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1¾ VI OF: PLANIMETRIC MAPPING OF WORLD CONTINENTAL LAND SURFACES

Mary Lynette Larsgaard

Map and Imagery Laboratory, Davidson Library

University of California, Santa Barbara

mary@sdc.ucsb.edu

Planimetric Mapping: The Twentieth Century

La determinacion de estas tres coordenadas [latitude, longitude, altitude] es bien conocida desde hace siglos, pero el progreso de los medios opticos, mecanicos y de calculo ha permitido que se haya facilitado y que la precision sea cada vez mayor.

(Tamayo 1962, p. 45)

Overview

At the beginning of the twentieth century there still remained unexplored areas in the world's continents. Atlases retained romantic spaces where rivers and lakes were shown by broken lines, with question marks next to dubious data, and that most seductive of words to the explorer, "UNEXPLORED," printed slantwise across an otherwise barren stretch of paper. Unknown areas had disappeared only from the European subcontinent. A blank space in northwest Alaska the size of New England, two areas in the Sahara (one twice as large and the other three times as large as New England), several vast mysterious spaces in Asia, and the tropical mysteries of New Guinea (the second largest island in the world next to Greenland, and almost as well known), Antarctica, and much of Amazonia (Adams 1907, p. 306). The correct location of Lake Albert Edward, one of the sources of the Nile, was ascertained only in the early twentieth century; the Amazon retained some of its mysteries to the early 1970s. And even in the conterminous United States, the heads of rivers in Texas and New Mexico did not in all cases have a firm location. As for Alaska, it was comforting to know that at least no mountain ranges were undiscovered, all but two of the larger river courses were surveyed, "and perhaps nearly all of the larger geographical features are outlined" (Ibid., p. 311).

Due to hard work by the Russians, Asia's major land forms were known, but Australia's desert areas and tropical north did not enjoy that status, and even today Antarctica's exploration is still in progress.

By 1935 there remained only a few scattered blank spots in continents other than Antarctica - the interiors of Canada's Arctic islands, interior Amazonia (between river courses), a small area on the northeast border of India with China, and the interiors of Borneo, New Guinea, Ethiopia (toward Somalia), and south Africa (the last group being either unexplored or poorly known) (Outhwaite 1938, p. 325).

After the Second World War, mapping and exploration resumed, leading to such corrections as the location of the Equator in Ecuador being corrected during the International Geophysical Year (Kish 1978). Nonetheless, large regions of Antarctica, the central mountains of New Guinea, parts of the Amazon and African jungles, the Greenland icecap, and northwest Siberia remained little known.

In the late 1960s there remained only the constant - Antarctica - and tropical regions with weather conditions unfavorable to aerial photography until radar was called to the attack (Zarzycki 1969, pp. 7, 21). Even in the mid-1970s location corrections were being made and some small areas were being explored by manipulation of Landsat images. Landsat Island, a small island near the north coast of Labrador, was the largest of several uncharted features positioned during a 1976 survey of that coast aided by Landsat detection work ("Landsat Island" 1980, p. 48).

Planimetric Mapping of Africa: The Twentieth Century

From the beginning of the century to 1930, filling in details (primarily in the Sahara, the Libyan Desert, southern Abyssinia, the northeast corner of the continent in general, the Nile/Congo divide, and the Ruwenzori (this latter closing out discovery in central Africa) was the order of the day, and was carried on almost entirely by the French, in distinction to the nineteenth century when the English were the more active (Baker 1967, pp. 303, 346, 352). By about 1910 the whole of the country from Nigeria to the Gambia was accurately known with the exception of certain parts of Liberia. In 1925 the whole coastline of Africa was charted by the British Admiralty (Curnow 1925, p. 33). The Sahara was still unexplored in parts such as the Libyan desert (in the east) and the Igidi desert (in the west) even in the 1930s (Outhwaite 1938, p. 325). The hinterland between Cape Bojador and Wadi Draa in the Sahara was only sketchily mapped (Cana 1915, p. 340).

Why was Africa, a portion of which was well mapped in classic times, one of the last continents to be explored by Europeans? According to S.W. Boggs (1943, pp. 188, 191), this was because of the character of its coasts, ocean currents, topography, climate, and vegetation. The Sahara is a formidable barrier to southward travel; the coastline of Africa is nearly harborless, and exploration was - until the twentieth century - done primarily by sail or steam ship; the currents and winds favor clockwise navigation and sailing passages, the exact opposite of the route the shipborne Europeans took; the great rivers are not completely navigable, being broken by falls and cataracts; the heat, the luxuriant vegetation - or the striking lack thereof - make travel arduous. Thus it was not until the 1940s that all of Africa could be considered explored and planimetrically mapped.

Planimetric Mapping of Australia: The Twentieth Century

In 1930 the large blank space in the center of the continent was finally filled in, and for all practical purposes, the discovery and location of Australia's major features finally ended (Baker 1967, pp. 426-35).

Planimetric Mapping of Eurasia: The Twentieth Century

Asia

Pemakochung did not improve on second acquaintance. Perhaps the advent of an unaccustomed tourist season so soon after a smallpox epidemic was altogether too much for them .... I could have put myself in their [the monks'] shoes, but I was uncomfortable enough in my own boots patched up with the hypsometer strap. I lost my temper and told them that if they wanted us to leave the monastery, they would have to provide me with food for the journey and two men for porterage.

(Bailey 1957, pp. 149-50)

At the beginning of the century Arabia and central Asia shared the palm with Antarctica as the largest little-known areas. Thousands of square miles in northern Arabia had not been seen by Western eyes, although the general nature - sandy - was known. The northwest, about 300 square miles (Nejran to Harik in the Nejd, bounded on the north by the Hanifa-Mecca road) is not wholey desert; an area in the southeast, south of Wady Yabra - the awesome Rub'al Khali, or Abode of Emptiness - is 300,000 square miles of sandy waste. Three explorers had looked at it, but - wisely - only from a distance:

This is all we know about the Great Southern Desert. It is about as much Istakhri knew in the tenth century, and about as much as Hajji Khalfah recorded in the seventeenth.

(Hogarth 1904, p. 337).

The early part of the century was the time of the private, occasionally aristocratic explorer - Sven Hedin in Tibet, Shackleton in the Antarctic, Colonel Kozlof in Mongolia, Lieutenant Boyd Alexander in western Africa, and the Duke of Abruzzi in the Mountains of India's frontier (Duncan Johnston 1909 pp. 505, 507). Such explorers were likely to run into situations like that of a traveler to Mongolia, who searched diligently for a city marked on the maps, only to find that it had been razed by Kublai Khan in the thirteenth century. Exploration had other problems, including the necessity of using unique measuring methods; Filchner noted that taking compass readings from the back of a yak tended to give inaccurate findings, while Lady Hosie mentioned her husband's "invariable custom" of finding the boiling point of water whilst on a pass, to discover altitude (Hosie 1926, pp. 20-21).

Yemen was scarcely explored; Oman's topography was more definitely depicted in about 1910, its southwest corner in good condition, but still possessed of an immense stretch of the unknown for the rest ("New map of Arabia" 1910, pp. 361-62). A 1916 map of Yemen corresponded "surprisingly closely to the real state of affairs" (Werdecker 1939, p. 92).

In 1933 Josef Werdecker constructed a map of Yemen from notes made by a visitor to that country in 1882-1884, because nothing better was available (Werdecker 1939, pp. 3, 5).

By 1902, almost all of Thailand had been examined; the same could not be said of such islands as Celebes (Sulawesi - explored only by 1919) and New Guinea. New Guinea was the site of systematic exploration by the Dutch government beginning in 1907, an exploration that was interrupted by World War I and resumed in 1921, using airplanes (T.J. Ormeling 1949/50, p. 270; Baker 1967, pp. 273, 445).

In 1913 the hitherto unsurveyed area of the Tsangpo River gorges, on the border between Assam and Tibet, was explored by Bailey; he found time to collect several new species of butterflies in his spare time (Bailey 1957, p. 9).

Comparatively few places in China had latitude and longitude determination; travelers were thus very careful to take readings. Even to the 1930s, some areas - such as the highlands of New Guinea - were virtually unknown, or unvisited for 100 years, like east Nepal (Brown 1950, p. 172; Biddle, Milne ... 1974, p. 3). To the late 1960s, the Arabian peninsula was still one of the least mapped parts of the world, although there had been considerable inroads in the south and east (Lock 1969, p. 254). Even in the late 1970s, a number of high peaks in the Himalayas were not correctly identified or measured (Snead 1980, p. 7).

The Soviet Union

Detailed knowledge of the Siberian coast came to light in 1918-1920 and 1922-1925 (Baker 1967, p. 465).

Planimetric Mapping of Latin America: The Twentieth Century

At the beginning of the century a thin strip in the southern Chilean Andes, the Amazon headwaters and south of the river, much of El Gran Chaco, the headwaters of the Parana, and the north and east cordillera in Peru were still blank (Debenham 1960, p. 238; Adams 1907, p. 307; Edinburgh Geographical Institute 1922, plate II). In 1907 a 1:500,000 map by M. Guffroy of all of French Guiana appeared (Brasseur 1974, p. 56). In the 1920s Colombia was "settled but unexplored" (F.O. Martin 1929, p. 62). In the 1930s many scientific expeditions devoted time to exploring unknown regions, specifically the great basin of the Amazon, from 1907 to 1925. The western Mato Grosso was still imperfectly known; the last visit for exploration purposes had been made in 1914 by Theodore Roosevelt (Baker 1967, pp. 415-16). The Sierra Nevada de Santa Marta in Colombia was, in 1939, unmapped but covered with aerial photographs (Walter A. Wood 1941, p. 639). Amazonia would not yield its secrets until Projeto RADAM, which imaged Brazil with radar, resulting in mapping from the radar images by 1975, in the process collecting such data as news of a river 400 mile long that had never appeared on a map before (McIntyre 1977, p. 692). Inland Panama and some of its interior, which had been inadequately charted in 1970, had been completely mapped (Kapp 1971b, p. 5).

Planimetric Mapping of North America: The Twentieth Century

The century began with all of North America explored and mapped except for the interiors of Greenland, Labrador, British Columbia, and Alaska, almost all such regions in the Arctic (a region where the mean temperature is less than 50 degrees F.) (Boyer 1953, p. 376; Debenham 1960, p. 238; Adams 1907, p. 305; Bjornbo and Peterson 1908, p. 3; Sargent 1912, p. 487). Maps of Ellesmere Island's north coast were still very indefinite (Markham 1903, p. 746).

The American Geographical Society's 1913 map of the Arctic regions left the northern part of Baffin Island tentative, and had used Eskimo maps as a source for the east coast of Fox Basin to obtain accuracy of outline ("Map of the Arctic regions" 1913, p. 610). Early in the century, Canadian officaldom had stated that the nation's mapping efforts would be concentrated in areas of more interest to Dominion citizens than the Arctic (Adams 1907, p. 311). In 1916 the unexplored area of Canada totaled 900,000 square miles (Langton 1935, p. 6).

Expeditions to the Arctic picked up in the 1930s. The Danes worked on mapping the area between 72 degrees N and 76 degrees N in Greenland between 1931 and 1934 (Koch 1940, p. 8). Lauge Koch did reconnaissance mapping in Greenland between 68 degrees N and 82 degrees N, in an assault on Inlandsis (the interior glacier) in 1932 and 1933. One problem in the mapping of Greenland was that only sextants and theodolites could be used, not compasses, because of the magnetic-pole disturbance (Helk 1966, p. 772).

The Canadians sent expeditions to the northern fringe, to the mainland north of Hudson Bay, and to the Arctic islands in the 1930s, an official map appearing in 1939 (John Lewis Robinson 1951, p. 25). Nonetheless, in 1945 Canada still had large areas, especially north of 60 degrees N, where no work had been done, and in 1946 satisfactory maps were lacking for all but small parts of Arctic North America. Parts of Canada had not even been viewed from the air, and small islands remained to be discovered. Mapping of some areas was in:

an almost unbelievably primitive state; Back River was surveyed in 1834, traveled in 1855, and never completely descended after that. Northwest of Hudson Bay, an area about the size of Scotland was blank on 1943 RCAF [Royal Canadian Air Force] charts, and described as 'gently rolling country rising to 1000 feet.'

(Arctic Institute of North America 1946, p. 3)

In the 1940s there remained the irony that Labrador, one of the first places reached by Europeans, was one of the least known parts of North America; parts of Labrador from Hamilton Inlet to Cape Chidley had incorrect latitude and longitude figures, the coast from White Cocade to Nain was conjectural, and the bottom and west coast of Ungave and the east coast of Baffin Island were indicated by dotted lines (Tanner 1944, p. 60). Spicer Island was finally located "for sure" in 1946; no white man had been to the interior of Ellef Kingnes Island until 1948, when a meteorological station was opened there (John Lewis Robinson 1951, p. 8; and 1952, p. 26).

In Greenland, the northeast coast was the last to be surveyed, left undone until the 1940s (Hobbs 1949, p. 19). Many noteworthy changes occurred in the outline of the coasts of the Arctic islands during the 1940s with new islands being discovered; in the early 1950s the shapes appearing on the Arctic map were essentially final, but much of Arctic Canada remained untrodden, and changes would still be made (John Lewis Robinson 1952, p. 26).

Even in the 1960s the size of Greenland was imprecisely known, and at least the northern one-third not accurately mapped, in part because there were less than seven good aerial photography days per year over the area, and mapping was based on photography (Helk 1966, p. 7710.

In 1971, northern Greenland was one of the few remaining parts of the world where large mapping errors (in excess of 15 nautical miles) existed - generally north of 80 degrees N - largely due to a lack of ground control points. Many measurements predated 1925 (Lillestrand and Johnson 1971, pp. 233-34). In the late 1970s Danish field parties confirmed a discovery originally made from an aerial photograph - a new island north of Greenland - as the most northerly point of land above sea level on the Earth's surface (see Photogrammetry and remote sensing 45(3):227, March 1979).