The United States Antarctic Research Report to the Scientific Committee on Antarctic Research (SCAR) Number 32 - 1990 (1991) / Chapter Skim
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Prospectus of Planned Activities, 1 April 1990 - 31 March 1990
Prospectus of Planned Activities, 1 April 1990 - 31 March 1990
Pages 24-58
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From page 24... ...
To obtain data, 20 balloons carrying various instruments will be launched near Amundsen-Scott South Pole Station. The instruments will measure water vapor, ozone, temperature, winds, infrared heat flux, and on some flights, nitric acid vapor.
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From page 25... ...
The investigative team will continue long-term measurements of trace atmospheric constituents that may influence climate. Working at the South Pole Station observatory, four scientists during the austral summer and two personnel during the austral winter will measure carbon dioxide, surface ozone, winds, pressure, air and snow temperature, atmospheric moisture, and trace constituents from the station's clean-air facility.
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From page 26... ...
Extending the work performed at Amundsen-Scott South Pole Station, this austral summer investigators will photograph halos and simultaneously sample falling ice crystal at the Soviet station Vostok. By comparing computer simulations of halos with observed halos and crystals, they hope to clarify the relationship between crystal types and halo types.
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From page 27... ...
These convergent features appear to dominate the antarctic surface climate. This austral summer will be the first phase of this project.
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From page 28... ...
The weather stations are used to study the barrier wind along the Transantarctic Mountains, vertical motion and sensible and latent heat flux from the Ross Ice Shelf, foehn winds flowing from the Beardmore and Byrd Glaciers onto the Ross Ice Shelf, katabatic flow in East Antarctica, and propagating weather systems at the South Pole. The weather stations also gather continuous and reliable meteorological data that support aircraft operations at McMurdo Station.
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From page 29... ...
The primary interest is in the extent to which aurora seen by DE-1 in the Northern Hemisphere mirror those observed at the South Pole. During this austral summer, a research team will inspect and service this equipment.
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From page 30... ...
from South Pole Station was utilized. With this telescope and a modified version used during the 1982-83 and 1984-85 austral summers, global solar oscillations have been observed and recorded.
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From page 31... ...
Because these radio waves are strongly absorbed by the atmosphere, especially water vapor, South Pole Station, which is the second driest inhabited place on Earth, is the best place to make these measurements. Another great advantage of this location is that the circumpolar motion of the sky makes it possible to observe any spot in the sky through a constant thickness of atmosphere for any length of time.
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From page 32... ...
During the 1990-91 austral summer, investigators will again collaborate with Princeton University researchers (S-1131 in their study of cosmic background ~, ~ ..
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From page 33... ...
The objectives are to explore the nature of long-term variations and North-South asymmetries of solar activity; to investigate the acceleration, coronal transport, and interplanetary transport of energetic solar particles; to learn more about the three-dimensional structure of interplanetary magnetic turbulence; and to improve understanding of the solar modulation of galactic cosmic rays. All-sky camera measurements of the aurora australis from Amundsen-Scott South Pole Station Frank T
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From page 34... ...
The objective is to install and operate a sodium lidar at Amundsen-Scott South Pole Station so that information relevant to ozone depletion can be obtained, particularly data concerning the dynamics of upper atmospheric regions. Low-frequency/high-frequency programmal~le frequency receiver to the antarctic automatic geophysical observatories James ~ LaBelle, Dartmouth College For decades, intermittent ground observations have given tantalizing hints that the Earth's high-latitude ionosphere emits radio waves in the low-frequency to highfrequengy band (0.15-9.6 megahertz)
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From page 35... ...
To gather data about this poorly understood frequency band, investigators will use a programmable low-frequency~igh-frequency receiver, an array of small ferriterod antennas, a power subsystem, and data compression software deployed at two automatic geophysical observatory sites. Spectroscopic and interferometric studies of airglow and auroral processes in the antarctic upper atmosphere over South Pole Station G
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From page 36... ...
comes from research conducted in the austral spring and summer. This study, which uses data obtained from a 20-year population study of seals in the McMurdo Sound region, focuses on the winter movements and diving behavior of adult Weddell seals near McMurdo Sound.
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From page 37... ...
During the austral summer, sufficient light penetrates the ice cover to support the algal and bacterial photosynthesis that sustains a microflora population that is similar to temperate lakes without plant nutrients but with plentiful amounts of oxygen. The project focuses on the chemical and biological changes that occur during the austral summer (constant daylight)
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From page 38... ...
The study objectives are to determine which notothenioids use lateral-line systems to feed in the dark. Working near McMurdo Station, investigators will focus on two theories-that the lateral-line system can be tuned to identity important prey and that fishes living in deeper waters have more sensitive systems.
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From page 39... ...
These inputs appear to be influenced strongly by inputs from sea-ice microbial communities and by the movement of water from the Ross Sea into McMurdo Sound. Investigators believe that the trophic role of nano- and microzooplankton reflects the episodic nature of primary production in this system.
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From page 40... ...
1ne Mcmuroo L,ry Valleys, the ice-free region of southern Victoria Land, are among the most extreme desert ecosystems in the world. Like other desert regions, water is limited in these valleys, and this limitation combined with extremely low temperatures has prevented the development of vascular plants.
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From page 41... ...
Near McMurdo Station, the average temperature of the water is approximately -1.9oC and in the Antarctic Peninsula about -l.lo to 0.30 C As part of their adaptation to the cold, most antarctic fish produce biological antifreeze compounds; however, biologists also have found that some of these fish, such as Channichthyidae, substantially reduce red blood cells and hemoglobin and are protected from the cold because this lowers the viscosity of the blood.
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From page 42... ...
Experiments conducted during previous austral summers demonstrated that cold stability of microtubules from these fishes is caused by alterations in the structures of tubulin subunits and, to a lesser extent, in the MAPs. To extend the research this austral summer, investigators will determine the structural adaptations that enable antarctic fish to chemically assemble and disassemble cold-stable microtubules, characterize the structure of tubulin and MAPs that are involved in these interactions, clone and sequence the DNA messages that encode alpha and beta chains in tubulins, and determine the structure of tubulin genes from antarctic fish.
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From page 43... ...
The south polar skua represents one of the few examples where sibling aggression is mediated by hunger. The investigators' hypothesis predicts that when food is plentiful for chicks, aggression will decrease and fewer deaths, higher growth rates, and increased reproductive success will result.
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From page 44... ...
Primary production in coastal antarctic ecosystems is characterized by an intensive spring bloom. During this two-three month bloom, 70-90 percent of the annual organic carbon is produced, which, in turn, increases biological productivity at all levels, from bacteria to baleen whales.
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From page 45... ...
Sedimentology of the Permian-Triassic Gondwanaland sequence in the central Transantarctic Mountains James ~ Collinson, Ohio State University (S-055) This study promises significant new insights into fluvial sedimentology, the evolution of the Transantarctic foreland basin, and the relationship of the Transantarctic basin with other Gondwanaland basins.
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From page 46... ...
The Beardmore Glacier region of the Transantarctic Mountains has the most complete Gondwanaland sequence in Antarctica. Deposits in this region give evidence to a major change in the tectonic environment of the Transantarctic Mountains from a foreland basin associated with an active plate margin to a continental rift related to the Gondwanaland breakup.
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From page 47... ...
Developing a thorough understanding of the Cenozoic evolution of West Antarctica is the key to understanding the breakup of the Pacific margin of Gondwanaland; however, the nature and history of two lowland regions of central West Antarctica-the interior Ross embayment (between western Marie Byrd Land and the Transantarctic Mountains) and the Byrd subglacial basin (between eastern Marie Byrd Land and the Whitmore Mountains)
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From page 48... ...
Throughout the fieldwork, some reconnaissance for additional fossil plant localities will also be undertaken. Geological and geophysical studies in the Ford Range of Marie Byrd Land, West Antarctica Bruce P
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From page 49... ...
During previous field seasons, the research team has investigated the nature of the upper and lower crust in southern Victoria Land as recorded in alkaline magmas of the Erebus Volcanic Province over the last few million years. This austral summer, they want to expand their knowledge of the antarctic crust by sampling contemporaneous alkaline magmas of the Hallett Volcanic Province that extend about 600 kilometers to northern Victoria Land.
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From page 50... ...
The study objective is to examine the glacial and volcanic history of the region and the origin of the volcanoes. Working as part of a U.S., British, and New Zealand investigation, these scientists will study the geochemistry, volcanology, and tectonic history of these Marie Byrd Land volcanoes.
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From page 51... ...
In this study, field and laboratory work will focus on determining pre-Sirius paleotopography and structural geology; taking measurements and recording observations; collecting macro- and microplant material; searching for fossil insect, crustacean, bivalve, and fish material; collecting additional samples from the Sirius Group with the aim of expanding the collection of Cretaceous/Paleogene/Neogene microfossils which were transported from the interior basins of East Antarctica during the Late Pliocene/Early Pleistocene; and continuing to test the hypothesis that Pliocene glaciation in this part of Antarctica involved high-frequency variations of relatively small ice sheets, the development of protracted warm periods, and major marine invasions of the antarctic interior associated with periodic higher sea levels. Geochemistry of Paleozoic granites of the Transantarctic Mountains: phase 2 Donald J
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From page 52... ...
During several austral summers, investigators surveyed sites and installed equipment in southern Victoria Land's ice-free valleys. Eventually, data will be transmitted in real time via a geosynchronous satellite to the U.S.
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From page 53... ...
This austral summer, investigators will continue sampling of volcanic deposits and interbedded glacial tills in Taylor Valley and in the nearby Asgard and Quartermain Ranges. The results of this research will improve antarctic glacial chronology and associated tectonic history of the Transantarctic Mountains and will allow numerical ice-sheet reconstructions that help scientists to develop atmospheric modeling experiments of the influence of these ice sheets on southern hemisphere climate.
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From page 54... ...
program will examine the plate boundary between East Antarctica and the Ross embayment. Investigators will first acquire a 150-kilometer-long multichannel seismic reflection line starting on the Ross Ice Shelf and entering the Transantarctic Mountains front through one of the outlet glaciers.
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From page 55... ...
During the 1990-91 austral summer, investigators will gather seismic reflection data and collect piston core samples in the Bransfield basin (north of Palmer Station to King George Island) and along the continental margin (north of the South Shetland Islands)
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From page 56... ...
The objective of this study is to resolve the major features of the carbon and silica cycles along the continental shelf in the western Ross Sea area. Investigators will examine the vertical flux and water column dissolution/decomposition of opal and organic matter as part of a multidisciplinary investigation with investigators from North Carolina State University (S-268~.
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From page 57... ...
A significant element of the differences in these two global budgets may relate to how efficiently the water column and seabed preserve particulate material. Continuing an investigation begun during the 1989-90 austral summer, investigators will measure rates of production in surface waters, water-column regeneration, vertical flux, seabed regeneration, and accumulation to determine the preservation efficiency for silica and carbon fluxes in the Ross Sea.
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From page 58... ...
Frazil ice may play a key role in the complex Southern Ocean regime, yet the formation, growth, and behavior of frazil ice in both horizontal and vertical dimensions are the least understood components of the ocean/sea-ice system. Investigators will examine the physical and structural properties of antarctic sea ice to determine the quantities of frazil, platelet, and congelation ice in Ross Sea pack ice.
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