bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Viking mission and the search for life on Mars
Authors: Klein Harold P. 
Published: February 2008

Modern scientific hypotheses concerning the origin of life generally have as their central theme the idea that living systems arise through "chemical evolution," a process in which simple compounds are generally transformed under the influence of various energy sources into more and more complex molecules, ultimately resulting in a system of replicating molecules [Buvet and Ponnamperuma, 1971; Miller and Orgel, 1974]. Based upon comparisons between the chemical composition of terrestrial living systems and cosmic abundances [Frieden, 1972] as well as upon theoretical considerations [Wald, 1962], it is further assumed that the key substances in this evolution are all carbon‐based compounds. Given a planet with a "hospitable" environment, these processes continue until the stage is set for biological infestation of the planet and further biological evolution follows.As it became clear that direct experimentation on other planets was technically feasible with the advent of spacecraft technology, attention turned to Mars as the most promising extraterrestrial object upon which to search for evidence of chemical evolution [Pittendrigh et al., 1966]. This view was reached despite significant gaps in our knowledge of that planet, most notably about the properties and composition of its surface. Even after the encounters by Mariners 4, 6, and 7 and the more encompassing Mariner 9 mission, virtually nothing was known about the chemistry of the Martian surface. Under these circumstances, the status of evolution of carbon compounds and particularly the question of the existence of life on Mars were entirely speculative.
Introduction to “Milankovitch Theory and climate” by A. Berger
Authors: Lal D. 
Published: February 2008

One of the most fascinating and challenging problems of modern interdisciplinary research is to understand the causes of global climatic changes. This is an area of research which has been extensively covered in the past at the various IUGG meetings by more than two associations, and the same holds for this assembly. And the thrust of research continues with all force from many directions.Presently there seems to be a general consensus that the influence of orbital variations on climate is real enough and that all efforts should be made to test the astronomical theory with climate models. The progress made in understanding and modeling physical mechanisms by which the climate system responds to the astronomically forced changes in the pattern of incoming solar radiation was recently evaluated at a climate symposium organized by Professor Andre Berger, who will deliver today'S talk.
Commission 5: Progress in Radio and Radar Astronomy
Authors: Erickson W. C. 
Published: February 2008

The institutions that contributed material for this report are:1. Arecibo Ionospheric Observatory.2. NASA‐Goddard Space Flight Center.3. Bell Telephone Laboratories.4. University of Texas.5. University of Maryland.6. University of Virginia.7. Florida State University.8. Air Force Cambridge Research Laboratories.9. Stanford University.10. MIT Lincoln Laboratory.11. Ohio State University.12. University of Colorado.13. National Radio Astronomy Observatory.14. Jet Propulsion Laboratory.15. Owens Valley Radio Observatory.Only a minor attempt has been made to mention work performed at other observatories in the U.S.A.
Arecibo heating experiments
Authors: Gordon W. E. , Carlson H. C. 
Published: February 2008

Enhancements of various features of the incoherent scatter spectrum are observed when the ionosphere is illuminated with powerful, high frequency radio waves. The radio waves excite plasma instabilities producing lines or more complex spectral features near the local plasma frequency, at the local ion acoustic frequency, near the local gyrofrequency, and near twice the gyrofrequency. The enhancements occur in a thin slab as observed by the incoherent scatter radar and at both upshifted and downshifted frequencies with respect to the probing radar frequency. The enhancements are observed to vary with time when the excitation is held constant and is turned on or off.The high power radio waves are produced by a 160 kw transmitter feeding a log‐periodic pair of curtains mounted at the focus of the 1000‐ft reflector and covering the frequency range from 5 to 12 MHz. The effects are observed with the incoherent scatter radar using the same reflector and with ionosondes and photometers.The frequencies of the enhanced plasma line and the ion line and their relation to the pump (high frequency radio wave) frequency are predictable from available parametric instability theory. Other spectral features are being explained as the theory develops with the help of the observations. There remain some discrepancies, in particular the asymmetries in intensity, width, and fluctuations of the upshifted compared to the downshifted plasma lines.
Basement tectonics of the Southern Pampean Ranges, Argentina
Authors: Salda Luis Dalla 
Published: February 2008

Upper Precambrian to lower Paleozoic crystalline basement of the Southern Pampean Ranges is composed of (1) a narrow western zone, having low to medium grade metamorphic rocks and relatively few granites and migmatites and (2) a wide central eastern Hercynotype low‐pressure zone with abundant granitoids. The internal structures fall into three distinct domains characterized by the following orientations: Dl, nearly E‐W; D2, NNW‐SSE; and D3, NNE‐SSW.The tectonic evolution is interpreted as having begun in an upper Precambrian orogenic cycle commencing with lithospheric rifting, followed by compression forming D1 structures. Next was a mobile belt cycle composed of two main stages. The first one, which generated the main tectonic features (D2) of the igneous—metamorphic complex, coincided with a syntectonic to late tectonic granitic intrusive event, with the principal metamorphic episode, and with Paleozoic Andean tectonic trends related to the activity of the Gondwanaland Pacific margin. The last one, was a fracturing and an open weak folding (D3) event with local low‐grade metamorphism; it occurred during the Silurian.
The Coast and Geodetic Survey magnetometer
Authors: Bauer L. A. 
Published: February 2008

The source of error complained of by Dr. Morize has been eliminated in the present form of magnetometer used by the Coast and Geodetic Survey.The above cut will show how this has been done, viz., the glass window in the front end of the box has been removed entirely, and there is used instead a cloth hood, fastened to the box and fitting snugly by means of a ring over the observing telescope. The window in the back end of the box can be turned aside, on a pin, when observing on the mark. It may also be pointed out that the azimuth mirror, which constitutes the weak part of the Kew magnetometer, is replaced in this form of instrument by a special theodolite attachment (as shown on the right of the cut) fitting on the same base as the magnetometer, the alt‐azimuth method for determining the meridian being used. By this method the observer is independent of the longitude of the place, and the need of great accuracy in the times of observation.
The magnetic observatories of the United States Coast and Geodetic Survey
Authors: Tittmann O. H. 
Published: February 2008

LOCATION.In connection with the magnetic survey of the United States and countries under its jurisdiction, the Coast and Geodetic Survey is operating magnetic observatories at the following places:Name Place Latitude Longitude Altitude North W. of Gr. meters ° ′ ° ′Cheltenham Cheltenham, Maryland 38 44.0 76 50.5 72Baldwin Baldwin, Kansas 38 47.0 95 10.0 335Sitka Sitka, Alaska 57 02.9 135 20.2 15Honolulu Ewa, Oahu Island 21 19.2 158 03.8 15Porto Rico2 Vieques, Porto Rico 18 08.9 65 26.4 40
Magnetic chart errors and secular changes in the Indian Ocean
Authors: Bauer L. A. , Peters W. J. 
Published: February 2008

In view of the exceptionally large errors in the most recent charts which are being disclosed in the Indian Ocean on the present cruise of the Carnegie, it was thought desirable to make early communication. Tables I and II give the values of the magnetic declination (“variation of the compass”) with the geographic positions, as determined on the Carnegie from Cape Town to Colombo, Ceylon, thence to Mauritius, April to August, 1911; a future communication will give the results from Mauritius northward to the Arabian Sear thence to Colombo and Batavia. While the present figures are not final, they are not likely to be changed by more than one‐tenth degree.The tables also give the corresponding values as scaled from the British Admiralty chart of 1907 (B); the German chart of 1910 (G); and the United States Hydrographic Office chart of 1910 (U); these chart values have been referred approximately to the time of our observations by applying the secular changes as indicated on the respective charts. The final three columns give the differences between the Carnegie values (C) and those of the various charts; the plus sign (+) means that the charts give west declinations too large, the minus sign (−) on the other hand signifying that the chart values are too low by the tabular amount.
On the magnetic field of the Earth
Authors: Steiner L. 
Published: February 2008

Dr. L. A. Bauer, in his very suggestive paper, “The external electric currents and the Earth's magnetization,”1 has come to the following “working hypothesis:” The Earth is chiefly an electromagnet, the magnetizing currents being outside and consisting of negative electric currents circulating overhead in the same general direction as that of the Earth's rotation, namely, from west to east. In the June issue of this Journal2 he continues the same topic and here3 he quotes Professor August Schmidt's views concerning the same object.As the supposition of the Earth's being an electromagnet and being magnetized by an outside primary magnetic field, if verified, would be of greatest importance in the explanation of magnetic phenomena and would—in connection with what we know about other kindred phenomena: diurnal variation, disturbances—produce a revolution in our views, the foundation of it must be carefully and thoroughly studied. I beg to make some remarks regarding that hypothesis. The importance of the question and my endeavor to avoid misunderstandings, may excuse if I treat the problem somewhat in length and often refer to things generally known.
Corpuscular theory of the aurora borealis
Authors: Störmer Carl 
Published: February 2008

It appears that the German physicist, Goldstein,1 was the first to publish the idea that the Sun sends out into space electrical rays analogous to cathode rays, and that we may thus explain the mysterious connection between variations in solar activity and corresponding fluctuations in the magnetic and electric phenomena, on the Earth. Some years later the Danish meteorologist, Adam Paulsen, from his auroral observations in Greenland was led to the hypothesis2 that the aurora is due to cathode rays; but instead of assuming that the rays came from the Sun, he believed that they originated in the upper strata of the atmosphere.Next, in the year 1896 Kr. Birkeland made his remarkable experiments with cathode rays in a magnetic field. He first found that a magnetic pole had an effect on a beam of parallel cathode rays analogous to that of a lens upon a beam of light, viz., to make the rays converge towards a point. This phenomenon led him to the idea3 that the aurora borealîs was due to a similar effect of the Earth's magnetic field on cathode rays coming from the Sun. In order to test his hypothesis, Birkeland exposed a small spherical electromagnet to a stream of cathode rays, and found a series of facts showing analogies to the shape and nature of the aurora. The aurora‐belts in particular were very beautifully produced. These remarkable experiments, which gave the first really good support to the corpuscular theory of aurora, were described on pages 39–42 of the paper “Expédition Norvégienne, 1899–1900, pour l'étude des aurores boréales.4 Notwithstanding that these remarkable experiments tend to show that the aurora is a direct effect of the precipitation of cathode rays in the upper air, Birkeland regarded the aurora as being caused rather by secondary cathode rays produced by strong electric currents in the upper atmosphere;5 in his later publication, however, he arrived at the conviction that the aurora is a direct effect of the electric rays from without.6
Preliminary results of ocean magnetic observations on the Carnegie from Lyttelton to Tahiti, Fanning Island, San Francisco, and Honolulu, November, 1920, to April, 1921
Authors: Ault J. P. 
Published: February 2008

NOTES ON TRIP FROM LYTTELTON TO PAPEETE, TAHITI.Some delay was occasioned by the tardy arrival of the stores ordered from San Francisco, but all business was finally transacted by November 19, and preparations for departure were completed. Leaving Lyttelton under tow at 1h 15m p.m., the tug was released by 3h p.m., and we proceeded with engine running until we had cleared Banks Peninsula, when all sails were set. For three days the wind blew from the north, then shifted to the west and remained westerly for four days. The 180th meridian of longitude was crossed on November 22, and the date November 22 was repeated.
Principal magnetic storms recorded at the Huancayo Magnetic Observatory, Peru, from April to June, 1924
Authors: Parkinson W. C. 
Published: February 2008

(Latitude, 12° 02.′7 S.; Longitude, 75° 20.′4 W. or 5h01m W. of Greenwich.)There were three principal magnetic storms recorded at the Huancayo Magnetic Observatory during the second quarter of the year 1924. The chief features are indicated in the following tabulation and descriptive notes:
Preliminary report on annual values of magnetic elements at the Swider Magnetic Observatory in Poland, 1921–1924
Authors: Kalinowski St. 
Published: February 2008

(Latitude, 52°07′N; Longitude, 21°15′E.)The Polish Magnetic observatory at Swider, built in 1914, is situated on the territory which was the scene of most fierce battles during the world war, as well as during the war with bolsheviks, and it is, accordingly, working regularly only since the beginning of 1921. Since that time quarterly bulletins of our magnetic character numbers are included in the “Lists” published by the De Bilt Observatory. Unfortunately, difficult financial conditions and, in consequence, inadequate personnel have hindered us from preparing immediately and publishing detailed reports of our observations. We have only been able to complete the reductions covering the years 1921 to 1924, inclusive, and although there are still some outstanding computations to be made before final results can be given, I consider it desirable to publish the preliminary values which follow:
The unsymmetrical distribution of magnetic secular variation
Authors: Fisk Harlan W. 
Published: February 2008

In his paper announcing the results of his analysis of the Earth's magnetic field for 1922, Bauer stated certain conclusions regarding secular variation which it is interesting to consider at the present time, in view of the more extended knowledge we now have of that phenomenon than was available when that paper was written. One of these conclusions is that “it must be recognized that the magnetic secular‐variation system is as complex as the Earth's total magnetic system existing at any one time, and that in addition to changes in the direction of magnetization with the lapse of time, there is also a change in the average equivalent intensity of magnetization.”That the secular‐variation system is even more complex than was then supposed by Bauer is made evident by reference to the series of isoporic charts (charts showing lines of equal annual change) of the elements recently prepared by the writer as a preliminary picture of the distribution of secular variation, subject to elaboration as data accumulate. These charts show that a large portion of the total secular change of any of the magnetic elements is concentrated within a few restricted areas, and that the centers of these areas (or isoporic foci) are surrounded by concentric ovals which are densely crowded near the centers, and are more openly arranged elsewhere. If we plot all these foci for the several elements on a single chart, and represent them by heavy shaded circles, we have the arrangement shown in Figure 1. The lighter unshaded circles represent centers of moderate secular‐change activity.
Harlan Wilbur Fisk, 1869–1932
Authors: Harradon H. D. 
Published: February 2008

The science of terrestrial magnetism has sustained a serious loss in the sudden death, December 26, 1932, of Professor Harlan Wilbur Fisk, chief of the Section of Land Magnetic Survey, Department of Terrestrial Magnetism, Carnegie Institution of Washington. During his long period of service with this organization extending over more than a quarter‐century, he contributed much to the success of the world magnetic survey, first as an observer in the field and later in planning and supervising the work at repeat‐stations with a view of obtaining data where most urgently required for advancing the investigations on which he was chiefly engaged. Readers of this JOURNAL are already acquainted with certain aspects of this work through a number of his papers which have from time to time appeared in these pages.Professor Fisk was born at Geneva, Kansas, September 25, 1869, of sturdy New England parentage. In 1875 his family moved to Freeborn, Minnesota, where he attended the district schools and later fitted himself for collegiate studies in the Preparatory Department of Carleton College at Northfield. At Carleton (1889–96) he received his fundamental scientific training and here his interest and enthusiasm for mathematics and astronomy were stimulated by association with such inspiring professors as W. W. Payne and H. C. Wilson. While still a student he spent his summers doing survey‐work for the Engineering Department of the Chicago, Milwaukee, and St. Paul Railway. After completing his course at Carleton College, he served for three years (1896–99) as principal of the high school at Grand Meadow, Minnesota. In 1899 he was appointed professor of mathematics at Fargo College (North Dakota) where he remained until 1906, serving as dean of the faculty during the last three years. It was here that the problems of terrestrial magnetism first engaged his attention and he devoted his summer vacations (1904–06) to magnetic observational work for the United States Coast and Geodetic Survey in the north central and western states. His interest in this field grew so rapidly that in October 1906 he adopted it as his life work when he became associated with the Department of Terrestrial Magnetism, then in the third year of its existence.
MAGNETIC RESULTS OF THE UNITED STATES EXPLORING EXPEDITION, 1838–1842, LIEUTENANT CHARLES WILKES, COMMANDER
Authors: Ennis C. C. 
Published: February 2008

A century seems a long lapse of time between the execution of a magnetic survey and the publication of its results. This contribution, containing a considerable number of magnetic results of the United States Exploring Expedition, 1838‐42, under the command of Lieutenant Charles Wilkes (1798‐1877), United States Navy, is offered not merely from a historical standpoint, but with the hope that it may supply some additional foundational material for investigations of the secular changes in the Earth's magnetism.HISTORICALThis Expedition was materialized as the result of an act of the Congress passed May 18, 1836. The act of authorization directed that comprehensive and detailed surveys be made of the multitudinous island‐groups of the Southern Pacific Ocean, the Hawaiian Group, and portions of the old ”Oregon Territory,” besides an investigation of the extreme southern limits of the Antarctic Ocean between the approximate limits of 90° and 160° east longitude. In addition to the hydrographic work entailed by these duties, directions were given for magnetic, meteorological, oceanographic, and graviometric observations, as well as in other branches of science. The Expedition was also instructed to obtain information concerning the social and economic conditions among the natives of the many regions to be visited.
WATHEROO MAGNETIC OBSERVATORY JANUARY TO MARCH, 1934
Authors: Parkinson W. C. 
Published: February 2008

(Latitude 30° 19′.1 S.; longitude, 115° 52′.6 or 7h 43m.5 E. of Gr.)March 4‐8—A moderate disturbance began March 4 at 13h 19m G.M.T., with sudden small oscillations in all three elements, the declination showing a sudden decrease of 1′ of westerly declination, the horizontal intensity an increase of 3γ, and the vertical intensity a decrease of about 3γ. These small oscillations continue for about 20 minutes of time, after which the traces show leisurely movements of larger amplitude. The minimum value of horizontal intensity occurred March 5 at 8h 08m when the force was about 100γ below its normal value. The leisurely movements continued until 16h on March 8, a period of small sharp oscillations being noteworthy, especially on the horizontal‐intensity trace, between 8h 50m and 9h 20m on March 6.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, April, May, and June 1934
Authors: Nicholson Seth B. , Sternberg Elizabeth E. 
Published: February 2008

A magnetic storm began May 11 at 20h 8m, G.M.T., and ended May 12 at about 8h; the range in the horizontal intensity (II) was 75γ. The only sunspot‐group observed on May 11 was very near the west limb of the Sun. Although the small group which crossed the central meridian on May 10.6, 9° north of the center of the disc, was not seen on May 11, its position was marked by bright hydrogen flocculi. Small bright hydrogen flocculi had been observed in this group on May 9 also; clouds prevented observations on May 10.A magnetic storm in which the range in II was 116γ began May 18 at about 3h, G.M.T., and ended May 19 at about 2h, A sudden increase in II was recorded on May 18 at 4h 06m, G.M.T. Bright; hydrogen flocculi were observed on several days in the group of spots which, on May 18, was 19° east. This group crossed the central meridian on May 19,6, 29° south of the center of the solar disc. Bright hydrogen flocculi were also observed in another group which was 27° north and 65° east on May 18.
Notes on radio fade‐out of August 25, 1936
Authors: Fleming J. A. 
Published: February 2008

An extensive fade‐out of radio signals in the Western Hemisphere occurred between 18h and 20h GMT, August 25, 1936. R. L. Garrison, Chief of Communications for Pan‐American‐Grace Airways, Inc., reported that communication was disturbed along the entire western coast of South America between these hours. P. D. Boothroyd, operator for the Mackay Radio Telephone and Telegraph Company at Seattle, Washington, sets the time of the fade‐out as from 18h 25m to 19h 20m GMT. Other reports indicate that the fade‐out was experienced from New York to Honolulu.The magnetic and earth‐current records at the Huancayo Magnetic Observatory of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington also exhibited disturbed conditions during the fade‐out according to reports received from O. W. Torreson and W. E. Scott. Reproductions (see Fig. 1) of magnetic record from the Huancayo Observatory and also from that of the Cheltenham Magnetic Observatory of the United States Coast and Geodetic Survey (by courtesy of Director Patton) show departures identical in time with the radio phenomenon. At Huancayo a marked change of some 70 gammas occurred in horizontal intensity, while at Cheltenham a marked change of 6′—equivalent there to about 35 gammas—occurred in declination. There was no marked change in vertical intensity at either station which indicates that the magnetic effects associated with the fade‐out induced currents within the Earth of sufficient magnitude to neutralize the vertical component of the field‐change.