Terrestrial Magnetism Research Articles

CIRES Fellowships

The Cooperative Institute for Research in Environmental Sciences (CIRES) offers 1‐year visiting fellowships to scientists with research interests in the areas of atmospheric science, solid earth science, atmospheric and terrestrial electromagnetic wave propagation, paleomagnetism, and rock magnetism. Recipients of these awards are completely free to pursue their own research programs. Selection is made on the basis of the likelihood of an active exchange of ideas between the visiting fellow and the scientists in CIRES and other local research groups. Stipend is scaled to research experience, and the program is open to scientists of all countries.

Terrestrial magnetism and the development of international collaboration in the early nineteenth century

Summary The establishment of Gauss's and Weber's Magnetische Verein in 1834, and the British Government's support of Edward Sabine's ‘Magnetic Crusade’ in 1838, marked the opening of a new era in international geomagnetic research. However, the British and German efforts, although initiating an increase in the scale of investigations of the earth's field, were also the culmination of over half a century of activity by individuals and institutions in several countries. This article traces the growth of international cooperation in terrestrial magnetism from the late eighteenth century until the 1830s, and examines the change in leadership in the field from France to Britain and Germany. The transition from individual to government-backed collaboration is described, and also the role of Alexander von Humboldt as an organiser of geomagnetic research and author of a cosmical approach to earth magnetism as one of a number of related ‘telluric’ forces.

Past changes in the geomagnetic field caused by glaciations and deglaciations

Contributions have been made to the theory of the relation between terrestrial magnetism and glaciations. The results are applied to the ice sheets of high‐latitude regions. A review of Pleistocene palcomagnetic dating is given.

Geomagnetic moment and polarity of the terrestrial magnetic field during the last 20 000 years, computed with respect to changes in differential rotation between core and mantle as caused by variation in the glaciation of the earth

Abstract Theoretical aspects concerning the relation between glacial ages and terrestrial magnetism leads to a reversal of the magnetic field of the earth at about 11 000 B.P. This is in good agreement with a number of palaeomagnetic measurements.

Annual report of the Director, Department of Terrestrial Magnetism, 1972–1973 : CARNEGIE INST. CARNEGIE INSTITUTION, WASHINGTON DC, DEC. 19873. 318P

Annual report of the Director, Department of Terrestrial Magnetism, 1972–1973 : CARNEGIE INST. CARNEGIE INSTITUTION, WASHINGTON DC, DEC. 19873. 318P

The relation between glacial ages and terrestrial magnetism

An attempt is made to show that the change of angular momentum of the earth, caused by glaciations, may compensate the slowing down effect from tidal friction forces and even reverse the polarity in the terrestrial magnetic field.

A study of spiral structure for 270° ≤ lII ≤ 310°

A survey of the distribution of the intensity of the 21 cm-line of atomic hydrogen in the region with galactic coordinates 270° ≤ lII ≤ 310°, −3° ≤ bII ≤ 2°, was made with the 100-foot radiotelescope and 56-channel receiver of the Radio Astronomy Station of the Instituto Argentino de Radioastronomía and the Department of Terrestrial Magnetism of the Carnegie Institution of Washington. The angular and velocity resolution of the system is 28′ of arc and 2 km s−1.

Soviet geomagnetism, aeronomy and solar‐terrestrial physics

During December 1968, each of us made separate visits to a number of Soviet institutes and laboratories engaged in space‐physics research. Akasofu visited the Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation of the Academy of Sciences (IZMIRAN) in Moscow; the Institute of Physics of the Atmosphere and the Institute of Physics of the Earth, both of the Academy of Sciences in Moscow; as well as the Moscow State University, and the Leningrad State University in Leningrad. Wilcox visited the Crimean Astrophysical Observatory and Pulkovo Observatory. In Moscow he visited IZMIRAN, the Lebedev Institute, and the Astronomical Council of the Academy of Sciences.

The earliest maps of the moon

The aim of the present paper is to give a brief account of the history of lunar mapping in the pre-telescopic era, and that immediately following the discovery of the telescope. It is pointed out that the first (and also last) extant map of the Moon based on naked-eye observations was prepared some time before 1603 by William Gilbert - discoverer of the terrestrial magnetism - though it was published only posthumously in 1651. Moreover, the recently unearthed drawings of the Moon by Thomas Harriott in England based on telescope observations between 1609 and 1610 are in no way inferior (if not otherwise) than those published by Galileo Galilei at the same time. As G. C. La Galla's drawings of the Moon published in Venice in 1612 are in reality identical with those of Galileo, the third independent contribution to lunar mapping was made by P. Christoph Scheiner in Germany between 1611 and 1613; preceding those by C. Malapert (1916) or Gassendi and Mellan more than twenty years later.

Pre-gilbertian conceptions of terrestrial magnetism

It is now well known that William Gilbert, in his De Magnete of 1600, first suggested that the earth behaves as a great magnet. By their very nature, however, such explicit statements tend, in retrospect, to be emphasised at the expense of less explicit antecedent ideas and experiments, with the result that, in the example under consideration here, the impression has sometimes been given that before Gilbert there was not the slightest suspicion that the earth exerts influence on the magnetic needle. In fact, Gilbert's conclusion represented the culmination of many centuries of thought and experimentation on the subject. This essay traces the main steps in the evolutionary process from the idea that magnetic ‘virtue’ derived from the heave, through the gradual realisation that magnetism is closely associated with the earth, up to the time of Gilbert's definite statement.

Sixth Presentation of the John Adam Fleming Award, April 19, 1967

The honor paid to Ernest Harry Vestine by be award of the John Adam Fleming Medal would have greatly pleased Dr. Fleming, as it has Dr. Vestine's many friends and colleagues. Dr. Vestine is the fourth recipient of this award who was on Dr. Fleming's staff at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington. This indicates Dr. Fleming's skill in choosing promising young scientists for appointment to that Department. Though Minneapolis born, Dr. Vestine spent part of his youth in Canada and studied there as an undergraduate and graduate. From there came his first contributions to geomagnetism and aeronomy as leader of the Canadian expedition to Meanook during the Second International Polar Year, 1932–1933. There he set up and operated a new magnetic observatory, which has since provided important magnetic data from the auroral cap of the Earth, above 60° dipole latitude. While at Meanook he observed noctilucent clouds and made one of the earliest reliable reports of them from this continent. In 1934 he wrote an important review article on this remarkable and beautiful phenomenon.

The effects of antimicrobial agents on ribonucleic acid polymerase.

A range of antibiotics and other drugs was tested for possible inhibitory activity toward the DNA-dependent RNA polymerase of Escherichia coli . Several agents believed to interfere primarily with protein or DNA synthesis in microorganisms were shown to have no significant effect on AMP incorporation into RNA by the enzyme system. Neomycin, Antrycide, and pentamidine precipitated the DNA primer and gave substantial inhibition; suramin, prothidium bromide, proflavin, and ethidium bromide were more powerfully inhibitory, and actinomycin D was the most potent inhibitor found. These results are discussed with reference to the probable modes of action of the drugs in vivo . Inhibition by ethidium bromide was found to be related to the concentration of DNA, as would be expected if the inhibition were due to the drug’s forming a complex with the primer. Calculations of the expected level of binding of ethidium to DNA under the assay conditions led to the conclusion that RNA polymerase activity was inhibited in direct proportion to the amount of drug bound to the primer. ACKNOWLEDGMENTS This work was supported by a Scholarship for training in research methods from the Medical Research Council. The author wishes to thank Dr. Kenneth McQuillen for much valuable discussion and the staff of the Carnegie Institution of Washington, Department of Terrestrial Magnetism, for assistance in the preparation of the manuscript.

ADDRESS OF THE PRESIDENT, SIR HOWARD FLOREY, AT THE ANNIVERSARY MEETING, 30 NOVEMBER 1964.

The Copley Medal is awarded to Professor S. Chapman, F. R .S. Professor Chapman is distinguished for his contributions to many aspects of physics, astronomy and geophysics. His work on the kinetic theory of gases now forms the basis for much detailed study of gaseous phenomena, and over forty years ago his interest in these problems led him to consider the processes of diffusion and viscosity in stars. In addition to these important studies Chapman’s name has, for over half a century, been inseparably linked with problems in terrestrial magnetism and with a wide range of studies concerned with the high atmosphere, ionosphere and interplanetary space. From a statistical analysis of a great mass of data Chapman succeeded in demonstrating the existence of a small lunar component in the Earth’s quiet magnetic field variations, and he showed that the solar and lunar diurnal variations could be separated into a predominant component originating above the Earth’s surface and a subsidiary component within the Earth itself. From this standpoint he developed the general theory of the relation of the magnetic variations to the solar and lunar atmospheric tidal effects, a theory which has been fundamental to all subsequent work.

Address of the President, Sir Howard Florey, at the Anniversary Meeting, 30 November 1964

The Copley Medal is awarded to Professor S. Chapman, F.R.S. Professor Chapman is distinguished for his contributions to many aspects of physics, astronomy and geophysics. His work on the kinetic theory of gases now forms the basis for much detailed study of gaseous phenomena, and over forty years ago his interest in these problems led him to consider the processes of diffusion and viscosity in stars. In addition to these important studies Chapman’s name has, for over half a century, been inseparably linked with problems in terrestrial magnetism and with a wide range of studies concerned with the high atmosphere, ionosphere and interplanetary space. From a statistical analysis of a great mass of data Chapman succeeded in demonstrating the existence of a small lunar component in the Earth’s quiet magnetic field variations, and he showed that the solar and lunar diurnal variations could be separated into a predominant component originating above the Earth’s surface and a subsidiary component within the Earth itself. From this standpoint he developed the general theory of the relation of the magnetic variations to the solar and lunar atmospheric tidal effects, a theory which has been fundamental to all subsequent work.

Linear Polarization of Discrete Sources at 2.07 CM Wavelength.

The linear polarization of five discrete sources has been measured at 2.07-cm wavelength using the 60-ft reflector of the Department of Terrestrial Magnetism, Carnegie Institution of Washington. No polarization was observed for the Orion Nebula or the Omega Nebula, and the result for Cassiopeia A was marginal, 1.2%+0.5% at 410 ~ 1 1~. The observed linear polarization for Taurus A, 8.6%~0.3% at 146o~2o, falls in line with the results of observations made at other wavelengths. The observed linear polarization of Cygnus A, 3.9%~0.6% at 173o~6o, is only about half that to be expected from simple interpretations of the longer-wavelength observations. This is further evidence for a complex distribution of polarization over Cygnus A and a large amount of Faraday rotation in the source region. Check observations made using the 85-ft reflector at the National Radio Astronomy Observatory gave ~imilar results.

Helen B. Warner Prize

Bernard F. Burke of the Carnegie Institution in Washington, D.C. has been named to receive the 1963 Helen B. Warner Prize of the American Astronomical Society. The award honors Dr. Burke's contributions to radio astronomy, especially the discovery of radio emission from the planet Jupiter, and will be presented to him at the Society's December meeting in Washington. Dr. Burke received a doctorate in physics from the Massachusetts Institute of Technology in 1953 and in the same year joined the staff of the Carnegie Institution. In 1961 he was appointed to his present post of chairman of the Radio Astronomy Section in the Carnegie Institution's Department of Terrestrial Magnetism. During 1958–61, he served on the National Radio Astronomy Observatory Advisory Committee, and for the last three years has been a member of the National Science Foundation Astronomy Panel. Dr. Burke is a member of the American Physical Society, the AAS, and the Royal Astronomical Society.

American Geophysical Union Prizes

During its honors meeting in Washington, D.C. last spring, the American Geophysical Union awarded Merle A. Tuve its 25th William Bowie Medal for outstanding contributions and unselfish cooperation in geophysical research. Dr. Tuve has been a staff member of the Department of Terrestrial Magnetism at the Carnegie Institution for over thirty‐five years and since 1946 has served as the Department's director. During World War II, he was attached to the Office of Scientific Research and Development and was awarded a Presidential Medal of Merit for his work in developing the proximity fuse. His present research activities include seismic‐data analysis of the earth's crust, development of image tubes for large telescopes, and studies of hydrogen gas clouds by radio‐astronomy techniques. In addition to his long service with the Carnegie Institution, Dr. Tuve has been a member of the US National Commission for UNESCO, the Board of Scientific Consultants of the Sloan Kettering Institute, and, since 1960, chairman of the Geophysics Research Board. He is a fellow of the American Physical Society and the American Geophysical Union.

Second Presentation of the John Adam Fleming Award

James A. Van Allen, physicist and professor, has sustained an eminent record of achievement in his chosen professions for almost twenty‐five years. Graduating summa cum laude in physics from Iowa Wesleyan College in 1935, he then attended the State University of Iowa where he received his doctor's degree in nuclear physics in 1939.Upon graduation, he joined the Department of Terrestrial Magnetism of the Carnegie Institution of Washington under Dr. John A. Fleming to carry on research in nuclear physics. In 1940 he joined a war‐time group at DTM which developed photoelectric and radio proximity fuses; subsequently Dr. Van Allen joined the Pacific Fleet as technical and gunnery officer to advise upon and direct the use of proximity fuses in naval combat. He returned to civilian research in 1946 with the Applied Physics Laboratory of Johns Hopkins University, where he organized and directed a research team conducting high‐altitude experimental work. In 1950 he accepted a post at the Brookhaven National Laboratory as Guggenheim Memorial Foundation research fellow. In 1951 Dr. Van Allen returned to his graduate alma mater, the State University of Iowa, as Professor of Physics and Head of the Department of Physics and Astronomy.

Astronomical Society

The new president of the American Astronomical Society for the next two years, and the first Canadian astronomer to hold that office, is Carlyle S. Beals of the Dominion Observatory in Ottawa, who succeeded the previous president, Lyman Spitzer, Jr., of Princeton University, following the Society's annual meeting last year. He received his doctorate from the University of London in 1926, and became a member of the staff of the Dominion Astrophysical Observatory at Victoria in the following year. He remained at the Observatory until 1946, when he went to Ottawa, and in 1947 he was appointed to the post of Dominion Astronomer in charge of all federal astronomical and geophysical work in terrestrial magnetism, seismology, and gravity in Canada. He is known for his research in observational astrophysics, particularly in connection with studies of interstellar matter and the emission spectra of Wolf‐Rayet and P Cygni stars, and he has also made contributions in the field of color temperatures and in photoelectric photometry. During the past ten years he has carried out studies having to do with the occurrence of ancient meteorite craters in Canada.

Two unpublished accounts of the British Antarctic Expedition, 1839–43

[The British Antarctic Expedition, 1839–43, consisted of two Naval vessels, H.M.S. Erebus and Terror, with Sir James Clark Ross as leader and Captain F. R. M. Crozier as second-in-command. The objects of the expedition were mainly concerned with terrestrial magnetism, a subject of particular interest to Ross who had discovered the North Magnetic Pole in 1831. The expedition circumnavigated the Antarctic continent and made a number of important geographical discoveries. It twice penetrated the pack ice.of the Ross Sea; it discovered, and roughly charted, 500 miles of new coastline in Victoria Land; it discovered Ross Island and the Ross Ice Front, also the James Ross Island group; it visited Prince Edward Islands, les Crozet and les Kerguelen; and it sighted Joinville Island and the Balleny Islands. Observations of terrestrial magnetism were made from stations, either permanent or temporary, set up during the voyage.