bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seismology in the United States, 1983–1986
Authors: Hanks Thomas C. 
Published: February 2008

Any seismologist trying even to carry, let alone read, the EOS abstract volumes for recent AGU Meetings knows full well of the substantial growth in seismological research during this reporting period, the four years of 1983 through 1986. Indeed, the number of Seismology Section abstracts has grown from 188 (Fall, 1982) to about 320 (Fall, 1986), to be more or less precise. At a time when research monies seem to be no better than stable (and declining in real terms) and when job opportunities for seismologists seem to have never been worse, at least in the professional lifetimes of most of us, something must be amiss, but certainly this is not the great vitality and diversity in seismological research during the past four years.The current reporting period saw the consortium approach brought to full flower in several fields of seismology, and these include CALCRUST, a consortium of California universities to investigate the crustal structure of the southwestern United States with seismic reflection data; DOSECC (Deep Observation and Sampling of the Earth's Continental Crust), a consortium to drill and make measurements within scientifically dedicated deep holes to sample active processes that make and remake the continents; EDGE, a consortium of university, government, and private industry scientists intent on exploring the oceanic/continental transitions along U.S. continental margins, using seismic and potential field methods; and IRIS (Incorporated Research Institutions for Seismology), whose prospectus includes a major upgrading of the global seismic network, an advanced portable array of 1000 seismic units for a host of active and passive experiments, and a data management center to store and utilize the vast quantities of data forthcoming from the first two activities. Each of these fledglings can trace their basic nature and motivation, if not their specific scientific agendas, to COCORP (Consortium for Continental Reflection Profiling), now a teenager, whose activities were summarized by Phinney and Odom[1983] for the last reporting period and by W. D. Mooney for the current one.
Tectonophysics 1983–1986: An overview
Authors: Chapman David S. 
Published: February 2008

Exciting developments in concepts, technology, and analyses have marked the last four years of research in tectonophysics. This introduction to the Tectonophysics section of the 1983–1986 IUGG Quadrennial Report serves as a sketch of some of these developments. My observations are drawn from, and are largely restricted to, the ten review articles that follow; selected or comprehensive reading of the reviews is recommended for the specialist.Most of the topics have been reviewed in previous IUGG reports, although not always in each one. For example rheology of the lithosphere, lithospheric stress and deformation, and mantle convection have all been reviewed in the previous two reports (1979, 1983) whereas plate motions have not been reviewed in this series since 1979 and the thermal state of the lithosphere since 1975. Other reviews substitute for subjects covered previously; the review on accretionary prisms, for example, substitutes for continental passive margins reviewed last time. Two areas of renewed or growing importance in tectonophysics are represented by the reviews on mineral and melt physics and on the role of pore fluids in tectonic processes.
Physics of the quiet magnetosphere
Authors: Stern David P. 
Published: February 2008

Global properties of the Earth's magnetosphere are mainly studied in one of two ways : by focusing on specific events, e.g., substorms, or by analyzing average behavior. This collection of reviews deals with the second aspect.All four articles began as invited reviews at the International Association of Geomagnetism and Aeronomy symposium on the quiet magnetosphere, held in Vancouver, Canada, August 17, 1987, as part of the nineteenth International Union of Geodesy and Geophysics General Assembly. One invited speaker, Igor I. Alexeev, was unable to attend, and one talk, by G.‐H. Voigt, was transferred to the symposium from the general contributions session.
Comparison of the Chemical Composition of Lunar Surface Material Determined by Radioastronomical Observations With the Results of Chemical Analysis Obtained by Surveyor
Authors: Troitskii V. S. , Bondar' L. N. , Zelinskaya M. R. , Strezhneva K. M. 
Published: February 2008

It is of great interest to compare the results of the chemical analysis of the lunar surface material made by ‘Surveyor’ with that based on the data of the radio astronomical investigations of the electromagnetic properties of the lunar material. The method of determining the chemical composition by the equipment brought onto the moon by Surveyor 7 has been described by Turkevich et al. [1968].From ground‐based optical observations of the moon, attempts to estimate the chemical composition of the lunar surface material have been made, for example, by comparing the polarization properties with those observed for terrestrial rocks. Yet, optical methods are not very effective, as their results depend chiefly on the geometrical properties of the surface (i.e. the roughness). Radar measurements provide the reflection coefficient and some limited data on the nature of the lunar material. They allow, for example, one to distinguish between a metallic and a dielectric reflector.
Focusing of Waves in Ducts
Authors: Sodha M. S. , Ghatak A. K. , Tewari D. P. , Dubey P. K. 
Published: February 2008

This paper presents an investigation of the propagation of cylindrical waves (the field being independent of x) along the z direction inducts described by

urn:x-wiley:00486604:media:rds618:rds618-math-0001
where c(y, z) is the wave velocity, C0 and ϵ0 are constants, ϵ2(z) is an arbitrary function of z, and ϵ corresponds to the dielectric constant for electromagnetic waves.It has been shown that the intensity A02 of the wave is in general given by

urn:x-wiley:00486604:media:rds618:rds618-math-0002
where E0 is a constant, yo is a constant, F is an arbitrary function of [y/yoƒ(z)L], and ƒ(z) is a dimensionless beam‐width parameter given by

urn:x-wiley:00486604:media:rds618:rds618-math-0003
in the geometrical optics approximation.The nature of the variations of ƒ with z has been discussed for some simple profiles of ϵz(z) in the geometrical optics approximation; diffraction has also been taken into account when the beam (F) is Gaussian.
Commission 1. Radio measurement methods and standards
Authors: Altschuler H. M. 
Published: February 2008

K. Evenson (USA) delivered the paper, ‘Stabilized laser‐frequency measurements: Methane‐stabilized HeNe 3.39 μm and CO2‐stabilized 9.3 and 10.2 μm.’The most notable results reported were the measurements by the National Bureau of Standards (NBS), Boulder, Colorado of both the frequency and wave‐length of the HeNe laser stabilized on the 3.39‐µm saturated absorption in methane. By this means the velocity of light has been deduced with an estimated accuracy of about 3 parts in 109. This result is at least 100 times more accurate than previous determinations of the velocity of light and is in reasonable agreement with the previously adopted value published by Froome and Essen [1969]. The new value for the velocity of light determined by NBS with to the fundamental standards of time (cesium) and length (krypton) is:

urn:x-wiley:00486604:media:rds710:rds710-math-0001
Some new thoughts on magnetospheric substorms
Authors: Akasofu S.‐I. , Kan J. R. 
Published: February 2008

Several important new observations of magnetospheric substorms now allow us to examine many substorm features in terms of the solar wind‐magnetosphere dynamo and of four rates, the merging rate M of the interplanetary and geomagnetic field lines, the transport rate T of the merged field lines from the dayside magnetosphere to the magnetotail, the reconnection rate R of the transported field lines and the return rate R of the reconnected field lines to the dayside magnetophere. It is shown that magnetospheric observations of great variety are consistently explainable by the deduced result that the expansive phase of a typical intense substorm occurs when the combination of the four rates is such that

urn:x-wiley:00486604:media:rds769:rds769-math-0001
while a weak substorm occurs when the combination of the four rates is such that

urn:x-wiley:00486604:media:rds769:rds769-math-0002
where an upward‐pointing arrow denotes an increasing rate. The first combination corresponds to a negative Bz component of the interplanetary magnetic field, while the second one to a positive Bz component. Thus, the Bz component does not control triggering mechanisms of substorms, but does control the intensity of substorms. Indeed, there are also periods in which the combination may be such that M(∼T)↑, ℜ = const., R = const., which does not consistently result in substorm activity.
Recent developments and outstanding problems in the theory of the D region
Authors: Thomas L. 
Published: February 2008

The present understanding of the ionization processes, and of the positive and negative ion chemistry of the D region, is reviewed with particular attention being given to outstanding problems.Rocket‐borne mass spectrometer observations carried out in the past decade have shown that the change in positive ion composition with height (from NO+, O2+ and metallic ions above to water cluster ions H+· (H2O)n below) is a general feature of the D region at all latitudes and under all geophysical conditions. Furthermore, these observations indicate that this change occurs over a very small range of heights, between 82 and 86 km under normal conditions and at lower heights during auroral or Polar Cap Absorption conditions. These results are discussed in terms of current ideas concerning the formation of water cluster ions from O2+ and NO+ ions.Mass spectrometer observations by two experimental groups have provided conflicting results concerning the negative ion composition in the D region and cannot be used to test theoretical models. Such models have been derived from laboratory measurements, and involve reaction schemes leading from O2− ions, formed by electron attachment, to ions O3−, O4−, CO3−, CO4−, NO2− and NO3−. The effect on these models of including recent laboratory measurements of negative ion hydration is considered, and the importance of photodetachment is also mentioned.
Tidal effects in the E region from incoherent scatter radar observations
Authors: Salah J. E. , Wand R. H. , Evans J. V. 
Published: February 2008

Measurements of the neutral temperature in the altitude region 100 to 130 km during the past several years at Millstone Hill (42°N) and St. Santin (45°N) have revealed that, on the average, there exist strong semidiurnal tidal effects which can be identified with the (2,4) tidal mode propagating from the stratomesosphere. The average amplitude of the temperature oscillation reaches a maximum of about 35 K at 116 km with maxima at 0630 and 1830 hr LT. At each station, large variability is found in amplitude and phase from one observing period to another, particularly during winter. From classical tidal theory, the average temperature behavior implies a semidiurnal zonal wind oscillation with an amplitude of about 45 m sec−1 at 110 km having eastward maxima at about 0500 and 1700 hr LT, and a meridional component with similar amplitude having southward maxima at 0800 and 2000 hr LT. The downward phase velocity is about 4 km hr−1. These results are in good agreement with direct wind measurements at St. Santin, and with some recently reported characteristics of the height variations of sporadic‐E at midlatitudes.At Arecibo (18°N), semidiurnal oscillations have also been found to dominate the E‐region temperature and wind structure with similar amplitude and phase velocities as above; however, the observed phase behavior is more variable than at midlatitudes and the average results do not allow reliable mode identification. Some results of recent simultaneous observations at low and midlatitudes are presented which imply that during any particular observing period, the E‐region structure must be controlled by local effects.
The physical decomposition of the Earth's permanent magnetic field—No. I. the assumed normal magnetization and the characteristics of the resulting residual field
Authors: Bauer L. A. 
Published: February 2008

The object of this paper is to resolve the earth's so‐called permanent field into component ones physically interpretable. It is an elaboration of a preliminary communication read in 1896 before the American Association for the Advancement of Science and the British Association, and entitled “On the Component Fields of the Earth's Permanent Magnetism”2 In this first paper the deductions were based on the measured magnetic components at 84 symmetrically distributed points; namely, at the intersections of meridians 30° apart, with the parallels of latitude ±60°, ±40°, ±20°, and the equator. The present investigation, on the other hand, depends upon the measured magnetic components at 1800 points, situated at the intersections of meridians, 5° apart, with the 5° parallels between 60°N. and 60°S.If we take a cursory glance at a series of magnetic charts of the Earth, we are at once impressed with the complexity of the distribution of its magnetism. Turn to an isogonic chart, for instance, and behold the peculiar condition of things existing at the present time in Eastern China and Japan. You will note that here we have a closed curve along which the needle is “true to the pole.” Within the oval the needle everywhere points W. of N., while outside, the compass everywhere bears East. What is the cause of the peculiar distribution in this region? Is it due, for example, to peculiarities in the geological structure of this part of the earth? We find, moreover, that this oval is not a permanent feature of that region. It has formed only within the present century, and is now enlarging. In the sixteenth century we had a somewhat similar state of affairs in the Atlantic Ocean, only that in this case the oval inclosed places where the needle stood East, instead of West as in the Asiatic oval.
Erdmagnetische Beobachtungen im Umanaks‐Fjord (Nordwest‐Grönland), 1892–93
Authors: Stade Von Dr. H. 
Published: February 2008

Während meines einjährigen Aufenthaltes im dänischen Nordgrönland gelegentlich der von der Gesellschaft für Erdkunde zu Berlin im Frühjahr 1892 dorthin entsandten Forschungs‐Kxpedition, an welcher ich mich als Meteorologe beteiligte, habe ich im Umaiiaks‐Fjord zwölfmal, und zwar elfmal an der von uns gegründeten Station Karajak und einmal bei der dänischen Kolonie Umanak, die absoluten Werte der erdmagnetischen Elemente (Declination, Inclination, Total‐Intensität) bestimmt.Die Beobachtungen zu Karajak wurden sämtlich streng an demselben Punkte und zwar 40 Meter nördlich vom Stationshaus angestellt; derselbe lag in 23 Meter Meereshöhe und wurde im N, E und S bis 300 Meter Entfernung von niedrigen Felsen nur wenig überragt, während 20 Meter weit im W ein schroffer Abfall zum Fjord stattfand. Zu Umanak wurden die Beobachtungen in etwa 30 Meter Höhe etwas westlich von der Kolonie auf einem' die nördliche und östliche Umgebung ein wenig überragenden, nach Wund S steil zum Meere abfallenden Felsen ausgeführt. Der Boden, auf dem beide Beobachtungspunkte lagen, bestand aus Gneiss, ebenso wie die nähere und weitere Umgebung derselben. Neben demselben finden sich andere Gebirgsglieder im Umanaks‐Fjord nur in ganz untergeordneter Ausdehnung und fern von den beiden genannten Punkten.
Dr. Lüdeling's researches on the diurnal variation and on magnetic disturbances in polar regions
Authors: Bauer L. A. 
Published: February 2008

By request of the Editor, Dr. Lüdeling has contributed the foregoing summary of the results of his recent investigations. It had been the intention to have the article translated into English, as the author had already published his paper in German. This could not, however, be done in time for the present issue, and accordingly the following brief abstract is given for the benefit of those who have difficulty in reading German.The author investigates graphically the phenomena of the diurnal variation of the earth's magnetism for the eleven stations enumerated on page 246, with the aid of von Bezold's vector‐diagrams. A vector‐diagram is the curve which the north end of a horizontally suspended needle, freed from the mean action of the earth, would describe in the course of a day in consequence of the diurnal variation, if at every instant the half length of the needle represented the magnitude of the horizontal deflecting force. Such diagrams were employed originally by Airy and Lloyd. They, however, took as components of change those along the magnetic meridian and perpendicular thereto, while von Bezold takes his components along the astronomical directions. Von Bezold first showed the full significance of such diagrams. Thus, for example, if the diurnal variation could be referred to an invariable system of magnetic forces revolving around the earth once in twenty‐four hours, then the vector‐diagram for all places along a parallel of latitude would be the same for the same local mean time at each1
Magnetic intensity variometers
Authors: Eschenhagen M. 
Published: February 2008

For the measurement of the variations of the Earth's magnetic force, advantage is taken of a comparison with a compensating force; e.g., the magnetism of a bar and the directive force of the bifilar suspension. Both forces mentioned are not free from changes in the course of time, and are greatly affected by temperature.The force of torsion of a unifilar suspension has only been applied with advantage since the invention of quartz fibers. The systems of magnets and suspensions, which weigh at least 20–30 grams usually employed with magnetometers are not suited for quartz fiber suspensions, as too strong fibers must be used. Magnetometers have, therefore, been built at my request by the firm of O. Toepfer, of Potsdam, which are provided with a light system of magnets (weighing about 1.5 g.), and possess several advantages over the instruments used hitherto. Among these are to be mentioned : easy accessibility to the system of magnets, clamping of the lower suspension, so that slight displacements of the mirrors can be made; moreover, a damping adjustable at pleasure; finally, a fixed mirror for photographic registration, which can be displaced with ease and certainty. The system of magnets carries two mirrors, inclined at a certain angle to each other, so that the range of registration is increased twofold. The magnet consists of a well‐hardened laminar piece of watch‐spring steel, 25 mm. long, which can be turned at pleasure about the axis of the system. The frame, supporting mirrors and magnet, is made of aluminum, and is hung, by means of a double hook, on a small cross piece attached to the bottom of the fiber suspension.
Summary of the results of recent investigations in atmospheric electricity
Authors: Exner Franz 
Published: February 2008

IV. VARIATION WITH ALTITUDE OF FALL OF POTENTIAL.That the Earth possesses a negative charge is shown by the generally positive fall of potential. Whether there exist also in the air electric charges, and, if so, whether they be positive or negative, can not be decided by observations made at the surface of the Earth; for this purpose observations in the upper regions alone suffice. If we premise a uniform distribution in the air of the charges in question along horizontal layers, then, in the absence of a charge of the air of its own, the fall of potential should remain constant for the same altitude; in the case of a positive charging of the air the fall of potential must decrease, and for a negative charge, the same should increase. I, therefore, some time ago pointed out the importance of such measurements, and have shown how it would be possible to carry them out in a balloon without conduction with the Earth. Parenthetically it may be remarked, that similar observations on high mountains, on account of the disturbances in the equipotential planes, can not replace, for this purpose, the balloon observations.
The hysical decomposition of the earth's permanent magnetic field: No. II. The composition and characteristics of the uniform magnetic field
Authors: Bauer L. A. 
Published: February 2008

In my previous paper, I separated from the Earth's total magnetic field that portion which could be referred to a uniform or homogeneous magnetization about a single diameter inclined 11° 25′.7 to the axis of rotation and intersecting the Northern Hemisphere in longitude 68° 30′.6 west of Greenwich. This diameter is the same as that termed by Gauss, in his celebrated memoir on the theory of the Earth's magnetism, the “magnetic axis” of the Earth, and its position is determined by the coefficients of the spherical harmonic of the first order entering in Gauss's mathematical analysis of the distribution of the so‐called permanent magnetism of the Earth.The position as above given was based upon the latest and most complete analysis made thus far; viz., that of Dr. Adolf Schmidt, of Gotha. The magnetic moment of this uniform or “normal field,” as I called it in my previous paper, was 0.32298 R8, c. g. s. units, R being the Earth's mean radius.
Wild's new method for determining the variations of magnetic inclination
Authors: Cady W. G. 
Published: February 2008

This is one of the the most important contributions to the study of the Earth's magnetism since the invention of the Weber earth‐inductor, of which it is a modification. The fact that the Weber inductor is always used with the zero‐method, makes it unfit for use as a variation instrument. This defect has been entirely removed in the Wild inductor; a needle hung from a vertical suspension not only shows the same variations in a horizontal plane that a frictionless dipping‐needle would experience in a vertical plane, but the absolute value of the total deflection is the same in each case.If we have two equal coils of wire, the one turned about a horizontal, the other on a vertical axis with equal velocities, the two induced currents are:Iz = Z. C and Ih = H. C′respectively, H and Z being the horizontal and vertical components of the Earth's field, C and C′ constants involving character of the coils, velocity, etc. If the two coils are exactly alike, C = C′ and we have for the inclination,

urn:x-wiley:00968013:media:tma3107:tma3107-math-0001
Report on the magnetic observations made at the magnetic observatory at Zi‐Ka‐Wei, China, during the total solar eclipse of May 17–18, 1901
Authors: de Moidrey J. 
Published: February 2008

The Observatory at Zi‐ka‐wei has been desirous of co‐operating in the simultaneous observations suggested in the December, 1900, number of “Terrestrial Magnetism.” Our station (8h 5m 44s east of Greenwich, 31° 11′ 33″ north) is situated outside the zone of visibility of the eclipse, but very near the line of single contact.An unforeseen accident prevented our beginning the observations, as we wished, one hour before the eclipse. The registration could not be set going until 11h 20m (15h 14m Gr. m. t.). I send, nevertheless, what we have obtained. On the 17th a scale determination, made with care and at two distances, showed that the self‐registering instruments, and in particular the Lloyd balance, were in perfect condition. On the 18th the sensitiveness of the bifilar was doubled, and a new scale determination was made at two distances.