Parallels Between Antarctic Travel in 1950 and Planetary Travel in 2050 (to Accompany Notes on "The Norwegian British-Swedish Antarctic Expedition 1949-52")

Objectives (Slides 2, 12, 21-22) To explore as much as possible of 1 million km2 of unexplored territory. We were the first expedition to winter in Antarctica between 95 E and 57 W - nearly half the coastline of Antarctica. It was understood that we must be self-sufficient in every respect for 2 years. There could be no firm or detailed plans for inland exploration until we found where it was possible to make a landing. Geology (Slide 20) Our two geologists traveled far from the Advance Base during both field seasons. Carrying fuel supplies (dog food) for a month, man food (dehydrated) and rock specimens acquired along the way, they covered a vast area. The surveyor drove his own dogs with the geophysicist as assistant. While the geologists were hacking away at rocks, the survey team lugged a theodolite up peaks to extend a triangulation network. Glaciology (Slides 21-22) The glaciologists each had an assistant from the support staff, so they could either travel together or divided into two parties to cover more ground. At each camp they dug a pit to determine the rate of snow accumulation, drilled (by hand) to a depth of 10 m to measure ice temperatures, and in places set up and surveyed ice-movement markers to be resurveyed the following season. Geophysics (Slides 33, 34-36, 38) The principal object was to determine the thickness of ice by seismic sounding the only means known at the time. After experiments as far as the Advance Base in the 1950-51 summer, both Weasels were devoted to a seismic sounding traverse in 1951-52 as far inland as supplies would allow. The party reached 620 km inland and found ice thicknesses of 2,500 m

Satellite image atlas of glaciers of of the world - Antarctica

Of all the world?s continents Antarctica is the coldest, the highest, and the least known. It is one and a half times the size of the United States, and on it lies 91 percent (30,109,800 km3) of the estimated volume of all the ice on Earth. Because so little is known about Antarctic glaciers compared with what is known about glaciers in populated countries, satellite imagery represents a great leap forward in the provision of basic data. From the coast of Antarctica to about 81?south latitude, there are 2,514 Landsat nominal scene centers (the fixed geographic position of the intersection of orbital paths and latitudinal rows). If there were cloud-free images for all these geographic centers, only about 520 Landsat images would be needed to provide complete coverage. Because of cloud cover, however, only about 70 percent of the Landsat imaging area, or 55 percent of the continent, is covered by good quality Landsat images. To date, only about 20 percent of Antarctica has been mapped at scales of 1:250,000 or larger, but these maps do include about half of the coastline. The area of Antarctica that could be planimetrically mapped at a scale of 1:250,000 would be tripled if the available Landsat images were used in image map production. This chapter contains brief descriptions and interpretations of features seen in 62 carefully selected Landsat images or image mosaics. Images were chosen on the basis of quality and interest; for this reason they are far from evenly spaced around the continent. Space limitations allow less than 15 percent of the Landsat imaging area of Antarctica to be shown in the illustrations reproduced in this chapter. Unfortunately, a wealth of glaciological and other features of compelling interest is present in the many hundreds of images that could not be included. To help show some important features beyond the limit of Landsat coverage, and as an aid to the interpretation of certain features seen in the images, 38 oblique aerial photographs have been included. Again, these represent only a small fraction of the large number of aerial photographs now available in various national collections. The chapter is divided into five geographic sections. The first is the Transantarctic Mountains in the Ross Sea area. Some very large outlet glaciers flow from the East Antarctic ice sheet through the Transantarctic Mountains to the Ross Ice Shelf. Byrd Glacier, one of the largest in the world, drains an area of more than 1,000,000 km2. Next, images from the Indian Ocean sector are discussed. These include the Lambert Glacier- Amery Ice Shelf system, so large that about 25 images must be mosaicked to cover its complex system of tributary glaciers. Shirase Glacier, a tidal outlet glacier in the sector, flows at a speed of 2.5 km a-l. About 200 km inland and 200 km west of Shirase Glacier lie the Queen Fabiola (?Yamato?) Mountains, whose extensive exposures of `blue ice? lay claim to being the world?s most important meteorite-collecting locality, with more than 4,700 meteorite fragments discovered since 1969. The Atlantic Ocean sector is fringed by ice shelves into which flow large ice streams like Jutulstraumen, Stancomb-Wills, Slessor, and Recovery Glaciers. Filchner and Ronne Ice Shelves together cover an area two-thirds the size of Texas. From the western margin of the Ronne Ice Shelf, the north-trending arc of the Antarctic Peninsula, with its fjord and alpine landscape and fringing ice shelves, stretches towards South America. The Pacific Ocean sector begins with the Ellsworth Mountains, which include the highest peaks (Vinson Massif at 4,897 m) in Antarctica. The area between the Ellsworth Mountains and the eastern margin of the Ross Ice Shelf is fringed with small ice shelves and some major outlet glaciers. One of these, Pine Island Glacier, was found from comparing 1973 and 1975 images to have an average ice-front velocity of 2.4 km a-l. This part of Antarctic

Towards an inventory of the great ice sheets

In view of the global effects of climatic change there is an urgent need to detect even a small mass imbalance in the polar ice sheets. The relative merits of possible methods of achieving this are compared. No current and no planned experiments can provide a reliable answer. However, satellite altimetry could measure even small changes within a few years

A distant look at the cryosphere

Ninety nine per cent of all the fresh water on the surface of the Earth is in the form of ice. Observations from space have revealed more about the ice than about most other parts of the environment because at the dawn of the satellite era, less was known about it. The cryosphere includes all forms of naturally occurring ice but here we review what space science has done for knowledge of glaciers and ice sheets. Whereas in global terms the cryosphere exists as a response to climate, over large areas it controls climate. While imaging spacecraft systems have proved easiest to interpret, microwave sensors with poor spatial resolution are able to distinguish transient and stable surface features that are invisible to the eye. Imaging radars quite effectively describe sea ice, but precision altimetry is the only practicable method for monitoring changes in the total mass of ice on land

Giant icebergs in the Weddell Sea, 1967–68

Two giant icebergs are moving westwards along the coast of Antarctica in the Weddell Sea. They were conspicuous throughout the 1967–68 season in ESSA-3 satellite photographs supplied by the United States National Environmental Satellite Center to the British Antarctic Survey. The two icebergs were first unmistakeably seen during orbit No 4699 on 11 October 1967 and last clearly seen before the winter during orbit No 6408 on 24 February 1968. The leading iceberg, which is roughly 45 km by 100 km, was last seen moving out to sea westwards from a position about 100 km north of Halley Bay station. The second, some 70 km by 100 km, was parallel with Riiser-Larsen Ice Front in long 21°W, and separated from it by only a few kilometres of open water. Although there were periods of weeks in which there was no movement, presumably owing to the grounding of the icebergs on shoals, both moved some 500 km along the coast in four months