Probe of Suri’s interior based in Antarctica

Press, 10 September 1984, Page 30

Probe of Suri’s interior based in Antarctica

NZPA staff correspondent Washington Scientists working from the South Pole will probe the Sun’s interior soon to learn more about the processes that created life on Earth.

The project, according to America’s, National Science Foundation (NdSJF.), will be the biggest and most ambitious astronomy programme yet undertaken in Antarctica.

Other Antarctic projects this southern summer will include release of a methane tracer south of New Zealand to test seasonal distribution and composition of aerosols; geological observations, oceanography, biological research, and studies of the atmosphere and of glaciology. Altogether, the N.S.F. says, some 96 science projects will be conducted, with more than 300 researchers involved.

French and American scientists will use recently developed equipment to observe oscillations of the Sun, providing a “window” to its interior and a means of study similar to using earthquakes or induced shockwaves to learn some of the secrets of the interior of the Earth.

The scientists hope these experiments will reveal details about the solar processes that have, warmed the Earth for some 4.6 billion years.

It was only in 1975 that global oscillations, or pulsations, were first observed, the N.S.F. says. The , seismology project will begin in November under the direction of Dr Martin Pomerantz, of the University of Delaware’s Bartol Research Foundation.

“Long-term observations of the Sun from the South Pole enable us to obtain data essential for understanding the dynamics of the convection zone — the region beneath the Sun’s visible surface where much solar activity originates,” Dr Pomerantz said.

“By studying long-period oscillations we will probe more deeply into the Sun’s interior, than has been possible previously. Such observations provide crucial information about rotational rates beneath the Sun’s surface.”

The researchers will use a 12.5 cm optical telescope and a special resonance spectrophotometer which looks at one spectral line and determines minute shifts in wave lengths every five minutes, allowing the researchers to determine whether the Sun’s surface is moving towards them or receding.

In another important astronomy project Dr Pom-.' erantz and his team will use; a submillimeter photometer ’ to observe, for the first time from the South Pole, the southern part of the galactic plane and nearby molecular clouds to try to solve one of astronomy’s biggest puzzles: whether star formation is a continuing process “ ’or whether it proceeds 1 in bursts. The scientists hope this research will also help tp provide an answer to the importance of the temperature of dust on the fragmentation that precedes star formation, and the chemical composition of the Milky Way. Other teams will study several stars and changes in the transparency of the Earth’s atmosphere. Telescopes at the South Pole, because of its clear skies, are the equivalent of those on top of mountains about the height of Mount Cook, the N.S.F. says. In another experiment 19, researchers will visit barren ’ Seyihourl Island, off. the east coast of the Antarctic peninsula, to follow up a 1982 discovery of mammal fossils that apparently confirmed theories that land mammals, marsupials in particular, once roamed a much warmer and larger Antarctica.

, 4 They will examine sedi--4 ment from the upper cretaceous and lower tertiary, periods (from about 100 million to 40 million years ago) for fosisils of plants, fish, mammals, reptiles and birds. They will also be on the look-out for a layer of the rare element, iridium, similar to layers found in some other places at the creta-ceous-tertiary boundary and which would tend to support the theory that an asteroid slammed into Earth about 65 million years ago, leading to the extinction of dinosaurs and ammonites and many other life-forms. The theory, disputed by many scientists, holds that the impact resulted in a cloud of dust that blocked out sunlight and led to a cold period that caused the death of much of the plant and animal life existing then. The fine dust that settled all over the world afterwards, the theory goes, contained relatively large amounts . .. of iridium . and other rate elements Usually associated with iron meteorities. Geologists will investigate the Jones Mountain on the east coast in Ellsworth Land, near the base of the Antarctic peninsula, as part of a continuing effort to

comprehend the relationship between east and west Antarctica.

Oceanographers will study a strange layer of deep water near the coast of Wilkes Land which has a lower temperat-are, lower salinity and higher oxygen content than water above and below it

They will work from a United States Coast Guard icebreaker, making the first physical and chemical oceanographic study of the layer, to see if the deep water . formed in the area affects global mixing processes.

In another project scientists will take seabed cores to try to determine how sediments are carried from land to the continental shelf to the deep-sea floor, and also glacier movements. Biologists will study life under the Ross Ice Shelf, a sheet of ice about the size of France and about 350 metres thick.

Researchers used to believe life was sparse there, but recent data from divers and from deep-water, photography suggests that life is abundant and varied near White Island, about 30 kilometres south of McMurdo Station and near the edge of the shelf. The idea of abundant under-ice life there is sup-

ported by the presence of 25 to 30 plump seals.

Research will include underwater photography down to 450 metres.

Another team will survey the behaviour of king penguins on South Georgia. A new atmospheric sciences research facility will be built on Arrival Heights, a hill about three kilometres north of McMurdo Station. This is considered to be an area of low electromagnetic noise, an important consideration in sensitive upper atmospheric studies. Experiments there will study important but poorly understood regions of the Earth’s 1 magnetosphere — an aid to planning placement of satellites and space stations and for manned space flights.

The methane tracer to be released south of New Zealand by a United States Air Force plane will indicate the global spread of pollutants, carbon dioxide, and suspended particles. Those researchers hope their study will giVe some indication of how Antarctic weather patterns influence global climate. Glaciologists will study the west Antarctic ice sheet in a bid for greater understanding of ’ global atmospheric changes.