Physiographic Diagrams Research Articles

Marie Tharp, oceanographic cartographer, and her contributions to the revolution in the Earth sciences

Abstract In the early 1950s, two American geologists, Bruce Charles Heezen (1924–1977) and Marie Tharp, began mapping the sea floor to improve understanding of ocean-basin geology and to connect the oceans to the continents theoretically. Both were researchers at the Lamont Geological Observatory of Columbia University, now Lamont-Doherty Earth Observatory. Heezen and Tharp used the ‘physiographic mapping’ technique, which makes it possible to relate topographic features to underlying geology. The diagrams mostly utilized light and texture, rather than colour, and were sketched using a hachuring technique. Heezen collected data for research purposes and Tharp used his information to compile their physiographic diagrams. During this process, she confirmed previous predictions when she made an important discovery: a rift on the Mid-Atlantic Ridge. Tharp’s visual interpretations of the sea-floor data contributed to the reintroduction of continental drift theory and the 1960s geological revolution. At a time when most women were excluded from scientific careers, Tharp, initially a research assistant, succeeded in this competitive arena. Working with Heezen as a geologist and cartographer, she had an unusual opportunity to participate in the era’s exciting discoveries; and her contributions were acknowledged. While their data-gathering activities and analyses stimulated change and contributed to the revolution in the Earth sciences, Heezen and Tharp were not directly involved in the plate-tectonics revolution, but favoured expanding-Earth theory.

QUANTITATIVE PHYSIOGRAPHIC METHOD OF LANDFORM PORTRAYAL

A new cartographic technique, superimposing planimetrically adjusted contours on Mock diagrams prepared by the physiographic method, permits more quantitative use of three-dimensional drawings of landforms than heretofore possible. The framework of adjusted contours provides the easiest means of three dimensionally positioning a landform. The physiographic diagram is frequently the most satisfactory method of representing a landform because the landform is represented as it looks in nature. Comparisons, using a landform model, show this new technique to be considerably more effective than conventional methods of illustrating landforms because it combines on the same diagram useful features of the qualitative physiographic method with the quantitative aspects of the contour map. The new technique has been used effectively in the preparation of diagrams of various ocean floor and borderland regions. Une nouvelle technique de cartographie par laquelle des courbes de niveau compensées planimétriquement sont surimposées a des blocs-diagrammes établis selon la méthode physiographique permet de multiplier les applications quantitatives des représentations topographiques tridimensionnelles. Le réseau de courbes compensées constitue la meilleure manière de situer les accidents du terrain dans une représentation tridimensionnelle. Le diagramme physiographique est souvent préférable lorsqu'il faut représenter les accidents du terrain car il offre plus de similitude avec la nature. Des comparaisons faites à l'aide d'un modèle de terrain ont révélé que la technique en question est supérieure aux méthodes classiques d'illustration de la topographie parce qu'elle permet de réunir en un seul diagramme les éléments utiles de la méthode physiographique qualitative et les aspects quantitatifs de la carte en relief. La nouvelle technique a été appliquée avec succès a la preparation de diagrammes représentant les fonds marins et certaines régions frontalières.

THE PROPORTIONAL RELIEF LANDFORM MAP1

THE problem of representing surface configuration in the plane of a map remains a major challenge to the cartographer. For many purposes, pictorial methods of terrain mapping have proved successful as a means of coping with this problem.2 Some useful techniques are available for the construction of pictorial terrain maps. The physiographic diagram of Lobeck, stressing structural influences in terrain formation, and the more refined landform map of Raisz,3 emphasizing the existing product of geomorphic processes, are splendid devices for orienting the viewer to the physiographic patterns of broad regions. Both techniques are based upon the use of symbols to represent general landform types and are designed for use in small-scale maps. Generally these maps are drawn at scales less than 1: 1,000,000. However, the map reader is often interested in detail which cannot be drawn into smallscale maps nor depicted by noncommensurable symbols. Robinson and Thrower have elaborated on a technique introduced by Tanaka Kitiro which utilizes inclined traces to preserve planimetry in the pictorial terrain map.4 This method is especially valuable for overlay work where continuous planimetry is essen-

The Ocean Floor

The Floors of the Oceans 1: The North Atlantic. Text to Accompany the Physiographic Diagram of the North Atlantic. By Bruce C. Heezen, Marie Tharp, and Maurice Ewing. (Geological Society of America Special Paper 65.) Pp. xii + 122 + 30 plates. (New York: Geological Society of America, 1959.) 4.50 dollars. Physiographic Diagram 1.50 dollars.

The Floors of the Oceans. I. The North Atlantic: Text to Accompany the Physiographic Diagram of the North Atlantic

The Floors of the Oceans. I. The North Atlantic: Text to Accompany the Physiographic Diagram of the North Atlantic

ARMIN KOHL LOBECK, GEOMORPHOLOGIST AND LANDSCAPE ARTIST, 1886–1958

ARMIN KOHL LOBECK was born in New York City on August 16, 1886. When he was three years of age his family moved to Haworth, New Jersey, where he grew up and received his early schooling. He died on April 26, 1958, at the age of 71 in Englewood, New Jersey, where he had resided since 1929. As the eldest of five sons, he withdrew from school to help support the family when his father became ill. However, he was soon able to return to high school and complete his secondary education. Older than most high school graduates he was 21 when he entered Columbia College in 1907. Being of serious mien he tried to make the most of his educational opportunity. He continued to live in Haworth and made the arduous round trip to the University each day. He studied in the fields of botany and architecture, both to become significant in his professional career. He graduated in 1911 with the A.B. degree. In his senior year at Columbia he enrolled in the Graduate School and made some progress on his Master's degree, which was awarded in 1913. He began his teaching career at the Philadelphia College of Pharmacy, where he taught botany for three years, 1911-14. After concluding his teaching service in Philadelphia he returned to the University and continued graduate work in physiography and geology. Here he came under the influence of Douglas W. Johnson, a noted scholar in the field of geomorphology. It was in the study of geomorphology and structural geology that he began to apply his knowledge of architecture to the representation of landforms, a method that become known as physiographic drawing. After spending a season in Puerto Rico doing field work for his dissertation he returned to the University and completed the requirements for the Ph.D. degree, which he received in 1917. He entered the United States Army during World War I and was sent to Camp Dix. He was soon transferred to the Department of State and assigned to Inquiry, organized by Colonel E. M. House during the war to prepare for the making of peace. When the war was over he became a member of the Geography Section of the American Commission to Negotiate Peace and went to France in December 1918. He became closely associated with Isaiah Bowman, Mark Jefferson, Lawrence Martin, and other distinguished geographers who were attached to the Commission. His duties consisted chiefly of the preparation of a number of physiographic maps of problem areas, such as the Balkans, the Istrian Peninsula, Albania, and others. After the war these maps were published by the American Geographical Society. It was at the Peace Conference in Paris that he met Professor C. K. Leith, Chairman of the Department of Geology at the University of Wisconsin. Professor Leith was looking for a physiographer-geographer who could fill the position in the Department that had been vacant for two years because of the resignation of Lawrence Martin. Lobeck accepted the position as an assistant professor and he and Mrs. Lobeck moved to Madison in the autumn of 1919. He remained at the University of Wisconsin for 10 years and during this period his first physiographic maps of major scientific and educational importance were prepared and published. The large-scale Physiographic Diagram [map] of the United States was published by A. J. Nystrom Company in 1921. He began work at once on a small-scale edition of this map of the United States. The map and the accompanying text were published in 1922 by the Wisconsin Geographical Press wholly owned by him. This was the beginning of a most successful publishing business which he took to Columbia University and renamed The Geographical Press. In 1954 it was transferred to C. S. Hammond & Company as a division of that firm. In the autumn of 1929 Professor Lobeck returned to Columbia University as Professor of geology and was given responsibility for instruction in the elementary courses. In this aspect of his teaching service his influence was essentially dual in character. Not only the students in his classes came under his skillful

Production of broken line patterns with standard Ben Day

Broken line patterns, commonly necessary in geologic and physiographic diagrams, but not available in standard Ben Day sheets, can be produced by the use of standard linear patterns, overlain by various negative patterns. Methods of producing broken line patterns are herein described.

Notes on a Physiographic Diagram of Tyosen (Korea)

HE name of the peninsula, Korea, translated as High Mountains and Sparkling Streams, epitomizes the land. The Koreans have a special love for the austere beauty of their country. Pavilions on the highest summits, graves on picturesque slopes, and decaying cities of refuge hidden in the mountain fastnesses attest to the influence of the mountains on their lives. The sharpness of detail and lack of a solid vegetation cover on many of the hills give one an exaggerated impression of height and ruggedness, an effect accentuated by the narrow, flat-bottomed valleys. Minute as the plains are in the vast stretches of rough country, they are significant; for on them are grown the crops, preferably rice, which govern the economy of the land. The physical factors of climate and relief are obviously important in regional and local differences in the economy of Tyosen.1 The climatic regions have been the subject of previous publications.2 The geomorphological study follows a similar pattern. There is such a confusion of landforms in Korea, however, that a physiographic diagram (Fig. I) is of particular aid as a means of clarification.