hinds, Michael DeCourcy

2000-01-01

131

Improvement of an Esocid Bioenergetics Model for Juvenile Fish CASEY W. SCHOENEBECK*  

E-print Network

Improvement of an Esocid Bioenergetics Model for Juvenile Fish CASEY W. SCHOENEBECK* Department the accuracy of a juvenile esocid bioenergetics model, we used a regression-based approach to develop the following variables: initial body weight (g), water temperature (8C), and relative growth rate (cal gÃ?1 dÃ?1

132

Towards Versatile Document Analysis Systems Henry S. Baird and Matthew R. Casey  

E-print Network

document analysis systems, DAS methodology, document image content extraction, classification, k NearestTowards Versatile Document Analysis Systems Henry S. Baird and Matthew R. Casey Computer Science@cse.lehigh.edu, mrc8@lehigh.edu Abstract. The research goal of highly versatile document analysis systems, ca- pable

Baird, Henry S.

133

Transmittal.txt From: Clark, Casey On Behalf Of Lehman, Daniel  

E-print Network

Transmittal.txt From: Clark, Casey On Behalf Of Lehman, Daniel Sent: Monday, June 30, 2003 4:09 PM the report further, please contact Stephen Meador at 301-903-2490. Regards, Daniel Lehman Director Construction Management Support Division, SC-81 301-903-4840 daniel.lehman@science.doe.gov

Large Hadron Collider Program

134

Extending Ladders: Findings from the Annie E. Casey Foundation's Jobs Initiative.  

ERIC Educational Resources Information Center

In 1995, the Anne E. Casey Foundation launched the Jobs Initiative (JI) in six cities to change labor market prospects for low-income young people in order to help them get jobs that could move their families out of poverty. The JI attempts to change the way employers recruit and supervise workers and how work is structured; to prepare workers and…

Fleischer, Wendy

135

Antarctic temperatures since the late 1950s: SAM cooling,1 background warming, and West Antarctica heating up2  

E-print Network

Antarctic temperatures since the late 1950s: SAM cooling,1 background warming, and West Antarctica to take advantage of a recently revised key temperature record from West7 Antarctica (Byrd Station.42±0.21 C decade-1 ), West Antarctica (0.21±0.10 C decade-1 ), and Antarctica as a14 whole (0.12±0.08 C

Howat, Ian M.

136

Discovery and exploration of Antarctica  

SciTech Connect

The continent of Antarctica, some 5000 mi/sup 2/ in area, lies almost wholly within the Antarctic Circle. Some ancient philosophers and cartographers postulated the existence of a southern landmass, but the concept remained untested for centuries. In 1772-1775, Captain James Cook circumnavigated the continent and crossed the Antarctic Circle, but he sighted no land and concluded that the existence of a continent was unlikely. The first definite sightings of land by American, British, and Russian ships occurred in the Antarctic Peninsula region near 1820. In 1840, parts of the coast were mapped and landings were made by American, British, and French expeditions led, respectively, by Wilkes, Ross, and d'Urville. The first systematic geological field work was conducted by the Borchgrevink expedition in 1899-1900 near Cape Adare, south of New Zealand. During the first years of the present century, major expeditions were led by such men as Nordenskiold, Scott, Shackleton, Amundsen, and Mawson, culminating in the journeys to the South Pole by Amundsen and Scott during the 1911-1912 field season. The US has sent a number of expeditions to Antarctica during the last 60 years, beginning with the Byrd Expeditions of 1928-1930 and 1933-1935 when aircraft were used extensively and a flight was made to the South Pole. These expeditions were followed by the US Antarctic Service Expedition in 1939-1941. After World War II, US activities resumed with Operation Highjump in 1946-1947, followed the next year by Operation Windmill and the Ronne Antarctic Research Expedition. As late as 1955, most of Antarctica remained poorly known geologically. The International Geophysical Year (IGY) in 1957-1958 led to the building of 48 new stations in Antarctica by 12 nations and marked the beginning of the current period of sustained research.

Craddock, C.

1987-05-01

137

Mineral resources of Antarctica  

USGS Publications Warehouse

Although the existence of mineral deposits in Antarctica is highly probable, the chances of finding them are quite small. Minerals have been found there in great variety but only as occurrences. Manganese nodules, water (as ice), geothermal energy, coal, petroleum, and natural gas are potential resources that could perhaps be exploited in the future. On the basis of known mineral occurrences in Antarctica and relationships between geologic provinces of Antarctica and those of neighboring Gondwana continents, the best discovery probability for a base-metal deposit in any part of Antarctica is in the Andean orogen; it is estimated to be 0.075 (75 chances in 1,000).

Compiled and edited by Wright, Nancy A.; Williams, Paul L.

1974-01-01

138

Antarctica Part Two  

NSDL National Science Digital Library

In this video, Jonathan treks all the way to Antarctica to investigate life south of the polar circle. Along the way he dives in the majestic kelp forests of Patagonia, where crabs rule the sea floor. Once he arrives in Antarctica, his adventures continue. He swims with penguins, dives under an iceberg, meets a massive jellyfish 3 feet across, and has an incredible encounter with a Leopard seal, the apex predator of Antarctica. Part 2 finds Jonathan continuing his exploration of Antarctica including an encounter with a Leopard seal. This program won a New England Emmy Award! Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.

Productions, Jonathan B.

2011-06-06

139

Magnetotelluric measurements in Antarctica  

NASA Astrophysics Data System (ADS)

During austral summer 1984-1985 magnetotelluric measurements were carried out in North Victoria Land, Antarctica. The magnetic field was measured by a three-component fluxgate magnetometer. Copper screens (50 cm × 50 cm) were used as electrodes for recording the electric field, connected to a two channel electrograph with an input impedance of 10 12 ?. Analogue data are digitized with 12 bit resolution by a data acquisition system. 1 Mb of solid state CMOS-RAM memory was used to store the data in the field until it could be played back onto 3.5 inch floppy discs during station control. All equipment is designed for low power consumption. In the field it is supplied by a battery, which is charged by solar panels. Time series of measured data are presented. The influence of the polar electrojet (PEJ) on the source fields is clearly seen by comparing 24-h time series with the position of the auroral oval at different times of the day. Despite the clear effect of the PEJ in the data, the calculated apparent resistivity and phase curves seem to be rather uninfluenced. Initial interpretations have led to a typical continental resistivity distribution, showing decreasing resistivity with increasing depth.

Beblo, M.; Liebig, V.

140

Some Background on Antarctica  

NSDL National Science Digital Library

This online article provides an overview of Antarctica and the reasons so many scientists are drawn to the continent. It includes a compilation of facts, an overview of the kinds of questions that can be answered in Antarctica, and insight into the scientific importance of the research conducted there.

141

Research on the Web: Antarctic Weather Stations  

NSDL National Science Digital Library

This activity will help students see the link between wind speeds and geographical features. Students begin by gathering wind-speed measurements for 10 weather stations in Antarctica, converting the data, as needed, to allow comparisons. Next, they record wind data for five consecutive days and calculate the average wind speed for each station. They then examine elevation data for the stations and end by developing an hypothesis for the different patterns they have observed. In Antarctica, scientists often have trouble measuring katabatic winds, which are so strong they can knock down the instruments. Students discover for themselves why Antarctica is the windiest place on Earth.

142

Antarctica: little paying perspectives  

SciTech Connect

The continent of Antarctica has a surface of 14,200,000 sq km. It rests upon one of the deeper epicontinental platforms of the world, which descends steeply to the oceanic depths. The 200-m isobath is almost in its totality inside of the main ice zone. More than 95% of the continent itself is found under a layer of terrestrial ice composed of ca. 3,000,000 cu km of ice, with an average thickness of 2000 m. The ice and sea impede the access to the continent, and cyclonic storms surround the Antarctica in an endless sequence that moves from west to east. Almost all Antarctica geology is under ice, and only the highest places of mountains outcrop. The geologic structure is composed of 6 tectonic units. Antarctica has mineral resources, but the obstacles encountered in personnel and material movement make the Antarctica petroleum perspective very poor, since the recovery cost goes beyond the present selling price.

Ivanhoe, L.F.

1981-07-01

143

Antarctica Part One  

NSDL National Science Digital Library

In this video, Jonathan treks all the way to Antarctica to investigate life south of the polar circle. Along the way he dives in the majestic kelp forests of Patagonia, where crabs rule the sea floor. Once he arrives in Antarctica, his adventures continue. He swims with penguins, dives under an iceberg, meets a massive jellyfish 3 feet wide, and has an incredible encounter with a Leopard seal, the apex predator of Antarctica. Part 1 finds Jonathan diving in Ushuaia, Patagonia in Argentina before boarding the ship to Antarctica, then he finally gets to Antarctica and meets some penguins! This program won a New England Emmy Award! Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.

Productions, Jonathan B.

2011-05-04

144

Redescription of Stenolophus thoracicus Casey (Coleoptera, Carabidae, Harpalini), a valid species  

PubMed Central

Abstract Stenolophus thoracicus Casey is revalidated. The species is redescribed based on a study of the syntypes and of several conspecific specimens from eastern North America. The species differs from the other eastern species of the subgenus Agonoleptus in having the metasternum shorter and the wings reduced to tiny stubs. The dorsal habitus and median lobe of the aedeagus, along with the structures of the internal sac, are illustrated. PMID:21594130

Bousquet, Yves; Messer, Peter W.

2010-01-01

145

Research results from Antarctic automatic weather stations  

Microsoft Academic Search

Automatic weather station (AWS) units have been deployed in Antarctica since 1980 by the U.S. Antarctic Research Program. As of June 1987, 25 AWS units are operating in Antarctica in support of meteorological research. The AWS units measure air temperature, wind speed, and wind direction at a nominal height of 3 m above the surface and air pressure at the

Charles R. Stearns; Gerd Wendler

1988-01-01

146

Ralf Siebenmorgen IR instrument from Antarctica (thermal) IR instruments from Antarctica  

E-print Network

Ralf Siebenmorgen IR instrument from Antarctica (thermal) IR instruments from Antarctica: what can Antarctica Atmospheric optical thickness spectrum #12;Ralf Siebenmorgen IR instrument from Antarctica Siebenmorgen IR instrument from Antarctica Paranal Dome C (30m) Atmospheric transmission #12;Ralf Siebenmorgen

Siebenmorgen, Ralf

147

Valley floor climate observations from the McMurdo dry valleys, Antarctica, 19862000  

E-print Network

Valley floor climate observations from the McMurdo dry valleys, Antarctica, 1986­2000 Peter T 2002. [1] Climate observations from the McMurdo dry valleys, East Antarctica are presented from of each station and changes over time are likely related to changes in cloudiness. During the nonsummer

Fountain, Andrew G.

148

Design and Development of a PC Controlled Acoustic Sounding System for Antarctica  

Microsoft Academic Search

Indian planetary boundary layer programme in Antarctica is being inducted in a phased manner. As part of this programme, a monostatic, PC controlled acoustic sounding system has been designed, developed and installed at the Indian station Maitri (70.7°S: 11.7°E) in Antarctica.

N. C. DEB; JAYA NAITHANI; MIRA KAPOOR

149

Temp. Satellite Earth Station, McMurdo  

NSF Publications Database

... EAM NSF Org: OD / OPP Date : December 30, 1991 File : opp93048 DIVISION OF POLAR PROGRAMS OFFICE OF ... the Area of McMurdo Station, Antarctica) To: (Files S.7 - Environment) This Environmental Action ...

150

Bird imagery and motif in Sean O'Casey's Dublin trilogy  

E-print Network

that his interest in birds was obviously important to him; it is extensive and on-going, expressed not only in his plays, which are the substance of his work, coming as they do at the height of his genius, but also in his very early English translations..., "The Corncrake, " which appeared in The Gael in June, 1922, and "Gulls and Bobbin Testers, " from The Irish Statesman on November 29, 1924, exhibit the barest hints of some of the techniques O'Casey was to perfect in his plays. The first, "Translated...

O'Valle, Violet May Owen

2012-06-07

151

MAJOR SHIFT IN ADLIE PENGUIN EGGSHELL ISOTOPE VALUES IN ANTARCTICA: EVIDENCE FOR DIET CHANGE ~200 YEARS AGO  

E-print Network

(Ellis, 1991) Sealing began on Falklands in 1766 and on South Georgia Island in 1786 In 1775, 13,000 fur YEARS AGO 0 30 60 90 120 150 180 -150 -120 -90 -60 -30 Grytviken, South Georgia Island Whales taken near island 110°15 110°45S 66°30S 66°15S 10 km Casey Station Shirley Island Peterson Island

Patterson, William P.

152

Recent changes in solar irradiance in Antarctica  

SciTech Connect

A significant decrease in the annual sums of global irradiance reaching the surface in Antarctica, averaging -0.28 W m{sup -2} yr{sup -1}, was derived from an analysis of all complete years of measurement available from 12 pyranometer stations, 10 of which were on the coast. The decrease was greater than could be attributed to the nonhomogeneous nature of the database, the estimated errors of measurement, or changes in the amount of cloud cover. The smaller database of radiation balance measurements available showed no statistically significant change. Possible causes of these results are discussed, as is the implication that the recent surface warming in Antarctica is not due to radiative forcing. 49 refs., 3 figs., 5 tabs.

Stanhill, G.; Cohen, S. [Institute of Soils and Water, Bet Dagan (Israel)] [Institute of Soils and Water, Bet Dagan (Israel)

1997-08-01

153

Annual Review 2008 Gateway Antarctica  

E-print Network

Annual Review 2008 Gateway Antarctica Centre for Antarctic Studies and Research #12;1 Table of Contents From the Board 2 Directors Comment 3 Gateway Antarctica 5 Research 7 PhD Candidates 27 Teaching 41 the Board As GatewayAntarctica heads into its second decade, we can reflect on 2008 as both a milestone year

Hickman, Mark

154

Recent Changes in Greenland & Antarctica  

E-print Network

Recent Changes in Greenland & Antarctica Kristin Poinar and Ian Joughin Polar Science Center of sea level rise? IPCC 21st Century Sea Level Change: 0.18 to 0.59 meters ... uncertainties about Ã?Antarctica: 57 meters Ã?West Antarctica: 5 meters #12;This talk: Recent lines of thought on what controls

Bitz, Cecilia

155

Living and Working in Antarctica.  

ERIC Educational Resources Information Center

This source book, designed for 11- to 14-year-old students, seeks to describe what life is like in Antarctica. In spite of extreme weather conditions, people go to Antarctica to work every summer. Some of them stay there during the winter as well. This book seeks to supply answers to such questions as: How do people get to Antarctica? Why do they…

Kemp, Noel

156

Federal court holds first live evidentiary hearing on mandatory delay since Casey.  

PubMed

Four days beginning on June 20, U.S. District Court Judge Nancy Edmunds heard testimony and argument in Northland Family Planning, Inc. vs. Engler, a challenge to Michigan's 1993 mandatory 24-hour delay and biased counseling law. Scheduled to take effect on April 1, the statute was temporarily blocked by Judge Edmunds on March 18--eight days after two dozen women's health care providers and advocates filed suite (see RFN III/5). The hearing this week on plaintiff's request for a preliminary injunction marked the first time since the U.S. Supreme Court's 1992 decision in Planned Parenthood vs. Casey that Witnesses have appeared in federal court to testify about the likely impact of such a measure. In the wake of Casey, an abortion restriction is unconstitutional if it poses an "undue burden" on a woman's right to choose abortion. Nationally renowned experts and clinic directors testified this week that the Michigan law is unnecessary to ensure informed consent for abortions and will particularly disadvantage battered women, rape and incest survivors, women carrying anomalous fetuses, and women who need abortions for severe medical and psychological conditions. CRLP attorneys Eve Gartner and Priscilla Smith represented plaintiffs during the hearing. Mandatory delay and biased counseling laws are currently in effect in Kansas, Mississippi, Nebraska, North Dakota, Ohio, Pennsylvania, and Utah; only Mississippi requires women to travel twice to a women's health care provider: once for the mandated information and a second time at least 24 hours later for the abortion. PMID:12345510

1994-06-24

157

The International Geophysical Year in Antarctica: Uncommon Collaborations, Unprecedented Results  

ERIC Educational Resources Information Center

When 1 July 1957 ''dawned'' in the dark of the south polar night, Americans at seven scientific stations scattered across Antarctica officially began systematic, synoptic observations of the air above and ice below. Joining scientists from 11 other countries on the polar continent, they were part of the International Geophysical Year, an 18-month…

Belanger, Dian Olson

2004-01-01

158

Robert Casey  

Cancer.gov

Skip to Main Content CCR Home | About CCR | CCR Intranet Main Navigation Home Profiles Research Newsworthy References Special Interest Groups Training Main Links Psycho-Oncology Home Profiles Research Publications Newsworthy/Resources References Special

159

The Annie E. Casey Foundation 2006 Kids Count Pocket Guide. State Profiles of Child Well-Being Series  

ERIC Educational Resources Information Center

Kids Count, a project of the Annie E. Casey Foundation, is a national and state by- state effort to track the status of children in the United States. By providing policymakers and citizens with benchmarks of child well-being, Kids Count seeks to enrich local, state, and national discussions concerning ways to secure better futures for all…

Annie E. Casey Foundation, 2006

2006-01-01

160

Free Parking Available for Famous Idaho Potato Bowl Media Contact: Casey Jones, Executive Director, Transportation & Parking Services  

E-print Network

Free Parking Available for Famous Idaho Potato Bowl Media Contact: Casey Jones, Executive Director Potato Bowl at Boise State University on Saturday, Dec. 15, can park for free in exchange for donations honoring free parking in exchange for donations include: Lincoln Ave Garage (1607 University Drive) Norco

Barrash, Warren

161

POP Goes Antarctica?  

NSDL National Science Digital Library

As students explore this Web site, they will learn how scientists work together to answer questions. This site follows several scientists to Antarctica where they are doing research on Persistent Organic Pollutants. A daily journal, glossary, and learning activities will help incorporate this into classroom lesson plans.

Cowles, Susan

2002-01-01

162

Antarctica: Observed Climate Changes  

E-print Network

Antarctica holds 90 % of the world’s freshwater in the form of a vast ice sheet thousands of feet thick. This ice covering also extends out to sea in the form of floating ice tongues or shelves connected to the land. The Antarctic

unknown authors

163

Married to Antarctica.  

ERIC Educational Resources Information Center

A novel theory about Earth's ancient history is presented. It is proposed that North America and Antarctica once lay side by side for perhaps as long as a billion years. The importance of these continental connections to geology and other disciplines is discussed. (KR)

Monastersky, Richard

1991-01-01

164

Getting Antarctica down Cold!  

ERIC Educational Resources Information Center

Outlines learning activities for applying geography's five fundamental themes to studying Antarctica and points out the learning potential, for studying the economic, historical, and political geography of the continent. Groups activities for grades K-5, 6-8, and 8-12. Stresses cooperative learning in general, and includes a role play activity for…

Sandmeier, Kay; Greeson, Linda

1990-01-01

165

Gateway Antarctica's Christchurch City Council Antarctic Scholarship  

E-print Network

Gateway Antarctica's Christchurch City Council Antarctic Scholarship The Christchurch City Council by Antarctica New Zealand. 1. The Scholarship will be known as the Christchurch City Council Antarctic Scholarship and administered by Gateway Antarctica, the Centre for Antarctic Studies and Research

Hickman, Mark

166

British Antarctic Survey: About Antarctica  

NSDL National Science Digital Library

This brief overview of Antarctica covers its wildlife (penguins and other birds, seals, whales, fish, plants) and its geography (ice features, geologic features, weather, the ozone hole). There is also a series of short articles on protecting Antarctica's environment, including waste disposal and cleanup, protecting wildlife and plants, and protecting special areas and historic sites. The teacher resources page features a link to 'Discovering Antarctica', a resource that is intended to enthuse young people in Antarctic research and to give teachers access to an authoritative resource from the UK's national Antarctic operator. Other topics include tourism in Antarctica and geopolitical issues (the Antarctic Treaty, place names, the British Antarctic Territory).

167

Learning About Antarctica's Past  

NSDL National Science Digital Library

Learning about Antarctica's past can give K-Grade 5 teachers and students lessons in geology, climate, and ecology along with literacy experiences in sequencing and time lines. The author identifies online resources for both adults and younger learners. A three-section unit plan begins with sequencing events and follows with earth's history over billions of years and the records found in rocks and fossils. The article appears in the free, online magazine Beyond Penguins and Polar Bears.

Landis, Carol

2011-01-01

168

The surface climatology of an ordinary katabatic wind regime in Coats Land, Antarctica  

Microsoft Academic Search

The surface climatology of Coats Land, Antarctica, is described through observations from automatic weather stations, from Halley station, from upper air soundings and from satellite remote sensing. Coats Land consists of the Brunt Ice Shelf and the adjoining continent to the south. The topography of this region is typical of much of the Antarctic coastal fringes: a modest slope (5%

IAN A. RENFREW; PHILIP S. ANDERSON

2002-01-01

169

Hydrology of Antarctica  

SciTech Connect

The hydrology of the Southern Ocean floor, the ice sheet covering Antarctica, and the bedrock underlying it is a matter of great interest. This article attempts to shed some light on the problem of the hydrology of this part of the world in the form of prognoses, because the available direct information on the subsurface waters of this vast region is completely inadequate. From the standpoint of their practical utilization, the fresh waters at the base of the Antarctic ice sheet and the waters below the permafrost of the larger islands of Antarctica are the most promising. The large artesian basins of Antarctica with a thick mantle of sedimentary rocks are of interest for their oil and gas potential. One can be certain also of obtaining thermal waters from some of the artesian structures of this continent. Special attention should be paid to the fumaroles and solfataras in areas of present-day volcanism, and to the rift zones, where thermal waters may also be obtained. 16 references.

Kiryukhin, V.A.; Tolstikhin, N.I.

1988-01-01

170

Comparison of an ionosonde drift model at a single station with polar convention patterns  

NASA Astrophysics Data System (ADS)

A study of convection at a single point in the polar cap is made by comparing vertical incidence ionosonde Doppler drift data with the Weimer 96 (W96) convection model. Four years of data are used to construct a local convention model at Casey, Antarctica (geographic 66.3°S, 110.5°W, geomagnetic 80.8°S). The Casey 97 (C97) model is capable of producing a drift velocity for any time and interplanetary magnetic field (IMF) vector in the By-Bz plane for either summer or winter seasons. The direct comparison of vectors predicted by C97 and W96 shows there is generally very good agreement between them at all IMF angles. Because of this, our findings consequently support the existence of multiple convection cells for IMF angles within 30° of northward (+Z). For all other angles there is a distortion of the two-cell pattern that becomes a minimum when the IMF is strongly southward with slightly a positive By component. Drawing on an earlier study with the Heppner-Maynard model [Smith et al., 1998], but now using the C97 model for comparison, we also find their patterns only begin to match the Casey results when |By|>>Bz. A significant seasonal dependence also exists within the C97 and W96 models, although the agreement with each other in winter is not as good. The presence of additional summer lobe cells embedded within the merging cells is supported, particularly for a rounder, expanded dusk cell.

Smith, Paul R.; Dyson, Peter L.; Morris, Ray J.

171

The ice-layer in Antarctica : preliminary results from seismology  

NASA Astrophysics Data System (ADS)

Since the International Polar Year (IPY), there has been a marked increase in the number of broad-band seismic stations deployed on the thick continental ice-layer in Antarctica. We are involved in one of these deployments, CASE-IPY (Concordia Antarctica Seismic Experiment), which comprises seven stations to be installed in January 2010 on a profile between the scientific bases of Concordia (Dome C) and Vostok. The data recorded by these seismic stations are rare, will be exploited using many methods, including receiver function analysis. Receiver functions obtained using data recorded on thick ice (e.g. TAMSEIS deployment and the permanent stations QSPA (South Pole) and CCD (Concordia)) are anomalous when compared to those obtained from data recorded at rock stations. The first five seconds contain much of the anomalous signal: we see a positive arrival due to the rock-ice interface, preceded by a strong negative arrival. This pattern is seen on all the 28 stations we have analyzed, and is likely to be a global feature for stations installed on thick ice. We present preliminary results concerning this anomalous signal and its relationship to ice structure.

Leveque, J.; Wittlinger, G.; Maggi, A.

2009-12-01

172

The role of women in abortion jurisprudence: from Roe to Casey and beyond.  

PubMed

The decision of the US Supreme Court in Roe vs. Wade called upon a woman's right to privacy to assert a woman's right to a previability abortion in a framework based upon a consideration of the trimester of the pregnancy. A state policy or abortion law would only survive a constitutional challenge if it passed the exacting test of serving a "compelling state interest." The Court's decision in Roe grew out of an analysis which ignored the possibility that women as individuals would be able to arrive at an abortion decision for themselves. Instead, a physician's right to exercise medical judgement and perform a first-trimester abortion upon request was upheld. The decision of the Court in Planned Parenthood of Southeastern Pennsylvania vs. Casey upheld the constitutionality of abortion but allowed states to impose abortion regulations which would only be invalid if they imposed an "undue burden" upon women. In Casey, the Court linked the abortion decision to the concept of liberty embodied in the 14th Amendment. Thus, the abortion decision is seen as solely a woman's rather than a medical decision undertaken only with the guidance of a physician. The Court acknowledged that its ruling in Roe was sound and that there was no compelling reason to overturn it. This allowed the Court to maintain its legitimacy and, thus, its authority and sense of responsibility to the people who had acted in good faith under Roe. The new "undue burden" test was applied to the Pennsylvania statutes, and the real experiences of individual women were called into play to explain why spousal notification would pose an undue burden but the informed consent requirement would not. This test will likely continue to reflect the real experiences of women and reveal the underpinnings of state regulations (such as the "repugnant" view of a woman's status within a marriage forwarded by the proposed spousal consent requirement). Unlike Roe, which resulted in delineation and polarization of the "prochoice" and "prolife" positions in the abortion debate, the "undue burden" test may achieve reconciliation of these views in light of the commonality of women's experience. PMID:8293219

Martin, P A

1993-01-01

173

Informal STEM Education in Antarctica  

NASA Astrophysics Data System (ADS)

Tourism in Antarctica has increased dramatically with tens of thousands of tourists visiting the White Continent each year. Tourism cruises to Antarctica offer a unique educational experience for lay people through informal science-technology-engineering-mathematics (STEM) education. Passengers attend numerous scientific lectures that cover topics such as the geology of Antarctica, plate tectonics, glaciology, and climate change. Furthermore, tourists experience the geology and glaciology first hand during shore excursions. Currently, the grand challenges facing our global society are closely connected to the Earth sciences. Issues such as energy, climate change, water security, and natural hazards, are consistently on the legislative docket of policymakers around the world. However, the majority of the world’s population is uninformed about the role Earth sciences play in their everyday lives. Tourism in Antarctica provides opportunities for informal STEM learning and, as a result, tourists leave with a better understanding and greater appreciation for both Antarctica and Earth sciences.

Chell, K.

2010-12-01

174

Bicycles at McMurdo Station  

NSF Publications Database

This Environmental Action Memorandum describes the need for, and location of, proposed actions to employ all-terrain bicycles for various tasks at McMurdo Station, Antarctica. The purpose of the proposed activity is to purchase 20 to 25 all-terrain bicycles for use by U.S. Antarctic Program (USAP) personnel in conducting operations, maintenance and construction activities at McMurdo Station. Aesthetics within McMurdo Station and the surrounding environs would be improved from the use of ...

175

Climatology of GPS scintillations over Antarctica under solar minimum conditions  

NASA Astrophysics Data System (ADS)

We analyse GNSS ionospheric scintillation data recorded in Antarctica to investigate the conditions of the near-Earth environment leading to scintillation scenarios, producing a "scintillation climatology" over a large geomagnetic quiet period. Within this scope we realize maps of scintillation occurrence as a function of the magnetic local time (MLT) and of the altitude adjusted corrected geomagnetic coordinates (AACGM). The maps are realized merging observations of two GISTMs (GPS Ionospheric Scintillation and TEC Monitor) located at Mario Zucchelli Station (74.7°S, 164.1°E) and Concordia Station (75.1°S, 123.2°E) in Antarctica during 2008. The results highlight the possibility to investigate the impact of ionospheric irregularities on the phase and amplitude of GNSS signals, evidencing the cusp/cap and auroral contributions. This works aims to contribute to the development of nowcasting and forecasting tools for GNSS ionospheric scintillation.

Spogli, Luca; Alfonsi, Lucilla; Romano, Vincenzo; de Franceschi, Giorgiana; Mitchell, Cathryn N.

2010-05-01

176

Antarctica Day: An International Celebration  

NASA Astrophysics Data System (ADS)

For more than half a century, the 1959 Antarctic Treaty continues to shine as a rare beacon of international cooperation. To celebrate this milestone of peace in our civilization with hope and inspiration for future generations, Antarctica Day is celebrated each year on December 1st , the anniversary of the Antarctic Treaty signing. As an annual event - initiated by the Foundation for the Good Governance of International Spaces (www.internationalspaces.org/) in collaboration with the Association of Polar Early Carer Scientists (www.apecs.is) - Antarctica Day encourages participation from around the world. The Antarctic Treaty set aside 10% of the earth, 'forever to be used exclusively for peaceful purposes in the interest of mankind.' It was the first nuclear arms agreement and the first institution to govern all human activities in an international region beyond sovereign jurisdictions. In this spirit, Antarctica Day aims to: - Demonstrate how diverse nations can work together peacefully, using science as a global language of cooperation for decision making beyond national boundaries, - Provide strategies for students learning about Antarctica through art, science and history at all school levels, - Increase collaboration and communication between classrooms, communities, researchers and government officials around the world, and - Provide a focus for polar educators to build on each year. Through close collaboration with a number of partners. Antarctica Day activities have included: a Polar Film Festival convened by The Explorers Club; live sessions connecting classrooms with scientists in Antarctica thanks to PolarTREC and ARCUS; an international activity that involved children from 13 countries who created over 600 flags which exemplify Antarctica Day (these were actually flown in Antarctica with signed certificates then returned to the classes); a map where Antarctica Day participants all over the world could share what they were doing; an Antarctic bird count involving the International Association of Antarctic Tour Operators; and public lectures and online videos (including a notable submission from Polar Educators International). Antarctica Day was initiated as a legacy of the 2009 Antarctic Treaty Summit (www.atsumit50.aq), which was convened at the Smithsonian Institution with 40 sponsoring institutions from around the world as part of the International Polar Year. Antarctic Day involved participants from 14 nations in 2010. 28 nations in 2011, and 26 nations in 2012 with representatives from all 7 continents. Antarctica Day 2013 will have recently taken place before the AGU Fall Meeting 2013, and we will present updates at that time. Our aim is to continue expanding Antarctica Day as a globally-accessible platform to share, interpret and cherish the values associated with Antarctica for the benefit of present and future generations. We look forward to the discussion and sharing that this session will provide.

Pope, A.; Hambrook Berkman, J.; Berkman, P. A.

2013-12-01

177

The crustal thickness of West Antarctica  

NASA Astrophysics Data System (ADS)

P-to-S receiver functions (PRFs) from the Polar Earth Observing Network (POLENET) GPS and seismic leg of POLENET spanning West Antarctica and the Transantarctic Mountains deployment of seismographic stations provide new estimates of crustal thickness across West Antarctica, including the West Antarctic Rift System (WARS), Marie Byrd Land (MBL) dome, and the Transantarctic Mountains (TAM) margin. We show that complications arising from ice sheet multiples can be effectively managed and further information concerning low-velocity subglacial sediment thickness may be determined, via top-down utilization of synthetic receiver function models. We combine shallow structure constraints with the response of deeper layers using a regularized Markov chain Monte Carlo methodology to constrain bulk crustal properties. Crustal thickness estimates range from 17.0±4 km at Fishtail Point in the western WARS to 45±5 km at Lonewolf Nunataks in the TAM. Symmetric regions of crustal thinning observed in a transect deployment across the West Antarctic Ice Sheet correlate with deep subice basins, consistent with pure shear crustal necking under past localized extension. Subglacial sediment deposit thicknesses generally correlate with trough/dome expectations, with the thickest inferred subice low-velocity sediment estimated as ˜0.4 km within the Bentley Subglacial Trench. Inverted PRFs from this study and other published crustal estimates are combined with ambient noise surface wave constraints to generate a crustal thickness map for West Antarctica south of 75°S. Observations are consistent with isostatic crustal compensation across the central WARS but indicate significant mantle compensation across the TAM, Ellsworth Block, MBL dome, and eastern and western sectors of thinnest WARS crust, consistent with low density and likely dynamic, low-viscosity high-temperature mantle.

Chaput, J.; Aster, R. C.; Huerta, A.; Sun, X.; Lloyd, A.; Wiens, D.; Nyblade, A.; Anandakrishnan, S.; Winberry, J. P.; Wilson, T.

2014-01-01

178

Crustal Thickness across West Antarctica from Polenet  

NASA Astrophysics Data System (ADS)

Recent data and methodological advances in deep seismic imaging have yielded invaluable information about the crust and mantle of continental and regional scales. Receiver function analysis, pioneered nearly 40 years ago, continues to be widely used to study abrupt velocity transitions at depth and to recover key information such as crustal thickness and Poisson's ratio, mantle transition zone thicknesses, and Moho topography. We examine P-to-S receiver functions, S-to-P receiver functions, and surface wave kernels to study crustal thicknesses and mantle transition zone depths across a wide extent of West Antarctica and the Transantarctic Mountains (TAM) as part of the POLENET project. The presence of thick ice sheets and, in some areas, underlying sedimentary basins, create complications in identifying key (e.g., Moho) conversions that are normally readily visible in continental settings. We have successfully applied several approaches to the entirety of available POLENET and other Antarctic stations to optimally circumvent these issues, including deconvolution, forward modeling, FK-filtering, and regularized Markov Chain Monte Carlo inversion methods. We report on the most recently obtained crustal thickness and other results in the context of Antarctic tectonics and the crustal structure of the WAIS, TAM and Marie Byrd Land (MBL) regions. Moho depths for West Antarctica vary from ~23-30 km towards MBL, with thinning on the coast of MBL.

Chaput, J. A.; Aster, R. C.; Nyblade, A.; Wiens, D. A.; Sun, X.; Huerta, A. D.; Wilson, T. J.; Hansen, S. E.; Anandakrishnan, S.

2012-12-01

179

Petroleum geology of western Antarctica  

SciTech Connect

Antarctica's geology is mostly obscured by thick, moving ice that covers 95% of the land and continental shelf. Reconnaissance investigations of outcrops, shallow boreholes, and geophysical surveys are limited and peripheral owing to ice coverage. However, it is possible to outline substantial elements of the regional geology. Further insight is gained by comparison to analogous sedimentary provinces, especially provinces once adjoined within the framework of the Gondwana supercontinent until middle Cretaceous. The petroleum potential of Antarctica, as in the case of the other related high-standing Gondwana continental fragments, is in Early Cretaceous rifts associated with the Gondwana breakup and with the Pacific convergence in the west Antarctica back arc. The Pacific-facing western Antarctica includes two structural provinces: (1) the Cretaceous and younger interior rift system on the east side of the Weddell and Ross Sea embayment, which contain aulacogens that form the boundary with East Antarctica and (2) the back-arc and fore-arc basins adjoining the Antarctica Peninsula and extending into Marie Byrd Land and the Bellingshausen Sea which are associated with the eastward convergence of the Pacific plate. The petroleum potential of the rifts may be assessed by analogies with related rifts of Australia, India, and South Africa; assessment of the convergent basins of western Antarctica depends upon analogy with similar basins of South America, New Zealand, and Indonesia. An estimate of the petroleum potential of western Antarctica generally is comparable with oil and gas occurrences (both in overall quantity and in field sizes) in the other Gondwana continental fragments. However, in view of the thict moving ice cover, the remote locale, and severe climate, petroleum production is largely beyond technology at this time and probably is economically unfeasible.

Kingston, J. (Geological Survey, Santa Barbara, CA (USA))

1990-05-01

180

Clostridia in soil of the Antarctica.  

PubMed

From the soil in the area around the Syowa Station, the East Ongul Island, the Antarctica, a total of 193 strains of clostridia were isolated and identified. It was surprising that the soil samples taken from the places which were considered to be scarcely contaminated by human beings and animals contained many clostridia. One hundred and fifty-five strains were assigned to 11 species, including C. perfringens, C. bifermentans, C. sordellii, C. sporogenes, C. plagarum, C. paraperfringens, C. septicum, C. tertium, C. cadaveris, C. butyricum and C. felsineum, but 38 strains remained unidentified. C. perfringens, C. bifermentans and C. sordellii were isolated very frequently and C. sporogenes less frequently. All the strains of C. sordellii were nonpathogenic and had almost the same characteristics as those of C. bifermentans except for the attitude in the urease test. The peculiar distribution and characteristics of the clostridia in the Antarctic soil were discussed in comparison with those found in the soil in Japan. PMID:175201

Miwa, T

1975-08-01

181

Geohydrology and distribution of volatile organic compounds in ground water in the Casey Village area, Bucks County, Pennsylvania  

USGS Publications Warehouse

Casey Village and the adjoining part of the U.S. Naval Air Warfare Center (NAWC) are underlain by the Late Triassic-age Stockton Formation, which consists of a dipping series of siltstones and sandstones. The direction of vertical ground-water gradients in the Stockton Formation varies among well locations and sometimes with time. Vertical gradients can be substantial; the difference in water levels at one well pair (two wells screened at different depths) was 7.1 ft (feet) over a 32-ft vertical section of the aquifer. Potentiometric-surface maps show a groundwater divide that bisects the Casey Village area. For wells screened between 18 and 64 ft below land surface (bls), the general ground-water gradient is to the east and northeast on the east side of the divide and to the south and southwest on the west side of the divide. For wells screened between 48 and 106 ft bls, the general ground-water gradient is to the northeast on the east side of the divide and to the southwest and northwest on the west side of the divide. An aquifer test at one well in Casey Village caused drawdown in wells on the opposite side of the ground-water divide on the NAWC and shifted the ground-water divide in the deeper potentiometric surface to the west. Drawdowns formed an elliptical pattern, which indicates anisotropy; however, anisotropy is not aligned with strike or dip. Hydraulic stress caused by pumping crosses stratigraphic boundaries. Between 1993 and 1996, the trichloroethylene (TCE) concentration in water samples collected from wells in Casey Village decreased. The highest concentration of TCE measured in water from one well decreased from 1,200 mg/L (micrograms per liter) in 1993 when domestic wells were pumped in Casey Village to 140 mg/L in 1996, 3 years after the installation of public water and the cessation of domestic pumping. This suggests that pumping of domestic wells may have contributed to TCE migration. Between 1993 and 1996, the tetrachloroethylene (PCE) concentration in water samples collected from wells in Casey Village decreased only slightly. The highest concentration of PCE measured in water from one well decreased from 720 mg/L in 1993 to 630 mg/L in 1996. The distribution of TCE and PCE in ground water indicates the presence of separate PCE and TCE plumes, each with a different source area. The TCE plume appears to be moving in two directions away from the ground-water divide area. The pumping of a domestic well may have caused TCE migration into the ground-water divide area. From the divide area, the TCE plume appears to be moving both to the east and the west under the natural hydraulic gradient. Aquifer-isolation tests conducted in the well with the highest TCE concentrations showed that concentrations of TCE in water samples from the isolated intervals were similar but slightly lower in the deeper isolated zones than in the shallower isolated zones. Upward flow was measured in this well during geophysical logging. If the source of TCE to the well was from shallow fractures, upward flow of less contaminated water could be flushing TCE from the immediate vicinity of this well. This may help explain why the concentration of TCE in water from this well decreased an order of magnitude between 1993 and 1996.

Sloto, Ronald A.; Conger, Randall W.; Grazul, Kevin E.

1998-01-01

182

The cryptoendolithic microbial environment in the Ross Desert of Antarctica: Satellite-transmitted continuous nanoclimate data, 1984 to 1986  

Microsoft Academic Search

A satellite mediated station for monitoring nanoclimate (climate in the millimeter range) data, suitable for use in polar regions is described. The station, located in the Ross desert of Antarctica, has been in operation for more than 3 years, measuring rock temperatures, air temperature, light, snow, wind, and moisture. The data indicate that biological activity in the cryptoendolithic microbial ecosystem

E. Imre Friedmann; Christopher P. McKay; James A. Nienow

1987-01-01

183

Investigating West Antarctica, Then and Now  

NSDL National Science Digital Library

This article profiles Charles Bentley, a geophysicist who has worked in Antarctica over a period of seven decades. The article provides an overview of his research as well as changes in the way scientists live and work in Antarctica.

Landis, Carol

184

Evaluation of the Effects of the Ultra-Violet Radiation of Antarctica on Bovine Corneas and Lenses by Raman Spectroscopy  

NASA Astrophysics Data System (ADS)

The Raman spectra of bovine corneas and lenses irradiated to the ultra violet radiation at Syowa station of Antarctica were observed. The bovine crystallin occurred photo-induced cataract by the exposure to the solar radiation of mid-summer at Antarctica. Photo-induced decrease of Raman signals assigned to Trp residues suggests that the structural change of crystallin is correlated with the decomposition of them. The Raman spectra of the collagen of cornea showed little change, however FT-IR measurements showed that the IamideII/IamideI decreased much by the exposure to the solar radiation of mid-summer at Antarctica.

Yamamoto, Tatsuyuki; Imura, Satoshi; Yamamoto, Naoyuki

2010-08-01

185

Let's Talk with Carol Finn about Using GPS (Global Positioning System) to Study Ice and Geology in Antarctica  

NSDL National Science Digital Library

In this interview, a geophysicist working in Antarctica describes her work reading the magnetic data of Antarctic rocks that lie below the ice's surface. She discusses her area of study, the Transantarctic Mountains near Byrd station, her study methods, and why her work is important. There is also a brief summary of personal information, and some advice for students about studying and conservation in Antarctica.

186

Research on the Web: Snapshots of Antarctica  

NSDL National Science Digital Library

This Web research activity gives students a broad overview of Antarctica. They are asked to work as scientists, making predictions and observations and recording their findings. All directions are included in a printable handout. Students begin by gathering background information on Antarctica and polar research. They then view images of Antarctica taken from space and ones that compare its size to the United States. They end by answering questions about Antarctica's size, physical conditions, and why scientists conduct research there.

187

Carbonaceous micrometeorites from Antarctica.  

PubMed

Over 100 000 large interplanetary dust particles in the 50-500 micrometers size range have been recovered in clean conditions from approximately 600 tons of Antarctic melt ice water as both unmelted and partially melted/dehydrated micrometeorites and cosmic spherules. Flux measurements in both the Greenland and Antarctica ice sheets indicate that the micrometeorites deliver to the Earth's surface approximately 2000x more extraterrestrial material than brought by meteorites. Mineralogical and chemical studies of Antarctic micrometeorites indicate that they are only related to the relatively rare CM and CR carbonaceous chondrite groups, being mostly chondritic carbonaceous objects composed of highly unequilibrated assemblages of anhydrous and hydrous minerals. However, there are also marked differences between these two families of solar system objects, including higher C/O ratios and a very marked depletion of chondrules in micrometeorite matter; hence, they are "chondrites-without-chondrules." Thus, the parent meteoroids of micrometeorites represent a dominant and new population of solar system objects, probably formed in the outer solar system and delivered to the inner solar system by the most appropriate vehicles, comets. One of the major purposes of this paper is to discuss applications of micrometeorite studies that have been previously presented to exobiologists but deal with the synthesis of prebiotic molecules on the early Earth, and more recently, with the early history of the solar system. PMID:11543069

Engrand, C; Maurette, M

1998-07-01

188

Survey of waste water disposal practices at Antarctic research stations  

Microsoft Academic Search

To inform the future practices to be employed for handling waste water and grey water at the Swedish Antarctic station, Wasa, in Dronning Maud Land, the Swedish Polar Research Secretariat took the initiative to survey the practices of the 28 nations with stations in Antarctica. A questionnaire was sent out to all members of the Antarctic Environment Officers Network during

Fredrik Gröndahl; Johan Sidenmark; Ann Thomsen

2009-01-01

189

Precipitation regime of Dronning Maud Land, Antarctica, derived from Antarctic Mesoscale Prediction System (AMPS) archive data  

Microsoft Academic Search

The precipitation regime of Dronning Maud Land (DML), Antarctica, was studied using Antarctic Mesoscale Prediction System (AMPS) archive data. Precipitation is the most important component of the mass balance of the Antarctic ice sheet. Precipitation studies of DML are particularly important because two deep ice core drilling sites, Kohnen Station and Dome Fuji, are located in this region. For the

E. Schlosser; M. G. Duda; J. G. Powers; K. W. Manning

2008-01-01

190

The Neumayer Array and Its Impact on Seismological Research in the South Atlantic and Antarctica  

Microsoft Academic Search

In the austral summer season of 1997, a small-aperture seismological array was installed in the vicinity of the Neumayer German base in western Dronning Maud Land, Antarctica. Small-aperture arrays are important seismological tools for the detection and localisation of weak earthquakes on a local and regional scale. The advantage of seismological arrays over single station recordings is the possibility of

T. BÜSSELBERG; C. MÜLLER; A. ECKSTALLER

191

Occurrence of nematodes, tardigrades and rotifers on ice-free areas in East Antarctica  

Microsoft Academic Search

Nematodes, rotifers and tardigrades were collected on three nunataks (mountain peaks penetrating the ice sheet) in Vestfjella, on six nunataks in Heimefrontfjella and on the Schirmacher Oasis in East Antarctica in the austral summers of 1996\\/97 and 2001\\/02. Most samples were taken on the nunatak Basen in Vestfjella where the Swedish station Wasa is located. The microfauna was patchily distributed

Björn Sohlenius; Sven Boström; K. Ingemar Jönsson

2004-01-01

192

Energy efficiency and renewable energy under extreme conditions: Case studies from Antarctica  

Microsoft Academic Search

This article showcases a range of small and large scale energy efficiency and renewable energy deployments at Antarctic research stations and field camps. Due to the cold and harsh environment, significant amounts of fuel are needed to support humans working and living in Antarctica. The purchase, transportation and storage of large amounts of fossil fuel entail significant economic costs and

Tina Tin; Benjamin K. Sovacool; David Blake; Peter Magill; Saad El Naggar; Sven Lidstrom; Kenji Ishizawa; Johan Berte

2010-01-01

193

Initiation of Irrigation Effects on Temporal Nitrate Leaching F. X. M. Casey,* N. Derby, R. E. Knighton, D. D. Steele, and E. C. Stegman  

E-print Network

Initiation of Irrigation Effects on Temporal Nitrate Leaching F. X. M. Casey,* N. Derby, R. E that was converted from dryland to center- 1980). Albus and Knighton (1998) found that the initia- pivot irrigation in 1989. The vadose zone was monitored with four tion of irrigation caused a flush of NO3­N to the shallow

Steele, Dean D.

194

Semantic Awareness in Product Lifecycle Management Systems Casey James Baker, Douglas Eddy, Dr. Sundar Krishnamurty, Dr. Ian Grosse, Dr. Jack Wileden  

E-print Network

time to market. Semantic awareness has the potential to enrich PLM systems, yet semantic functionalitySemantic Awareness in Product Lifecycle Management Systems Casey James Baker, Douglas Eddy, Dr for adopting semantic functionality. A case study was performed with a widely used PLM system (PTC's Windchill

Mountziaris, T. J.

195

Preparing Young People to Succeed in College and Beyond. The Connection Strategy: Stories and Results from the Annie E. Casey Foundation's Education Investments  

ERIC Educational Resources Information Center

For many young people, the "pipeline" to educational and economic success is truly broken. This report describes how some of the Annie E. Casey Foundation's education grantees in Atlanta are working to mend the pipeline for young people in their communities by connecting standards and expectations for learning from early childhood to college entry…

Jehl, Jeanne

2007-01-01

196

Tectonic development of West Antarctica and its relation to East Antarctica  

SciTech Connect

Over several years, the author has compiled data and conducted field research to gain an understanding of the relationship between East and West Antarctica through geologic time. The investigations have focused on the Scotia Arc and the region at the base of the Antarctic Peninsula extending to the Ellsworth, Thiel, and Whitmore mountains. During the 1983-1984 austral summer, US and British geologists began an intensive investigation in the Ellsworth Mountains and Martin Hills, at Mount Smart, and near Siple Station. Field work includes geology, paleomagnetism, geochronology, and geophysics, with radio-echo sounding and aeromagnetic surveys conducted by British geophysicists. This investigation attempts to define the limits of the crustal blocks and determine the tectonic nature of the ice-covered area between them.

Dalziel, I.W.D. (Univ. of Texas, Austin (USA))

1987-09-01

197

IPY: Engaging Antarctica: Bringing Antarctic Geoscience to the Public Through a NOVA Documentary and an Innovative Flexible Exhibit for Informal Science Education Venues  

NASA Astrophysics Data System (ADS)

IPY: Engaging Antarctica is an informal science education project designed to increase the general public's understanding of scientific research conducted in Antarctica. The project focuses specifically on the multi- national, NSF-funded Antarctic Drilling Project (ANDRILL). The ANDRILL project is the newest geological drilling program in an ongoing effort to recover stratigraphic records from Antarctica. ANDRILL's primary objectives are to investigate Antarctica's role in global environmental change over the past 65 million years and to better understand its future response to global changes. Additionally, through ANDRILL's Research Immersion for Science Educators program (ARISE), 12 science educators from four countries will work on science research teams in Antarctica and produce educational materials that feature Antarctic geoscience. The Engaging Antarctica project will produce both a NOVA television documentary and an innovative informal learning exhibit. The documentary, Antarctica's Icy Secrets, will provide a geological perspective on how Antarctica continues to play a major role in affecting global climate by altering ocean currents and sea levels. The learning exhibit, one that blends standards- and inquiry-based learning with the latest information technologies, is coined the Flexhibit. The Engaging Antarctica Flexhibit will provide a digital package of high resolution images for banners as well as learning activities and ideas for exhibit stations that can be implemented by youth groups. Flexhibit images will feature ANDRILL scientists at work, and audio files, available as podcasts, will tell scientists' stories in their own words, speaking directly to the public about the joys and challenges of Antarctic geological research.

Rack, F.; Diamond, J.; Levy, R.; Berg, M.; Dahlman, L.; Jackson, J.

2006-12-01

198

Antarctica: A Cold Desert Ecosystem  

NSDL National Science Digital Library

This Antarctica lesson has students locate the continent on a globe and on a map, describe and illustrate major Antarctic ecosystems, and explain relationships between those ecosystems. They will also construct a rough map of Antarctic ecosystems and explore relationships among the creatures that populate them. This lesson can be adapted to focus on other regions, including the one in which students live.

199

Surface winds over West Antarctica  

NASA Technical Reports Server (NTRS)

Five winter months (April-August 1988) of thermal infrared satellite images were examined to investigate the occurrence of dark (warm) signatures across the Ross Ice Shelf in the Antarctic continent. These features are inferred to be generated by katabatic winds that descend from southern Marie Byrd Land and then blow horizontally across the ice shelf. Significant mass is added to this airstream by katabatic winds blowing from the major glaciers that flow through the Transantarctic Mountains from East Antarctica. These negatively buoyant katabatic winds can reach the northwestern edge of the shelf - a horizontal propagation distance of up to 1,000 km - 14 percent of the time. Where the airstream crosses from the ice shelf to the ice-covered Ross Sea, a prominent coastal polynya is formed. Because the downslope buoyancy force is near zero over the Ross Ice Shelf, the northwestward propagation of the katabatic air mass requires pressure gradient support. The study shows that the extended horizontal propagation of this atmospheric density current occurred in conjunction with the passage of synoptic cyclones over the southern Amundsen Sea. These cyclones can strengthen the pressure gradient in the interior of West Antarctica and make the pressure field favorable for northwestward movement of the katabatic winds from West Antarctica across the ice shelf in a geostrophic direction. The glacier winds from East Antarctica are further accelerated by the synoptic pressure gradient, usually undergo abrupt adjustment beyond the exit to the glacier valley, and merge into the mountain-parallel katabatic air mass.

Bromwich, David

1993-01-01

200

Antarctica: geology and hydrocarbon potential  

SciTech Connect

The first impression of the hydrocarbon potential of Antarctica is generally negative. The environment is hostile and only 2% of the continent is seen through the ice. Careful study of the surprisingly ample volume of published data available on the geology and geophysics and Antarctica, coupled with the application of the principles and mechanics of plate tectonics relative to the oceans and adjacent land masses, gives a different and very positive attitude toward the hydrocarbon potential of this vast unexplored frontier area. On the basis of limited data, 21 sedimentary basins are identified for Antarctica and immediately adjacent areas. These include six onshore subglacial basins and 15 offshore basins. Excluding 11 basins considered to have little or no potential, the other 10 basins contain an estimated 16.9 million km/sup 3/ (4.05 million mi/sup 3/) of sediment having a potential hydrocarbon yield of 203 billion bbl oil equivalent. The problems associated with hydrocarbon exploration in Antarctica are formidable. Technology is adequate for seismic surveys and exploratory drilling of the Antarctic continental shelf, as concluded from current operations in the Arctic and from operating requirements of drilling rigs under construction. However, a working relationship among involved nations must first be evolved and production, storage, and transportation problems solved.

St. John, B.

1984-09-01

201

Multiple meteoroid impact in Antarctica  

Microsoft Academic Search

In the late 1950's, geophysical field parties undertaking gravity surveys across Antarctica observed over a large area of Wilkes Land (> 240km across) an exceptionally pronounced negative free air anomaly ((to -158.3 mgal). This area was later interpreted as a possible meteor impact site because the gravity profiles were similar to those of known impact sites (apparent rim structures, circular

J. W. Weihoupt; A. Rice; F. van der Hoeven

2006-01-01

202

Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica  

NASA Technical Reports Server (NTRS)

In December 1985, an automated meteorological station was established at Lake Hoare in the dry valley region of Antarctica. Here, the first year-round observations available for any site in Taylor Valley are reported. The mean annual solar flux at Lake Hoare was 92 W/sq m during 1986, the mean air temperature -17.3 C, and the mean 3-m wind speed 3.3 m/s. The local climate is controlled by the wind regime during the 4-month sunless winter and by seasonal and diurnal variations in the incident solar flux during the remainder of the year.

Clow, Gary D.; Mckay, Christopher P.; Simmons, George M., Jr.; Wharton, Robert A., Jr.

1988-01-01

203

A Case Study in Reengineering Design Models D. Casey Tucker, Devon M. Simmonds  

E-print Network

commercial sector as an advertising service. Revenues are obtained through local business sponsorships unnecessary. Before any development could take place, it was necessary to interview the stakeholders table. Each station has a number of time-slots available for advertising, stored as Avails. Every

Simmonds, Devon M.

204

Fecal Coliforms in Antarctica  

NSDL National Science Digital Library

In this interrupted case study, students explore the environmental consequences of Antarctic research as they design experiments to assess the impact of disposing untreated sewage from a research station into the ocean. Students review experimental methods to measure coliform bacteria, examine data, and decide what actions, if any, should be taken. The can be used in either a non-majors course in science literacy or a general microbiology class studying bacterial detection methods. For non-majors, the instructor would emphasize the mechanics of data collection and analysis and may touch on the environmental implications of finding fecal coliforms in Antarctic waters. For microbiology students, the instructor would highlight the bacteriology and pair the case with a lab.

Nold, Stephen C.

2002-01-01

205

Let's Talk with David Nold about Safety and Wintering Over in Antarctica  

NSDL National Science Digital Library

At this site students discover that Antarctica's winter runs from mid-February through late August and if one decides to stay, one is there for the duration since all aircraft traffic is stopped. They will also learn how research crews prepare to go it alone. This in-depth profile of a safety and health engineer offers a look at what it takes to keep an Antarctic research station running year-round. In the question and answer profile the engineer answers more than 15 questions, including why kids should know about deep sea Antarctica, what the big deal is about wintering over, and if things change drastically when the summer crew arrives. He also describes a typical workday in the winter there and explains what he misses about Antarctica when he is not there.

206

Relationship between total ozone amounts and stratospheric temperature at Syowa, Antarctica  

SciTech Connect

Using statistical methods, the relationship has been studied between total ozone and 100-mbar temperatures at Syowa Station, Antarctica (69[degrees]S, 40[degrees]E), based on data obtained in 1961-1981 and 1982-1988, the time of ozone depletion in Antarctica. Results indicate a strong, positive correlation between total ozone and 100-mbar stratospheric temperatures during September-March for all years, but lower ozone values at 100-mbar stratospheric temperatures colder than about [minus]60[degrees]C during the 1982-1988 period. Ozone destruction by heterogeneous photochemical processes is the main cause of ozone depletion over Syowa during the 1980's, with a lesser contribution from a change in air dynamics (heat, ozone, and momentum transport to Antarctica during the austral spring) that increased polar vortex stability, thereby promoting photochemical ozone depression within the vortex. 27 refs., 9 figs., 2 tabs.

Shigeru Chubachi (Meteorological Research Inst., Ibaraki (Japan))

1993-02-20

207

Antarctica as an Educational Resource  

NSDL National Science Digital Library

"As an educational resource, Antarctica is extremely broad in scope with the potential to contribute to a number of study areas," from the sciences to history, sociology, and politics. Authored by molecular biologist Clive Evans at the University of Auckland, this Web site provides a convenient resource for introducing Antarctica into the classroom and could be adapted for a range of grade levels. Luckily for life science educators, the site focuses primarily on Antarctic biology, adaptation, human impact, and the environment. Web pages contain detailed background information, as well as questions and suggested activities to stimulate discussion and help students explore the material. A more in-depth exploration of the material requires additional resources; references and Web links are provided.

208

REVIEW ARTICLE Astronomy in Antarctica  

E-print Network

Abstract Antarctica provides a unique environment for astronomers to practice their trade. The cold, dry and stable air found above the high Antarctic plateau, as well as the pure ice below, offers new opportunities for the conduct of observational astronomy across both the photon and the particle spectrum. The summits of the Antarctic plateau provide the best seeing conditions, the darkest skies and the most transparent atmosphere of any earth-based observing site. Astronomical activities are now underway

Michael G. Burton; M. G. Burton (b

2010-01-01

209

Controlled stimulation of VLF emissions from Siple Station, Antarctica  

NASA Astrophysics Data System (ADS)

Attention is given to the evidence for a new plasma phenomenon, presently designated 'coherent wave instability' (CWI), which is characterized by an extremely narrow bandwidth of the frequency of oscillation. It is shown that the CWI can be suppressed by a noisy signal having a spectral width of the order of 20 Hz. The coherence of the output often breaks down after the signal reaches saturation, giving rise to amplitude and frequency pulsations of 2-100 Hz. The results presently reported regarding the coherence of the bandwidth indicate that the minimum magnetospheric response is observed when the spectral component spacing of the applied signal is about 20 Hz. An application of the CWI is in the modification of the radiation belts.

Helliwell, R. A.

1983-12-01

210

CONCORDIASI, Long Duration Stratospheric Balloons over Antarctica  

NASA Astrophysics Data System (ADS)

CNES, the French space agency, has been developing and operating stratospheric balloons for scientific purposes for many years. One particular type of balloon has been designed for ultra long duration flights in the lowermost stratosphere: the superpressure balloon. A constellation of typically 10 to 20 balloons, fitted with light payloads can be deployed, forming a regional airborne observatory. The first use of this kind of observation system has been for atmospheric sciences, each of the balloons carrying various sets of scientific instruments. Concordiasi is the latest program built on the use of this observation system in its most recent development stage. 19 balloons were released from McMurdo Station Antarctica over September to October 2010 in the Winter Polar Vortex. It carried a variety of instruments, for remote and in-situ measurement of the atmosphere. The average flight duration of the balloons was 69 days, cumulating to 1316 days over the whole balloon constellation. We will present briefly the scientific objectives of the project; describe the flight system and the flight campaign, including the launch phase and the long flight monitoring through the control centres. Flight results will be presented, with an overview of the scientific results, but focussing mainly on the technical achievements and on lessons that can be drawn from this project.

Cocquerez, Philippe

2012-07-01

211

Temperature trend estimates in the troposphere over Antarctica by use of analysis of the GPS radio occultation data  

NASA Astrophysics Data System (ADS)

Analyses of the Antarctic climate change during recent decades have demonstrated a positive continent-wide average near-surface temperature trend. Strong warming of the Antarctic Peninsula in contrast to slight cooling of the Antarctic continental interior in the last five decades has been emphasised [Turner et al. 2005]. Recently, it has been reported that significant warming of the Antarctic ice-sheet surface extends well beyond the Antarctic Peninsular to cover most of West Antarctica with a warming rate exceeding 0.1°C per decade over the past 50 years, and is strongest in winter and spring [Steig et al. 2009]. Assessments of atmospheric temperature trends have also found significant warming of the Antarctic winter troposphere. Analysing data from nine Antarctic radiosonde stations, it has been shown that regional midtropospheric temperatures have increased at a statistically significant rate of 0.5 to 0.7°C per decade over the past three decades - a major warming of the Antarctic winter troposphere that is larger than any previously identified regional tropospheric warming on Earth [Turner et al. 2006]. Analysis of climate change over the Polar Regions is particularly challenging due to the scarcity of observations from a small number of sparsely located weather stations. Obviously, data obtained by various satellite remote sensing techniques are invaluable in order to obtain spatially-complete distributions of near-surface and atmospheric temperature trends in high latitudes. For example, using the climate quality records of satellite Microwave Sounding Unit (MSU) observations, it has been shown that significant tropospheric warming prevails during Antarctic winters and springs, with the largest winter tropospheric warming of about 0.6°C per decade for 1979-2005 between 120°W and 180°W [Johanson and Fu 2007]. Recently, a new atmospheric observation technique, GPS radio occultation (RO), has been developed for acquiring the Earth's atmospheric characteristics. Latest research results have demonstrated the great potential of the new technique to global climate monitoring and numerical weather prediction. With the newly launched six FORMOSAT-3 LEO satellites in 2006, thousands of high-quality, globally-distributed daily vertical profiles of refractivity, temperature and moisture have been obtained [Liou et al. 2007]. It is anticipated that GPS RO technique will play an important role in meteorological studies because of the significantly increased amount of atmospheric observations and improved data processing methodology. In this study, we use GPS RO data and collocated radiosonde data from three Australian weather observation stations (Casey, Davis and Mawson) to evaluate impacts of different collocation criteria (specifically, 100, 200 and 300 km spatial buffers and 1, 2 and 3 hour temporal buffers). Spatial and temporal variations in troposhperic temperatures over Antarctica are also investigated using the GPS RO data. Detailed analysis of refractivity and temperature profiles is presented and seasonal temperature variations in the troposphere are discussed. References Johanson, C. M., and Q. Fu, 2007: Antarctic atmospheric temperature trend patterns from satellite observations. Geophys. Res. Lett. 34, L12703, doi:10.1029/2006GL029108. Liou, Y.-A., A. G. Pavelyev, S. F. Liu, A. A. Pavelyev, N. Yen, C. Y. Huang, and C. J. Fong, 2007: FORMOSAT-3 GPS radio occultation mission: preliminary results. IEEE Trans. Geosci. Remote Sensing, 45(10), doi:10.1109/TGRS.2007.903365. Steig, E. J., D. P. Schneider, S.D. Rutherford, M. M. Mann, J. C. Comiso, and D. T. Shindell, 2009: Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year. Nature 457, 22 January 2009, doi: 10.1038/nature07669. Turner, J., S.R. Colwell, G.J. Marshall, T.A. Lachlan-Cope, A.M. Carleton, P.D. Jones, V. Lagun, P.A. Reid, and S. Iagovkina, 2005: Antarctic climate change during the last 50 years. Int. J. Climatol. 25, 279-294. Turner, J., T. A. Lachlan-Cope, S. Colwell, G. J. Marshall, and W. M. Connolley, 2006: Signif

Zhang, Kefei; Fu, Erjiang; Wang, Chuan-Sheng; Liou, Yuei-An; Pavelyev, Alexander; Kuleshov, Yuriy

2010-05-01

212

Variation in the ribosomal ITS-sequence of the lichens Buellia frigida and Xanthoria elegans from the Vestfold Hills, eastern Antarctica  

Microsoft Academic Search

Abstract:Thalli of the lichens Buellia frigida and Xanthoria elegans were collected from five different locations each 5–15km apart in the Vestfold Hills, Princess Elizabeth Land, eastern Antarctica. A further collection was made from Mawson Station, Mac Robertson Land, eastern Antarctica, 660km away. DNA was extracted from whole thalli and the ribosomal ITS region amplified by PCR using fungal specific primers.

P. S. Dyer; G. J. Murtagh

2001-01-01

213

Seismic anisotropy of the Victoria Land region, Antarctica  

NASA Astrophysics Data System (ADS)

We present shear wave splitting results obtained from the analysis of core-refracted teleseismic phases recorded by permanent and temporary seismographic stations located in the Victoria Land region (Antarctica). We use an eigenvalue technique to isolate the rotated and shifted shear wave particle motion, to determine the best splitting parameters. Average values show clearly that dominant fast axis direction is NE-SW oriented, in accordance with previous measurements obtained around this zone. Only two stations, OHG and STAR, show different orientations, with N-S and NNW-SSE main directions. On the basis of the periodicity of single shear wave splitting measurements with respect to backazimuths of events under study, we infer the presence of lateral and vertical changes in the deep anisotropy direction. To test this hypothesis we model waveforms using a cross-convolution technique for the cases of one and two anisotropic layers. We obtain a significant improvement on the misfit in the double layer case for the two stations. For stations where a multilayer structure does not fit, we investigate lateral anisotropy changes at depth through Fresnel zone computation. We find that anisotropy beneath the Transantarctic Mountains (TAM) is considerably different from that beneath the Ross Sea. This feature influences the measurement distribution for the two permanent stations TNV and VNDA. Our results show a dominant NE-SW direction over the entire region, however other anisotropy directions are present and maybe interpreted in the context of regional tectonics.

Salimbeni, S.; Pondrelli, S.; Danesi, S.; Morelli, A.

2010-07-01

214

Antarctica and the Detection of Environmental Change  

Microsoft Academic Search

Antarctica plays a critical role in global change because major interactions in this region between the atmosphere, ice, oceans, and biota affect the entire global system through feedbacks, dynamic biogeochemical cycles, deep ocean circulation, atmospheric transport of energy and pollutants, and changes in mass balance. Antarctica is also sensitive to global change and is a key area for detecting and

Gunter Weller

1992-01-01

215

Examination of calibration performance of multiple POS sensors using measurements over the Dome C site in Antarctica  

Microsoft Academic Search

The Dome C site, located at Dome Concordia in Antarctica, has one of the most homogeneous land surfaces on Earth in terms of reflectance and temperature. An in-situ research-based automatic weather station (AWS) provides a continuous record of surface climate conditions. The extreme cold, dry and clean atmosphere of the site is ideal to collect overpass data for sensor validation

Aisheng Wu; Xiaoxiong Xiong; Changyong Cao

2008-01-01

216

Crust and Upper Mantle Structure of Antarctica from Rayleigh Wave Tomography  

NASA Astrophysics Data System (ADS)

We combine data from three temporary arrays of seismometers (AGAP/GAMSEIS 2007-2010, ANET/POLENET 2007-2012, TAMSEIS 2001-2003) deployed across Antarctica, along with permanent stations in the region, to produce a large scale shear velocity model of the continent extending from the Gamburtsev Subglacial Mountains (GSM) in East Antarctica, across the Transantarctic Mountains (TAM) and West Antarctic Rift System (WARS) to Marie Byrd Land (MBL) in West Antarctica. Our combined dataset consists of Rayleigh wave phase and amplitude measurements from 112 stations across the study region. We first invert for 2-D Rayleigh wave phase velocities using the two-plane wave method. These results are then inverted for shear velocity structure using crustal thicknesses derived from ambient noise tomography and teleseismic receiver functions. We refine our shear velocity model by performing a Monte Carlo simulation that explores the tradeoff between crustal thickness and upper mantle seismic velocities. The resulting model is higher resolution than previous studies (~150 km resolution length) and highlights significant differences in crustal and uppermost mantle structure between East and West Antarctica in greater detail than previously possible. East Antarctica is underlain by thick crust (reaching ~55 km beneath the GSM) and fast, cratonic lithosphere. West Antarctica is defined by thinner crust and slow upper mantle velocities indicative of its more recent tectonic activity. The observed boundary in crustal thickness closely follows the TAM front. MBL is underlain by a thicker lithosphere than that observed beneath the WARS, but slow mantle velocities persist to depths greater than 200 km, indicating a 'deep seated' (i.e. deeper than the deepest resolvable features of our model) thermal source for volcanism in the region. The slowest seismic velocities at shallow depths are observed in the Terror Rift region of the Ross Sea along an arc following the TAM front, where the most recent extension has occurred, and in another region of active volcanism. The Ellsworth-Whitmore Mountains are underlain by relatively thick crust and an intermediate thickness lithosphere, consistent with its hypothesized origin as a remnant Precambrian crustal block. We also produce upper mantle viscosity models for the study region using a temperature-dependent rheology, assuming that mantle seismic anomalies are dominated by temperature variations. Initial results closely correlate with the velocity model, with viscosities beneath West Antarctica inferred to be orders of magnitude lower than beneath East Antarctica. These viscosity results have important implications for our understanding of glacial isostatic adjustment, which is of particular interest in producing models of past and future changes in the Antarctic Ice Sheets.

Wiens, D. A.; Heeszel, D. S.; Sun, X.; Chaput, J. A.; Aster, R. C.; Nyblade, A.; Anandakrishnan, S.; Wilson, T. J.; Huerta, A. D.

2012-12-01

217

Balloon-borne ozone soundings and ground based optical thickness measurements above Antarctica - A contribution to global change  

Microsoft Academic Search

First results of balloon-borne vertical ozone soundings and ground-based total aerosol optical thickness measurements above Antarctica are presented. Since May 1985, ozone soundings have been regularly carried out above the GDR-Research Base located near the Novolazarevskaya Station. The total aerosol optical thickness measurements took place from November 1984 to April 1985 at the Molodezhnaya, Mirny, and Vostok polar stations. Both

U. Leiterer; P. Gloede

1987-01-01

218

Distribution of mean surface stable isotope values in East Antarctica : observed changes with depth in the coastal area  

Microsoft Academic Search

Mean samples of the snow accumulated during the last 10 years have been collected at 48 stations distributed along a 850-km traverse in East Antarctica, from Dumont d'Urville station towards Vostok. Up to 1000 m a.s.l. the mean deuterium values remain constant (8(D) = — 150°\\/00); then they decrease with various parameters (distance, elevation) and in particular with mean annual

C. Loriiis; L. Merlivat

219

Potential methane reservoirs beneath Antarctica.  

PubMed

Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14?kilometres thick and an estimated 21,000 petagrams (1?Pg equals 10(15)?g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300?metres in West Antarctica and 700?metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage. PMID:22932387

Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

2012-08-30

220

Detection of Seismic Sources Associated with Ice Movement in Antarctica using the AGAP and POLENET Seismic Deployments  

NASA Astrophysics Data System (ADS)

Antarctica has a very low level of seismicity in global seismic catalogs. In addition, although many long period “glacial earthquakes” have been found in Greenland, only a few have been detected around Antarctica [Nettles and Ekstrom, 2010]. The sparse seismicity of Antarctica must be due at least in part to poor seismic station coverage in the global network. Recent seismic deployments offer the opportunity to characterize the seismic sources of Antarctica at a much lower magnitude level, as well as investigate the occurrence of long period seismic sources such as those from Whillans Ice stream (WIS) basal slip events [Wiens et al., 2008] and other types of seismicity related to ice movement. We use data from permanent GSN stations and two regional broadband seismic arrays, the AGAP (GAMSEIS) array in East Antarctica, and POLENET array in West Antarctica, to identify and locate local and regional seismic events. Data for approximately 20 seismic stations are available for 2007-2008 and 40 seismic stations for 2008-2009. We detect and locate events using the traditional method of identifying the first arriving high frequency P phases with an STA/LTA algorithm and association programs provided by the ANTELOPE seismic database. In addition to locating these fast slipping events, we implement a modified time reversal method to locate and identify ‘slow’ events that would otherwise go undetected. These slow events generally show emergent arrivals and lack the high frequency phases used in traditional methods. For our modified time reversal, the long period envelopes of all the stations are first shifted by their Rayleigh wave propagation time and then stacked at each of a grid of equidistantly spaced potential source locations. The source time and location of actual seismic events can then be identified by large amplitude stacked signals at one of the potential source locations. The method has been tested using several trial cases; the first using known small earthquakes (MS 4.6-5.3) at coastal locations and the second using a well recorded example of the daily slip of the WIS. The analysis method was able to correctly detect all of the test cases. We are now applying the method to catalog slip events of the WIS and to search for unknown long period sources in Antarctica and the southern oceans surrounding it. Our integrated catalog of events detected using long period methods and traditional high frequency methods will give insight into current seismic activity and its association with ice movement in Antarctica.

Lough, A. C.; Wiens, D. A.; Nyblade, A.; Aster, R. C.; Anandakrishnan, S.; Huerta, A. D.

2010-12-01

221

Characterization of Micrococcus antarcticus sp. nov., a psychrophilic bacterium from Antarctica  

Microsoft Academic Search

A Gram-positive, cold-adapted, aerobic, spherical actinobacterium (strain T2T) with a quite low cardinal growth temperature was isolated from Chinese Great-Wall station in Antarctica. Sequence comparisons of the 16S rDNA indicated the isolate to be a phylogenetic member of the genus Micrococcus, family Micrococcaceae, in which it represents a novel lineage. The phylogenetic distinctness of the isolate with respect to the

Hongcan Liu; Yi Xu; Yanhe Ma; Peijin Zhou

2000-01-01

222

Radiative and hydrological fluxes in the McMurdo Dry Valleys, Antarctica  

Microsoft Academic Search

The spatial and temporal distributions of solar radiation and temperature were investigated to predict glacial meltwater discharge in the McMurdo Dry Valleys, Antarctica (77o30'S 162o00'E). Average annual incoming solar radiation, as measured by pyranometer data, ranged from 84 to 117 W m-2 during 1994 and 1995. Differences among stations were attributed primarily to terrain effects, but coastal cloudiness and orographic

Gayle Lynn Dana

1997-01-01

223

Seasonal and interannual variability in temperature, chlorophyll and macronutrients in northern Marguerite Bay, Antarctica  

Microsoft Academic Search

We report data from the first 8 years of oceanographic monitoring in Ryder Bay, northern Marguerite Bay, Antarctica. These data form the oceanographic component of the Rothera Oceanographic and Biological Time-Series (RaTS) project. When weather and ice permit, the RaTS station is occupied every 5 days in summer and weekly in winter. Observations comprise a conductivity–temperature–depth (CTD) cast to 500m

Andrew Clarke; Michael P. Meredith; Margaret I. Wallace; Mark A. Brandon; David N. Thomas

2008-01-01

224

Assessing and Improving the Quality of Unattended Radiation Observations in Antarctica  

Microsoft Academic Search

The quality of atmospheric radiation measurements made at automatic weather stations (AWSs) in Antarctica is assessed. The AWSs are placed on the coastal ice shelf in the katabatic wind zone and on the high Antarctic plateau, and they measure shortwave and longwave radiation fluxes using unheated\\/unventilated Kipp and Zonen (KZ) CM3\\/CG3 sensors. During three summertime Antarctic experiments, the AWS sensors

Michiel van den Broeke; Dirk van As; Carleen Reijmer; Roderik van de Wal

2004-01-01

225

Glacial isostatic crustal uplift in southern Victoria Land, Antarctica, from geologic and geodetic records  

NASA Astrophysics Data System (ADS)

Geologic records and geodetic measurements of glacial isostatic crustal motions are presented from the southern Victoria Land region of Antarctica. In much of the world, key records used for mapping and modeling glacial isostatic crustal motions come from raised paleoshorelines and beaches of ice-marginal lakes and seas. While such records are scarce in Antarctica, preserved paleoshorelines are present in the southern Victoria Land region of Antarctica. Light detection and ranging (LiDAR) data coverages of these features were acquired during the 2001-2002 austral summer field season by NASA's Airborne Topographic Mapper (ATM) system, resulting in 2 meter horizontal resolution digital elevation models (DEMs). This study utilizes these DEM data to derive crustal tilt values from observed changes in elevation along the length of the shorelines. Radiocarbon age data are correlated with the associated degree of shoreline tilt to derive a rate of crustal deformation since deglaciation. Modern rates of glacial isostatic crustal motion are derived from GPS stations in the same region. Campaign station occupation began in 1996-1997 under the TAMDEF (Transantarctic Mountain DEFormation Network) project, and continuous GPS data collected began in 1999 and continues under the ANET/POLENET (Antarctica Polar Earth Observing Network) project, enabling analysis of decadal scale time series. Integrated gradient curves from paleoshoreline records and GPS crustal velocities show exponential form and indicate tilting down to the east. Eastward tilt may be the result of substantial loss of East Antarctic ice, a collapsing forebulge linked to ice centers in the Ross Sea region or in interior West Antarctica, or differences in earth response due to laterally varying earth structure. Modeling of these new data, along with comparison of tilt directions to centers of ice mass loss, provide tests of these scenarios and yield new insights into earth models and ice history.

Konfal, S.; Wilson, T.; Bevis, M. G.; Kendrick, E. C.; Hall, B. L.

2011-12-01

226

Atmospheric transport of trace elements toward Antarctica  

NASA Astrophysics Data System (ADS)

Since 1960, at the French station of Dumont d'Urville (Terre Adelie coast), during more or less long periods, we have monitored Rn-222 and its decay product Pb-210, fission products due to atmospheric nuclear tests, and the cosmonuclides Be-7 and P-32. Almost all these species show seasonal variations, whose general features are maximum concentrations during the local summer (December January), and minima in the middle of winter (June July). A long-term change in the Pb-210 concentrations was also observed at Dumont d'Urville, for all seasons, with a more-or-less continuous decrease since 1969 to 1986, from 2.5 to 1.5 dpm per 1000m3. Such variations seem to be quite usual, because an ice core sampled at the South Pole also displays important fluctuations of the Pb-210 concentration in the fresh snow between 1888 and 1974, from 1 to 3 dpm/kg, particularly from 1920 to 1954. The latitudinal profiles of both Rn-222 and Pb-210 showing minima between 40° and 60° South at sea level, the long-range transport of these nuclides from mid-latitudes toward Antarctica should occur through the higher rather through the lower layers of the troposphere. Therefore, the Pb-210 long-term changes observed can be ascribed to global changes of the general circulation in the Southern hemisphere. The concentrations of Pb-210 at Dumont d'Urville, and the ozone vertical column in October at Halley Bay, show common features, more particularly a significant decrease in the 1980s, meaning that changes in the atmospheric circulation occurred in the Antarctic area from the middle of the 1970s, which can partly account for the ozone decrease beside variations of trace species concentrations.

Lambert, G.; Ardouin, B.; Sanak, J.

1990-02-01

227

The United States in Antarctica -- Report of the U.S. Antarctic Program External Panel  

NSF Publications Database

... States in Antarctica Report of the U. S. Antarctic Program External Panel HTML version Adobe ... 3.0 Antarctica -- The Environment 3.0 Antarctica -- The Environment (continued) 4.0 Antarctica -- ...

228

Lithospheric Structure of Antarctica and Implications for Geological and Cryospheric Evolution  

NASA Astrophysics Data System (ADS)

Recent broadband seismic deployments, including the AGAP/GAMSEIS array of 24 broadband seismographs over the Gamburtsev Subglacial Mountains (GSM) in East Antarctica and the POLENET/ANET deployment of 33 seismographs across much of West Antarctica, reveal the detailed crust and upper mantle structure of Antarctica for the first time. The seismographs operate year-around even in the coldest parts of Antarctica, due to novel insulated boxes, power systems, and modified instrumentation developed in collaboration with the IRIS PASSCAL Instrument Center. We analyze the data using several different techniques to develop high-resolution models of Antarctic seismic structure. We use Rayleigh wave phase velocities at periods of 20-180 s determined using a modified two-plane wave decomposition of teleseismic Rayleigh waves to invert for the three dimensional shear velocity structure. In addition, Rayleigh wave group and phase velocities obtained by ambient seismic noise correlation methods provide constraints at shorter periods and shallower depths. Receiver functions provide precise estimates of crustal structure beneath the stations, and P and S wave tomography provides models of upper mantle structure down to ~ 500 km depth along transects of greater seismic station density. The new seismic results show that the high elevations of the GSM are supported by thick crust (~ 55 km), and are underlain by thick Precambrian continental lithosphere that initially formed during Archean to mid-Proterozoic times. The absence of lithospheric thermal anomalies suggests that the mountains were formed by a compressional orogeny during the Paleozoic, thus providing a locus for ice sheet nucleation throughout a long period of geological time. Within West Antarctica, the crust and lithosphere are extremely thin near the Transantarctic Mountain Front and topographic lows such as the Bentley Trench and Byrd Basin, which represent currently inactive Cenozoic rift systems. Slow seismic velocities beneath Marie Byrd Land at asthenospheric depths suggest a major thermal anomaly, possibly due to a mantle plume. Volcanic earthquakes detected in this region indicate the presence of currently active magma systems. The results suggest large lateral changes in parameters needed for glaciological models, including lithospheric thickness, mantle viscosity, and heat flow. Extremely high heat flow is predicted for much of West Antarctica, consistent with recent results from the WAIS ice drilling. Using the seismic results to estimate mantle viscosity, we find several orders of magnitude difference in viscosity between East and West Antarctica, with lowest viscosities found beneath Marie Byrd Land and the West Antarctic Rift System. Realistic glacial isostatic adjustment models must take these large lateral variations into account.

Wiens, Douglas; Heeszel, David; Sun, Xinlei; Lloyd, Andrew; Nyblade, Andrew; Anandakrishnan, Sridhar; Aster, Richard; Chaput, Julien; Huerta, Audrey; Hansen, Samantha; Wilson, Terry

2013-04-01

229

Ecology of Soil Microorganisms of Antarctica.  

National Technical Information Service (NTIS)

Continental Antarctica possesses a characteristic flora and fauna, which varies both qualitatively and quantitatively among the different habitats. Bacteria and other microorganisms are usually present in numbers far lower than those encountered in temper...

W. L. Boyd, J. T. Staley, J. W. Boyd

1966-01-01

230

Petroleum and mineral resources of Antarctica  

SciTech Connect

Following the introduction, this publication contains the following papers: (1) Are there petroleum resources in Antarctica. by John C. Behrendt; (2) Mineral occurrences of Antarctica by Peter D. Rowley, Paul L. Williams, and Douglas E. Pride; and (3) Dufek intrusion of Antarctica and a survey of minor metals and possible resources by Arthur B. Ford. The first report summarizes the information relevant to petroleum resources. Although uneconomic at present, petroleum is generally considered more likely to be exploited (if supergiant fields were ever found) in the next few decades than hard minerals. The second report reviews the reported occurrences of minerals in Antarctica and discusses their significance. The final report discusses the Dufek layered mafic intrusion, second only to the Bushveld Complex in size in the world; the Dufek intrusion might be considered as a potential target for mineral exploration. 370 references, 28 figures, 4 tables.

Behrendt, J.C. (ed.)

1983-01-01

231

Geoethical approach to mineral activities in Antarctica  

NASA Astrophysics Data System (ADS)

Antarctica is the outermost from civilization space continent. From 14.0 million km2 of surface area about 98% of Antarctica is covered by ice that averages at least 1.6 km in thickness. Geologically, the continent is the least explored in the world, and it is almost absolutely unknown what mineral resources Antarctica has as they are buried in rock that is covered by a thick ice sheet. It is thought to have large and valuable mineral deposits under the ice. This is because of what has been found in samples taken from the small areas of rock that are exposed, and also from what has been found in South Africa and South America. Up until 180 million years ago, Antarctica was a part of the Gondwanaland super continent, attached to South America, the Southern part of Africa, India and Australia, these continents then drifted apart until they reached their current positions. This leads to a possibility that Antarctica may also share some of the mineral wealth of these continents. Right now on the ice-free areas of Antarctica iron ore, chromium, copper, gold, nickel, platinum, coal and hydrocarbons have been found. The Protocol on Environmental Protection to the Antarctic Treaty, also known as the Madrid Protocol, was signed in 1991 by the signatories to the Antarctic Treaty and became law in January 1998. The Protocol provides for comprehensive protection of the Antarctic environment and associated ecosystems and includes a ban on all commercial mining for at least fifty years (this is up for review in 2041). Current climate change and melting ice in Polar Regions is opening up new opportunities to exploit mineral and oil resources. Even Antarctica's weather, ice and distance from any industrialized areas mean that mineral extraction would be extremely expensive and also extremely dangerous, the depletion of mineral recourses on the Earth can reverse banning of mining in Antarctica in future. There is no question that any resource exploitation in Antarctica will cause severe not only permanent, local impact on the environment, but also will have implications for other Earth's systems as a whole. Mineral prospecting and exploration in Antarctica need to be reflected and respected in any concept of environmental sustainability. Anyway, first stage of the geological surveying should be carried purely scientific and not designed to explore for and identify mineral deposits. It's obvious that although various countries claim sovereignty in certain regions of Antarctica, the continent should be continued to be politically neutral. Efforts of scientists and politicians should respect their own responsibility for the protection of the fragile Antarctic environment and of our planet in the whole taking care for future generations.

Talalay, Pavel

2013-04-01

232

Microbial ecology of terrestrial Antarctica: Are microbial systems at risk from human activities?  

SciTech Connect

Many of the ecological systems found in continental Antarctica are comprised entirely of microbial species. Concerns have arisen that these microbial systems might be at risk either directly through the actions of humans or indirectly through increased competition from introduced species. Although protection of native biota is covered by the Protocol on Environmental Protection to the Antarctic Treaty, strict measures for preventing the introduction on non-native species or for protecting microbial habitats may be impractical. This report summarizes the research conducted to date on microbial ecosystems in continental Antarctica and discusses the need for protecting these ecosystems. The focus is on communities inhabiting soil and rock surfaces in non-coastal areas of continental Antarctica. Although current polices regarding waste management and other operations in Antarctic research stations serve to reduce the introduction on non- native microbial species, importation cannot be eliminated entirely. Increased awareness of microbial habitats by field personnel and protection of certain unique habitats from physical destruction by humans may be necessary. At present, small-scale impacts from human activities are occurring in certain areas both in terms of introduced species and destruction of habitat. On a large scale, however, it is questionable whether the introduction of non-native microbial species to terrestrial Antarctica merits concern.

White, G.J.

1996-08-01

233

THE BIRDS OF SEYMOUR ISLAND, ANTARCTICA  

Microsoft Academic Search

During January-February 2000, we obtained information on the abundance and distribution of seabirds in Seymour Island, Antarctica. Six species breed in this area: Adélie Penguin (Pygoscelis adeliae; 28,255 pairs), Wilson's Storm-petrel (Oceanites oceanicus; 22), Brown Skua (Catharacta antarctica; 30), South Polar Skua (C. maccormicki; 33), Kelp Gull (Larus dominicanus; 296) and Antarctic Tern (Sterna vittata; 107). In addition, five non-breeding

Diego Montalti; Guillermo E. Soave

234

In Brief: New map of Antarctica  

Microsoft Academic Search

A new map of Antarctica that provides the most geographically accurate, true-color, high-resolution views of the continent to date was unveiled on 27 November. The Landsat Image Mosaic of Antarctica-completed by researchers from NASA, the U.S. Geological Survey, the U.S. National Science Foundation, and the British Antarctic Survey-is a realistic, nearly cloudless satellite view of the continent, piecing together 1100

Randy Showstack

2007-01-01

235

Potential seaways across West Antarctica  

NASA Astrophysics Data System (ADS)

The West Antarctic ice sheet (WAIS) has long been considered vulnerable to rapid retreat and today parts are rapidly losing ice. Projection of future change in WAIS is, however, hampered by our poor understanding of past changes, especially during interglacial periods that could be analogs for the future, but which undoubtedly provide an opportunity for testing predictive models. We consider how ice-loss would open seaways across WAIS; these would likely alter Southern Ocean circulation and climate, and would broadly define the de-glacial state, but they may also have left evidence of their existence in the coastal seas they once connected. We show the most likely routes for such seaways, and that a direct seaway between Weddell and Ross seas, which did not pass through the Amundsen Sea sector, is unlikely. Continued ice-loss at present rates would open seaways between Amundsen and Weddell seas (A-W), and Amundsen and Bellingshausen seas (A-B), in around one thousand years. This timescale indicates potential future vulnerability, but also suggests seaways may have opened in recent interglacial periods. We attempt to test this hypothesis using contemporary bryozoan species assemblages around Antarctica, concluding that anomalously high similarity in assemblages in the Weddell and Amundsen seas supports recent migration through A-W. Other authors have suggested opening of seaways last occurred during Marine Isotope Stage 7a (209 ka BP), but we conclude that opening could have occurred in MIS 5e (100 ka BP) when Antarctica was warmer than present and likely contributed to global sea levels higher than today.

Vaughan, David G.; Barnes, David K. A.; Fretwell, Peter T.; Bingham, Robert G.

2011-10-01

236

Results from BESS-Polar I 2004 Antarctica Flight  

NASA Astrophysics Data System (ADS)

The Search for Antimatter in the galactic cosmic radiation is one of the main scientific objectives of the BESS-Program. A flatter antiproton spectrum below the secondary production peak at 1 GeV would suggest novel antiproton source, such as evaporating black-holes or decaying super-symmetric particles. The BESS-Polar experiment is designed as a highly transparent magnetic rigidity spectrometer that can precisely detect antiprotons down to energies of 0.1 GeV where a potential excess of antiprotons over the secondary production might be more apparent. The BESS-Polar instrument had its first successful balloon flight in December 2004, from McMurdo Station in Antarctica. During the 8.5-day long flight 900 million events where recorded. In this paper, we discuss the spectra of antiproton and proton as well as the search for antihelium.

Hams, T.; Abe, K.; Fuke, H.; et al.

237

Antarctica natural laboratory and space analogue for psychological research.  

PubMed

This introduction to the special issue traces the history of psychosocial concerns related to Antarctic exploration, from the heroic age of early explorers through the International Geophysical Year (IGY) of 1957 to 1958 to recent and current systematic research projects. The introduction discusses the organization and topics of international psychological investigations in polar stations and summarizes the articles that follow. Living in Antarctica imposes some unusual restrictions as well as opportunities, and it requires psychological adaptation to extreme environmental circumstances. The thrust of previous scientific and popular literature has been to focus on the negative effects of the situation and ignore the positive ones; however, ongoing studies are bringing about a more balanced view. Having an accurate understanding is important not only intrinsically and for appropriate application in the Antarctic itself but also in analogous extreme and unusual environments. These include extended space flight and space habitation, such as the projected voyage to Mars. PMID:11542946

Suedfeld, P; Weiss, K

2000-01-01

238

Ice-forming nuclei in Antarctica: New and past measurements  

NASA Astrophysics Data System (ADS)

The paper provides a review of past and a few new measurements of Ice-forming Nuclei (IN) in Antarctica. The few available published data were mostly obtained adopting different devices and methods and for a limited period of time. Consequently, data are scattered and give an incomplete picture of the Antarctic situation. It should be pointed out, however, that ice nucleation is an intricate process, depending on many parameters (supersaturation relative to ice and water, aerosol physical-chemical properties, possible conditioning and preactivation of particles, different modes of nucleation). Therefore, the uncertainty does not concern the Antarctic continent alone, but all measurements performed world-wide. A comparison of the published data can be made between Saxena and Weintraub (1988) at Palmer Station, and Ardon-Dryer et al. (2011) at the South Pole, as both studies measured IN in the immersion mode, even if at different temperature. Saxena and Weintraub (1988) obtained in three filters IN concentrations of about 104 m- 3 at T = - 6 °C, - 11 °C and - 13 °C, and 103 m- 3 at T = - 17 °C, in an additional filter (February-December 1983). At the South Pole Ardon-Dryer et al. (2011) obtained a concentration of about 5 × 102 m- 3 at T = - 19 °C, and the IN concentration increased until about 40 × 103 m- 3 at the activation temperature of - 26 °C. Such values are higher than those measured by Bigg (1973) near Antarctica, using a thermal diffusion chamber (deposition or deposition-condensation modes). IN concentrations measured at Terra Nova Bay are lower than those reported above, and are comparable to values reported for the Scott Base, Byrd Station and cruises at latitude 60°-70° S.

Belosi, F.; Santachiara, G.; Prodi, F.

2014-08-01

239

No Household Plants in Antarctica  

NSF Publications Database

... EAM NSF Org: OD / OPP Date : February 06, 1991 File : opp93023 DIVISION OF POLAR PROGRAMS OFFICE OF ... Antarctic Program Stations and Facilities) To: Files (S.7 - Environment) In line with requirements ...

240

Space Station  

NASA Technical Reports Server (NTRS)

The official start of a bold new space program, essential to maintain the United States' leadership in space was signaled by a Presidential directive to move aggressively again into space by proceeding with the development of a space station. Development concepts for a permanently manned space station are discussed. Reasons for establishing an inhabited space station are given. Cost estimates and timetables are also cited.

Anderton, D. A.

1985-01-01

241

Finding, Food Waste Management Program at McMurdo Station  

NSF Publications Database

The current food waste management program consists of the disposal of small volumes of liquid wastes, volume reduction, and storage of food wastes at McMurdo Station, Antarctica. Food wastes originate in the galley at McMurdo Station and consist of food preparation wastes, plate scrapings, food scraps, perishable foods and cooking oil/lard. Ice Staging or Ocean Dumping within the Antarctic Treaty Area for food waste and food-related wastes accumulated at McMurdo Station; and o Alternative B5.

242

INTRODUCTION The Antarctic midge, Belgica antarctica Jacobs 1900, is the  

E-print Network

806 INTRODUCTION The Antarctic midge, Belgica antarctica Jacobs 1900, is the southernmost insect in early summer, mate, oviposit and die within 10days. B. antarctica is apterous, a common adaption in wind Peninsula. Not surprisingly, given its habitat, larvae of B. antarctica are extremely tolerant of a number

Lee Jr., Richard E.

243

Gateway Antarctica's Ministry of Foreign Affairs and Trade Scholarship  

E-print Network

Gateway Antarctica's Ministry of Foreign Affairs and Trade Scholarship in Antarctic and Southern in support of research and teaching in Antarctic Studies in recognition of Antarctica as a continent devoted to the understanding of Antarctica or the Southern Ocean. At least one of the scholar's supervisors of studies

Hickman, Mark

244

Belgische wetenschappers ontdekken 18 kilo zware meteoriet op Antarctica  

E-print Network

Belgische wetenschappers ontdekken 18 kilo zware meteoriet op Antarctica donderdag 28 februari 2013 Antarctica', zegt ULB-geoloog en teamleider Vincent Debaille. `Dit is de grootste meteoriet die in 25 jaar gevonden is in oostelijk Antarctica.' De chondriet is momenteel in Japan voor onderzoek, waar hij aan een

Claeys, Philippe

245

Post Graduate Research Opportunities Aquatic Ecosystem Research at Gateway Antarctica  

E-print Network

Post Graduate Research Opportunities Aquatic Ecosystem Research at Gateway Antarctica In existence moved to Gateway Antarctica at the University of Canterbury. The programme comes with a legacy of multidisciplinary research into all types of aquatic ecosystems in Antarctica, a network of international

Hickman, Mark

246

TROPOSPHERIC CLOUDS IN ANTARCTICA David H. Bromwich,1,2  

E-print Network

TROPOSPHERIC CLOUDS IN ANTARCTICA David H. Bromwich,1,2 Julien P. Nicolas,1,2 Keith M. Hines,1 regions, little is known about clouds in Antarctica. This arises in part from the challenging deployment, and aerosol concentrations found in Antarctica create unique conditions for cloud for- mation that greatly

Howat, Ian M.

247

A BARREL of fun in AntARcticA  

E-print Network

A BARREL of fun in AntARcticA National Aeronautics and Space Administration www.nasa.gov Volume 10 balloon scientists, are having a BARREL of fun in Antarctica. The Balloon Array for Radiation belt--to launch over Antarctica. The balloon-borne instruments will gather data on magnetic systems and send

Christian, Eric

248

HYDROLOGIC PROCESSES INFLUENCING STREAMFLOW VARIATION IN FRYXELL BASIN, ANTARCTICA  

E-print Network

HYDROLOGIC PROCESSES INFLUENCING STREAMFLOW VARIATION IN FRYXELL BASIN, ANTARCTICA Peter of southern Victoria Land, Antarctica is a large polar desert located along the west coast of the Ross Sea Union 93 #12;ECOSYSTEM DYNAMICS IN A POLAR DESERT: THE MCMURDO DRY VALLEYS, ANTARCTICA94 alluvium

MacDonald, Lee

249

Space analogue studies in Antarctica  

NASA Astrophysics Data System (ADS)

Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mltogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

Lugg, D.; Shepanek, M.

1999-09-01

250

Space analogue studies in Antarctica  

NASA Technical Reports Server (NTRS)

Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mitogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

Lugg, D.; Shepanek, M.

1999-01-01

251

Concentration of trace inorganic species in surface snow along the route to Dome Fuji, Antarctica  

NASA Astrophysics Data System (ADS)

In the southern hemisphere, especially Antarctica, it is considered that ocean and stratosphere are major sources of halogen species. However, there is little data about halogen species contained in snow and ice in Antarctica. In this research, trace inorganic species (Br, Cl, F, I) in Antarctica snow were analyzed. The snow samples were collected along ca. 1000 km traverse route from Mikaeridai (S16; 69°01'S, 40°03'E, 590 m) to Dome Fuji station (77°19'S, 39°42'E, 3810 m) by the Japan Antarctica research expedition. The snow samples were also collected from a pit dug at Dome Fuji station. Those samples were collected in the 2009/2010 austral summer. The samples were transported to Japan without thawing. The quantitative analyses of elements were performed using an ion chromatograph mass spectrometer (IC-MS) and a quadrupole type inductively-coupled plasma mass spectrometer (ICP-MS). The IC-MS system consists of a single quadrupole type mass spectrometer (Agilent Technologies 6150) connected to an ion chromatograph (Dionex ICS-2000). 14 anion species including halogen species (Br-, BrO3-, CH3COO-, CH3SO3-, Cl-, C2O42-, F-, HCOO-, I-, IO3-, NO2-, NO3-, PO43-, SO42-) were analyzed by this system. The maximum concentration of Br- and I- was observed around 71°S and near 74°S on the traverse route. Average concentrations and maximum concentration of Br- were 0.2 ng/ml and 0.4 ng/ml, respectively. Average concentrations and maximum concentration of I- were 0.05 ng/ml and 0.3 ng/ml, respectively. Further results and discussion about the behavior and origin of halogen ion species in snow will be presented.

Hirabayashi, M.; Motoyama, H.

2013-12-01

252

Anthropogenic impacts on marine ecosystems in Antarctica.  

PubMed

Antarctica is the most isolated continent on Earth, but it has not escaped the negative impacts of human activity. The unique marine ecosystems of Antarctica and their endemic faunas are affected on local and regional scales by overharvesting, pollution, and the introduction of alien species. Global climate change is also having deleterious impacts: rising sea temperatures and ocean acidification already threaten benthic and pelagic food webs. The Antarctic Treaty System can address local- to regional-scale impacts, but it does not have purview over the global problems that impinge on Antarctica, such as emissions of greenhouse gases. Failure to address human impacts simultaneously at all scales will lead to the degradation of Antarctic marine ecosystems and the homogenization of their composition, structure, and processes with marine ecosystems elsewhere. PMID:21449967

Aronson, Richard B; Thatje, Sven; McClintock, James B; Hughes, Kevin A

2011-03-01

253

Atmospheric trace gas studies in Antarctica  

SciTech Connect

This paper overviews trace gas studies that were carried out in Antarctica, with an emphasis on those by the Washingon State University Laboratory for Atmospheric Research. The results of trend analysis revealed that, although the atmospheric concentrations of F-11, F-12, CH3CCl3, and other halocarbons are still increasing, their rate of increase has slowed from the increasing rates observed in the 1970s. Vertical concentration profiles in Antarctica are shown to be dependent upon the seasonal variations in circulation patterns associated with the final warming and breakup of the polar vortex. It is shown that the stratospheric-tropospheric air exchange over Antarctica is influenced primarily by the following factors: (1) general circulation patterns with subsidence over the polar regions, (2) stratospheric air injection in the vicinity of jet streams and injection from tropopause folding upstream of troughs, and (3) mountain waves of sufficient magnitude to displace air parcels across the tropopause. 120 references.

Cronn, D.R.; Schilling, K.J.

1988-08-01

254

Radarsat survey provides accurate map of Antarctica  

NASA Astrophysics Data System (ADS)

Explorers of Antarctica have trudged with dog sleds, wintered in boats trapped in ice, and daringly flown across the coldest, windiest, highest, driest, and most desolate continental expanse. Their names are legendary: Ross, Scott, Amundsen, Byrd. And now add Radarsat.Taking about 5,500 microwave images over 18 days—from September 26 through October 14—a synthetic aperture radar (SAR) on this Earth-orbiting satellite completed the first-ever, real-time and high-resolution radar survey of Antarctica last week. The Canadian Space Agency (CSA) satellite, orbiting 800 km above Antarctica, accomplished this task by performing an unusual 180° yaw, or rotational maneuver, for NASA and the National Oceanic and Atmospheric Administration (NOAA).

Showstack, Randy

255

by Hugh Casey Independent  

E-print Network

, which was built with both Russ- ian and IPP funds. Gas turbine disks for Russian aircraft a private sector. Consequently, thousands of scientists skilled in the various as- pects of weapons) addresses the threat of "brain drain" by engaging weapons scientists from the New Inde- pendent States (NIS

256

Casey Griffith Professor Kachroo  

E-print Network

fan through the use of the Arduino microcontroller/unit. Using a six hour per night sleep average, I, the transistor and the Arduino unit. By constructing the fan's circuit first, next incorporating the relay, then adding the transistor and, finally, programming and connecting the Arduino board, I greatly reduced

Kachroo, Pushkin

257

Biographical Sketch CASEY BROWN  

E-print Network

on adaptation to climate change and will involve undergraduate students and K12 students in a 4H program on STEM on Water Systems Planning under Climate Change and founding chair of the AGU Hydrology Section Technical, International Research Institute for Climate and Society, Columbia University, August 2005 to August 2008

Mountziaris, T. J.

258

Antarctica: Challenging Forecasts for a Challenging Environment  

NSDL National Science Digital Library

Antarctica: Challenging Forecasts for a Challenging Environment features two educational pieces. The first is the overview giving the general audience a broad look at Antarctica including some history, interesting facts, real-life experiences, climate, and the challenges inherent to this frozen continent. The second is the main presentation where experts in Antarctic research and forecasting, share their knowledge of the continent. They discuss forecasting challenges as well as present and future research topics while providing elaborations on the uniqueness in Antarcticaâs location, topography, and forecasting techniques as compared to other parts of the globe.

Comet

2007-08-14

259

Sensible and latent heat flux estimates in Antarctica  

NASA Technical Reports Server (NTRS)

The assumption has been made that the net annual contribution of water by the processes of deposition and sublimation to the Antarctic Ice Sheet is zero. The U.S. Antarctic Program started installing reliable automatic weather stations on the Antarctic Continent in 1980. The initial units were equipped to measure wind speed, wind direction, air pressure, and air temperature. During the 1983-1984 field season in Antarctica, three units were installed that measured a vertical air temperature difference between the nominal heights of 0.5 m and 3.0 m and relative humidity at a nominal height of 3 m. The measurements of the vertical air temperature difference and the relative humidity are the minimum required to estimate the sensible and latent heat fluxes to the air, while not exceeding the available energy requirements for the weather stations. The estimates of the net annual sublimation and deposition on the Ross Ice Shelf amount to 20 to 80 percent of the annual accumulation. We conclude that the assumption that annual sublimation and deposition are zero is not valid under Antarctic conditions.

Stearns, Charles R.; Weidner, George A.

1993-01-01

260

Meteorological Data for the Astronomical Site at Dome A, Antarctica  

NASA Astrophysics Data System (ADS)

We present an analysis of the meteorological data collected at Dome A, Antarctica by the Kunlun Automated Weather Station, including temperatures and wind speeds at eight elevations above the snow surface between 0 m and 14.5 m. The average temperatures at 2 m and 14.5 m are -54°C and -46°C, respectively. We find that a strong temperature inversion existed at all heights for more than 70% of the time, and the temperature inversion typically lasts longer than 25 hr, indicating an extremely stable atmosphere. The temperature gradient is larger at lower elevations than at higher elevations. The average wind speed was 1.5 m s-1 at 4 m elevation. We find that the temperature inversion is stronger when the wind speed is lower, and the temperature gradient decreases sharply at a specific wind speed for each elevation. The strong temperature inversion and low wind speed result in a shallow and stable boundary layer with weak atmospheric turbulence above it, suggesting that Dome A should be an excellent site for astronomical observations. All the data from the weather station are available for download.

Hu, Yi; Shang, Zhaohui; Ashley, Michael C. B.; Bonner, Colin S.; Hu, Keliang; Liu, Qiang; Li, Yuansheng; Ma, Bin; Wang, Lifan; Wen, Haikun

2014-11-01

261

Mapping Sediment Contamination and Toxicity in Winter Quarters Bay, Antarctica  

SciTech Connect

Winter Quarters Bay (WQB) is a small embayment located adjacent to McMurdo Station, the largest researchbase in Antarctica. The bay is approximately 250 m wide andlong, with a maximum depth of 33 m. Historically, trashfrom the McMurdo Station was piled on the steep shoreline ofWQB, doused with fuel and ignited. That practice hasceased, and the adjacent land area has been regraded tocover the residual waste. The bottom of WQB remainslittered with drums, equipment, tanks, tires, cables, andother objects, especially the southeastern side of the baywhere dumping took place. Sediments are contaminated withPCBs, metals, and hydrocarbon fuels. The objectives of this study were to map the distributionof organic contaminants in WQB, assess the toxicity of WQB sediments using a simple microbial test, anddetermine correlations between toxicity and contaminantlevels. The study suggests that adverse ecological effectshave occurred from one or more of the contaminants found inWQB but the source of the toxic impacts to bay sedimentsremains unknown. Whole sediment toxicity was onlycorrelated with oil-equivalent while solvent extracts ofsediments were correlated with PAHs and oil-equivalent. Theauthors recommend that an integrated research plan bedeveloped that focuses on determining what additionalinformation is needed to make informed decisions on possibleremediation of WQB.

White, Gregory J; Crockett, Alan Bronson

2003-07-01

262

The BESS-Polar II Long Duration Flight above Antarctica  

NASA Astrophysics Data System (ADS)

The Balloon-borne Experiment with a Superconducting Spectrometer, BESS, has been developed to study elementary particle phenomena in the early universe through measurements of low energy antiprotons to investigate their origin and through a search for antihelium. The BESS collaboration carried out nine northern latitude flights between 1993 and 2002. BESS- Polar is an advanced program of the BESS collaboration to study these topics with much greater precision using long duration flights above Antarctica. The BESS-Polar spectrometer was successfully developed to accumulate much larger numbers of events during long duration flights around the South Pole. Approximately a factor of four reductions in the amount of material in the particle beam enables measurement of much lower energy antiprotons down to 100 MeV (at top of atmosphere). The first BESS-Polar flight (BESS-Polar I) of 8.5 days was carried out above Antarctica in December 2004, recording 900 million cosmic-ray events. The second BESS-Polar flight (BESS-Polar II) was successfully carried out in the austral summer season of 2007-2008. Based on experience with BESS-Polar I, the spectrometer was improved in performance and achieved long term stability during the flight. A newly constructed magnet with a larger liquid He capacity and improved thermal insulation and an upgraded data storage system with larger capacity of hard disk drives (HDDs) enabled longer observation time. BESS-Polar II was launched on December 22, 2007 from Williams Field, McMurdo Station, in Antarctica. The spectrometer worked properly and observed cosmic rays for about 24.5 days at float altitude, recording 4.6 billion events on the HDDs until the limit of the magnet operation was reached on January 16, 2008. The flight was terminated and the spectrometer was safely landed on the West Antarctic ice sheet ( 1000 km from the South Pole) on January 21, 2008. Here, the BESS-Polar instrument is discussed, highlighting improvements made for BESS-Polar II, and overviews of the flight and performance are reported.

Sasaki, Makoto

263

Polar stratospheric clouds statistics and climatological analysis over a 9 years period at McMurdo, Antarctica  

Microsoft Academic Search

All year around measurements on Polar Stratospheric Clouds(PSCs)have been taken at McMurdo station,the American base in Antarctica,since 1993 until 2001. A statistical analysis and climatology of PSC events has been performed by a numerical code application in order to discriminate between synoptic PSCs (generated by extended low temperatures fields) and mesoscale PSCs (locally induced by lee waves), often observed above

P. Massoli; A. Adriani; G. di Donfrancesco; M. L. Moriconi; M. Snels

2003-01-01

264

From Antarctica to space: use of telepresence and virtual reality in control of a remote underwater vehicle  

Microsoft Academic Search

We describe an experiment which simulated many aspects of control of a remote vehicle on another planetary surface. We have developed a Telepresence-controlled Remotely Operated underwater Vehicle (TROV) and used it to perform scientific exploration in an ice-covered marine environment near McMurdo Station, Antarctica. The goal of the mission was to use telepresence and virtual reality technology to operate a

Carol R. Stoker

1995-01-01

265

Validation of EOS Aqua AMSR Sea Ice Products for East Antarctica  

NASA Technical Reports Server (NTRS)

This paper presents results from AMSR-E validation activities during a collaborative international cruise onboard the RV Aurora Australis to the East Antarctic sea ice zone (64-65 deg.S, 110-120 deg.E) in the early Austral spring of 2003. The validation strategy entailed an IS-day survey of the statistical characteristics of sea ice and snowcover over a Lagrangian grid 100 x 50 km in size (demarcated by 9 drifting ice beacons) i.e. at a scale representative of Ah4SR pixels. Ice conditions ranged h m consolidated first-year ice to a large polynya offshore from Casey Base. Data sets collected include: snow depth and snow-ice interface temperatures on 24 (?) randomly-selected floes in grid cells within a 10 x 50 km area (using helicopters); detailed snow and ice measurements at 13 dedicated ice stations, one of which lasted for 4 days; time-series measurements of snow temperature and thickness at selected sites; 8 aerial photography and thermal-IR radiometer flights; other satellite products (SAR, AVHRR, MODIS, MISR, ASTER and Envisat MERIS); ice drift data; and ancillary meteorological (ship-based, meteorological buoys, twice-daily radiosondes). These data are applied to a validation of standard AMSR-E ice concentration, snowcover thickness and ice-temperature products. In addition, a validation is carried out of ice-surface skin temperature products h m the NOAA AVHRR and EOS MODIS datasets.

Massom, Rob; Lytle, Vicky; Allison, Ian; Worby, Tony; Markus, Thorsten; Scambos, Ted; Haran, Terry; Enomoto, Hiro; Tateyama, Kazu; Pfaffling, Andi

2004-01-01

266

Depth to Magnetic ‘Basement’ in West Antarctica  

Microsoft Academic Search

The results of aero.magnetic flights in a portion of West Antarctica are pre- sented and discussed. On the basis of short-wavelength magnetic anomalies, Byrd basin is shown to represent a geologic boundary. Depth determinations to anomaly sources show the absence of a thick sedimentary rock section within and to the north and west of Byrd basin and suggest a probable

John C. Behrendt; R. J. Wold

1963-01-01

267

Glacial Earthquakes in Greenland and Antarctica  

E-print Network

Glacial Earthquakes in Greenland and Antarctica Meredith Nettles and G¨oran Ekstr¨om Lamont Glacial earthquakes are a new class of seismic events, first discovered as signals in long of Greenland, where they are spatially related to large outlet glaciers. Glacial earthquakes show a strong

Jellinek, Mark

268

Digital Satellite Image Mapping of Antarctica  

Microsoft Academic Search

Summary: It ts current practice to usc gcodctic control for thc rcctification and absolute oricntation of digitally rccorded satcllite imagc data. In Antarctica this control regularly can bc rcprcsented by nunataks or orher stationarytopographie fcatures. Howcver. normally we lack sufficicnt ground control. Fixed points are orten dcrennined in various. independcnt coordinatc systems. Vast areas containing no control at all have

Jörn Sievers; Andreas Grindel; Willi Meier

269

Hydrogen emissions from Erebus volcano, Antarctica  

E-print Network

Hydrogen emissions from Erebus volcano, Antarctica Yves Moussallam1 , Clive Oppenheimer1, 2, 3 of molecular hydrogen (H2) emissions from passively degassing volcanoes has recently been made possible using with SO2, H2O and CO2, in the gas and aerosol plume emitted from the phonolite lava lake at Erebus volcano

Paris-Sud XI, Université de

270

Antarctica: As seismic as other plates  

Microsoft Academic Search

Antarctica shakes, rattles, and rolls just as much as other slow-moving plates. Emile Okal, a Yale University seismologist, told colleagues at the AGU Fall Meeting that although the Antarctic plate is not moving across the earth as fast as other continents, it has a seismicity similar to other plates. His findings refute the claim that a ring of spreading ridges

Barbara T. Richman

1981-01-01

271

Antarctica's role in global change research examined  

Microsoft Academic Search

The greatest discoveries about Antarctica's late Mesozoic and Cenozoic geologic history have been made since the International Geophysical Year in 1957. These discoveries were made by Earth scientists who conduct research in many countries under their National Antarctic Programs, which in turn follow the broad science guidelines recommended by the Scientific Committee on Antarctic Research (SCAR). SCAR has many subgroups

Peter-Noel Webb; Alan K. Cooper

1998-01-01

272

Antarctica: Is It More Than Just Ice?  

ERIC Educational Resources Information Center

The authors introduced polar science in a fourth-grade classroom by means of 3 hands-on activities that addressed (1) the melting of glaciers and ice, (2) the differences between the North and the South Pole, and (3) the geography and landforms of Antarctica. An assessment 4 months after the original activity showed that students remembered the…

Johnson, Cheryl; Gutierrez, Melida

2009-01-01

273

Groenlandaspis in Antarctica, Australia and Europe  

Microsoft Academic Search

Groenlandaspis is a member of the Arthrodira, a group of Devonian armoured fishes. In the past Groenlandaspis has been found only in eastern Greenland but now Alexander Ritchie has recognised at least six species from sites in Greenland, Europe, Australia and Antarctica. His account demonstrates that these arthrodires enjoyed a very wide geographical distribution during the Upper Devonian and that

Alexander Ritchie

1975-01-01

274

Antarctica--the Ultimate Summer Institute.  

ERIC Educational Resources Information Center

Describes personal experiences of a participant in the National Science Foundation program, Teachers Experiencing Antarctica. Uses the study of the temperature history of Taylor Dome to provide teachers with the experience of research and help other teachers recognize that there are opportunities outside the classroom for personal and professional…

Van Wey, Nate J.

1995-01-01

275

CyberHunt: Head Off to Antarctica.  

ERIC Educational Resources Information Center

Explains how to take an elementary class on a cyber visit to the continent of Antarctica, the highest, driest, and coldest continent on earth. A student reproducible page presents eight web sites to visit in this quest as well as questions to answer about each site. Answers to the questions are included. (SM)

Kloza, Brad

2001-01-01

276

Antarctica: What Shall We Do with It?  

ERIC Educational Resources Information Center

Describes a role playing exercise in which students act as delegates to a meeting at which they will revise the Antarctic Treaty. Background information is presented about Antarctica, the Antarctic Treaty, and positions of 19 nations with regard to the Treaty. (Author/DB)

Branson, Margaret S.; Long, Cathryn J.

1977-01-01

277

Video podcasts as a long-distance outreach tool: Polar science from Byrd Camp, West Antarctica  

NASA Astrophysics Data System (ADS)

Video Podcasts offer a unique opportunity to actively engage the public in ongoing research projects by revealing faces and stories from field, lab and engineering efforts that often happen behind the scenes. Podcasts thus allow the science community to not only present their accomplishments, but also the where, how and why. Publishing these videos in real time while stationed at remote field camps brings particular challenges to the process. This was the case during the POLNET (Polar Earth Observing Network) field seasons at Byrd Camp, West Antarctica. With no internet connection and limited flights in and out of camp, the team worked to produce a series of Video Podcast field updates that were flown to McMurdo Station and uploaded to a web server off the continent. These videos provided glimpses of living and working on a remote ice sheet while installing GPS and seismic stations. At a time when climate science is under extreme scrutiny, this project offered a tangible and human view of efforts to model how ice masses are changing. In any science education effort, the risk of diluting the science until it is no longer meaningful poses certain challenges. At the same time, going into great depth about the methods and theories using technical vocabulary can immediately turn away an audience that is already inundated with information. These videos represent an attempt to creatively and accurately present scientific concepts in short, digestible segments that bring elements of fun from the unique field setting and personalities of Byrd Camp, West Antarctica.

Berg, M.; Science; Engineering Team Of Polenet Field Seasons 2009-10; 2010-11

2011-12-01

278

A re-consideration of the taxonomic status of Nebria lacustris Casey (Coleoptera, Carabidae, Nebriini) based on multiple datasets - a single species or a species complex?  

PubMed Central

Abstract This study gathered evidence from principal component analysis (PCA) of morphometric data and molecular analyses of nucleotide sequence data for four nuclear genes (28S, TpI, CAD1, and Wg) and two mitochondrial genes (COI and 16S), using parsimony, maximum likelihood, and Bayesian methods. This evidence was combined with morphological and chorological data to re-evaluate the taxonomic status of Nebria lacustris Casey sensu lato. PCA demonstrated that both body size and one conspicuous aspect of pronotal shape vary simultaneously with elevation, latitude, and longitude and served to distinguish populations from the southern Appalachian highlands, south of the French Broad, from all other populations. Molecular analyses revealed surprisingly low overall genetic diversity within Nebria lacustris sensu lato, with only 0.39% of 4605 bp varied in the concatenated dataset. Evaluation of patterns observed in morphological and genetic variation and distribution led to the following taxonomic conclusions: (1) Nebria lacustris Casey and Nebria bellorum Kavanaugh should be considered distinct species, which is a NEW STATUS for Nebria bellorum. (2) No other distinct taxonomic subunits could be distinguished with the evidence at hand, but samples from northeastern Iowa, in part of the region known as the “Driftless Zone”, have unique genetic markers for two genes that hint at descent from a local population surviving at least the last glacial advance. (3) No morphometric or molecular evidence supports taxonomic distinction between lowland populations on the shores of Lake Champlain and upland populations in the adjacent Green Mountains of Vermont, despite evident size and pronotal shape differences between many of their members. PMID:22379387

Kavanaugh, David H.; Archambeault, Sophie L.; Roopnarine, Peter D.; Ledford, Joel

2011-01-01

279

Multiple meteoroid impact in Antarctica  

NASA Astrophysics Data System (ADS)

In the late 1950's, geophysical field parties undertaking gravity surveys across Antarctica observed over a large area of Wilkes Land (> 240km across) an exceptionally pronounced negative free air anomaly ((to -158.3 mgal). This area was later interpreted as a possible meteor impact site because the gravity profiles were similar to those of known impact sites (apparent rim structures, circular basins, central peaks or rings), they possessed appropriate aspect ratios (e.g., crater diameter vs crater depth), anomalously steep negative free air gravity anomaly gradients (to 4.71 mgal/km) were characteristic of impact craters and uncharacteristic of solely mantle-related or geologic crustal variations, etc. The condition of the ice covering the anomaly (heavily crevassed), the apparent lack of isostatic compensation with surrounding environs, etc suggested the impact was geologically recent and that perhaps a tektite strewn field was associated with it. The distance from the postulated impact to the Australian strewn field was appropriate as are the ages of the tektites there. This early work has been augmented with the detection of a dominant cluster of negative free air gravity anomalies crossing the continental-oceanic boundary, and the East and West Antarctic structural boundary (i.e., Transantarctic Mountains). These anomalies are coincident with complex subglacial craterform topographic features inferred from radiosounding (to -500m below MSL). The major interior positive free air gravity anomalies are associated with subglacial topographic highs. The elliptical distribution of the negative gravity anomalies resemble known multiple impact distributions (scatter ellipses with the larger anomalies forward and the lesser ones aft). This more recent information favors expanding the original proposal to that of a multiple meteoroid impact. The multiple impact hypotheses would explain aeromagnetic surveys revealing ring-shaped structures in the subglacial rock surface much like those of known impact structures (the magnetic anomalies are unusual in magnitude themselves: amplitudes to 3600nT for sensors at 3.5 km elevation). Deviations from this topography can be attributed to glacial scour. Certainly glacial surging should accompany such an impact. The distribution of the apparent impact structures extends beyond the original discovery and on the basis of negative free air anomalies, into the Wilkes Subglacial Basin to the south, athwart the Transantarctic Mountains and into the Ross Embayment to the east. No multiple impact sites of comparable size on Earth have been reported. The above suggestions have been augmented by recent work on cores taken from the Ross Sea which has revealed the presence of material of high magnetic susceptibility often taken as an indicator of meteor impact and tektites. The age of this material is placed in the Late Pliocene. The oldest ages reported for meteorites collected from the Antarctic Blue Ice is ca. 700,000y.

Weihoupt, J. W.; Rice, A.; van der Hoeven, F.

2006-12-01

280

Seismic monitoring at Deception Island volcano (Antarctica): Recent advances  

NASA Astrophysics Data System (ADS)

Deception Island (South Shetland Island, Antarctica) is an active volcano with recent eruptions (e.g. 1967, 1969 and 1970). It is also among the Antarctic sites most visited by tourists. Besides, there are currently two scientific bases operating during the austral summers, usually from late November to early March. For these reasons it is necessary to deploy a volcano monitoring system as complete as possible, designed specifically to endure the extreme conditions of the volcanic environment and the Antarctic climate. The Instituto Andaluz de Geofísica of University of Granada, Spain (IAG-UGR) performs seismic monitoring on Deception Island since 1994 during austral summer surveys. The seismicity basically includes volcano-tectonic earthquakes, long-period events and volcanic tremor, among other signals. The level of seismicity is moderate, except for a seismo-volcanic crisis in 1999. The seismic monitoring system has evolved during these years, following the trends of the technological developments and software improvements. Recent advances have been mainly focused on: (1) the improvement of the seismic network introducing broadband stations and 24-bit data acquisition systems; (2) the development of a short-period seismic array, with a 12-channel, 24-bit data acquisition system; (3) the implementation of wireless data transmission from the network stations and also from the seismic array to a recording center, allowing for real-time monitoring; (4) the efficiency of the power supply systems and the monitoring of the battery levels and power consumption; (5) the optimization of data analysis procedures, including database management, automated event recognition tools for the identification and classification of seismo-volcanic signals, and apparent slowness vector estimates using seismic array data; (6) the deployment of permanent seismic stations and the transmission of data during the winter using a satellite connection. A single permanent station is operating at Deception Island since 2008. In the current survey we collaborate with the Spanish Army to add another permanent station that will be able to send to the IAG-UGR seismic information about the activity of the volcano during the winter, using a communications satellite (SPAINSAT). These advances simplify the field work and the data acquisition procedures, and allow us to obtain high-quality seismic data in real-time. These improvements have a very important significance for a better and faster interpretation of the seismo-volcanic activity and assessment of the volcanic hazards at Deception Island volcano.

Carmona, E.; Almendros, J.; Martín, R.; Cortés, G.; Alguacil, G.; Moreno, J.; Martín, B.; Martos, A.; Serrano, I.; Stich, D.; Ibáñez, J. M.

2012-04-01

281

Sensible heat exchange at the Antarctic snow surface: a study with automatic weather stations  

Microsoft Academic Search

Data of four automatic weather stations (AWSs) are used to calculate the turbulent exchange of sensible heat at the Antarctic snow surface for a 4 year period (1998-2001). The AWSs are situated on the ice shelf, in the coastal\\/inland katabatic wind zone and on the interior plateau in Dronning Maud Land, East Antarctica. Sensible heat flux (SHF) is calculated using

Michiel van den Broeke; Dirk van As; Carleen Reijmer; Roderik van de Wal

2005-01-01

282

Planetary geomorphology field studies: Iceland and Antarctica  

NASA Technical Reports Server (NTRS)

Field studies of terrestrial landforms and the processes that shape them provide new directions to the study of planetary features. These studies, conducted in Iceland and in Antarctica, investigated physical and chemical weathering mechanisms and rates, eolitan processes, mudflow phenomena, drainage development, and catastrophic fluvial and volcanic phenomena. Continuing investigations in Iceland fall in three main catagories: (1) catastrophic floods of the Jokulsa a Fjollum, (2) lahars associated with explosive volcanic eruptions of Askja caldera, and (3) rates of eolian abrasion in cold, volcanic deserts. The ice-free valleys of Antarctica, in particular those in South Victoria Land, have much is common with the surface of Mars. In addition to providing independent support for the application of the Iceland findings to consideration of the martian erosional system, the Antarctic observations also provide analogies to other martian phenomena. For example, a family of sand dunes in Victoria Valley are stabilized by the incorporation of snow as beds.

Malin, M. C.

1984-01-01

283

Norwegian-United States IPY Science Traverse in East Antarctica: Route Planning and Firn Temperature Investigation  

NASA Astrophysics Data System (ADS)

In austral summers of 2007-2008 and 2008-2009, Norway and the United States will conduct a collaborative traverse in Dronning Maud Land, East Antarctica. The objective of the traverse is to obtain field measurements (ice cores, snow pits, AWS's, firn temperatures, GPR profiling) that will aid us in advancing our understanding of climate variability of a vast yet under-explored sector of Antarctica and its roll in the global climate system. University of Colorado will assist the traverse route planning using remote sensing and conduct a study of multi-decadal scale climate change using firn temperature measurements. In the first season, the traverse will leave from Norwegian Troll Station (72° S, 2.5° E), and end at Amundsen-Scott Station at the South Pole, visiting Plateau (72.3° S, 40.5° E) and Pole of Inaccessibility (83.8° S, 65.8° E), sites of now abandoned stations. The first-season traverse will connect these four locations, the distance totaling to about 2500 km. Second-season traverse, from South Pole to Troll, will take a different route near the western edge of the Dronning Maud Land. The duration of both traverses is around 80 days including stops for ice coring and setting up AWS's etc. Details of routes and sites of scientific tasks are decided upon examinations of MOA (Mosaic of Antarctica) and RAMP (Radarsat Antarctic Mapping Project) images. Megadune fields and blue ice areas are identified in images that are of interest for studies of snow accumulation variations and interaction of local topography with the atmosphere. The firn temperature investigation aims at obtaining reliable surface temperature trend in multi-decadal to century scale in the interior of Antarctica. Our approach is to monitor temperature changes at several discrete depths in the firn over an extended period of time. This provides a time-series of the borehole temperature profile. Simulations by simple heat transfer model with artificial surface temperature history show that the trend of several tens of degrees (~0.5° C) per century is detectable with well-calibrated PRT's (Platinum Resistance Thermometers) placed at the depth of around 50 ~ 60 m and monitored over 1 ~ 2 years. Further, careful monitoring of intermediate depths (10 ~ 30 m) will help to discriminate between inter-annual to decadal scale variations and longer-term trends. We will set up at least four automated firn temperature recording systems with 10 to 12 PRT's distributed over the upper 50 to 60 m in the firn, together with standard AWS data at sites. Data will be transmitted multiple times per day by a satellite system (ARGOS).

Muto, A.; Scambos, T.

2006-12-01

284

THE GENUS SARCOGYNE ( ACAROSPORACEAE ) IN ANTARCTICA  

Microsoft Academic Search

Sarcogyne angulosaC. W. Dodge & G. E. Baker, described as an endemic from continental Antarctic localities, is reduced to synonymy withS. privigna(Ach.) A. Massal., a species known from Europe, North America, North Africa and Saudi Arabia, and now Antarctica. The relationship to Polysporina simplex (Davies) V|$$|Ahezda is discussed. It is suggested that the nameSarcogyne griseaDodge, also described as an Antarctic

R. D. SEPPELT; P. L. NIMIS; M. CASTELLO

1998-01-01

285

Radarsat survey provides accurate map of Antarctica  

Microsoft Academic Search

Explorers of Antarctica have trudged with dog sleds, wintered in boats trapped in ice, and daringly flown across the coldest, windiest, highest, driest, and most desolate continental expanse. Their names are legendary: Ross, Scott, Amundsen, Byrd. And now add Radarsat.Taking about 5,500 microwave images over 18 days---from September 26 through October 14---a synthetic aperture radar (SAR) on this Earth-orbiting satellite

Randy Showstack

1997-01-01

286

PERSPECTIVE How committed are we to monitoring human impacts in Antarctica?  

NASA Astrophysics Data System (ADS)

Under the Antarctic Treaty System, environmental monitoring is a legal obligation for signatory nations and an essential tool for managers attempting to minimize local human impacts, but is it given the importance it merits? Antarctica is a vast frozen continent with an area around 1.5 times that of Europe (14 000 000 km2), but the majority of its terrestrial life is found on multiple outcrops or 'islands' of ice-free coastal ground, with a combined area of ~6000 km2, equivalent to four times that of Greater London (Tin et al 2009). The biological communities of these ice-free terrestrial habitats are dominated by a small number of biological groups, primarily mosses, lichens, microinvertebrates and microorganisms. They include many endemic species, while birds and marine mammals use coastal areas as breeding sites (Chown and Convey 2007). Figure 1 Figure 1. Map of the Antarctic Treaty area (south of latitude 60°S) showing the locations of year-round and seasonal stations built on rock or permanent ice (i.e. ice sheets or ice shelves). Data on station locations were taken from the Council of Managers of National Antarctic Programs website (COMNAP 2010). There is evidence to suggest that although these stations are registered on the COMNAP list, a number of stations are not regularly occupied or in use (see United Kingdom et al 2006, p 9). Since the influx of national scientific research programmes and infrastructure that accompanied the International Geophysical Year (1957-1958), Antarctica's habitats have been encroached upon increasingly by human activities. Over 120 research stations have been built (~75 currently operational) with the great majority located on ice-free coastal ground to allow ease of access by ship. (Headland 2009, COMNAP 2010). Construction of cargo and personnel landing and handling facilities, station buildings, airport infrastructure, roads and fuel storage areas have, to varying degrees, destroyed native vegetation and terrestrial fauna and displaced bird and marine mammals from breeding sites in their immediate environment. An early history of poor environmental management and waste disposal practices around many stations has left a legacy of fuel-contaminated ground and abandoned waste sites in adjacent marine and terrestrial environments (Tin et al 2009). Construction of research stations and other infrastructure fulfils two national objectives: (1) supporting geopolitical aspirations of claimant nations and (2) demonstrating a significant commitment to undertaking science in Antarctica, which is a prerequisite for attaining consultative status at the Antarctic Treaty Consultative Meeting. However, these objectives may not be supported equally, with little or no science performed routinely at some stations (United Kingdom et al 2006). In addition, co-ordination of science activities between nations—another aspiration under the Antarctic Treaty—is often lacking, leading to duplication of research between national programmes, and even that undertaken at nearby stations. In some cases, components of national research programmes lack any international, open or objective assessment of quality. Nevertheless, new nations continue to become involved in Antarctic affairs, and almost inevitably seek to establish their own infrastructure, while some established Treaty Parties continue to further expand their existing logistic and infrastructure footprints. Despite calls for nations to share existing infrastructure or reuse abandoned stations (ATCM 2006), new stations continue to be constructed on pristine sites, with the Antarctic terrestrial environment in particular coming under increased pressure. The Protocol on Environmental Protection to the Antarctic Treaty (commonly known as the Environmental Protocol), which came into force in 1998, sets out common minimum standards for environmental management by all Antarctic Treaty Parties. Under the Protocol, it is mandatory to regularly monitor the environmental impacts caused by any new infrastructure that requires the completion of a Comprehensive E

Hughes, Kevin A.

2010-12-01

287

A New 15-year Multisite AWS Temperature and Pressure Record for West Antarctica  

NASA Astrophysics Data System (ADS)

Improved interpretation of the ever growing body of ice-core-based paleoclimate records from Antarctica requires a deeper understanding of Antarctic meteorology. New field campaigns and improved numerical forecasting models will ultimately provide long-term benefits but neither addresses the existing observational archive. In contrast, our work with automatic weather station (AWS) data addresses this issue directly. AWS currently provide the only year-round, continuous direct measurements of weather on the ice sheet. As the spatial coverage of the network has expanded year to year (thanks to C. Stearns and his University of Wisconsin AWS group), so has our meteorological database. Unfortunately, many of the records are relatively short and/or incomplete due to the vagaries of the harsh environment and station relocations. This reduces their usefulness for climatological studies. Building on climate downscaling results in temperate latitudes we have used GCM-scale meteorological data sets (e.g., ECMWF reanalysis products) to both fill the gaps in AWS records and extend them back in time to create a uniform and complete database of West Antarctic surface meteorology at selected AWS. Such records are highly relevant to the improved interpretation of the expanding library of snow-pit and ice-core data sets. Our solution uses artificial neural network (ANN) techniques to predict the near-surface meteorology recorded by AWS instruments (e.g., temperature) using large-scale features of the atmosphere (e.g., 500 mb geopotential height) from a region around the AWS. ANNs are trained to predict observed AWS data from the corresponding GCM-scale data. Intrayear prediction (of observations in the training year) has been very successful (e.g., RMS errors < 2 mbar). Interyear prediction (of observations not in the training year) are acceptable but open to improvement from further refinements in methodology. Our methodology has thus far been applied to five AWS on a transect spanning West Antarctica from the Ross Island area (Ferrell) to the Bellingshausen Sea region (Siple Station) for the period 1979-1993. EOF analysis of the 15-year temperature records suggests significant (though as yet uninterpreted) differences between the easterly/ice-sheet (Siple Station and Byrd) and westerly/ice-shelf (Lettau, Marilyn, Ferrell) stations. Short-term trends in annual high and low temperatures are also present. These results support high confidence in the ANN-based predictions from ECMWF data for periods where AWS data are unavailable, e.g., before installation. ANNs thus provide a means to expand our surface meteorological records significantly in West Antarctica.

Reusch, D. B.; Alley, R. B.

2002-05-01

288

LiDAR in extreme environment: surveying in Antarctica  

NASA Astrophysics Data System (ADS)

This study was performed under the patronage of the Italian National Research Programme in Antarctica (PNRA) with the aim to realize a high resolution Digital Elevation Model (DEM) of the moraine named "Boulder Clay" which insists approximately 7 km far from the Italian Research Base "Mario Zucchelli Station" in the Terra Nova Bay area. The DEM will be included in the project for the construction of two runways to be used as support facilities for the scientific research campaigns which take place on regular basis each year. Although the research efforts to realize a detailed cartography of the area is on-going, for the specific aim and urgency of this project it was decided to perform a laser scanning survey in this extreme environment in order to obtain contour lines describing the terrain elevation each 50 cm and volume analysis. The final result will be super imposed on a photogrammetric DEM with contour lines each 2.5 m and satellite images. This paper focus both on the final scientific data and on all the challenges have to be faced in such extreme and particular environment during the laser scanning survey.

Abate, D.; Pierattini, S.; Bianchi Fasani, G.

2013-10-01

289

Site testing for submillimetre astronomy at Dome C, Antarctica  

E-print Network

Over the past few years a major effort has been put into the exploration of potential sites for the deployment of submillimetre astronomical facilities. Amongst the most important sites are Dome C and Dome A on the Antarctic Plateau, and the Chajnantor area in Chile. In this context, we report on measurements of the sky opacity at 200 um over a period of three years at the French-Italian station, Concordia, at Dome C, Antarctica. We also present some solutions to the challenges of operating in the harsh polar environ- ment. Dome C offers exceptional conditions in terms of absolute atmospheric transmission and stability for submillimetre astron- omy. Over the austral winter the PWV exhibits long periods during which it is stable and at a very low level (0.1 to 0.3 mm). Higher values (0.2 to 0.8 mm) of PWV are observed during the short summer period. Based on observations over three years, a transmission of around 50% at 350 um is achieved for 75% of the time. The 200-um window opens with a typical transmission...

Tremblin, P; Schneider, N; Durand, G Al; Ashley, M C B; Lawrence, J S; Luong-Van, D M; Storey, J W V; Durand, G An; Reinert, Y; Veyssiere, C; Walter, C; Ade, P; Calisse, P G; Challita, Z; Fossat, E; Sabbatini, L; Pellegrini, A; Ricaud, P; Urban, J

2011-01-01

290

Meteorological data for the astronomical site at Dome A, Antarctica  

E-print Network

We present an analysis of the meteorological data collected at Dome A, Antarctica by the Kunlun Automated Weather Station, including temperatures and wind speeds at eight elevations above the snow surface between 0m and 14.5m. The average temperatures at 2m and 14.5m are $-54^{\\circ}$C and $-46^{\\circ}$C, respectively. We find that a strong temperature inversion existed at all heights for more than 70% of the time, and the temperature inversion typically lasts longer than 25 hours, indicating an extremely stable atmosphere. The temperature gradient is larger at lower elevations than higher elevations. The average wind speed was 1.5m/s at 4m elevation. We find that the temperature inversion is stronger when the wind speed is lower and the temperature gradient decreases sharply at a specific wind speed for each elevation. The strong temperature inversion and low wind speed results in a shallow and stable boundary layer with weak atmospheric turbulence above it, suggesting that Dome A should be an excellent site...

Hu, Yi; Ashley, Michael C B; Bonner, Collin S; Hu, Keliang; Liu, Qiang; Li, Yuansheng; Ma, Bin; Wang, Lifan; Wen, Haikun

2014-01-01

291

Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica.  

USGS Publications Warehouse

In December 1985, an automated meteorological station was established at Lake Hoare in the dry valley region of Antarctica. Here, we report on the first year-round observations available for any site in Taylor Valley. This dataset augments the year-round data obtained at Lake Vanda (Wright Valley) by winter-over crews during the late 1960s and early 1970s. The mean annual solar flux at Lake Hoare was 92 W m-2 during 1986, the mean air temperature -17.3 degrees C, and the mean 3-m wind speed 3.3 m s-1. The local climate is controlled by the wind regime during the 4-month sunless winter and by seasonal and diurnal variations in the incident solar flux during the remainder of the year. Temperature increases of 20 degrees-30 degrees C are frequently observed during the winter due to strong fo??hn winds descending from the Polar Plateau. A model incorporating nonsteady molecular diffusion into Kolmogorov-scale eddies in the interfacial layer and similarity-theory flux-profiles in the surface sublayer, is used to determine the rate of ice sublimation from the acquired meteorological data. Despite the frequent occurrence of strong winter fo??hns, the bulk of the annual ablation occurs during the summer due to elevated temperatures and persistent moderate winds. The annual ablation from Lake Hoare is estimated to have been 35.0 +/- 6.3 cm for 1986.

Clow, G. D.; McKay, C. P.; Simmons, Jr. , G. M.; Wharton, Jr. , R. A.

1988-01-01

292

The local deposition of heavy metal emissions from point sources in Antarctica  

NASA Astrophysics Data System (ADS)

Surface snow samples have been analysed for the heavy metals Cd, Cu, Pb and Zn to investigate the spatial scale of local sources of pollution in Antarctica. Samples from around an isolated petrol generator showed vastly increased levels (up to 800,000 times background) directly under the exhaust. Concentrations fell sharply with distance from the exhaust, reaching background levels at 40 m, even in the downwind direction. Snow was also collected at various distances from a manned scientific station. The data are more difficult to interpret, but the influence of the station could not be detected beyond 10 km. These findings indicate the areas that are influenced by local emissions, and that are therefore unsuitable for air and snow sampling intended to study larger-scale pollution input.

Suttie, E. D.; Wolff, E. W.

293

Anthropogenic and natural disturbances to marine benthic communities in Antarctica  

SciTech Connect

Sampling and field experiments were conducted from 1975 to 1990 to test how the structure of marine benthic communities around McMurdo Station, Antarctica varied with levels of anthropogenic contaminants in marine sediments. The structure of communities (e.g., infauna density, species composition, and life history characteristics) in contaminated and uncontaminated areas were compared with the structure of communities influenced by two large-scale natural disturbances, anchor ice formation and uplift or iceberg scour. Benthic communities changed radically along a steep spatial gradient of anthropogenic hydrocarbon, metal, and PCB contamination around McMurdo Station. The heavily contaminated end of the gradient, Winter Quarters Bay, was low in infaunal and epifaunal abundance and was dominated by a few opportunistic species of polychaete worms. The edge of the heavily contaminated bay, the transition area, contained several motile polychaete species with less opportunistic life histories. Uncontaminated sedimentary habitats harbored dense tube mats of infaunal animals numerically dominated by populations of polychaete worms, crustaceans, and a large suspension feeding bivalve. These species are generally large and relatively sessile, except for several crustacean species living among the tubes. Although the community patterns around anthropogenic and natural disturbances were similar, particularly motile and opportunistic species at heavily disturbed and marginal areas, the natural disturbances cover much greater areas of the sea floor about the entire Antarctic continent. On the other hand, recovery from chemical contamination is likely to take many more decades than recovery from natural disturbances as contaminant degradation is a slow process. 77 refs., 6 figs., 5 tabs.

Lenihan, H.; Oliver, J.S. [Moss Landing Marine Labs., CA (United States)

1995-05-01

294

A Vibroseis Seismic Source for Climate, Ice Sheet and Tectonic Studies in Antarctica  

NASA Astrophysics Data System (ADS)

Seismology's role in Antarctica is to help determine the geology of the subsurface of this still largely unexplored continent. Seismic reflection surveys in Antarctica have traditionally been collected as marine multichannel and single channel data. However, controlled or active source seismic experiments have played an integral, albeit limited, part in geophysical surveys of the Antarctic ice sheet. In more recent years, sea-ice and ice-shelf seismic reflection surveys have shown promise for producing useful data for regions not accessible by ship. Unfortunately a thick firn layer that covers much of the Antarctica ice sheet has limited the use of surface-based active seismic sources. To overcome attenuation caused by the firn layer, explosives are typically placed in 10 to 30 m-deep boreholes. These shot holes can be drilled by a variety of techniques but all require significant time and energy. In contrast to an impulsive seismic source that releases energy over about a millisecond duration, a seismic vibrator (vibroseis) emits energy as a controlled sweep of frequencies over several seconds. As a consequence, energy losses due to inelastic processes are less because of reduced ground pressure and the total energy produced is integrated over the length of the sweep. Long seismic reflection profiles across Antarctica could be accomplished efficiently by using a vibroseis that in turn pulls a snow streamer. We propose the acquisition of a vibroseis for Antarctic research by scientists within the U.S. Antarctic Program (USAP). Antarctic research objectives that could be impacted by the use of a seismic vibrator include (1) mapping of sub-ice stratigraphic sequences suitable for sampling by scientific drilling, (2) correlating offshore and onshore seismic data and complementing airborne geophysical surveys to help determine Antarctica's geologic history, (3) identifying ice-bedrock interface properties and exploring grounding-line processes, (4) exploring sub-glacial lakes and water-routing systems, and (5) investigating the seismic properties of ice sheets. Suggested seismic profiles include the South Pole traverse route across the Ross Ice Shelf with diversion routes to Coulman High and the Siple Coast. Additional profiles are planned for Byrd Station to West Antarctic Ice Sheet (WAIS) Divide camp and continuing to Pine Island Glacier, and over the 'Discovery Deep' trough, seaward of Byrd Glacier in the eastern Ross Embayment. Projects to consider for the long term include the boundary between West and East Antarctica that is expressed as the Transantarctic Mountains Front. Existing seismic data to define the structures at this boundary are limited. Basins in bedrock behind these mountains are proposed to be sediment free but no seismic reflection data exist to support that hypothesis. The recent detailed mapping of the bedrock of the Gamburtsev Mountains and the nearby Lambert Graben offer further targets for exploration of East Antarctica. An overland traverse has been established between South Pole and the AGAP South site where aerogeophysical surveys over these mountains were based, and this traverse route could be the starting point of a vibroseis research program in East Antarctica.

Speece, M. A.; Luyendyk, B. P.; Powell, R. D.; Wilson, D. S.; Pekar, S. F.; Harwood, D. M.; Tulaczyk, S. M.

2012-12-01

295

ASTER Satellite Imagery of Antarctica: a new tool for Glaciology  

Microsoft Academic Search

Satellite imagery is well suited for studying remote regions such as Antarctica. Until relatively recently, however, the availability and coverage of high-resolution imagery (pixel size < 30 m) over Antarctica have been rather limited. This situation has improved with the success of the Radarsat-1 and Landsat-7 missions. The successful launch of Terra provides another opportunity to collect satellite imagery over

G. S. Hamilton

2001-01-01

296

Rock glaciers in the South Shetland Islands, Western Antarctica  

Microsoft Academic Search

Rock glaciers are found in the peripheral regions of Antarctica particularly in the Antarctic Peninsula region. Study of these features is relevant for the palaeoenvironmental reconstruction of maritime Antarctica because they are indicators of permafrost and periglacial conditions. This paper reports and analyzes the results of an inventory of rock glaciers and protalus lobes in the South Shetland Islands. Nine

Enrique Serrano; Jerónimo López-Mart??nez

2000-01-01

297

Antarctica Australian. Law Text Culture 8:pp. 1-18.  

E-print Network

This article begins with a statement, and with a scene. The statement is a reasonably straightforward one: Australia claims 42 % of the distant offshore continent of Antarctica as its national territory. Or, to make this article's governing statement speak directly to the themes of this issue: nearly half of Antarctica is part of the Australian nation; it is Australian space. This

Christy Collis

298

Quaternary glacial and climate history of Antarctica lafur Inglfsson  

E-print Network

climate changes. A good un- derstanding of the Late Quaternary glacial and climate history of AntarcticaQuaternary glacial and climate history of Antarctica �lafur Ingólfsson University of Iceland, and is important for understanding the relative timing of climate changes between the polar hemispheres (Denton et

Ingólfsson, �lafur

299

Polar Stratospheric Clouds over1 Antarctica from the CALIPSO2  

E-print Network

1 / 19 Polar Stratospheric Clouds over1 Antarctica from the CALIPSO2 Spaceborne Lidar3 4 Vincent Antarctica from3 June to October 2006 using observations from the CALIOP spaceborne lidar, part of the4 CALIPSO mission. Synoptic-scale changes in their geographic and temporal distribution5 are documented

Paris-Sud XI, Université de

300

Birth of a Large Iceberg in Pine Island Bay, Antarctica  

NSDL National Science Digital Library

This lithograph shows the break-off of a large iceberg from the Pine Island Glacier in West Antarctica. This event occurred between November 4th and 12th, 2001, and provides powerful evidence of rapid changes underway in this area of Antarctica. The images were acquired by the MISR instrument onboard NASA's Terra spacecraft.

301

Antarctica: King of Cold: Grades 2-3: Illustrated Book  

NSDL National Science Digital Library

This informational text explains that while both the Arctic and Antarctica are cold, Antarctica is much colder and drier - a polar desert. The text is written at a grade two through grade three reading level. This version is a full-color PDF that can be printed, cut and folded to form a book. Each book contains color photographs and illustrations.

Fries-Gaither, Jessica

302

Tracking the sources and sinks of Antarctica's subglacial waterways  

NASA Astrophysics Data System (ADS)

Deep beneath Antarctica's kilometers-thick layer of glacial ice is a complex network of rivers and lakes. Research suggests that this water may affect the flows of the southern continent's massive ice streams, though the nature of its effect remains unclear. Adding to scientists' understanding of Antarctica's subglacial hydrology, Christoffersen et al. studied five ice streams that flow into the Ross Sea.

Schultz, Colin

2014-09-01

303

Rapid and early export of Phaeocystis antarctica blooms in the Ross Sea, Antarctica.  

PubMed

The Southern Ocean is very important for the potential sequestration of carbon dioxide in the oceans and is expected to be vulnerable to changes in carbon export forced by anthropogenic climate warming. Annual phytoplankton blooms in seasonal ice zones are highly productive and are thought to contribute significantly to pCO2 drawdown in the Southern Ocean. Diatoms are assumed to be the most important phytoplankton class with respect to export production in the Southern Ocean; however, the colonial prymnesiophyte Phaeocystis antarctica regularly forms huge blooms in seasonal ice zones and coastal Antarctic waters. There is little evidence regarding the fate of carbon produced by P. antarctica in the Southern Ocean, although remineralization in the upper water column has been proposed to be the main pathway in polar waters. Here we present evidence for early and rapid carbon export from P. antarctica blooms to deep water and sediments in the Ross Sea. Carbon sequestration from P. antarctica blooms may influence the carbon cycle in the Southern Ocean, especially if projected climatic changes lead to an alteration in the structure of the phytoplankton community. PMID:10766240

DiTullio, G R; Grebmeier, J M; Arrigo, K R; Lizotte, M P; Robinson, D H; Leventer, A; Barry, J P; VanWoert, M L; Dunbar, R B

2000-04-01

304

Rapid and early export of Phaeocystis antarctica blooms in the Ross Sea, Antarctica  

NASA Astrophysics Data System (ADS)

The Southern Ocean is very important for the potential sequestration of carbon dioxide in the oceans and is expected to be vulnerable to changes in carbon export forced by anthropogenic climate warming. Annual phytoplankton blooms in seasonal ice zones are highly productive and are thought to contribute significantly to pCO2 drawdown in the Southern Ocean. Diatoms are assumed to be the most important phytoplankton class with respect to export production in the Southern Ocean; however, the colonial prymnesiophyte Phaeocystis antarctica regularly forms huge blooms in seasonal ice zones and coastal Antarctic waters. There is little evidence regarding the fate of carbon produced by P. antarctica in the Southern Ocean, although remineralization in the upper water column has been proposed to be the main pathway in polar waters. Here we present evidence for early and rapid carbon export from P. antarctica blooms to deep water and sediments in the Ross Sea. Carbon sequestration from P. antarctica blooms may influence the carbon cycle in the Southern Ocean, especially if projected climatic changes lead to an alteration in the structure of the phytoplankton community.

DiTullio, G. R.; Grebmeier, J. M.; Arrigo, K. R.; Lizotte, M. P.; Robinson, D. H.; Leventer, A.; Barry, J. P.; VanWoert, M. L.; Dunbar, R. B.

2000-04-01

305

Ecological role of Phyllophora antarctica drift accumulations in coastal soft-sediment communities of McMurdo Sound, Antarctica  

Microsoft Academic Search

At Cape Evans on Ross Island, Antarctica, the rhodophyte Phyllophora antarctica is the dominant primary producer in terms of biomass from 10 to >30 m depth. The vast majority of Phyllophora occurs as accumulations of unattached plants. Whilst decomposition and incorporation of macroalgal drift material into the food web is rapid in temperate ecosystems, we predicted these processes to be slow

Alf Norkko; Simon F. Thrush; Vonda J. Cummings; Greig A. Funnell; Anne-Maree Schwarz; Neil L. Andrew; Ian Hawes

2004-01-01

306

Upper Mantle Velocity Structure of the East Antarctica Derived from P, PP, S, and SS Waveforms  

NASA Astrophysics Data System (ADS)

We examined P, PP, S, and SS waveforms at epicentral distances of 25 to 60 degree, primarily sampling the East Antarctica. Broadband recordings on the Antarctica were used, with shallow earthquakes which occurred southwest of New Zealand. At the South Pole (SPA), significant phases arrive after the P waves, about 30 seconds before the IASP91 travel times of PP wave. The phases were clearly identified in a range of the epicentral distance from 28 to 34 degree. The apparent velocity is slower than that of the P wave. Beyond 35 degree, the phases are insignificant. The arrivals of the P waves, on the other hand, do not significantly deviate from the IASP91 travel times. In the transverse components of the recordings, clear phases were also observed between the IASP91 travel times of S and SS waves. The apparent velocity is slower than that of the S wave. In a farther range of the epicentral distance, we saw that the PP waveforms vary with the distance, based on the recordings at the Showa station (69.0S, 39.6E). At distances around 42 degree, the PP waveforms are simple with a short duration, and the amplitude is a few times larger than that of the P waves. The duration tends to be longer at distances around 45 degree. At distances beyond 46 degree, the waveforms are complicated and the amplitude is comparable to that of the P waves. A similar variation of the waveforms was observed at Station SNAA. These features of the P, PP, S, and SS waveforms we observed is likely to be attributed to the upper mantle velocity structure of the East Antarctica. Whereas synthetic P waveforms calculated from oceanic upper mantle velocity models or models of velocity smoothly increasing with depth cannot generate seismic energy between the P and PP waves at distances around 30 degree, upper mantle models with a lid and deep low-velocity zone can do. Beneath the East Antarctica, the region of high velocity, down to a depth below 200 km, was found in previous surface-wave analyses (e.g., Danesi and Morelli, 2001). Thus, our observations of the P, PP, S, and SS waveforms can be the result of velocity structure with a lid and deep low-velocity zone.

Kuge, K.; Fukao, Y.

2002-12-01

307

Optical sky brightness at Dome C, Antarctica  

NASA Astrophysics Data System (ADS)

Dome C, Antarctica is a prime site for astronomical observations in terms of climate, wind speeds, turbulence, and infrared and terahertz sky backgrounds (for example, see Aristidi et al. 2005; Storey et al. 2005). However, at present little is known about the optical sky brightness and atmospheric extinction. Using a variety of modelling techniques, together with data from the South Pole, the brightness of the night sky at Dome C is estimated in Kenyon & Storey (2006) including the contributions from scattered sunlight, moonlight,aurorae, airglow, zodiacal light, integrated starlight, diffuse Galactic light and artificial sources. The results are compared to Mauna Kea, Hawaii. We summarise the main conclusions.

Kenyon, Suzanne L.; Storey, John W. V.

2007-08-01

308

Mercury in aquatic systems in Antarctica  

NASA Astrophysics Data System (ADS)

We have measured Hg concentrations in one of the most remote aquatic systems in the world, Taylor Valley (˜78°S), Antarctica. These measurements, along with the previous work of Vandal et al. [1998], provide baseline concentrations of Hg, as well as an assessment of Hg speciation, in a remote aquatic environment. Dissolved Hg concentrations in the surface waters of these lakes and glacial streams range from 0.10 to 0.44 ngL-1. These values are similar to those reported from other remote locations and suggest these values represent current baseline values globally.

Lyons, W. Berry; Welch, Kathleen A.; Bonzongo, Jean-Claude

309

Autonomous Observations in Antarctica with AMICA  

E-print Network

The Antarctic Multiband Infrared Camera (AMICA) is a double channel camera operating in the 2-28 micron infrared domain (KLMNQ bands) that will allow to characterize and exploit the exceptional advantages for Astronomy, expected from Dome C in Antarctica. The development of the camera control system is at its final stage. After the investigation of appropriate solutions against the critical environment, a reliable instrumentation has been developed. It is currently being integrated and tested to ensure the correct execution of automatic operations. Once it will be mounted on the International Robotic Antarctic Infrared Telescope (IRAIT), AMICA and its equipment will contribute to the accomplishment of a fully autonomous observatory.

Di Rico, Gianluca; Dolci, Mauro; Straniero, Oscar; Valentini, Angelo; Valentini, Gaetano; Di Cianno, Amico; Giuliani, Croce; Magrin, Demetrio; Bonoli, Carlotta; Bortoletto, Favio; D'Alessandro, Maurizio; Corcione, Leonardo; Riva, Alberto

2010-01-01

310

The Exploration of the ISM from Antarctica  

NASA Astrophysics Data System (ADS)

Antarctica presents a unique environment for the exploration of the interstellar medium. The low column of water vapor opens windows for sub-mm and THz astronomy from ground and sub-orbital observatories while the stable atmosphere holds promise for THz interferometry. Various current and potentially future facilities occupy a niche not available to current space or stratospheric instruments. These allow line and continuum observations addressing key questions in e.g., star formation, galactic evolution, and the life-cycle of interstellar clouds. This review presents scientific questions that can be addressed by the suite of current and future Antarctic observatories.

Wolfire, Mark G.

2013-01-01

311

Antarctica: measuring glacier velocity from satellite images  

SciTech Connect

Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.

Lucchitta, B.K.; Ferguson, H.M.

1986-11-28

312

Low deuterium content of Lake Vanda, Antarctica  

USGS Publications Warehouse

Lake Vanda in Victoria Land, Antarctica, is permanently ice-covered and permanently stratified, with warm, salty water near the bottom. Deuterium analyses of lake water from several levels indicate that the lake has a low deuterium content, and that it is stratified with respect to this isotope. This low deuterium content supports the evidence from the lake's ionic content that the saline layer is not of marine origin, and it indicates that evaporation from the ice surface has taken place. The stratification of the lake with respect to deuterium suggests that the upper and lower layers of water were formed at different times from different sources of glacial melt water.

Ragotzkie, R. A.; Friedman, I.

1965-01-01

313

Antarctica: Measuring glacier velocity from satellite images  

USGS Publications Warehouse

Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.

Lucchitta, B. K.; Ferguson, H. M.

1986-01-01

314

Recent Controlled Meteorological Balloon experiments in Queen Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

Controlled Meteorological (CMET) balloons are unique in that their altitude can be changed at any time during flight. They are remotely controlled via the Iridium network and use GPS for positioning. Over the past seven years, they have been operated at altitudes from sea-level to six kilometers and have flown for periods as long as five days. Campaigns have been carried out from the Amazon via Mexico City to polar regions. CMET balloons can perform repeated soundings in order to probe evolving thermal and chemical structure, measure wind shear, and track atmospheric layers. Typical ascent/descent rate is 1 m/s and the data sampling rate is 10 sec. The standard CMET balloon consists of zero-pressure balloon (~300-500 liters at sea level) which itself contains a much smaller (~100 liter) super-pressure balloon. Transferring helium between the super-pressure balloon and the zero-pressure balloon regulates the volume (and density) of the system, leading to controlled ascent and descent. Due to the rarity of meteorological observations from the Antarctic, especially from inland and over the sea, CMET balloons have potential to provide strongly needed data for evaluation of numerical weather prediction and climate models. Here, we present data from a CMET campaign carried out at the Finnish Aboa station in Antarctica (73° 03' S, 13° 25' W) in January 2013. The campaign was unique in that three CMET balloons were shipped to the station and launched by the local team. After the launch, they were controlled by scientists located in MA, USA and Norway. One balloon, Bravo, cruised for more than 100 hours over the coastal slopes of Queen Maud Land and nearby sea ice with a total trajectory length of over 3000 km (Fig. 1). It also passed nearby the UK Halley station. The altitude was generally kept at about 3000-3500 masl, but 8 controlled soundings down to 400-500 masl were carried out. The balloon data were compared with the Weather Research and Forecasting model (WRF) simulations using one domain with 2km horizontal resolution and the Yonsei University boundary layer scheme which has proven robust in Arctic and Antarctic applications. Significant discrepancies are revealed in both temperature and relative humidity. Few other measurements with high time resolution exist in the free troposphere in this region, but large discrepancies between observations and models were also observed by others such as Tastula and Vihma, (2011). In this presentation we attempt to find reasons why the WRF model is not able to reproduce the observed atmospheric structure and we also compare our measurements with radiosonde observations from Halley. Fig 1: Trajectory of the Bravo flight 18-23 January.

Hole, L. R.; Voss, P. B.; Vihma, T. P.

2013-12-01

315

The impact of marginal ice zone processes on the distribution of 21OPb, 21OPo and 234Th and implications for new production in the Bellingshausen Sea, Antarctica  

Microsoft Academic Search

The vertical distributions of 21OPb, 210Po and 234Th in both dissolved and particulate phases of seawater were measured at five stations along the 85°W meridian in the Bellingshausen Sea, Antarctica. Sea-ice conditions during the expedition ranged from fully ice-covered (fast ice) to open water away from the marginal ice zone. Concurrent primary productivity and algal chlorophyll measurements revealed a band

Graham B. Shimmield; George D. Ritchie; Timothy W. Fileman

1995-01-01

316

What Hazards Do Humans Encounter in Antarctica?  

NSDL National Science Digital Library

This six-day unit has students investigate the challenges of living and working in Antarctica and how researchers prepare for them, and then evaluate the insulating properties of a variety of fabrics, collecting their findings in a portfolio. The comprehensive curriculum materials at this site include an online activity in which students review the preparation materials given to researchers before traveling to Antarctica, two classroom activities - an experiment to test the insulation and waterproof properties of a variety of fabrics, and a Jeopardy-style game in which students write answers and questions - and several readings that provide a broad perspective, including an excerpt from Edmund Hillary's journal and question and answer interviews with a safety engineer and a field support services manager. Teacher tools for this unit include individually downloadable readings, detailed daily breakdowns of tasks, teacher strategies for using the activities, a portfolio grading sheet, a project rubric sheet, additional readings, and a student handout with guidance for putting together their portfolios and examples of creative final projects.

317

First photometric properties of Dome C, Antarctica  

NASA Astrophysics Data System (ADS)

Here we present the first photometric extinction measurements in the visible range performed at Dome C in Antarctica, using PAIX photometer (Photometer AntarctIca eXtinction). It is made with "off the shelf" components, Audine camera at the focus of Blazhko telescope, a Meade M16 diaphragmed down to 15 cm. For an exposure time of 60 s without filter, a 10th V-magnitude star is measured with a precision of 1/100 mag. A first statistics over 16 nights in August 2007 leads to a 0.5 magnitude per air mass extinction, may be due to high altitude cirrus. This rather simple experiment shows that continuous observations can be performed at Dome C, allowing high frequency resolution on pulsation and asteroseismology studies. Light curves of one of RR Lyrae stars: SAra were established. They show the typical trend of a RRLyrae star. A recent sophisticated photometer, PAIX II, has been installed recently at Dome C during polar summer 2008, with a ST10 XME camera, automatic guiding, auto focusing and Johnson/Bessel UBVRI filter wheels.

Chadid, M.; Vernin, J.; Jeanneaux, F.; Mekarnia, D.; Trinquet, H.

2008-07-01

318

Development of a 30-cm submillimeter-wave telescope for the operation at Dome Fuji in Antarctica  

NASA Astrophysics Data System (ADS)

We have developed a 30-cm submillimeter-wave telescope intended to survey the Milky Way in 500 GHz emission lines at the Dome Fuji station in Antarctic plateau. Transportability and low power consumption are required while keeping low system noise temperature for the operation in Antarctica. The telescope is designed to be divided into five components and to operate with less than 2.5 kW of electric power. Its receiver noise temperature is less than 85 K in SSB at 461 and 492 GHz. We succeeded in operating the telescope at -30°C in laboratory that is a typical temperature of the Dome Fuji in summer.

Ishii, S.; Seta, M.; Nagasaki, T.; Nakai, N.; Nagai, M.; Miyamoto, Y.; Imada, H.; Doihata, K.; Saito, K.; Sekimoto, Y.

2014-07-01

319

The role of atmospheric rivers in anomalous snow accumulation in East Antarctica  

NASA Astrophysics Data System (ADS)

Recent, heavy snow accumulation events over Dronning Maud Land (DML), East Antarctica, contributed significantly to the Antarctic ice sheet surface mass balance (SMB). Here we combine in situ accumulation measurements and radar-derived snowfall rates from Princess Elisabeth station (PE), located in the DML escarpment zone, along with the European Centre for Medium-range Weather Forecasts Interim reanalysis to investigate moisture transport patterns responsible for these events. In particular, two high-accumulation events in May 2009 and February 2011 showed an atmospheric river (AR) signature with enhanced integrated water vapor (IWV), concentrated in narrow long bands stretching from subtropical latitudes to the East Antarctic coast. Adapting IWV-based AR threshold criteria for Antarctica (by accounting for the much colder and drier environment), we find that it was four and five ARs reaching the coastal DML that contributed 74-80% of the outstanding SMB during 2009 and 2011 at PE. Therefore, accounting for ARs is crucial for understanding East Antarctic SMB.

Gorodetskaya, Irina V.; Tsukernik, Maria; Claes, Kim; Ralph, Martin F.; Neff, William D.; Van Lipzig, Nicole P. M.

2014-09-01

320

Three-dimensional Shear Wave Velocity Structure of The Upper Mantle Below Antarctica  

NASA Astrophysics Data System (ADS)

We measure fundamental-mode Rayleigh and Love surface wave group dispersion curves from seismograms recorded by stations in the Antarctic continent and neigh- boring lands at latitude below -30. Our growing regional dataset is merged with the global dataset of phase velocity measurements by Ekström et al. (1997, JGR 102, 8137-8157). Our inversion procedure is divided in two steps. The first is a linear to- mographic inversion of the dispersion measurements to model laterally heterogeneous group velocity at different periods. Wave slowness is parameterized by spline interpo- lation on a geographical grid, with knots equally spaced by 250 km in an orthographic projection. For each point in these maps we then compute the vertical profile of shear wave velocity vs. depth by iterative nonlinear inversion. Crustal properties are as- sumed to be known and follow the CRUST2.0 model (Bassin et al., 2000, EOS Trans AGU, 81 F897). The resulting vS model shows intense negative anomalies under oceanic ridges, at least down to 150 km. The strongest values are related to young oceanic crust near rapidly opening ridges. Shallow low velocity anomalies characterize volcanic provinces and hot-spots in Marie Byrd Land, Ross Sea, Kerguelen, Balleny and South Sandwich archipelagoes. Only few slow anomalies reach depths below 150km (West Antarctica, Ross Sea and the triple junction among Southeast Pacific-South Pacific- Indian Ridges). The East Antarctica archean craton has deep, fast (cold) continental roots reaching at least 200km in depth.

Danesi, S.; Morelli, A.

321

High resolution 900 yr volcanic and climatic record from the Vostok area, East Antarctica  

NASA Astrophysics Data System (ADS)

Detailed volcanic record of the last 900 yr (1093-2010 AD) has been received using high resolution (2-3 samples per accumulation year) sulfate measurements in four snow/firn cores from the Vostok station area, East Antarctica. Totally, 33 volcanic events have been identified in the record, including well-known low latitude eruption signals found in many polar ice cores (e.g., Pinatubo 1991, Agung 1963, Krakatoa 1883, Tambora 1815, Huanaputina 1600, Kuwae 1452), however in comparison with other Antarctic sites the record has more events covering the last 900 yr. The strongest volcanic signals occurred during mid-13th, mid-15th and 18th centuries. The largest volcanic signal of Vostok (both in sulfate concentration and flux) is the 1452 AD Kuwae eruption. Average snow accumulation rate calculated for the period 1093-2010 AD is 21.3 ± 2.3 mm H2O. Accumulation record demonstrates a slight positive trend, however sharply increased accumulation rate during the periods from 1600 to 1815 AD (by 11% from long-term mean) and from 1963 to 2010 AD (by 15%) are typical features of the site. Na+ record shows strong decadal-scale variability probably connected with coupled changes in atmospheric transport patterns over Antarctica (meridional circulation change) and local glaciology. The obtained high resolution climatic records suggest a high sensitivity of the Vostok location to environmental changes in Southern Hemisphere.

Osipov, E. Yu.; Khodzher, T. V.; Golobokova, L. P.; Onischuk, N. A.; Lipenkov, V. Ya.; Ekaykin, A. A.; Osipova, O. P.

2013-05-01

322

Automatic Weather Stations  

NSF Publications Database

... in Antarctica. Only one RTG-powered unit remains. Located at Dome C, 74.50?S, 123.00?E, it is to be ... If properly removed, no trace of the unit will remain. The principal direct impacts of AWS unit ...

323

Crustal Vp-Vs ratios and thickness for Ross Island and the Transantarctic Mountain front, Antarctica  

NASA Astrophysics Data System (ADS)

We investigate crustal Vp-Vs ratios and thickness along the Transantarctic Mountain (TAM) front and on Ross Island, Antarctica to determine if the TAM crust has been modified by the Neogene magmatism associated with Ross Island. A seismic low velocity zone (LVZ) in the upper mantle beneath Ross Island extends laterally ˜80 km under the TAM front, and mantle temperatures within the LVZ may be sufficiently elevated for partial melting to have occurred and modified the crust. Data for the study come from 16 temporary seismic stations that were part of the TAM Seismic Experiment and three permanent stations. Estimates of Vp/Vs (?) and crustal thickness (H) have been obtained from receiver functions analysed using the H-? stacking method for 10 of the stations, and for the remaining stations, crustal thickness has been calculated by using the Moho Ps arrival time with an assumed Vp/Vs value. A Vp/Vs value of 1.88 is obtained for Ross Island, consistent with the mafic composition of the volcanic rocks from Mt. Erebus. Vp/Vs values for stations in the TAM situated away from the LVZ range from 1.63 to 1.78, with a mean of 1.73, while values for stations in the TAM lying above the LVZ range from 1.67 to 1.78, with a mean of 1.72. This result indicates that there is little difference in bulk crustal composition for areas above and away from the LVZ, and together with a Vp/Vs value (1.73) that is typical for felsic to intermediate composition crust, suggests that the crust along the TAM front has not been altered significantly by mafic magmatism. Crustal thickness estimates along the coast are quite variable, ranging from 18 to 33 km, and increase to 39 km inland beneath the crest of the TAM. On Ross Island, crustal thickness estimates range between 19 and 27 km.

Finotello, Marco; Nyblade, Andrew; Julia, Jordi; Wiens, Douglas; Anandakrishnan, Sridhar

2011-04-01

324

Long-term changes in the upper stratospheric ozone at Syowa, Antarctica  

NASA Astrophysics Data System (ADS)

Analyses of stratospheric ozone data determined from Dobson-Umkehr measurements since 1977 at the Syowa (69.0° S, 39.6° E), Antarctica, station show a significant decrease in ozone at altitudes higher than that of the 4 hPa pressure level during the 1980s and 1990s. Ozone values over Syowa have remained low since 2001. The time series of upper stratospheric ozone from the homogenized NOAA SBUV (Solar Backscatter Ultraviolet Instrument)(/2) 8.6 overpass data (±4°, 24 h) are in qualitative agreement with those from the Syowa station data. Ozone recovery during the austral spring over the Syowa station appears to be slower than predicted by the equivalent effective stratospheric chlorine (EESC) curve. The long-term changes in the station's equivalent latitude (indicative of vortex size/position in winter and spring) are derived from MERRA (Modern Era Retrospective-analysis for Research and Applications) reanalyses at ~ 2 and ~ 50 hPa. These data are used to attribute some of the upper and middle stratospheric ozone changes to the changes in vortex position relative to the station's location. In addition, high correlation of the Southern Hemisphere annular mode (SAM) with polar upper stratospheric ozone during years of maximum solar activity points toward a strong relationship between the strength of the Brewer-Dobson circulation and the polar stratospheric ozone recovery. In the lower stratosphere, ozone recovery attributable to CFCs (chlorofluorocarbons) is still not definitive, whereas the recovery of the upper stratosphere is slower than predicted. Further research indicates that dynamical and other chemical changes in the atmosphere are delaying detection of recovery over this station.

Miyagawa, K.; Petropavlovskikh, I.; Evans, R. D.; Long, C.; Wild, J.; Manney, G. L.; Daffer, W. H.

2014-04-01

325

Differential leucocyte cell counts from the pygoscelid penguins of Antarctica.  

PubMed

Differential leucocyte counts were obtained for three cogeneric species of wild antarctic penguins, Pygoscelis adelie (adelie), Pygoscelis papua (gentoo), and Pygoscelis antarctica (chinstrap). Significant differences between the differential leucocyte counts of the three species were not observed. PMID:3625920

Zinsmeister, V A; VanDerHeyden, M J

1987-07-01

326

Nitrogen uptake kinetics in the Ross Sea, Antarctica  

NASA Astrophysics Data System (ADS)

The first estimates of uptake kinetic parameters for NH 4+, NO 3-, and urea in the Ross Sea, Antarctica were measured on three cruises during austral late winter-early spring 1996 (pre-bloom), late spring 1997 (bloom development), and summer 1997 (bloom decline). Nitrogen (N) uptake experiments were conducted with water collected at the 50% light penetration depth using trace-metal clean protocols and 15N tracer techniques. At all sites, ambient NO 3- concentrations ranged from 5.8 to 30.5 ?g-at N l -1 and silicic acid concentrations were greater than 62.0 ?g-at Si l -1. The following trends were observed. First, based on maximum uptake rates ( Vmax), apparent N utilization followed the order NO 3->NH 4+>urea during the pre-bloom and bloom development cruises. During the summer cruise, as the bloom was declining, the apparent order of utilization was NH 4+>NO 3->urea. Second, evidence for possible repression of NO 3- uptake by elevated NH 4+ concentrations was only observed at one site. Third, the kinetic parameters of NH 4+ uptake rates corrected for isotope dilution were compared with the kinetic parameters determined from uncorrected rates. In this comparison, the measure of substrate affinity, ? ( ?= Vmax/ Ks) increased by an average of 4.6-fold when rates were corrected for isotope dilution, but values of Vmax remained unchanged. Fourth, using bacterial production data, the magnitude of bacterial N uptake was estimated. Assuming that all bacterial N demands were met with NH 4+, the estimated bacterial portion of NH 4+ uptake ranged from <1%, when the ratio of bacteria to autotrophic biomass was low, to 35%, when bacterial abundance and biomass were highest. Finally, dramatic changes in NH 4+ uptake capacity were observed at one station (Stn. O), where kinetic parameters were measured during all three cruises. We hypothesize that a mutualistic relationship exists between phytoplankton and heterotrophic bacteria, and that the creation of microzones of high NH 4+ concentrations contributed to the changes seen at this station.

Cochlan, William P.; Bronk, Deborah A.

327

It?s good to be big--- Phaeocystis antarctica colony size under the influence of zooplankton grazers  

EPA Science Inventory

The haptophyte Phaeocystis antarctica forms extremely dense accumulations in the Ross Sea, Antarctica, and accounts for over 60% of the seasonal primary production. Similar to the Phaeocystis species in the northern hemisphere, P. antarctica exists as solitary cells and mucilagin...

328

IT?S GOOD TO BE BIG?PHAEOCYSTIS ANTARCTICA COLONY SIZE UNDER THE INFLUENCE OF ZOOPLANKTON GRAZERS  

EPA Science Inventory

The haptophyte Phaeocystis antarctica forms extremely dense accumulations in the Ross Sea, Antarctica, and accounts for over 60% of the seasonal primary production. Similar to the Phaeocystis species in the northern hemisphere, P. antarctica exists as solitary cells and mucilagin...

329

Within-day variability of particulate organic carbon and remote-sensing reflectance during a bloom of Phaeocystis antarctica in  

E-print Network

of Phaeocystis antarctica in the Ross Sea, Antarctica Pierre Gernez*, Rick A. Reynolds, and Dariusz Stramski in the Ross Sea, Antarctica, during development of the annual spring phytoplankton bloom. Measurements

Stramski, Dariusz

330

Proposal to protect marine areas around Antarctica  

NASA Astrophysics Data System (ADS)

Forty percent of Antarctica's Southern Ocean should be protected in a network of marine protected areas (MPAs) and no-take marine reserves, according to a 21 May report by the Antarctic Ocean Alliance, which is composed of about 20 environmental groups. The protected areas should include the 19 Antarctic marine habitats outlined in the report, along with existing MPAs and areas identified through previous conservation and planning analyses, the report notes. Protected areas should include the Antarctic Peninsula, the Weddell and Ross seas, the Indian Ocean Benthic Environment, and Pacific seamounts, according to the report. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), which manages living resources for the Southern Ocean, has already agreed to establish an initial network of Antarctic MPAs this year, the report states.

Showstack, Randy

2012-05-01

331

Extraordinary blowing snow transport events in East Antarctica  

Microsoft Academic Search

In the convergence slope\\/coastal areas of Antarctica, a large fraction of snow is continuously eroded and exported by wind\\u000a to the atmosphere and into the ocean. Snow transport observations from instruments and satellite images were acquired at the\\u000a wind convergence zone of Terra Nova Bay (East Antarctica) throughout 2006 and 2007. Snow transport features are well-distinguished\\u000a in satellite images and

Claudio Scarchilli; Massimo Frezzotti; Paolo Grigioni; Lorenzo De Silvestri; Lucia Agnoletto; Stefano Dolci

2010-01-01

332

Triassic Leech Cocoon From Antarctica Contains Fossil Bell Animal  

E-print Network

KU ScholarWorks | http://kuscholarworks.ku.edu Triassic Leech Cocoon From Antarctica Contains Fossil Bell Animal 2012 by Benjamin Bomfleur, Hans Kerp, Thomas N. Taylor, Øjvind Moestrup, and Edith L. Taylor This work has been made available.... The original published version can be found at the link below. Bomfleur, B., Kerp, H., Taylor, T., Moestrup, Ø., and Taylor, E. 2012. Triassic Leech Cocoon From Antarctica Contains Fossil Bell Animal. Proceedings of the National Academy of Sciences 109...

Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.; Moestrup, Ø jvind; Taylor, Edith L.

2012-01-01

333

Birth of a Large Iceberg in Pine Island Bay, Antarctica  

NSDL National Science Digital Library

This lithograph shows the break-off of a large iceberg from the Pine Island Glacier in West Antarctica. This event occurred between November 4th and 12th, 2001, and provides powerful evidence of rapid changes underway in this area of Antarctica. The three images presented were acquired by the vertical-viewing (nadir) camera of the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra spacecraft.

2004-10-02

334

Oxygen isotope studies and compilation of isotopic dates from Antarctica  

SciTech Connect

The Quaternary Isotope Laboratory, alone or in collaboration with other investigators, is currently involved in a number of oxygen-isotope studies mainly in Antarctica. Studies of a drill core from the South Pole, seasonal oxygen-18 signals preserved in the Dominion Range, isotope dating of the Ross Ice Shelf, oxygen-18 profiles of the Siple Coast, McMurdo Ice Shelf sampling, and a data compilation of radiometric dates from Antarctica are discussed.

Grootes, P.M.; Stuiver, M.

1986-01-01

335

Antarctica: King of Cold: Grades K-1: Electronic Book  

NSDL National Science Digital Library

This informational text explains that while both the Arctic and Antarctica are cold, Antarctica is much colder and drier - a polar desert. The text is written at a kindergarten through grade one reading level. This is an onscreen version that contains recorded narration allowing students to listen to the text as they read along. Highlighted vocabulary words have individually recorded definitions heard by clicking on the links.

Fries-Gather, Jessica

336

Manganese-rich rock varnish does occur in Antarctica  

Microsoft Academic Search

Dorn, R.I., Krinsley, D.H., Liu, T., Anderson, S., Clark, J., Cahill, T.A. and Gill, T.E., 1992. Manganese-rich rock varnish does occur in Antarctica. Chem. Geol., 99: 289-298. Despite accounts to the contrary, we have found that Mn-rich rock varnish is present in Antarctica, as others have before. It is chemically and texturally similar to many varnishes found in lower latitudes.

Ronald I. Dorn; David H. Krinsley; Tanzhuo Liu; Steve Anderson; James Clark; Thomas A. Cahill; Thomas E. Gill

1992-01-01

337

Concentration of trace inorganic species in surface snow near Dome Fuji, Antarctica  

NASA Astrophysics Data System (ADS)

In the southern hemisphere, especially Antarctica, it is considered that ocean and stratosphere are major source of halogen species. However, there is little data about halogen species contained in snow and ice in Antarctica. In this research, trace inorganic species (Br, Cl, F, I) in the snow samples collected in the Antarctica were analyzed. The snow samples were collected along ca. 1000 km traverse route from Mikaeridai (S16; 69°1'S, 40°3'E, 590 m) to Dome Fuji station (77°19'S, 39°42'E, 3810 m) by the Japan Antarctica research expedition. The samples were transported to Japan without thawing. The quantitative analyses of elements were performed using the ion chromatograph mass spectrometer (IC-MS) and quadrupole type inductively-coupled plasma mass spectrometer (ICP-MS). The IC-MS system consists of a single quadrupole type mass spectrometer (Agilent Technologies 6150) connected to an ionchromatograph (Dionex ICS-2000). IonPac AS11-HC was used as the separation column of the ionchromatograph. 14 anion species (Br-, BrO3-, CH3COO-, CH3SO3-, Cl-, C2O42-, F-, HCOO-, I-, IO3-, NO2-, NO3-, PO43-, SO42-) were analyzed by this system. Average concentration of Cl- was 50 ng/ml. High concentration of Cl- was observed at the coast region compared with the inland region. The concentration was 150 ng/ml at the coast region. On the other hand, the maximum concentration of Br- and I- was observed around 71°S and near 74°S on the traverse route. Average concentration of Br- was 0.2 ng/ml. The maximum concentration of Br- was ca. 0.6 ng/ml. Average concentration of I- was 0.03 ng/ml. The maximum concentration of I- was ca. 0.1 ng/ml. While it is thought that the source of Cl- is mainly ocean, concentration distribution of Br- and I- differs from Cl-. suggesting the contribution of sources other than ocean. Further results and discussion about the behavior and origin of halogen ion species in snow will be presented.

Hirabayashi, M.; Motoyama, H.

2012-12-01

338

Atmospheric Boundary Layer Dynamics Near Ross Island and Over West Antarctica.  

NASA Astrophysics Data System (ADS)

The atmospheric boundary layer dynamics near Ross Island and over West Antarctica has been investigated. The study consists of two parts. The first part involved the use of data from ground-based remote sensing equipment (sodar and RASS), radiosondes, pilot balloons, automatic weather stations, and NOAA AVHRR satellite imagery. The second part involved the use of a high resolution boundary layer model coupled with a three-dimensional primitive equation mesoscale model to simulate the observed atmospheric boundary layer winds and temperatures. Turbulence parameters were simulated with an E-epsilon turbulence model driven by observed winds and temperatures. The observational analysis, for the first time, revealed that the airflow passing through the Ross Island area is supplied mainly by enhanced katabatic drainage from Byrd Glacier and secondarily drainage from Mulock and Skelton glaciers. The observed diurnal variation of the blocking effect near Ross Island is dominated by the changes in the upstream katabatic airflow. The synthesized analysis over West Antarctica found that the Siple Coast katabatic wind confluence zone consists of two superimposed katabatic airflows: a relatively warm and more buoyant katabatic flow from West Antarctica overlies a colder and less buoyant katabatic airflow from East Antarctica. The force balance analysis revealed that, inside the West Antarctic katabatic wind zone, the pressure gradient force associated with the blocked airflow against the Transantarctic Mountains dominates; inside the East Antarctic katabatic wind zone, the downslope buoyancy force due to the cold air overlying the sloping terrain is dominant. The analysis also shows that these forces are in geostrophic balance with the Coriolis force. An E-epsilon turbulence closure model is used to simulate the diurnal variation of sodar backscatter. The results show that the model is capable of qualitatively capturing the main features of the observed sodar backscatter. To improve the representation of the atmospheric boundary layer, a second-order turbulence closure model coupled with the input from a mesoscale model was applied to the springtime Siple Coast katabatic wind confluence zone. The simulation was able to capture the main features of the confluence zone, which were not well resolved by the mesoscale model.

Liu, Zhong

339

The penguin feathers as bioindicator of Antarctica environmental state.  

PubMed

Concentrations of biogenic and toxic elements (Na, K, Mg, Ca, P, S, Fe, Cu, Zn, Co, Mn, Se, Ni, Sr, Al, Cd, Pb, As) were determined for the first time in feathers of gentoo penguin (Pygoscelis papua) and chinstrap penguin (Pygoscelis antarctica) from Antarctica. A comparison of element levels was performed among these species in years 2002-2003. Penguins molt annually and this fact allows defining precisely the concentrations of accumulated toxic elements and heavy metals in plumage every year. A continual environmental biomonitoring could establish a possible trend to contamination of the Antarctica sea zones. The penguin feather is an excellent subject for monitoring because penguins have long life span, permanent ecological niche and dominate the aviafauna in Antarctica. Because of its remoteness, Antarctica is believed to be unpolluted. The relatively elevated levels of Cd established are due to the Cd-enrichment of the Antarctic marine food chain. Because of great bioaccumulation of lead in feathers, the concentration of Pb in penguin feather was higher (4-8 times) compared to that of Cd. In both penguin species the levels of Zn were 1.9 times higher than respective Fe levels. The concentrations of most of the investigated elements were significantly higher in P. papua than in P. antarctica and this probably could be explained by the different diet and feeding habit of these species. PMID:15967486

Metcheva, R; Yurukova, L; Teodorova, S; Nikolova, E

2006-06-01

340

Mass Casualty Incident Response and Aeromedical Evacuation in Antarctica  

PubMed Central

Antarctica is one of the most remote regions on Earth. Mass casualty incident (MCI) responses in Antarctica are prone to complications from multiple environmental and operational challenges. This review of the current status of MCI risks and response strategies for Antarctica focuses on aeromedical evacuation, a critical component of many possible MCI scenarios. Extreme cold and weather, a lack of medical resources and a multitude of disparate international bases all exert unique demands on MCI response planning. Increasing cruise ship traffic is also escalating the risk of MCI occurrence. To be successful, MCI response must be well coordinated and undertaken by trained rescuers, especially in the setting of Antarctica. Helicopter rescue or aeromedical evacuation of victims to off-continent facilities may be necessary. Currently, military forces have the greatest capacity for mass air evacuation. Specific risks that are likely to occur include structure collapses, vehicle incapacitations, vehicle crashes and fires. All of these events pose concomitant risks of hypothermia among both victims and rescuers. Antarctica’s unique environment requires flexible yet robust MCI response planning among the many entities in operation on the continent. PMID:21691470

Mills, Christopher N.; Mills, Gregory H.

2011-01-01

341

Review Mass Casualty Incident Response and Aeromedical Evacuation in Antarctica  

E-print Network

Antarctica is one of the most remote regions on Earth. Mass casualty incident (MCI) responses in Antarctica are prone to complications from multiple environmental and operational challenges. This review of the current status of MCI risks and response strategies for Antarctica focuses on aeromedical evacuation, a critical component of many possible MCI scenarios. Extreme cold and weather, a lack of medical resources and a multitude of disparate international bases all exert unique demands on MCI response planning. Increasing cruise ship traffic is also escalating the risk of MCI occurrence. To be successful, MCI response must be well coordinated and undertaken by trained rescuers, especially in the setting of Antarctica. Helicopter rescue or aeromedical evacuation of victims to off-continent facilities may be necessary. Currently, military forces have the greatest capacity for mass air evacuation. Specific risks that are likely to occur include structure collapses, vehicle incapacitations, vehicle crashes and fires. All of these events pose concomitant risks of hypothermia among both victims and rescuers. Antarctica’s unique environment requires flexible yet robust MCI response planning among the many entities in operation on the continent. [West J Emerg Med. 2011;12(1):37-42.] BACKGROUND

Christopher N. Mills; Gregory H. Mills

342

First light from the Dome C (Antarctica) of a phase knife stellar coronagraph  

E-print Network

We report on the first daytime on-sky results of a Phase Knife stellar Coronagraph operated in the visible from the French-Italian Concordia station at Dome C of Antarctica. This site has proven in the last few years to offer excellent atmospheric seeing conditions for high spatial resolution observations. The coronagraphic performances obtained from laboratory experiments and numerical models have been compared with those measured from daytime on-sky data recorded on bright single and multiple stars: Canopus (HD 45348), and alpha Centauri (HD 128620J). No correction system was used (adaptive optics or tip-tilt mirror) so that atmospheric turbulence alone defines the image quality, and thus the coronagraphic performances. Moreover, the experiment could not run under optimal operational conditions due to hardware/software problems. Satisfactory results have been obtained: broad band total rejection exceeding 15 were attained in the visible. This first day-time observation campaign yields an experimental feedba...

Guerri, Geraldine; Daban, Jean-Baptiste; Aristidi, Eric; Bendjoya, Philippe; Rivet, Jean-Pierre; Vakili, Farrokh

2009-01-01

343

Measurements of positive ions and air-earth current density at Maitri, Antarctica  

E-print Network

Simultaneous measurements of the small-, intermediate- and large- positive ions and air earth current density made at a coastal station, Maitri at Antarctica during January to February 2005, are reported. Although, small and large positive ion concentrations do not show any systematic diurnal variations, variations in them are almost similar to each other. On the other hand, variations in intermediate positive ion concentrations are independent of variations in the small/large positive ions and exhibit a diurnal variation which is similar to that in atmospheric temperature on fair weather days with a maximum during the day and minimum during the night hours. No such diurnal variation in intermediate positive ion concentration is observed on cloudy days when variations in them are also similar to those insmall/large positive ion concentrations. Magnitude of diurnal variation in intermediate positive ion concentration on fair weather days increases with the lowering of atmospheric temperature in this season. Sc...

Siingh, Devendraa; Kamra, A K; 10.1029/2006JD008101

2009-01-01

344

Time-series analysis of chemical trends in a dated ice core from Antarctica  

SciTech Connect

Polar ice sheets contain valuable information about past atmospheric conditions. Atmospherically produced or transported substances from natural and anthropogenic sources are preserved stratigraphically within the ice layers as a result of both wet and dry deposition mechanisms. Substances deposited include aerosols and gaseous compounds. The analysis of trace elements contained in dated annual snow layers provides a measure of the elemental chemistry content of the atmosphere during the same time interval. The aerosol content of the atmosphere and ice sheets is one of the most important parameters for cloud/radiation interaction processes. Ice cores were obtained from the Byrd Station, West Antarctica, in November, 1989. This study presents results obtained from instrumental neutron activation analysis and ion chromatography on 30 samples over a 20 year period.

Keskin, S.S.; Olmez, I. [Massachusetts Institute of Technology, Cambridge, MA (United States); Langway, C.C. Jr. [State Univ. of New York, Buffalo, NY (United States)

1994-12-31

345

Space Station fluid resupply  

Microsoft Academic Search

Viewgraphs on space station fluid resupply are presented. Space Station Freedom is resupplied with supercritical O2 and N2 for the ECLSS and USL on a 180 day resupply cycle. Resupply fluids are stored in the subcarriers on station between resupply cycles and transferred to the users as required. ECLSS contingency fluids (O2 and N2) are supplied and stored on station

Al Winters

1990-01-01

346

IESID: Automatic system for monitoring ground deformation on the Deception Island volcano (Antarctica)  

NASA Astrophysics Data System (ADS)

When establishing the relative distance between two GNSS-GPS stations with sub-centimeter accuracy, it is necessary to have auxiliary data, some of which can only be collected some time after the moment of measurement. However, for monitoring highly-active geodynamic areas, such as volcanoes and landslides, data precision is not as essential as rapid availability, processing of data in real-time, and fast interpretation of the results. This paper describes the development of an integrated automatic system for monitoring volcanic deformation in quasi real-time, applied to the Deception volcano (Antarctica). This experimental system integrates two independent modules that enable researchers to monitor and control the status of the GNSS-GPS stations, and to determine a surface deformation parameter. It comprises three permanent stations, one of which serves as the reference for assessing the relative distance in relation to the other two. The availability of GNSS-GPS data in quasi real-time is achieved by means of a WiFi infrastructure and automated data processing. This system provides, in quasi real-time, a time series of varying distances that tells us the extent to which any ground deformation is taking place.

Peci, Luis Miguel; Berrocoso, Manuel; Páez, Raúl; Fernández-Ros, Alberto; de Gil, Amós

2012-11-01

347

Snow pit studies from the 2008-9 Norway-US Scientific Traverse of East Antarctica  

NASA Astrophysics Data System (ADS)

The Norway-US Scientific Traverse of East Antarctica is an International Polar Year (IPY) collaborative effort to examine the mass balance of the East Antarctic plateau, focusing on the region of Dronning Maud Land. The traverse field campaign spanned two field seasons, with an inland-bound leg and outland-bound leg during the austral summers of 2007-8 and 2008-9, respectively. An international team of researchers conducted extensive field work en route, including shallow firn cores, shallow, deep and intermediate radar profiles, gravity measurements, firn temperature profiles, borehole stratigraphy, and snow pit studies. This report focuses on the results of snow pit studies of the second year's outland-bound leg from South Pole Station (US) to Troll Station (NOR), which consisted of density, stratigraphy, and snow grain geometry profiles. This traverse route crossed over a variety of features of the East Antarctic ice sheet, including a system of subglacial lakes, points crossed by the International Glaciological Year (IGY) Queen Maud Land traverses of 1964-1968, and a variety of depositional features. The area is predominantly a low-accumulation region where little previous field work had been conducted, the IGY Queen Maude Land traverses being the last scientific traverse to cross this region previous. We compare the physical property profiles collected to the snow pit studies of Koerner (1971) at Plateau Station and to satellite radar data of the larger region.

Courville, Z.; Albert, M. R.

2012-12-01

348

Long time-series monitoring of the ecosystem at Deception Island, Antarctica: description of instrumentation  

NASA Astrophysics Data System (ADS)

A description of the oceanographic instrumentation developed and deployed at Deception Island, Antarctica during the period 9 March 1999 to 20 November 2000 as part of the ERUPT program is presented. This instrumentation includes (1) an autonomous weather station (Terrestrial station) to record daily conditions and ice-cover, (2) an underwater time-lapse camera/sediment trap array to photograph the abundance and movements of bottom-dwelling animals and collect sinking particulate matter, (3) an acoustic array to monitor movements of macrozooplankton and nekton, (4) an autonomous, vertically profiling pump sampler to capture and preserve plankton and nekton from discrete depths, (5) thermistor arrays to record water temperature at various depths, (6) an acoustic Doppler profiler to record current velocities at discrete depths, and (7) a piston-operated grab respirometer to measure sediment community oxygen consumption and recover sediments. The Terrestrial station and thermistor arrays, current meter and grab respirometer were the most successful instruments deployed, producing large data sets. The acoustic array produced some data of limited value, while the camera tripod and pump sampler produced no useful data due to technical and operational problems.

Glatts, R. C.; Uhlman, A. H.; Smith, K. L.; Baldwin, R. J.

2003-06-01

349

Nutrient exchange in an Antarctic macrolichen during summer snowfall snow melt events  

Microsoft Academic Search

Concentrations of NH4+, NO3-, PO43-, K+, Ca2+ and Mg2+ in snow meltwater resulting from summer snow showers were monitored before and after its passage through monospecific stands of the Antarctic macrolichen Usnea sphacelata R. Br. The sampling was conducted under field conditions near Casey Station in East Antarctica between January and March. Total snow deposition during the 61-d period was

P. D. Crittenden

1998-01-01

350

Coastal-change and glaciological map of the Ross Island area, Antarctica  

USGS Publications Warehouse

Reduction in the area and volume of Earth?s two polar ice sheets is intricately linked to changes in global climate and to the resulting rise in sea level. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council. On the basis of these recommendations, the U.S. Geological Survey used its archive of satellite images to document changes in the cryospheric coastline of Antarctica and analyze the glaciological features of the coastal regions. The Ross Island area map is bounded by long 141? E. and 175? E. and by lat 76? S. and 81? S. The map covers the part of southern Victoria Land that includes the northwestern Ross Ice Shelf, the McMurdo Ice Shelf, part of the polar plateau and Transantarctic Mountains, the McMurdo Dry Valleys, northernmost Shackleton Coast, Hillary Coast, the southern part of Scott Coast, and Ross Island. Little noticeable change has occurred in the ice fronts on the map, so the focus is on glaciological features. In the western part of the map area, the polar plateau of East Antarctica, once thought to be a featureless region, has subtle wavelike surface forms (megadunes) and flow traces of glaciers that originate far inland and extend to the coast or into the Ross Ice Shelf. There are numerous outlet glaciers. Glaciers drain into the McMurdo Dry Valleys, through the Transantarctic Mountains into the Ross Sea, or into the Ross Ice Shelf. Byrd Glacier is the largest. West of the Transantarctic Mountains are areas of blue ice, readily identifiable on Landsat images, that have been determined to be prime areas for finding meteorites. Three subglacial lakes have been identified in the map area. Because McMurdo Station, the main U.S. scientific research station in Antarctica, is located on Ross Island in the map area, many of these and other features in the area have been studied extensively. The paper version of this map is available for purchase from the USGS Store.

Ferrigno, Jane G.; Foley, Kevin M.; Swithinbank, Charles; Williams, Richard S., Jr.

2010-01-01

351

Cloud and precipitation properties from ground-based remote sensing instruments in East Antarctica  

NASA Astrophysics Data System (ADS)

A new comprehensive cloud-precipitation-meteorological observatory has been established at Princess Elisabeth base, located in the escarpment zone of Dronning Maud Land, East Antarctica. The observatory consists of a set of ground-based remote sensing instruments (ceilometer, infrared pyrometer and vertically profiling precipitation radar) combined with automatic weather station measurements of near-surface meteorology, radiative fluxes, and snow accumulation. In this paper, the observatory is presented and the potential for studying the evolution of clouds and precipitating systems is illustrated by case studies. It is shown that the synergetic use of the set of instruments allows for distinguishing ice, mixed-phase and precipitating clouds, including some information on their vertical extent. In addition, wind-driven blowing snow events can be distinguished from deeper precipitating systems. Cloud properties largely affect the surface radiative fluxes, with liquid-containing clouds dominating the radiative impact. A statistical analysis of all measurements (in total 14 months mainly occurring in summer/autumn) indicates that these liquid-containing clouds occur during as much as 20% of the cloudy periods. The cloud occurrence shows a strong bimodal distribution with clear sky conditions 51% of the time and complete overcast conditions 35% of the time. Snowfall occurred 17% of the cloudy periods with a predominance of light precipitation and only rare events with snowfall > 1 mm h-1 water equivalent (w.e.). Three of such intensive snowfall events occurred during 2011 contributing to anomalously large annual snow accumulation. This is the first deployment of a precipitation radar in Antarctica allowing to assess the contribution of the snowfall to the local surface mass balance. It is shown that on the one hand large accumulation events (>10 mm w.e. day-1) during the measurement period of 26 months were always associated with snowfall, but that on the other hand snowfall did not always lead to accumulation. In general, this promising set of robust instrumentation allows for improved insight in cloud and precipitation processes in Antarctica and can be easily deployed at other Antarctic stations.

Gorodetskaya, I. V.; Kneifel, S.; Schween, J. H.; Crewell, S.; Van Lipzig, N. P. M.

2014-07-01

352

GPS water vapour estimation using meteorological data from Chinese Antarctic research stations  

Microsoft Academic Search

This paper mainly discusses the research deducing atmospheric Precipitable Water Vapor (PWV) from tropospheric zenith wet delay using ground-based GPS receivers. China GreatWall and ZhongShan stations in Antarctica were taken as the researching sites. The data from SCAR Antarctic GPS Campaigns Epoch 1998\\/1999\\/2000 are used to construct the GPS analytical networks. A high-accuracy GPS processing software package-GAMIT\\/GLOBK is utilized; Multiple

Xiao Cheng; Yanmei Zhang; E. Dongchen; Yun Shao

2003-01-01

353

The cryptoendolithic microbial environment in the Ross Desert of Antarctica: satellite-transmitted continuous nanoclimate data, 1984 to 1986  

NASA Technical Reports Server (NTRS)

A satellite mediated station for monitoring nanoclimate (climate in the millimeter range) data, suitable for use in polar regions is described. The station, located in the Ross desert of Antarctica, has been in operation for more than 3 years, measuring rock temperatures, air temperature, light, snow, wind, and moisture. The data indicate that biological activity in the cryptoendolithic microbial ecosystem is limited to the period from mid November to mid February. The total number of hours of biological activity, based on assumptions of the minimum light, temperature and moisture requirements of the community, is less than 1000 h/year. The time above 0 degrees C, representing more nearly optimal conditions, is between 50 and 550 h/year, depending on the orientation of the surface.

Friedmann, E. I.; McKay, C. P.; Nienow, J. A.

1987-01-01

354

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2010 CFR

...false Restrictions on collection of meteorites in Antarctica. 674.4 Section 674...NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may...

2010-10-01

355

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2012 CFR

...false Restrictions on collection of meteorites in Antarctica. 674.4 Section 674...NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may...

2012-10-01

356

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2011 CFR

...false Restrictions on collection of meteorites in Antarctica. 674.4 Section 674...NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may...

2011-10-01

357

45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.  

Code of Federal Regulations, 2013 CFR

...false Restrictions on collection of meteorites in Antarctica. 674.4 Section 674...NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may...

2013-10-01

358

Tropical Pacific Influence on the Source and Transport of Marine Aerosols to West Antarctica  

E-print Network

The climate of West Antarctica is strongly influenced by remote forcing from the tropical Pacific. For example, recent surface warming over West Antarctica reflects atmospheric circulation changes over the Amundsen Sea, ...

Criscitiello, Alison S.

359

An analysis of Pc3 and Pc4 pulsations at Terra Nova Bay (Antarctica)  

E-print Network

An analysis of Pc3 and Pc4 pulsations at Terra Nova Bay (Antarctica) U. Villante, M. Vellante, G) detected, during the austral summer 1994±95, at Terra Nova Bay (Antarctica, corrected latitude 80.0°S

Boyer, Edmond

360

The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating  

E-print Network

; ice; sublimation; Antarctica 1. Introduction Beacon Valley in the Dry Valleys region, Ant- arcticaThe oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating Jo March 2000 Abstract Beacon Valley, Antarctica, contains unique remnants of glacier ice underneath a till

Marchant, David R.

361

The biogeochemistry of Si in the McMurdo Dry Valley lakes, Antarctica  

E-print Network

The biogeochemistry of Si in the McMurdo Dry Valley lakes, Antarctica Heather E. Pugh1 *, Kathleen) of Antarctica. Our data and calculations indicate that biological uptake of Si is not a major process as in temperate systems. Accepted 1 October 2002 Key words: Antarctica, lakes, silica, biogeochemistry

Priscu, John C.

362

Seismic observations of sea swell on the floating Ross Ice Shelf, Antarctica  

E-print Network

Seismic observations of sea swell on the floating Ross Ice Shelf, Antarctica L. M. Cathles IV,1 by several orders of magnitude over the time period that sea ice surrounding Antarctica decreases from its of Alaska. These remote events emphasize how the iceberg calving margin of Antarctica is connected

Boyce, C. Kevin

363

Thickness of the Atmospheric Boundary Layer Above Dome A, Antarctica, during 2009  

E-print Network

Thickness of the Atmospheric Boundary Layer Above Dome A, Antarctica, during 2009 C. S. BONNER,1 M s at Dome A, Antarctica between 2009 February 4 and 2009 August 18. The median thickness of the boundary increase. Winds within the boundary layer over Antarctica are usually katabatic in na- ture. This suggests

Ashley, Michael C. B.

364

Relative humidity over Antarctica from radiosondes, satellites, and a general circulation model  

E-print Network

Relative humidity over Antarctica from radiosondes, satellites, and a general circulation model A to validate measurements of relative humidity (RH) over Antarctica from the Atmospheric Infrared Sounder (AIRS over Antarctica is well reproduced by the satellite. AIRS data are also compared to simulations from

Walden, Von P.

365

LIDAR AND RADAR INVESTIGATION OF INERTIA GRAVITY WAVE INTRINSIC PROPERTIES AT MCMURDO, ANTARCTICA  

E-print Network

LIDAR AND RADAR INVESTIGATION OF INERTIA GRAVITY WAVE INTRINSIC PROPERTIES AT MCMURDO, ANTARCTICA lidar campaign ongoing at McMurdo (77.8° S, 166.7° E), Antarctica has provided high Antarctica are rare yet important due to its potential influence on MLT temperatures and dynamics [4

Chu, Xinzhao

366

CALIPSO observations of wave-induced PSCs with near-unity optical depth over Antarctica in  

E-print Network

CALIPSO observations of wave-induced PSCs with near-unity optical depth over Antarctica in 2006 Antarctica during the 2006 and 2007 austral winters. These clouds are rare (less than 1% of profiles with daily temperature minimas across Antarctica. Lidar and depolarization ratios within these clouds suggest

Boyer, Edmond

367

A new high-latitude record for the macaroni penguin (Eudyptes chrysolophus) at Avian Island, Antarctica  

E-print Network

Island, Antarctica K. B. Gorman · E. S. Erdmann · B. C. Pickering · P. J. Horne · J. R. Blum · H. M penguins (Eudyptes chrysolophus) on Avian Island, Antarctica, approximately 1° south of the Antarctic of Antarctica. We also report more frequent extra-l

368

LETTER doi:10.1038/nature11616 Increased future ice discharge from Antarctica owing  

E-print Network

LETTER doi:10.1038/nature11616 Increased future ice discharge from Antarctica owing to higher snowfall over Antarctica, which would provide a direct offset of the future contribution to global sea Antarctica1,6 and thus in the ultimate fate of the precipitation- deposited ice mass. Here we show

Levermann, Anders

369

Application of Optical Flow and Scale Space Methods to Sea-Ice Motion in Antarctica  

E-print Network

Application of Optical Flow and Scale Space Methods to Sea-Ice Motion in Antarctica Salvador Guti computer vision and scale-space theory are applied to the study of sea-ice motion in Antarctica. The input into account that there is practically no ground-truth data available for Antarctica in the form of buoy

Long, David G.

370

Climatology of katabatic winds in the McMurdo dry valleys, southern Victoria Land, Antarctica  

E-print Network

Climatology of katabatic winds in the McMurdo dry valleys, southern Victoria Land, AntarcticaMurdo dry valleys, Antarctica. Winter wind events can increase local air temperatures by 30°C. The frequency (0315, 0325); 3349 Meteorology and Atmospheric Dynamics: Polar meteorology; KEYWORDS: Antarctica, dry

Fountain, Andrew G.

371

Geophysical models for the tectonic framework of the Lake Vostok region, East Antarctica  

E-print Network

Geophysical models for the tectonic framework of the Lake Vostok region, East Antarctica Michael of East Antarctica were used to develop a conceptual tectonic model for the Lake Vostok region. The model a tectonic boundary within East Antarctica. Based on our kinematic and flexural gravity modelling

Levin, Vadim

372

Snow grain-size measurements in Antarctica Michel GAY,1,2  

E-print Network

Snow grain-size measurements in Antarctica Michel GAY,1,2 Michel FILY,1 Christophe GENTHON,1-known characteristic of snow at the surface of Antarctica. In the past, grain-size has been reported using various-size distribution from fieldwork in Antarctica. In particular, except at sites affected by a very particular meteor

Paris-Sud XI, Université de

373

S125JULY 2010STATE OFTHE CLIMATE IN 2009 | 6. ANTARCTICA  

E-print Network

S125JULY 2010STATE OFTHE CLIMATE IN 2009 | 6. ANTARCTICA a. Overview--R. L. Fogt The calendar year 2009 was relatively calm, climatologically speaking, for much of Antarctica, especially compared, the tropical El Niño event in late 2009 did influence Antarctica, particularly through ridging in the South

374

Two-dimensional structure of long-period pulsations at polar latitudes in Antarctica  

E-print Network

1 Two-dimensional structure of long-period pulsations at polar latitudes in Antarctica N.V. Yagova-periods about ten minutes are analyzed using data from magnetometer arrays in Antarctica. Examination of the 2D be monitored with ground-based magnetic observations at polar latitudes in Antarctica and the Arctic. Because

375

COMPUTER VISION APPLICATIONS TO THE STUDY OF SEA-ICE MOTION IN ANTARCTICA  

E-print Network

COMPUTER VISION APPLICATIONS TO THE STUDY OF SEA-ICE MOTION IN ANTARCTICA Salvador Guti ­ The motion of sea-ice in Antarctica is stud- ied using QuikSCAT scatterometer imagery using meth- ods from covered or in the dark side of the earth, such as Antarctica. Among available data it is worthy to note

Long, David G.

376

Tropical Pacific Influence on the Source and Transport of Marine Aerosols to West Antarctica*  

E-print Network

Tropical Pacific Influence on the Source and Transport of Marine Aerosols to West Antarctica 2013) ABSTRACT The climate of West Antarctica is strongly influenced by remote forcing from the tropical Pacific. For example, recent surface warming over West Antarctica reflects atmospheric circulation

Karnauskas, Kristopher

377

Soil Biology & Biochemistry 38 (2006) 30193034 Terrestrial ecosystem processes of Victoria Land, Antarctica  

E-print Network

, Antarctica J.E. Barretta,�, R.A. Virginiaa , D.W. Hopkinsb , J. Aislabiec , R. Bargaglid , J.G. Bockheime , I, Antarctica are ideal systems to test hypotheses about the sensitivity of ecosystem processes to climate in Victoria Land, Antarctica are constrained by combinations of extreme conditions includ- ing low

Wall, Diana

378

Energetic consequences of repeated and prolonged dehydration in the Antarctic midge, Belgica antarctica  

E-print Network

antarctica Nicholas M. Teets a, , Yuta Kawarasaki b , Richard E. Lee Jr. b , David L. Denlinger a of the Antarctic midge, Belgica antarctica, routinely face periods of limited water availability in their natural environments on the Antarctic Peninsula. As a result, B. antarctica is one of the most dehydration

Lee Jr., Richard E.

379

100 Years of Humans in Antarctica1 by Lily Whiteman, National Science Foundation2  

E-print Network

100 Years of Humans in Antarctica1 by Lily Whiteman, National Science Foundation2 3 This winter marks the 100th anniversary of the race to the South Pole. After crossing Antarctica -- the coldest on Anvers Island in the Antarctic Peninsula Region. Forbidding though Antarctica is, the Amundsen

South Bohemia, University of

380

Optical Flow and Scale-Space Theory applied to Sea-Ice Motion Estimation in Antarctica  

E-print Network

Optical Flow and Scale-Space Theory applied to Sea-Ice Motion Estimation in Antarctica Salvador-- Sea-ice motion in Antarctica is studied applying methods from computer vision and scale-space theory-ice directions and speeds on Antarctica has been previously approached with correlation [1] or wavelet [2], [3

Long, David G.

381

Rayleigh wave phase velocity analysis of the Ross Sea, Transantarctic Mountains, and East Antarctica  

E-print Network

Antarctica from a temporary seismograph array Jesse F. Lawrence,1,2 Douglas A. Wiens,1 Andrew A. Nyblade,3 from the Ross Sea (RS) region of the West Antarctica rift system, the Transantarctic Mountains (TAMs), and part of East Antarctica (EA). The Transantarctic Mountain Seismic Experiment deployed 41 three

382

Quantifying sulfate components and their variations in soils of the McMurdo Dry Valleys, Antarctica  

E-print Network

Quantifying sulfate components and their variations in soils of the McMurdo Dry Valleys, Antarctica 2006; published 16 August 2006. [1] Many soils of the McMurdo Dry Valleys (MDV), Antarctica, being oldMurdo Dry Valleys, Antarctica, J. Geophys. Res., 111, D16301, doi:10.1029/2005JD006669. 1. Introduction 1

Marchant, David R.

383

A New Species of Nototheniid (Perciformes: Notothenioidei) Fish from McMurdo Sound, Antarctica  

E-print Network

A New Species of Nototheniid (Perciformes: Notothenioidei) Fish from McMurdo Sound, Antarctica PAUL Sea region of Antarctica. The new species closely resembles the only known congener, C. peninsulae routine surveys at a heavily-sampled site in McMurdo Sound, Ross Sea, Antarctica happened upon a fish

Cheng, Chi-Hing Christina

384

Surface mass balance and stable oxygen isotope ratios from shallow firn cores on Fimbulisen, East Antarctica  

E-print Network

Antarctica E. SCHLOSSER,1 H. ANSCHU¨ TZ,2 E. ISAKSSON,3 T. MARTMA,4 D. DIVINE,5 O.-A. N�ST3 1 Institute, Tromsø, Norway ABSTRACT. The mass balance of Antarctica is one of the crucial factors for determining sea was carried out on Fimbulisen, an ice shelf in East Antarctica, to investigate its recent surface mass balance

Schlosser, Elisabeth

385

Eastern Australia: A possible source of dust in East Antarctica interglacial ice  

E-print Network

Eastern Australia: A possible source of dust in East Antarctica interglacial ice M. Revel-Rolland a and Marine Isotopic Stage 5.5) to Antarctica. During glacial times, studies have shown that the South Antarctica ice core dust Earth and Planetary Science Letters 249 (2006) 1­13 www

Demouchy, Sylvie

386

Ice Shelf Water plume flow beneath Filchner-Ronne Ice Shelf, Antarctica  

E-print Network

Ice Shelf Water plume flow beneath Filchner-Ronne Ice Shelf, Antarctica Paul R. Holland,1 Daniel L Filchner- Ronne Ice Shelf, Antarctica and its underlying ocean cavity. Ice Shelf Water (ISW) plumes-Ronne Ice Shelf, Antarctica, J. Geophys. Res., 112, C05044, doi:10.1029/2006JC003915. 1. Introduction [2

Feltham, Daniel

387

Seismic evidence for deep low-velocity anomalies in the transition zone beneath West Antarctica  

E-print Network

Seismic evidence for deep low-velocity anomalies in the transition zone beneath West Antarctica in Antarctica that were all restricted to the analysis of the fundamental mode. This paper is therefore mostly Byrd Land, West Antarctica and a portion of the Pacific^ Antarctic Ridge close to the Balleny Islands

388

Glaciological and climatic significance of Hercules Dome, Antarctica: An optimal site for deep ice core drilling  

E-print Network

variability and may provide new information on rapid climate change events in Antarctica. The sensitivity in Antarctica are tied to the magnitude of these changes. A great deal has been written about past changesGlaciological and climatic significance of Hercules Dome, Antarctica: An optimal site for deep ice

Jacobel, Robert W.

389

Understanding water effect on Candida antarctica lipase B activity and enantioselectivity towards  

E-print Network

1 Understanding water effect on Candida antarctica lipase B activity and enantioselectivity towardsW) on Candida antarctica lipase B (CALB) activity and enantioselectivity towards secondary alcohols was assessed that water has many effects on Candida antarctica lipase B (CALB) catalyzed enantioselective reactions

Paris-Sud XI, Université de

390

Odd cloud in the Ross Sea, Antarctica  

NASA Technical Reports Server (NTRS)

On January 28, 2002, MODIS captured this image of an interesting cloud formation in the boundary waters between Antarctica's Ross Sea and the Southern Ocean. A dragon? A snake? A fish? No, but it is an interesting example of the atmospheric physics of convection. The 'eye' of this dragon-looking cloud is likely a small spot of convection, the process by which hot moist air rises up into the atmosphere, often producing big, fluffy clouds as moisture in the air condenses as rises into the colder parts of the atmosphere. A false color analysis that shows different kinds of clouds in different colors reveals that the eye is composed of ice crystals while the 'body' is a liquid water cloud. This suggests that the eye is higher up in the atmosphere than the body. The most likely explanation for the eye feature is that the warm, rising air mass had enough buoyancy to punch through the liquid water cloud. As a convective parcel of air rises into the atmosphere, it pushes the colder air that is higher up out of its way. That cold air spills down over the sides of the convective air mass, and in this case has cleared away part of the liquid cloud layer below in the process. This spilling over of cold air from higher up in the atmosphere is the reason why thunderstorms are often accompanied by a cool breeze. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

2002-01-01

391

Intercomparison of ozone measurements over Antarctica  

SciTech Connect

Measurements of the abundances of ozone over Antarctic in August and September 1987 obtained during the Airborne Antarctic Ozone Experiment are intercompared. These measurements of ozone concentrations and total column abundance were obtained by three satellite instruments, two IR and one UV column-measuring instruments aboard the DC-8, one in situ DC-8, and two in situ ER-2 instruments, an upward looking lidar aboard the DC-8, and ozonesondes from four sites in Antarctica. Given the natural variability of ozone in the Antarctic and the fact that the data were not truly coincident spatially and temporally, this intercomparison is suitable only for identifying gross disparities among the techniques, rather than confirming the accuracies as rigorously as is normally done in an intercomparison. This paper presents a summary of the ozone data, using the data and accuracies given by the individual investigators in the individual papers in this issue, without any attempt to critically review or evaluate the data. In general, very good agreement (within about 10-20%, limited by natural variability) among the various techniques was found, with no systematic biases detected. These observations confirm the low ozone amounts reported in the Antarctic stratosphere.

Margitan, J.J.; Farmer, C.B.; Toon, G.C. (California Inst. of Tech., Pasadena (United States)); Brothers, G.A. (Chemal, Inc., Wallops Island, VA (United States)); Browell, E.V.; Gregory, G.L.; Hypes, W.; Larsen, J.C.; McCormick, M.P. (NASA Langley Research Center, Hampton, VA (United States)); Cariolle, D. (Centre National de la Recherches Meteorologiques, Toulouse (France)); Coffey, M.T.; Mankin, W. (National Center for Atmospheric Research, Boulder, CO (United States)); Farman, J.C. (British Antarctic Survey, Cambridge (United Kingdom)); Harder, J.W.; Mount, G.H.; Ravishankara, A.R.; Schemeltekopf, A.L.; Tuck, A.F. (NOAA Aeronomy Lab., Boulder, CO (United States)); Hofmann, D.J. (Univ. of Wyoming, Laramie (United States)); Ismail, S.; Kooi, S. (ST Systems, Inc., Hampton, VA (United States)); Jakoubek, R.O.; Proffitt, M.H.; Wahner, A.; Watterson, I. (NOAA Aeronomy Lab., Boulder, CO (United States) Univ. of Colorado, Boulder (United States)); Komhyr, W. (NOAA Air Resources La

1989-11-30

392

Hydrogen emissions from Erebus volcano, Antarctica  

NASA Astrophysics Data System (ADS)

The continuous measurement of molecular hydrogen (H2) emissions from passively degassing volcanoes has recently been made possible using a new generation of low-cost electrochemical sensors. We have used such sensors to measure H2, along with SO2, H2O and CO2, in the gas and aerosol plume emitted from the phonolite lava lake at Erebus volcano, Antarctica. The measurements were made at the crater rim between December 2010 and January 2011. Combined with measurements of the long-term SO2 emission rate for Erebus, they indicate a characteristic H2 flux of 0.03 kg s-1 (2.8 Mg day-1). The observed H2 content in the plume is consistent with previous estimates of redox conditions in the lava lake inferred from mineral compositions and the observed CO2/CO ratio in the gas plume (˜0.9 log units below the quartz-fayalite-magnetite buffer). These measurements suggest that H2 does not combust at the surface of the lake, and that H2 is kinetically inert in the gas/aerosol plume, retaining the signature of the high-temperature chemical equilibrium reached in the lava lake. We also observe a cyclical variation in the H2/SO2 ratio with a period of ˜10 min. These cycles correspond to oscillatory patterns of surface motion of the lava lake that have been interpreted as signs of a pulsatory magma supply at the top of the magmatic conduit.

Moussallam, Yves; Oppenheimer, Clive; Aiuppa, Alessandro; Giudice, Gaetano; Moussallam, Manuel; Kyle, Philip

2012-11-01

393

Fabric and texture at Siple Dome, Antarctica  

USGS Publications Warehouse

Preferred c-axis orientations are present in the firn at Siple Dome, West Antarctica, and recrystallization begins as shallow as 200 m depth in ice below -20??C, based on digital analysis of c-axis fabrics, grain-sizes and other characteristics of 52 vertical thin sections prepared in the field from the kilometer-long Siple Dome ice core. The shallowest section analyzed, from 22 m, shows clustering of c axes toward the vertical. By 200 m depth, girdle fabric and other features of recrystallized ice are evident in layers (or regions), separated by layers (regions) of typically finer-grained ice lacking evidence of recrystallization. Ice from about 700-780 m depth, which was deposited during the last ice age, is especially fine-grained, with strongly vertical c axes, but deeper ice shows much larger crystals and strong evidence of recrystallization. Azimuthal asymmetry of some c-axis fabrics, trends in grain-size, and other indicators reveal additional information on processes and history of ice flow at Siple Dome.

Diprinzio, C. L.; Wilen, L. A.; Alley, R. B.; Fitzpatrick, J. J.; Spencer, M. K.; Gow, A. J.

2005-01-01

394

The Center for Astrophysics in Antarctica  

NASA Technical Reports Server (NTRS)

Nowhere on Earth are the infrared skies clearer, darker, or more stable than on the high Antarctic Plateau. At some wavelengths, Antarctic telescopes may be more than one to two orders of magnitude more efficient than at other sites. However, exploiting these advantages requires first addressing the formidable practical difficulties of working in the remote and frigid polar environment. This was the motivation for the Center for Astrophysical Research in Antarctica (CARA), one of twenty-five National Science Foundation Science and Technology Centers. At its inception, the Center organized its research into four projects. Three - AST/RO, COBRA, and SPIREX - address key problems in star formation, evolution of galaxies, and the distribution of matter in the early universe. They feature surveys which can be conducted effectively with moderate-size telescopes operated in a highly automated mode. They also explore the potential of the Antarctic Plateau for a broad range of astrophysical research over a spectral range extending from the near-infrared to millimeter wavelengths. A fourth, ATP, was created to obtain quantitative data on the qualities of the South Pole site and to plan for future scientific projects. During the next five years, AST/RO, COBRA, and SPIREX will become operational, and the Center will begin to build a second generation of telescopes which can address a broader range of problems and accommodate a larger community of users.

Pernic, Robert J.; Harper, D. AL, Jr.; Bausch, Judith A.

1995-01-01

395

Tectonic evolution of west Antarctica and its relation to east Antarctica  

SciTech Connect

West Antarctica consists of five major blocks of continental crust separated by deep sub-ice basins. Marie Byrd Land appears to have been rifted off the adjacent margin of the East Antarctic craton along the line of the Transantarctic Mountains during the Mesozoic. Ellsworth-Whitmore mountains and Haag Nunataks blocks were also rifted from the margin of the craton. They appear to have moved together with the Antarctic Peninsula and Thurston Island blocks, segments of a Pacific margin Mesozoic-Cenozoic magmatic arc, during the Mesozoic opening of the Weddell Sea basin. Paleomagnetic data suggest that all four of these blocks remained attached to western Gondwanaland (South America-Africa) until approximately 125 m.y. ago, and that the present geographic configuration of the Antarctic continent was essentially complete by the mid-Cretaceous, although important Cenozoic rifting has also occurred. Fragmentation of the Gondwanaland supercontinent was preceded in the Middle to Late Jurassic by an important and widespread thermal event of uncertain origin that resulted in the emplacement of an extensive bimodal igneous suite in South America, Africa, Antarctica, and Australia. This was associated with the development of the composite back-arc basin along the western margin of South America. Inversion of this basin in the mid-Cretaceous initiated Andean orogenesis. The presentation will include new data from the joint US-UK West Antarctic Tectonics Project.

Dalziel, I.W.D.

1987-05-01

396

Station Tour: Russian Segment  

NASA Video Gallery

Expedition 33 Commander Suni Williams concludes her tour of the International Space Station with a visit to the Russian segment, which includes Zarya, the first segment of the station launched in 1...

397

Climatology of the East Antarctic ice sheet (100[degrees]E to 140[degrees]E) derived from automatic weather stations  

SciTech Connect

The authors present a climate picture of a large share of eastern Antarctica, arrived at from records obtained from automatic weather stations. These stations have permitted sampling of such data over extended periods of time, which have not been possible before. Data from remote sensing units has been sampled by the ARGOS data collection system on the NOAA series satellites since the late 1970's. Data is presented on temperature, pressure, and wind speed and direction.

Allison, I. (Antarctic Cooperative Research Centre, Hobart (Australia)); Wendler, G. (Univ. of Tasmania, Hobart (Australia)); Radok, U. (Univ. of Colorado, Boulder (United States))

1993-05-20

398

CURRICULUM VITAE James F. Casey  

E-print Network

with Farmers in Calakmul, Campeche."(Funded through United States Forest Service International Grant) M. Research Associate, Cooperative Tourism Research Center, North Carolina State University, 2004. Visiting Willingness to Pay to Avoid Crowding at Dive Sites. (With Pete Schuhmann and David Gill), Tourism in Marine

Marsh, David

399

Kerem Pekkan S. Casey Jones  

E-print Network

and computational fluid dynamics (CFD). All the previous CFD studies have employed the structured mesh generation tunnel through the right atrium or an external conduit that diverts blood around the right atrium 1 been investi- gated by in vitro experiments 5,6 and computational fluid dy- namic CFD studies

Pekkan, Kerem

400

World Hydrogen Fueling Stations  

NSDL National Science Digital Library

This document provides information on hydrogen fueling stations in the United States and other countries including Canada, Australia, Germany and Japan. Individual fueling stations are profiled, including the fuel type provided, when it was opened, how the hydrogen is produced and other details. Small photographs of each station are also included. This document may be downloaded in PDF file format.

2012-09-06

401

Southwestern Research Station  

NSDL National Science Digital Library

This Web site profiles AMNH's Southwestern Research Station (SWRS), a year-round field station that allows biologists, geologists, and anthropologists to study the diverse environments and biotas of the Chiricahua Mountains in southeastern Arizona. The site includes an overview of the field station and its work, information on courses offered, and information for visitors, researchers, interns and volunteers.

402

Permafrost and periglacial research in Antarctica: New results and perspectives  

NASA Astrophysics Data System (ADS)

In the last two years the research within the Antarctic Permafrost, Periglacial Environments and Soils (ANTPAS) Expert Group of the Scientific Committee on Antarctic Research (SCAR) and Working Group of the International Permafrost Association (IPA) provided new results on the dynamics of periglacial environments both in Maritime and Continental Antarctica. In continental Antarctica despite the absence of air warming, in the last 15 years an active layer thickening and acceleration of permafrost degradation erosional phenomena were reported, these being mainly related to the increase of solar radiation. On the other hand, in Maritime Antarctica, with a dramatic air warming, permafrost degradation has been observed, but the role of snow cover on the ground energy balance and consequently on permafrost and active layer has been underlined. Moreover, many contributions on the knowledge on the characteristics of the Antarctic soils were carried out in several areas along a wide latitudinal range.

Guglielmin, Mauro; Vieira, Gonçalo

2014-11-01

403

Ecological biogeography of the terrestrial nematodes of victoria land, antarctica.  

PubMed

The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems. PMID:25061360

Adams, Byron J; Wall, Diana H; Virginia, Ross A; Broos, Emma; Knox, Matthew A

2014-01-01

404

Alternative regimes for mineral-resource development in Antarctica  

SciTech Connect

Alternative regimes for Antarctica are evaluated within which nonliving resources of the continent and adjacent offshore areas can be developed and managed. The study estimates: (a) the better options for each of the states active in Antarctica, and (b) the minerals regime which would best serve the interest of the Antarctic Treaty Consultative States. Multi-Attribute Utility Analysis was used to evaluate alternative regimes, including: (1) identification of relevant interests of states in Antarctica, (2) estimation of the relative importance of these interests for all relevant actors, (3) definition of alternative minerals regimes, and (4) evaluation of the probable effect of each alternative on satisfaction of the interests of each state. The data were used to calculate each state's utilities for the twelve options considered. A questionnaire was sent to Antarctic experts in all Consultative countries.

Westermeyer, W.E.

1982-01-01

405

Cryoconite and Ice-bubble Microbial Ecosystems in Antarctica  

NASA Technical Reports Server (NTRS)

During the Antarctica 2000 Expedition samples of rocks and ice bubbles entrained in ice were collected from the blue ice fields near the Moulton Escarpment of the Thiel Mountains (85S, 94W) and the Morris Moraine of the Patriot Hills (80S, 8 1 W) Ellsworth Mountains of Antarctica. Investigation of the microbiota of these cryoconite and ice bubble ecosystems are now being conducted to help refine chemical and morphological biomarkers of potential significance to Astrobiology. The Antarctica 2000 Expedition will be discussed and the preliminary results of the studies of the ice bubble and cryoconite microbial ecosystems discussed. Recent ESEM images of the Antarctic microbiota will be presented a the relevance of ice ecosystems to Astrobiology will be discussed.

Hoover, Richard B.; Rose, M. Franklin (Technical Monitor)

2000-01-01

406

Arctic, Antarctic, and Alpine Research, Vol. 35, No. 2, 2003, pp. 214217 Populations of Antarctic Hairgrass (Deschampsia antarctica)  

E-print Network

Hairgrass (Deschampsia antarctica) Show Low Genetic Diversity Rolf Holderegger,* Ivana Stehlik,à Ronald I, Deschampsia antarctica. Populations of D. antarctica from two widely separated regions of the maritime that new populations of D. antarctica are founded by one or few individuals, which mainly reproduce by self

Barrett, C.H.

407

Rifting beneath Antarctica's ice sheet: A plate tectonic Supervisors: Graeme Eagles (RHUL) & Fausto Feraccioli (British Antarctic Survey)  

E-print Network

Rifting beneath Antarctica's ice sheet: A plate tectonic approach Supervisors: Graeme Eagles (RHUL Pacific can be used to determine by how much, and when, eastern and western Antarctica moved apart from Antarctica-West Antarctica motion. One specific advantage will come from using a modelling tool

Royal Holloway, University of London

408

Dehydration-induced cross tolerance of Belgica antarctica larvae to cold and heat is facilitated by trehalose accumulation  

E-print Network

that changes in temperature tolerance in B. antarctica are linked to the rate and severity of dehydrationDehydration-induced cross tolerance of Belgica antarctica larvae to cold and heat is facilitated Antarctica Midge Larvae of the Antarctic midge, Belgica antarctica (Diptera: Chironomidae), are frequently

Lee Jr., Richard E.

409

Ice plug prevents irreversible discharge from East Antarctica  

NASA Astrophysics Data System (ADS)

Changes in ice discharge from Antarctica constitute the largest uncertainty in future sea-level projections, mainly because of the unknown response of its marine basins. Most of West Antarctica's marine ice sheet lies on an inland-sloping bed and is thereby prone to a marine ice sheet instability. A similar topographic configuration is found in large parts of East Antarctica, which holds marine ice equivalent to 19 m of global sea-level rise, that is, more than five times that of West Antarctica. Within East Antarctica, the Wilkes Basin holds the largest volume of marine ice that is fully connected by subglacial troughs. This ice body was significantly reduced during the Pliocene epoch. Strong melting underneath adjacent ice shelves with similar bathymetry indicates the ice sheet's sensitivity to climatic perturbations. The stability of the Wilkes marine ice sheet has not been the subject of any comprehensive assessment of future sea level. Using recently improved topographic data in combination with ice-dynamic simulations, we show here that the removal of a specific coastal ice volume equivalent to less than 80 mm of global sea-level rise at the margin of the Wilkes Basin destabilizes the regional ice flow and leads to a self-sustained discharge of the entire basin and a global sea-level rise of 3-4 m. Our results are robust with respect to variation in ice parameters, forcing details and model resolution as well as increased surface mass balance, indicating that East Antarctica may become a large contributor to future sea-level rise on timescales beyond a century.

Mengel, M.; Levermann, A.

2014-06-01

410

Distribution of Narrow-Width Magnetic Anomalies in Antarctica.  

PubMed

Data for aeromagnetic profiles obtained in Antarctica during the 1963-64 austral summer were used together with earlier results to construct a map showing the areal distribution of narrow-width magnetic anomalies. Numerous anomalies are associated with known volcanic mountains in western Antarctica. A large area of few anomalies is probably a result of an extension of the thick metasedimentary section observed in the Ellsworth Mountains. Portions of the Trans-Antarctic Mountains have associated anomalies which are probably caused by late Cenozoic volcanic rocks. PMID:17811603

Behrendt, J C

1964-05-22

411

Antarctic hypsometry and the source of East Antarctica's anomalous topography  

NASA Astrophysics Data System (ADS)

The re-examined hypsometry of Antarctica based on BEDMAP2 data reveals deglaciated modal elevations of ~-450 m and ~650 m for West and East Antarctica, respectively. Although the East Antarctic modal elevation is 300 m lower than the original measurement, it still renders the plateau topographically anomalous by ~400-600 m with respect to the existing global continental modal elevation estimates of 87 m and 250 m. Superimposed on the plateau are the Gamburtsev Subglacial Mountains, the Dronning Maud Land Mountains and the Vostok Highlands with modal elevations ~400 m in excess of the East Antarctic mode. To ascertain whether East Antarctica's anomalous topography can be attributed to Airy-type crustal compensation, a continental-scale crustal thickness model is derived from the inversion of GOCO03S satellite gravity data constrained by seismic crustal thickness measurements. The average crustal thickness of East Antarctica is ~40 km (for West Antarctica ~24 km), a value typical of Archean shields. While crustal thickening to >50 km locally beneath the Gamburtsev Subglacial Mountains and Dronning Maud Land can account for their differential modal elevation above the plateau, the evidently typical Archean crust elsewhere across East Antarctica offers no suggestion of crustal-level continental-scale support for the broader plateau. The plateau of southern Africa offers a tectonic analogue: Like East Antarctica, the lithosphere is largely Archean and cratonic, the crust is of typical shield thickness, there is no obvious Cenozoic tectonism and the upper mantle does not appear to be unduly perturbed. The relative accessibility of the African continent, meanwhile, has led to conclusive imaging of large-scale perturbations in the lower mantle beneath the southern African plateau pointing to dynamic, rather that isostatic, support of the associated long wavelength topography. While several global seismic tomography models infer somewhat anomalously slow lower mantle structure beneath Antarctica, the resolution presently offered by such models in this region is poor. That said, the apparent absence of crustal-level continental-scale support for the East Antarctic plateau coupled with the fact that the underlying upper mantle does not appear unduly anomalous suggest, by analogy with southern Africa, lower mantle generated epeirogeny as a likely explanation for the anomalous topography. The incorporation of data from the Antarctic seismic deployments of recent years in the next generation of global tomography models should resolve the issue.

O'Donnell, J.; Nyblade, A.

2013-12-01

412

Epicormic Schoots in a Permian Gymnosperm from Antarctica  

E-print Network

KU ScholarWorks | http://kuscholarworks.ku.edu Epicormic Shoots In A Permian Gymnosperm From Antarctica 2010 by Anne-Laure Decombeix, Edith L. Taylor , and Thomas N. Taylor This work has been made available by the University of Kansas Libraries... version can be found at the link below. Decombeix, A., Taylor, E., and Taylor, T. 2010. Epicormic Shoots in a Permian Gymnosperm from Antarctica. International Journal of Plant Sciences 171(7): 772-782. Published version: http://dx.doi.org/10...

Decombeix, Anne-Laure; Taylor, Edith L.; Taylor, Thomas N.

2010-01-01

413

Macrofossil Evidence For Pleuromeialean Lycophytes From the Triassic of Antarctica  

E-print Network

KU ScholarWorks | http://kuscholarworks.ku.edu Macrofossil Evidence For Pleuromeialean Lycophytes From the Triassic of Antarctica 2010 by Benjamin Bomfleur, Michael Krings, Edith L. Taylor, and Thomas N. Taylor This work has been made available...-203. Published version: http://dx.doi.org/10.4202/app.2010.0022 Terms of Use: http://www2.ku.edu/~scholar/docs/license.shtml Macrofossil evidence for pleuromeialean lycophytes from the Triassic of Antarctica BENJAMIN BOMFLEUR, MICHAEL KRINGS, EDITH L. TAYLOR...

Bomfleur, Benjamin; Krings, Michael; Taylor, Edith L.; Taylor, Thomas N.

2010-01-01

414

Climate change during the last deglaciation in Antarctica  

SciTech Connect

Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated. 21 refs,. 2 figs.

Mayewski, P.A.; Twickler, M.S.; Whitlow, S.I. [and others

1996-06-14

415

The GRAD high-altitude balloon flight over Antarctica  

SciTech Connect

The Gamma Ray Advanced Detector(GRAD) consists of a n-type germanium detector inside an active bismuth-germanate Compton and charged particle shield with additional active plastic shielding across the aperture. It will be flown on a high altitude balloon at 36 km altitude at a latitude of 78{degree} S over Antarctica for observations of gamma radiation emitted by the radioactive decay of {sup 56}Co in the Supernova SN1987A, for assessment of the performance of bismuth-germanate scintillation material in the radiation environment of near space, for gathering information on the gamma-ray background over Antarctica, and for testing fault-tolerant software.

Eichhorn, G. (Space Astronomy Laboratory, University of Florida, Gainesville, FL 32609 (US)); Coldwell, R.L.; Dunnam, F.E.; Rester, A.C. (Institute of Astrophysics and Planetary Exploration, University of Florida, Alachua, FL 32615 (US)); Trombka, J.I.; Starr, R. (NASA Goddard Spaceflight Center, Greenbelt, MD 20771 (US)); Lasche, G.P. (DARPA/NMO, Arlington, VA (US))

1989-05-15

416

Space Station Live: Station Communications Upgrade  

NASA Video Gallery

NASA Public Affairs Officer Nicole Cloutier-Lemasters recently spoke with Penny Roberts, one of the leads for the International Space Station Avionics and Software group, about the upgrade of the K...

417

Radar BackscatterMeasurementsFrom RADARSAT S A R Imagery of South Pole Station, Antarctica  

E-print Network

Lake City, UT 84112-0115USA. Tel: (801) 581-3611Fax: (801) 581-8219 sohn@iceberg.mps,ohio-state.edu;jezek@iceberg.mps.ohio-state.edu; baum@iceberg.mps.ohio-state.edu;rick.forster@geog.u~.edu;thompson.4@osu.edu ABSTRACT Ice Sheet

Howat, Ian M.

418

Temporary Storage of Fuel-Contaminated Soil at McMurdo Station, Antarctica  

NSF Publications Database

... drums may hinder fuel spill remediation this season. Cleanup of a fuel spill near Tank D-6 at ... minimize accidental fuel spills and reduce their impact. Overfill alarms on fuel storage tanks have ...

419

FY 1993 environmental sampling and analysis report for wastewater discharge at McMurdo Station, Antarctica  

SciTech Connect

Wastewater impact assessment at McMurdo has been or is being conducted by four organizations: Antarctic Support Associates (ASA), which conducts the effluent monitoring; Moss Landing Marine Laboratories, which conducts all of the benthic monitoring and most of the biological monitoring; Montana State University, which conducted water quality and water current measurements; and EG&G Idaho, which conducted water quality and sea ice monitoring. All four programs are interrelated and were needed to determine the impact of the wastewater discharge on the marine environment. This report summarizes the relevant monitoring work being conducted by Antarctic Support Associates, Moss Landing, and Montana State personnel, and specifically documents the results of EG&G Idaho`s efforts.

Crockett, A.B.

1994-04-01

420

Estimations of the age of the ice beneath Dome A, Antarctica  

NASA Astrophysics Data System (ADS)

The drilling of a deep ice core at the Chinese Kunlun station, Dome A, East Antarctica, is about to start with high expectations on obtaining the oldest possible ice so far. The Alpine type bedrock of the Gamburtsev mountains in combination with a largely undetermined geothermal heat flux distribution raises questions on the basal thermal conditions that via the melting rate have a strong feedback on the vertical flow velocity and in consequence on the age/depth horizons. Additionally, the undetermined ice fabric introducing anisotropic effects in rheology have to be taken into account. By deploying a full Stokes ice sheet model (http://elmerice.elmerfem.org) we investigate the influence of those parameters, namely anisotropy as well as geothermal heat flux values, on the spatial distribution of the age close to the bedrock. Results are compared with dated radar isochrones in the upper one third of the ice sheet. We find that a non-unique combination of parameters is able to closely reproduce those measured values, leading to the conclusion, that without additional information, the basal age beneath Kunlun station remains undetermined. However, our simulations suggest that vast spatial variation of basal melting rates and, in consequence, the age/depth distribution over a relative small domain exists, increasing the motivation for ice coring, obtaining both high resolution as well as possibly oldest ice from the same site.

Zwinger, Thomas; Sun, Bo; Liyun, Liyun; Moore, John C.; Steinhage, Daniel; Martin, Carlos

2014-05-01

421

Seismic anisotropy beneath Dronning Maud Land, Antarctica, revealed by shear wave splitting  

NASA Astrophysics Data System (ADS)

Shear wave splitting analyses have been carried out using teleseismic data from broad-band seismograph stations deployed at temporary and permanent locations in Dronning Maud Land (DML), Antarctica. In most cases, the observed anisotropy can be related to major tectonic events that formed the present-day Antarctic continent. We rule out an anisotropic contribution from recent asthenospheric flow. At the Russian base Novolazarevskaya near the coast in central DML, waveform inversion suggests a two-layer model where the fast direction of the upper layer is oriented parallel to Archean fabrics in the lithosphere, whereas the anisotropy of the lower layer is interpreted to have been created during the Jurassic Gondwana break-up. Recordings at the South African base Sanae IV, however, show enigmatic results. For narrow backazimuthal segments, splitting parameters show strong variations together with a multitude of isotropic measurements, indicative of complex scattering that cannot be explained by simple one- or two-layer anisotropic models. In the interior of the continent, the data are consistent with single-layer anisotropy, but show significant spatial variations in splitting parameters. A set of temporary stations across the Heimefront shear zone in western DML yield splitting directions that we interpret as frozen anisotropy from Proterozoic assembly of the craton. An abrupt change in fast axis direction appears to mark a suture between the Grunehogna craton, a fragment of the Kalahari-Kaapvaal craton in southern Africa and the Mesoproterozoic Maudheim Province.

Bayer, Bettina; Müller, Christian; Eaton, David W.; Jokat, Wilfried

2007-10-01

422

Study of PCBs and PBDEs in King George Island, Antarctica, using PUF passive air sampling  

NASA Astrophysics Data System (ADS)

Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of ? indicator PCBs and ?14 PBDEs ranged from 1.66 to 6.50 pg m-3 and from 0.67 to 2.98 pg m-3, respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m-3 (average 15.2 pg m-3). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere.

Li, Yingming; Geng, Dawei; Liu, Fubin; Wang, Thanh; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

2012-05-01

423

Balloon-borne observations of stratospheric aerosol in Antarctica from 1972 to 1984  

NASA Technical Reports Server (NTRS)

Stratospheric levels of particles with r or = 0.15 microns were monitored with optical particle counters in approximately monthly balloon soundings at Laramie, Wyoming (41 deg N) since 1971. These measurements were used to characterize the background stratospheric aerosol layer and the disturbed layer following major volcanic eruptions. Levels of particles with r or = 0.01 microns have also been measured with balloon-borne counters since 1973. The latter are collectively called condensation nuclei (CN) as they are characteristic of aerosol in the early stages of growth. While they dominate the size distribution in the tropsophere, they are a trace species in the undisturbed stratosphere. From 1972 until 1980, annual balloon soundings from McMurdo Station (78 deg S) and/or Amundsen-Scott Station (90 deg S), in Antarctica, have also been conducted to crudely monitor Southern Hemisphere aerosol levels. These measurements were continued in 1983 and 1984. Profiles of r 0.15 microns aerosol concentrations as measured during January at the south pole from 1972 to 1975 and in 1980 are given. The former are typical of undisturbed conditions and indicate the small degree of variability under these conditions. The latter indicates the effect of minor volcanic activity, visible in the 10 to 15 km region.

Hofmann, D. J.

1985-01-01

424

Space Radar Image of Weddell Sea, Antarctica  

NASA Technical Reports Server (NTRS)

This Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar color composite shows a portion of the Weddell Sea, which is adjacent to the continent of Antarctica. The image shows extensive coverage of first-year sea ice mixtures and patches of open water inside the ice margin. The image covers a 100 kilometer by 30 kilometer (62 mile by 18.5 mile) region of the southern ocean, centered at approximately 57 degrees south latitude and 3 degrees east longitude, which was acquired on October 3, 1994. Data used to create this image were obtained using the L-band (horizontally transmitted and vertically received) in red; the L-band (horizontally transmitted and received) in green; and the C-band (horizontally transmitted and received) in blue. The sea ice, which appears rust-brown in the image, is composed of loosely packed floes from approximately 1 meter to 2 meters (3 feet to 6.5 feet) thick and ranging from 1 meter to 20 meters (3 feet to 65.5 feet) in diameter. Large patches of open water, shown as turquoise blue, are scattered throughout the area, which is typical for ice margins experiencing off-ice winds. The thin, well-organized lines clearly visible in the ice pack are caused by radar energy reflected by floes riding the crest of ocean swells. The wispy, black features seen throughout the image represent areas where new ice is forming. Sea ice, because it acts as an insulator, reduces the loss of heat between the relatively warm ocean and cold atmosphere. This interaction is an important component of the global climate system. Because of the unique combination of winds, currents and temperatures found in this region, ice can extend many hundreds of kilometers north of Antarctica each winter, which classifies the Weddell Sea as one of nature's greatest ice-making engines. During the formation of sea ice, great quantities of salt are expelled from the frozen water. The salt increases the density of the upper layer of sea water, which then sinks to great depths. Oceanographers believe this process forms most of the oceans' deep water. Sea ice covering all of the southern oceans, including the Weddell Sea, typically reaches its most northerly extent in about September. As periods of daylight become gradually longer in the Southern Hemisphere, ice formation stops and the ice edge retreats southward. By February, most of the sea ice surrounding Antarctica disappears. Imaging radar is extremely useful for studying the polar regions because of the long periods of darkness and extensive cloud cover. The multiple frequencies of the SIR-C/X-SAR instruments allow further study into ways of improving the separation of the various thickness ranges of sea ice, which are vital to understanding the heat balance in the ice, ocean and atmospheric system. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

1994-01-01

425

Low-power magnetometer observation with satellite data transmission at unmanned site in Antarctica  

NASA Astrophysics Data System (ADS)

We will report technical experiences from 6 years of unmanned low power magnetometer observation in Antarctica with daily data transmission via Iridium satellite telephone link. One of the difficulties of unmanned observation in Antarctica is dark winter months in which power supply from solar panel can not be expected. One solution for this difficulty is to minimize the power consumption (as small as ~1 W) to manage the observation in winter months with limited amount of batteries (~400Ah). Another difficulty is to collect data from the observation site. It is quite expensive and laborious to send a party to the observation site to obtain the data in Antarctica. Although cost for satellite communication is expensive, it is much more economical to collect data via satellite data link by installing a telephone terminal into the observation system. It seems that power consumption of a satellite phone (~10 W) does not fit to the low power system. However, as long as the observed data is not too large (<1 Mbyte per day), turn on period of the satellite phone is short (<1 hour per day) and the daily average of total power consumption lies within the available power of ~1 W. We have developed low-power magnetometer system with Iridium satellite phone data link. Basic design of the low-power system is similar to that developed by British Antarctic Survey (intermittent operation of magnetometer and GPS). However, we have made some improvements; reduced power consumption (0.2 W) at high sampling rate (1Hz) and increased sensitivity (0.2nT), so that geomagnetic pulsation study can be possible. In our observation system, satellite data transfer is only made in sunlit season with the total power consumption of 1 W (0.8W for Iridium phone and 0.2W for others). During dark winter months, observed data are stored in CF memory with diminished power consumption of 0.2W. When the sun comes in spring, the stored data are transmitted along with the daily observed data. It takes nearly two months to complete the transmission of data stored in winter months. We have installed two sets of low-power magnetometer at inland and coastal area in January, 2007. We added one set every austral summer and, by January 2010, 5 magnetometers are deployed within a radius of 700km from Syowa Station. The observed data can be used for the study of magnetic pulsations, as well as small and medium scale structure of ionospheric currents at the time of auroral substorm.

Yamagishi, H.; Kadokura, A.

2012-12-01

426

Onset on Ice Stream D, West Antarctica  

NASA Technical Reports Server (NTRS)

Surface flow in a 10,000 sq km area of the onset area of ice stream D was measured by repeat, precise GPS (Global Positioning System) surveys over a one-year interval. The pattern of velocity and strain rate illustrates the development of ice stream D. The major flow into D originates south of Byrd Station. Using flow parameters derived by assuming ice at Byrd is not sliding, the deformation component of velocity at all grid locations was calculated using the local ice thickness and a surface slope averaged over 40 km (-20 ice thicknesses). The results imply that ice entering the grid from its upstream boundary is already sliding. However, calculation of the relationship between the driving stress, the ice thickness and the velocity shows that the developing ice stream is very different from ice at Byrd Station, possibly due to warmer effective ice temperatures or a different rheology.

Bindschadlar, Robert; Chen, X.; Vornberger, P.

1998-01-01

427

Airborne geophysical study in the pensacola mountains of antarctica.  

PubMed

A seismic reflection, gravity, and aeromagnetic reconnaissance was made in the Pensacola Mountains, Antarctica, during the 1965-66 austral summer. Prominent ice streams located between the Neptune and Patuxent Ranges and east of the Forrestal Range overlie channels in the rock surface 2000 meters below sea level which are probably of glacial origin. Seismic reflections show that the Filchner Ice Shelf is 1270 meters thick near its southern margin. Along the boundary between West and East Antarctica, Bouguer anomalies decrease from +60 milligals in West Antarctica to -80 milligals in East Antarctica. An abrupt change in crustal structure across this boundary is required to explainl the 2 milligals per kilometer gradient. This may indicate a fault extending through the crust into the mantle. Aeromagnetic profiles delineate anomalies up to 1800 gamma associated with the basic stratiform intrusion which comprises the Dufek and Forrestal ranges. A probable minimum area of 9500 square kilometers is calculated for the intrusive body on the basis of the magnetic anomalies, making it one of the largest bodies of its type. The extension of this magnetic anominaly across a fault forming the north border of the Pensacola Mountains probably precludes transcurrent movement. PMID:17814385

Behrendt, J C; Meister, L; Henderson, J R

1966-09-16

428

Average September Ozone Levels over Antarctica for 1979 to 1998  

NSDL National Science Digital Library

The evolution of the ozone hole over Antarctica as shown through measurements of average ozone for September for the years 1979 through 1998, excluding 1995. These measurements were made by the TOMS instruments on Nimbus-7, Meteor-3 and Earth Probe. Dark blue represent regions of low ozone and red represents regions of high ozone.

Shirah, Greg; Newman, Paul

1998-10-02

429

Discovery of new hydrothermal vent sites in Bransfield Strait, Antarctica  

Microsoft Academic Search

We carried out a search for hydrothermal vents in the Central Basin of Bransfield Strait, Antarctica. The ZAPS (zero angle photon spectrometer) chemical sensor and instrument package (Oregon State University), OFOS (ocean-floor observation system) camera sled and TVG (TV-grab) (GEOMAR) were used to explore the water column and underlying seafloor. These operations were supplemented with a series of dredges. Hydrothermal

G. P. Klinkhammer; C. S. Chin; R. A. Keller; A. Dählmann; H. Sahling; G. Sarthou; S. Petersen; F. Smith; C. Wilson

2001-01-01

430

Large Chemical Variations in ice Formed Above Lake Vostok, Antarctica  

Microsoft Academic Search

Lake Vostok is the largest subglacial lake identified in Antarctica. It is 260 km long, 80 km wide, over 500 m deep and lies beneath ˜4 km of ice. It has received great scientific interest since it may provide clues to the survival of life on Earth during global glaciations, and provides an analogue for environments that may harbour life

G. W. Royston-Bishop; M. Tranter; M. J. Siegert

2004-01-01

431

INTRODUCTION The midge, Belgica antarctica, is the southernmost  

E-print Network

). In these experiments we examined how adults of B. antarctica cope with the desiccating Antarctic environment. We did so coast of the Antarctic Peninsula and the South Shetland Islands where clusters of larvae can number in the thousands (Sugg et al., 1983). Only two other dipterans, also midges, exist in sub-Antarctic regions

Lee Jr., Richard E.

432

Satellite remote sensing of blowing snow properties over Antarctica  

Microsoft Academic Search

A new technique for the detection of blowing snow events using satellite lidar data is applied to Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) observations to obtain the spatial and temporal frequency, layer height, and optical depth of blowing snow events over Antarctica for 2007 through 2009. In addition, spatially and temporally collocated multichannel Moderate resolution Imaging Spectroradiometer (MODIS) data are

Stephen P. Palm; Yuekui Yang; James D. Spinhirne; Alexander Marshak

2011-01-01

433

Surface temperature and salinity variations between Tasmania and Antarctica, 19931999  

E-print Network

the temperature data. The Levitus climatological and Reynolds satellite monthly mean sea surface temperature dataSurface temperature and salinity variations between Tasmania and Antarctica, 1993­1999 Alexis 2002. [1] Continuous surface temperature and salinity measurements have been collected onboard a supply

434

Looking for Life in Antarctica  and on Mars  

NSDL National Science Digital Library

This online article, from Earth: Inside and Out, reports on the search for microscopic organisms on Earth and Mars. It discusses the work of Chris McKay, an astrobiologist with NASA, the planetary similarities between Earth and Mars and current research in the valleys of Antarctica.

435

Microbial community composition in soils of Northern Victoria Land, Antarctica  

E-print Network

Microbial community composition in soils of Northern Victoria Land, Antarctica Thomas D- tribution, structure and activity of soil communities anywhere in Victoria Land are available, and their sensitivity to potential climate change remains largely unknown. We investigated soil microbial communi- ties

Wall, Diana

436

Observations in Hemichloris antarctica Tschermak-Woess & Friedmann . . . .  

E-print Network

The chlorococcalean genus Hemichloris is characterized by the possession of two chloroplasts per vegetative cell. The occurrence of a second species of the genus is reported (H. polyspora sp. nov.). Just as H. antarctica it grows cryptoendolithically in sandstone in Southern Victoria Land, Antarctica. In H. antarctica propagation by two autospores prevails over four, whilst in the new species H. polyspora in general four or eight (rarely 16 or 32) autospores are produced and Borodinellastages do occur typically. Sexuality and zoosporulation do not exist in both species. Internal structures of chloroplasts can be observed by light microscopy more regularly in H. polyspora than in H. antarctica and under various conditions. Investigations of both Hemichloris species by transmission electron microscopy show them to go back to more or less extended assemblages of plastoglobuli. In both species the plastoglobuli are arranged around tubular inflations of thylakoids and apparently attached to the thylakoids. Keeping the cultures for three (even up to seven) months without light makes them survive and causes coming forth of the chloroplast structure throughout.

E. Tschermak-Woess; M. Hua; G. Gärtner; M. Hesse

2006-01-01

437

Desiccation tolerance of three moss species from continental Antarctica  

Microsoft Academic Search

Tolerance of desiccation was examined in three species of moss, Grimmia antarctici Card., Ceratodon purpureus (Hedw.) Brid. and Bryum pseudotriquetrum (Hedw.) Gaertn., Meyer et Scherb. collected from two sites of contrasting water availability in the Windmill Islands, continental Antarctica. Physiological tolerance to desiccation was measured using chlorophyll fluorescence in plugs of moss during natural drying in the laboratory. Differences in

Sharon A. Robinson; J. Wasley; M. Popp; C. E. Lovelock

2000-01-01

438

Parts of Antarctica's King George Island are littered with trash  

NASA Astrophysics Data System (ADS)

A report released 7 February by ecologists from Germany's Friedrich Schiller University Jena reveals that parts of King George Island, a logistical hub for international research in Antarctica, are home to open pits of trash, decaying field huts, and other forms of pollution.

Kumar, Mohi

2013-02-01

439

Antarctica: Arena for South American Cooperation or Conflict.  

ERIC Educational Resources Information Center

A number of converging circumstances suggest that Antarctica may be a major object of geopolitical attention in South America in the decade to come. The Malvinas/Falklands crisis focused geopolitical attention on the South Atlantic and the chain of Southern (Austral) Islands which link the southern tip of South America to the Antarctic Peninsula.…

Child, Jack

440

A late winter hydrographic section from Tasmania to Antarctica  

Microsoft Academic Search

A hydrographic section between Tasmania and Antarctica was occupied in late winter 1991 as part of the World Ocean Circulation Experiment (WOCE). The primary purpose of the WOCE repeat section SR3 is to measure the exchange between the Indian and Pacific Oceans south of Australia. This paper describes the fronts, water masses and transport observed on the first occupation of

Stephen R. Rintoul; John L. Bullister

1999-01-01

441

Accelerated Sea-Level Rise from West Antarctica  

Microsoft Academic Search

Recent aircraft and satellite laser altimeter surveys of the Amundsen Sea sector of West Antarctica show that local glaciers are discharging about 250 cubic kilometers of ice per year to the ocean, almost 60% more than is accumulated within their catchment basins. This discharge is sufficient to raise sea level by more than 0.2 millimeters per year. Glacier thinning rates

R. Thomas; E. Rignot; G. Casassa; P. Kanagaratnam; C. Acuña; T. Akins; H. Brecher; E. Frederick; P. Gogineni; W. Krabill; S. Manizade; H. Ramamoorthy; A. Rivera; R. Russell; J. Sonntag; R. Swift; J. Yungel; J. Zwally

2004-01-01

442

Vascular plants as bioindicators of regional warming in Antarctica  

Microsoft Academic Search

Monitoring selected populations of the only two native Antarctic vascular plant species (Colobanthus quitensis andDeschampsia antarctica) over a 27-year period has revealed a significant and relatively rapid increase in numbers of individuals and populations at two widely separated localities in the maritime Antarctic. There is strong evidence that this increase is a response to a warming trend in summer air

R. I. Lewis Smith

1994-01-01

443

Epilithic lichens in the Beacon sandstone formation, Victoria Land, Antarctica  

NASA Technical Reports Server (NTRS)

The epilithic lichen flora on the Beacon sandstone formation in Victoria Land consists of seven species: Acarospora gwynnii Dodge & Rudolph, Buellia grisea Dodge & Baker, B. pallida Dodge & Baker, Carbonea capsulata (Dodge & Baker) Hale comb. nov., Lecanora fuscobrunnea Dodge & Baker, Lecidea cancriformis Dodge & Baker, and L. siplei Dodge & Baker. The typification of the species is given along with descriptions and distribution in Antarctica.

Hale, M. E.; Friedmann, E. I. (Principal Investigator)

1987-01-01

444

Airborne geophysical study in the pensacola mountains of antarctica  

USGS Publications Warehouse

A seismic reflection, gravity, and aeromagnetic reconnaissance was made in the Pensacola Mountains, Antarctica, during the 1965-66 austral summer. Prominent ice streams located between the Neptune and Patuxent Ranges and east of the Forrestal Range overlie channels in the rock surface 2000 meters below sea level which are probably of glacial origin. Seismic reflections show that the Filchner Ice Shelf is 1270 meters thick near its southern margin. Along the boundary between West and East Antarctica, Bouguer anomalies decrease from +60 milligals in West Antarctica to -80 milligals in East Antarctica. An abrupt change in crustal structure across this boundary is required to explain the 2 milligals per kilometer gradient. This may indicate a fault extending through the crust into the mantle. Aeromagnetic profiles delineate anomalies up to 1800 ?? associated with the basic stratiform intrusion which comprises the Dufek and Forrestal ranges. A probable minimum area of 9500 square kilometers is calculated for the intrusive body on the basis of the magnetic anomalies, making it one of the largest bodies of its type. The extension of this magnetic anomaly across a fault forming the north border of the Pensacola Mountains probably precludes transcurrent movement.

Behrendt, J. C.; Meister, L.; Henderson, J. R.

1966-01-01

445

Geochemical processes in the Lake Fryxell Basin (Victoria Land, Antarctica)  

Microsoft Academic Search

Major ion, nutrient, transition metal, and cadmium concentrations are presented for nine meltwater streams flowing into Lake Fryxell, a permanently stratified lake with an anoxic hypolimnion in Taylor Valley, Antarctica. For the major ions, stream compositions are considered in terms of dissolution of marine-derived salts and chemical weathering of local rocks. Although Lake Fryxell has undergone significant evaporative concentration, only

William J. Green; Thomas J. Gardner; Timothy G. Ferdelman; Michael P. Angle; Lawrence C. Varner; Philip Nixon

1989-01-01

446

Study of long path VLF signal propagation characteristics as observed from Indian Antarctic station, Maitri  

NASA Astrophysics Data System (ADS)

To examine the quality and propagation characteristics of the Very Low Frequency (VLF) radio waves in a very long propagation path, Indian Centre for Space Physics, Kolkata, participated in the 27th Indian scientific expedition to Antarctica during 2007-2008. One Stanford University made AWESOME VLF receiving system was installed at the Indian Antarctic station Maitri and about five weeks of data were recorded successfully from the Indian transmitter VTX and several other transmitting stations worldwide. The quality of the signal from the VTX transmitter was found to be very good, consistent and highly stable in day and night. The signal shows the evidences of the presence of the 24 h solar radiation in the Antarctic region during local summer. Here we report the both narrow band and broadband VLF observations from this site. The diurnal variations of VTX signal (18.2 kHz) are presented systematically for Antarctica path and also compared the same with the variations for a short propagation path (VTX-Kolkata). We compute the spatial distribution of the VTX signal along the VTX-Antarctica path using the most well-known LWPC model for an all-day and all-night propagation conditions. The calculated signal amplitudes corresponding to those conditions relatively corroborate the observations. We also present the attenuation rate of the dominant waveguide modes corresponding to those propagation conditions where the effects of the Antarctic polar ice on the attenuation of different propagating waveguide modes are visible.

Sasmal, Sudipta; Pal, Sujay; Chakrabarti, Sandip K.

2014-10-01

447

Upper Mantle Seismic Anisotropy Beneath West Antarctica from Shear Wave Splitting Analysis of POLENET/ANET Data  

NASA Astrophysics Data System (ADS)

We constrain azimuthal anisotropy in the Antarctic upper mantle using shear wave splitting parameters obtained from teleseismic SKS, SKKS, and PKS phases recorded at 30 broad-band seismometers deployed in West Antarctica, and the Transantarctic Mountains as a part of POLENET/ANET. The first seismometers were deployed in late 2007 and additional seismometers were deployed in 2008 and 2009. The seismometers generally operate year-round using solar power, insulated boxes, and either rechargeable AGM or primary lithium batteries. We used an eigenvalue technique to linearize the rotated and shifted shear wave particle motions and determine the best splitting parameters. Robust windows around the individual phases were chosen using the Teanby cluster-analysis algorithm. We visually inspected all results and assigned a quality rating based on factors including signal-to-noise ratios, particle motions, and error contours. The best results for each station were then stacked to get an average splitting direction and delay time. The delay times range from 0.33 to 1.33 s, but generally average about 1 s. We conclude that the splitting results from anisotropy in the upper mantle, since the large splitting times cannot be accumulated in the relatively thin crust (20-30 km) of the region. Overall, fast directions in West Antarctica are at large angles to the direction of Antarctic absolute plate motion in either hotspot or no-net rotation frameworks, showing that the anisotropic fabric does not result from shear associated with the motion of Antarctica over the mantle. The West Antarctic fast directions are also much different than those found in East Antarctica by previous studies. We suggest that the East Antarctic splitting results from anisotropy frozen into the cold cratonic continental lithosphere, whereas West Antarctic splitting is related to Cenozoic tectonism. Stations within the West Antarctic Rift System (WARS), a region of Cenozoic extension, show fast directions subparallel to the inferred WARS extension direction. Stations located in the Ellsworth-Whitmore Mountains (EWM) show fast directions parallel to those found within WARS. Furthermore, results from WARS and from EWM all show relatively large splitting times of 0.6 - 1.33 s. These results suggest upper mantle anisotropy that results from mantle flow and deformation related to the extensional deformation of the region. Two stations were installed in the Pensacola Mountains which are located grid-north of the EWM. The results from this region deviate from the dominant fast orientation seen in WARS but appear to be approximately perpendicular to the strike of the mountain range. Stations in Marie Byrd Land (MBL) show inconsistent fast directions and a wide range of delay times (0.3 - 0.9 s), perhaps as a result of complex mantle fabric related to a possible MBL hotspot.

Accardo, N.; Wiens, D. A.; Hernandez, S.; Aster, R. C.; Nyblade, A.; Anandakrishnan, S.; Huerta, A. D.; Wilson, T. J.

2011-12-01

448

Space station power system  

NASA Technical Reports Server (NTRS)

The major requirements and guidelines that affect the space station configuration and power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts are described and linked to the present concept. Trade study selections of photovoltaic system technologies are described in detail. A summary of present solar dynamic and power management and distribution systems is also given.

Baraona, Cosmo R.

1987-01-01