bluuebunny/crossref_metadata_2025 huggingface dataset:
Strike‐slip faulting in a foreland fold‐thrust belt: The Kalabagh Fault and Western Salt Range, Pakistan
Authors: McDougall James W. , Khan Shahid Hasan
Published: February 2008

The 120‐km‐long Kalabagh fault zone is formed by transpressive right‐lateral strike‐slip along the western Salt Range‐Potwar Plateau allochthon in northern Pakistan. Lateral ramping from a decollement thrust along an Eocambrian evaporite layer produced NNW‐ to NW‐trending folds and NE‐ to N‐dipping thrust faults in a topographically emergent zone up to 10 km wide. Piercing points along the main Kalabagh fault indicate 12–14 km of middle to late Quaternary right‐lateral offset. The older right‐lateral Surghar fault displaced axes of frontal folds of the eastern Surghar Range by 4–5 km. Total displacement is reduced northward in the Kalabagh fault zone where north‐dipping thrust faults splay to the west. Cumulative right‐slip offset in the Kalabagh fault zone is comparable to displacement along the Salt Range frontal thrust, at a minimum average displacement rate of 7–10 mm/year near the Indus River since 2 Ma. In the basement, which dips 2–3° north along the Kalabagh fault, a NNW‐trending discontinuous ridge beneath the lateral ramp is interpreted from residual gravity anomalies. The eastern flank of this basement ridge probably ramped allochthonous strata upward from a depth of over 5 km in the Kalabagh fault zone. Kalabagh faulting displaced and uplifted Holocene terrace deposits and shifted the course of the Indus River eastward. A high slip rate and associated seismicity indicate that the Kalabagh fault zone should be considered active and capable of earthquakes.
Remagnetization and northward coastwise transport of Franciscan Complex Rocks, northern California: A reinterpretation of the paleomagnetic data
Authors: Hagstrum Jonathan T.
Published: February 2008

Previous paleomagnetic studies of accreted oceanic rocks within the Franciscan Complex of northern California have concluded that these rocks originated far to the south of their present positions with respect to the North American continent. Based on positive “fold” tests, the characteristic remanent magnetizations were inferred to predate accretion‐related deformation and metamorphism, and to have been acquired during or soon after deposition of these rocks. Thus, the paleomagnetic data were thought to provide direct information on ancient oceanic plate motions. However, the plate motions implied by some of these paleomagnetic data are problematic (e.g., exceptional plate velocities), and uniform‐polarity magnetizations in almost all of these rocks indicate the possibility of remagnetization. Recent work on oceanic rocks in similar subduction complexes of Japan and Mexico have shown that they were most likely chemically remagnetized during accretion prior to disruption of the original stratigraphic sequences. Modern analogs indicate that the oceanic rocks in Mexico were probably remagnetized while still part of a shallow‐dipping subducting slab (<10°) at the base of an accretionary prism. Assuming these rocks were near horizontal at the time of remagnetization, paleolatitudes at which these rocks were subducted and subsequent arc‐parallel displacements along the western margin of North America can be inferred. In this paper, Franciscan rocks in northern California are reinterpreted as also having been remagnetized prior to accretion‐related deformation. This scenario satisfies both geologic and paleomagnetic constraints for these rocks, and resolves conflicts between data indicating both remagnetization and tectonic displacement. Transport of the Laytonville Limestone from the southern hemisphere is not required. Paleolatitudes of subduction and remagnetization in the northern hemisphere (12° to 33°) appear to be inversely proportional to age of accretion (middle Cretaceous to Oligocene) for the Franciscan rocks. Subsequent northward diplacements (800 to 3700 km) and clockwise rotations (56° and 154°) of these rocks inferred from the paleomagnetic data are consistent with potential displacements along the western margin of North America during late Mesozoic and Cenozoic time calculated using examples of modern subduction zones and current plate reconstruction models.
Dead horse graben: A west Texas accommodation zone
Authors: Maler Michael O.
Published: February 2008

The Cretaceous rocks of the Dead Horse graben area underwent two superposed deformations. Laramide (latest Cretaceous to early Tertiary) left‐transpression structures are overprinted by a Basin and Range (Miocene to Recent) accommodation zone. During Laramide shortening, two northwest trending sets of monoclines developed: an en echelon set over a left‐slip basement fault and a single monocline draped over the uplifted edge of a rotated basement block. Basin and Range extension caused northerly trending half‐grabens that have opposing asymmetry: downthrown‐to‐the‐east north of the study area and downthrown‐to‐the‐west south of the area. These half‐grabens are separated by an accommodation zone, expressed as a northwest trending, right‐lateral pull‐apart graben. The normal faults of the pull‐apart graben flatten at a shallower depth than those of the half‐grabens. This suggests not only that accommodation zones can be mechanically layered but that this layering can occur on a scale different from the adjacent half‐grabens. The northwest trend and superposition of both sets of structures implies a tectonic control by the preexisting structural fabric of the Texas Lineament.
The Ghomarides Nappes, Rif Coastal Range, Morocco: A Variscan chip in the Alpine Belt
Authors: Chalouan Ahmed , Michard André
Published: February 2008

The Ghomarides nappes are the uppermost basement nappes in the Rifan Alpine belt. Paleozoic rocks constitute the prominent part of these nappes, together with Triassic and younger cover sediments. Four nappes are distinguished, each one with a distinct stratigraphical sequence, especially for the Devonian and Carboniferous periods. Sedimentological and structural arguments plead for an initial location on the northern margin of the African continent. The main folding and metamorphic events are shown to be Eo‐Variscan (late Acadian). Tectonic vergence was to the north (present coordinates). Late Variscan (Hercynian) shortening gave upright, NW‐SE trending folds. Alpine ductile overprints are scarce except at the base of the lowest nappe where K/Ar phengite ages are about 25 Ma. The Ghomarides nappes correlate with the Malaguides nappes (Betic Cordilleras, southern Spain), the Kabylian (northern Algeria) and Calabrian (southern Italy) Paleozoic nappes, the Tuscan‐South‐Alpine basement and the Upper Austro‐Alpine nappes. The proposed correlations allow us to restaure the southern margin of the Hercynian belt along northwestern Africa.
Magnetic results of Halley's expedition, 1698–1700
Authors: Bauer L. A.
Published: February 2008

It will be recalled that the noted astronomer, Edmund Halley, in 1698, was placed by King George III in command of the sailing ship, the Paramour Pink, for “proceeding with her on an expedition to improve the knowledge of the Longitude and variations of the Cornpasse.” He was explicitly instructed that “in all the Course of your voyage you must be carefull to omit no opportunity of noting the variation of the Compasse, of which you are to keep a Register in your Journal.”1

Halley set out on his first voyage from Deptford on October 20, 1698; returning to England towards the end of June, 1699, he sailed again from Deptford, September 16, 1699, this second voyage terminating at Long‐reach, September 7, 1700. The two voyages together extended over the Atlantic Ocean from 50°N. to about 52°S. Halley's expedition is memorable as being the first scientific one sent out by any country with the specific object of ascertaming the direction in which a compass sets itself at various places; it was the first ocean magnetic survey. The expedition fully justified itself, not only in the results immediately obtained, but by the impetus given to further investigation in magnetism and other subjects. It seems strange, therefore, that Halley, though a prominent, member of the Royal Society, published no report on his work. He appears to have been satisfied with the graphical representation of his magnetic results as shown on his famous chart—the first successful one of its kind—giving the lines of equal magnetic declination (variation of the compass) for the year 1700.
Measurements of the electrical conductivity in the free atmosphere up to 9,000 meters in height
Authors: Wigand Albert
Published: February 2008

(Aerophysikalischer Forschungsfonds Halle, Abhandlung 11.)

For the measurement of the electrical conductivity of the air in manned free balloons, Gerdien has designed a serviceable piece of apparatus, and has accomplished with it successful measurements. He finds that the conductivity shows considerable variations in the lower 1,000 meters, but it increases considerably at greater heights, at 5,760 meters reaching the value 13.65×10−4 E. S. U., and at 6,000 meters, the value 20.6×10−4 E. S. U.; that is, 22 times the amount found for the Potsdam mean value for the normal day (λ = λ+ + λ− − 0.95×10−4 E. S. U.) at a height of 85 meters. At Davos, altitude 1,600 meters, the conductivity was found 3 times as great as that at Potsdam (2.8×10−4).
Magnetic storm of August 11–12, 1919, as recorded at the Honolulu Magnetic Observatory
Authors: Faris R. L.
Published: February 2008

Below are given the data for the magnetic storm of August 11‐12,1919, derived from the records of the Honolulu Observatory, similar to those for the other observatories of the United States Coast and Geodetic Survey, published in the December, 1919, issue (pp. 171‐173). Greenwich mean civil time is used in the Table.
The magnetic storm of May 13–16, 1921, at Apia Observatory, Samoa
Authors: Angenheister G. , Westland C. J.
Published: February 2008

In the following Greenwich Civil Mean Time is used. The geographic coordinates of the Samoa Observatory are: 13° 48′ S.; 171° 46′, or 11h 27m.1 W. The motions of north end of the magnet to east and downward are reckoned positive. D = 1′ corresponds to 10γ.
A new theory of magnetic storms
Authors: Chapman S. , Ferraro V. C. A.
Published: February 2008

PART I—THE INITIAL PHASE

1—Introduction and summary

2—The motion of an infinite plane‐slab stream in a uniform magnetic field

3—The motion of a cylindrical stream in a uniform magnetic field
Apparent vertical Earth‐current variations at the Huancayo Magnetic Observatory
Authors: Forbush S. E.
Published: February 2008

Continuous photographic registration at the Huancayo Magnetic Observatory, in Peru, of the potential‐difference between electrodes at the top and bottom of a dry well about 46 meters deep indicated apparent changes in the vertical earth potential gradient. Comparatively short time‐changes, during magnetic disturbances, occurred simultaneously on the magnetic horizontal‐intensity record, on the horizontal earth‐current records, and on the record of the potential‐difference between the electrodes in the well. For changes occurring in intervals of about ten minutes or less, an increase of current toward the northwest in the horizontal plane was always associated with an increase of current downward in the well; similarly an increase toward the southeast was always associated with an increase upward in the well. For all the changes investigated the increase of current in the horizontal plane was always approximately toward the northwest or toward the southeast. It is concluded that at this station the distortion of the normal horizontal earth‐current lines of flow by horizontal and vertical variations of resistivity near the well may be the sole source of the observed variations in the vertical direction and that the apparent vertical earth‐current probably does not cross the Earth's surface.
Theory of the ionosphere
Authors: Hulburt E. O.
Published: February 2008

Introduction—During the past ten years the ionization in the reaches of the atmosphere at several hundred kilometers above sea‐level has been explored by means of radio waves. Concurrently with the experimental investigations various possible causes of the ionization have been examined from the theoretical standpoint and this in turn has called for theoretical elaboration of the entire physics of the high atmosphere. The recent and detailed ionosphere‐measurements of the National Bureau of Standards and of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington permit a closer scrutiny of fact and theory than has been possible heretofore. In the following brief resume a few of the more important conclusions are outlined.
Non‐seasonal change of F2‐region ion‐density
Authors: Berkner L. V. , Wells H. W.
Published: February 2008

Observation of noon F2‐region ion‐density at stations in both the Northern and Southern hemispheres shows that variations in one are not predicted at the other with the hypotheses which have been advanced to explain them. Observations made at Washington by the National Bureau of Standards, and at Watheroo by the Department of Terrestrial Magnetism, Carnegie Institution of Washington, are analyzed. It is found that a variation‐component exists in the data from 1935–37 which is in the same phase at both stations. This term has a principal period which, over the period studied, is indistinguishable from one year. Its amplitude is about equal to that of the seasonal variation, maintaining a nearly constant ratio to the changing background ion‐density. This non‐seasonal variation is, therefore, of sufficient amplitude, if neglected, to vitiate quantitative calculations of seasonal effects based upon the observations from one hemisphere alone. While the average magnitude of the background ion‐density is closely related to annual averages of solar activity, departures of the non‐seasonal component from the mean show no sensible correlation with monthly sunspot‐averages. The data and methods are examined to determine whether inhomogeneity of data, or methods of analysis, could induce the effect artificially. It is concluded that the amplitude of such induced errors must be small compared to the amplitude of the non‐seasonal effect. Application of the heating hypothesis in its present form leads to a heating ratio more than 100 times as great at Washington as at Watheroo, which does not seem probable. Correction of the data for the non‐seasonal effect leads to a heating ratio for summer to winter of about 10 to 1 for both stations. Possible causes of the non‐seasonal term are considered. The paucity of data from widely separated locations through the 24 hours limits speculation. In reviewing the implications of the data, the writers are inclined to the view that the cause is associated with the Earth or its motion, though the arguments presented on the basis of existing data are not sufficient to establish this view unequivocally.
Geophysical Lunar Almanac
Authors: Bartels J. , Fanselau G.
Published: February 2008

Summary—The astronomical year‐books furnish complete data for the motion of the apparent Moon from day to day. Those tables, which so far have had no counterpart for the mean Moon, are frequently, because of their convenience, used as a basis for geophysical computations on lunar effects. Thereby, however, the connection is lost with the harmonic analysis of the tidal forces, which is based on the mean Moon; furthermore, the unequal length of the apparent lunar day is troublesome in the computations. Adolf Schmidt has introduced magnitudes μ, (π+μ), and (ρ+μ), which, in suitable form, indicate the phase of the mean Moon and its distance from mean perigee and from the mean ascending node of the Moon's orbit. Tables are given here for these magnitudes, from which they can be read easily for each day of the years 1850 to 1975. The differences between the motions of the apparent Moon and the mean Moon are illustrated by some extreme cases.
The diurnal variation of atmospheric condensation‐nuclei
Authors: Bradbury N. E. , Meuron H. J.
Published: February 2008

Records of the diurnal variation of the density of atmospheric condensation‐nuclei have been obtained over a period of four months. The apparatus employed consists of a Wilson cloud‐chamber with an expansion ratio of 1.15. At regular intervals the air in the chamber is replaced by a fresh sample, saturated with water‐vapor, and subjected to an expansion. A beam of light passing through the chamber is diminished in intensity by the resulting fog, and the degree of extinction may be related to the nuclei‐density. The diurnal variation in nuclei‐density shows a definite maximum in the forenoon and in the evening with a pronounced minimum prior to sunrise and a midday minimum of lesser extent. Such a variation might be expected in the normal daily convective cycle. The average hourly values of nuclei‐density have been compared with the hourly averages of the local component of the diurnal variation of the Earth's electric field for this Station. The results indicate that in a large measure, if not entirely, the variations in the local component of the Earth's potential‐gradient arise out of variations in the nuclei‐density.
Chapters in the history of terrestrial magnetism
Authors: Mitchell A. Crichton
Published: February 2008

Chapter III—The discovery of the magnetic inclination

1—It has been shown in Chapter II that the literature of the fourteenth century contains references to the fact that the direction of a suspended or pivoted magnetic needle is not, always and everywhere, that of the geographical meridian at the place of observation; that for nearly 200 years the existence of this variation was either denied, or doubted, or ascribed to irregularity in the magnetization of the needle or to faulty methods of observation; but that finally, about the middle of the fifteenth century, it was recognized as a general or world‐wide phenomenon. Thus was reached the conception of magnetic declination.
Tables on sunspot‐frequency for 1749–1938
Authors: Brunner W.
Published: February 2008

In view of the numerous requests received for the whole series of Zürich sunspot‐numbers and the depletion of the supply of reprints of the table of observed relative sunspot‐numbers for 1749–1933 published in this JOURNAL (September, 1934), Table 1 is reprinted here with additions for the years 1934–1938. The new Table 2 is added for the so‐called “smoothed monthly means” of sunspot‐numbers for the same period and Table 3 for the epochs of maxima and minima of sunspots from 1610 to 1938.

Table 1 gives the monthly means of the observed daily relative sunspot‐numbers compiled by Rudolf Wolf, using old observations of the Sun from 1749 to 1849 and published yearly since 1849 by the astronomers of the Zürich Observatory (Wolf, Wolfer, and Brunner in the Astronomische Mitteilungen of this Observatory). Since 1849 these means have been based upon careful daily observations (280 to 310 days a year) at our Observatory in which the same instrument has always been used. As is seen from the Astronomische Mitteilungen these observations are supplemented by observations made elsewhere with different instruments and by different observers. These observations are rendered comparable with our own by means of empirically determined reduction‐factors. Our daily relative spot‐numbers form therefore a completely unified system.
Ionospheric effects associated with magnetic disturbances
Authors: Berkner L. V. , Wells H. W. , Seaton S. L.
Published: February 2008

Consideration of ionospheric effects coinciding with magnetic disturbances must, as yet, be qualitative. Discussion in this paper is directed toward elucidating the nature of ionospheric changes coincident with magnetic activity in the temperate and equatorial zones as interpreted from automatic multifrequency ionospheric records. Observations at Kensington (Maryland) during summer are described and illustrated. During summer night, following commencement of a storm, ion‐density of the F‐ or F2‐regions decreases and height increases. The region loses its smooth horizontal distribution and appears to break up into “clouds” of non‐uniform ion‐density. There is evidence of turbulence in the F‐region during the disturbance. When a storm begins at night during summer, the F2‐region is observed to separate from the F1‐region immediately at daybreak, or for more severe disturbances to appear first at great heights above the F1‐region with greatly reduced ion‐density. Winter‐night and summer‐night conditions are similar. For moderate magnetic disturbances during the day in winter little ionospheric disturbance is noticed, the ionosphere recovering rapidly to nearly normal conditions after daylight. Penetration‐frequencies remain slightly disturbed during winter day, ranging from a little above normal to below normal depending upon intensity of the disturbance, and the region appears to be thicker than usual.

The severe magnetic disturbance of April 16, 1938, is selected for study in connection with equatorial‐zone ionospheric disturbances. It is shown that this ionospheric disturbance can be divided into three main phases. With the advent of the storm the maximum electron‐density of the F‐region fell by some three orders of magnitude (essentially to zero) in the first hour. This was followed by appearance of an intensely ionized absorbing region at about 85 km from which echoes were weak. After about 45 minutes this region disappeared as suddenly as it had appeared. Virtual heights of the F‐region then started to rise, first with increasing and then with decreasing ion‐density, until the maximum ion‐density again fell to substantially zero, with the few remaining electrons (about 5000 per cc) being at enormous heights. The surprising thing about these facts is that the ion‐density should fall essentially to zero throughout the stratosphere. The appearance of an absorbing region at low levels at different latitudes is considered in connection with sporadic E‐region ionization. Dependence of observed changes of radio transmission upon the observed ionospheric effects are considered.
Non‐seasonal behavior of the F‐region
Authors: Seaton S. L. , Berkner L. V.
Published: February 2008

Non‐seasonal variation in maximum electron‐density of the F‐region previously discussed using observations at noon of critical frequency at Washington (39° north), Watheroo (30° south), and Huancayo (12° south) is further examined using data for all 24 hours of the day. The effect of averaging over all hours is to reduce the seasonal variation much more than the non‐seasonal variation, so that variation of monthly mean electron‐density is substantially identical at all three stations. The reality of this result has been tested statistically. Harmonic analyses of the monthly mean maximum electron‐density averaged over all hours shows, after removing secular change associated with solar activity, a first harmonic of 9.3 (mc/sec)2 with maximum in January and a second harmonic of amplitude 7.4 (mc/sec)2 with maxima in April and October. These values are averages for the three stations. The mean correlation‐coefficient between pairs of stations is 0.87. The fact that the seasonal variation of period 12 months is relatively much smaller than that present in data at noon suggests that the seasonal variation in these data is principally a variation in amplitude of diurnal variation.
The electrical characterization of days at Colaba (Bombay, India) during 1930–38
Authors: Mukherji S. M. , Pillai A. R.
Published: February 2008

Systematic recording of atmospheric electric potential‐gradient at Colaba commenced from the middle of June, 1930, with a photographic electrograph of the Cambridge Scientific Instrument Co. The instrument was first installed in the old Milne Seismograph room of the Observatory but in February 1931 was transferred to a specially constructed hut in the open space near the sea‐coast in the northeast corner of the Observatory compound.

A radium‐spiral screwed to the outer end of an insulated metal rod which projects out horizontally through a hole in the western wall of the hut, is used as the collector. The spiral is placed 171 cm above the ground with its middle point 40 cm away from the outer surface of the wall during normal days. The distance of the collector from the wall is reduced suitably during disturbed weather.
Geomagnetic three‐hour‐range indices for the years 1938 and 1939
Authors: Bartels J. , Heck N. H. , Johnston H. F.
Published: February 2008

The paper gives three‐hour‐range indices K for seven observatories for July 1, 1938, to December 31, 1939 (Table 1), world‐wide three‐hour‐range indices Kw for 1938 and 1939 (Table 2, which will be used most often), and, based on Kw, daily indices B (Table 3) and monthly frequencies and averages (Table 4). Section (1) contains all the information necessary for using these Tables in geophysical or ionospheric work.

Sections (2) to (5) show how the indices K are standardized by means of keys for transforming K into reduced indices Kr. The world‐wide Kw is introduced as an average of the reduced indices Kr, in which the Kr from polar stations enter with higher weight than the Kr from equatorial stations. Kw is proposed as a measure of the intensity P of solar corpuscular radiation.

Note—Throughout this paper, a superior cross (×) denotes a half unit, thus, 0× =0.5, 1× = 1.5, etc.
Solar radiation and geomagnetism
Authors: Bartels J.
Published: February 2008

Summary—Solar wave‐radiation, W, and corpuscular radiation, P, may be estimated in their variations of intensity by their geomagnetic effects. A classification of magnetic storms is proposed, and geomagnetic evidence for the travel‐times of solar corpuscles is discussed.
Diurnal variations of the radon‐content of soil‐gas
Authors: Kovach Edward M.
Published: February 2008

At the meetings of the American Geophysical Union in 1944 and 1945 the author presented two papers on the influence of ground conditions and on the meteorological influences governing the radon‐content of soil‐gas taken from different depths (25 to 200 cm). The present paper is a report on a continuation of these experiments, on a lawn adjacent to the Blessed Sacrament Church, located in the East Bronx, New York, about four miles from the Campus of Fordham University where the previous experiments were performed. Purpose of the present study was to compare the radon‐content at different localities and to find out if there are regular diurnal variations. The measurements were made between April 24 and August 10, 1945. In 49 days of actual experiments, 322 individual measurements were made. Conclusions, based on discussion of the results obtained, are drawn.
Watheroo Magnetic Observatory January to March, 1946
Authors: Parkinson W. C.
Published: February 2008

(Latitude 30° 19′.1 S., longitude 115° 52′.6 or 7h 43m.5 E. of Gr.)

January 3–4— A magnetic disturbance of moderate severity began with a “sudden commencement” at 08h 10m GMT, January 3. At this time H increased very rapidly by 32 gammas, the westerly declination decreased by 4′.5, and Z decreased by 32 gammas. Rapid and irregular fluctuations began immediately afterwards, two periods of major disturbance being worthy of mention. Between 11h 00m and 11h 30m, January 3, H decreased by 137 gammas; between 11h 13m and 11h 43m Z decreased by 122 gammas, and between 11h 17m and 11h 42m westerly declination increased by 18′. The second period of activity was between 15h 10m and 16h 10m, January 3, when a peak appeared in the H‐trace, the maximum point of which was 161 gammas above the trace before and after. Corresponding movements appeared in D and Z. Small to moderate movements in all three elements continued until 20h, January 4, after which the traces were normal, with the H still slightly below its predisturbance value. Ranges: D, 26′.7; H, 226 gammas; Z, 168 gammas.
Measurement of magnetic susceptibility with the Hughes induction balance
Authors: Duffin R. J.
Published: February 2008

In this paper two methods of measuring magnetic susceptibility with the Hughes induction balance are described which are especially convenient for geophysical work. The paper also includes a simple approximate theory of the Hughes induction balance concerning detection of buried objects. The first method described here is for measuring the susceptibility of the ground and is a field‐method. The operation of measurement consiste of holding the exploring coils over the ground and measuring the height for standard response. The second method is for small samples of material in bottles and the operation of measurement consists in inserting the bottle in a coil and reading a meter. An instrument is described which can make use of either of the two methods. This device seems to be more portable and convenient than previous instruments for measuring susceptibility [see Heiland, “Geophysical exploration”]. The United States Geological Survey has found the device described here useful in relating the magnetic properties of soils with the geological structure.
An attempt at an identification of the M‐regions
Authors: Waldmeier M.
Published: February 2008

M‐regions develop in the vicinity of large sunspot‐groups after the disappearance of the spots and provided that no new spots are formed at the place considered. This last condition contains the explanation of the fact, that the appearance of M‐regions is confined to times of great sunspot scarcity preceding the minima of solar activity. Further phenomena accompanying the appearance of sunspots are the prominences, which only survive in the original sunspot‐region as long, as no new spots are formed in it. The velocity of the Pk‐radiation lies between 300 and 600 km/see. As in the years preceding the minimum the seat of solar disturbances lies in low heliocentric latitudes, and as on the other hand the angular velocity of the prominences, whose latitude is about 10° higher than that of the spots in which they originate, practically coincides with the angular velocity of the latter, a very narrow connection in space and time between the prominences and the M‐regions is strongly indicated. The special case of a disturbance center in high latitude has been studied in detail. The material presented goes to confirm the working hypothesis, suggested some time ago by the author [see 10 of “References” at end of paper], “that certain narrowly limited regions of the Sun's surface emit during comparatively long periods of time a corpuscular radiation. These so‐called M‐regions are always situated in the sunspot‐zone, but within this only in regions devoid of spots. With the appearance of photospheric disturbances the M‐regions disappear, possibly as a consequence of the magnetic fields accompanying the spots.”
Atmospheric electricity during disturbed weather
Authors: Simpson G. C.
Published: February 2008

From October, 1942, to May, 1946, a special investigation of, atmospheric electricity during disturbed weather was undertaken at Kew Observatory, England, with special reference to the electricity carried on rain and snow. The results obtained have been discussed in detail in a paper which is to be published as Geophysical Memoir No. 84 by the London Meteorological Office. Owing to shortage of paper and other difficulties resulting from the war it may be some considerable time before the Memoir is printed and distributed. The Director of the Meteorological Office has therefore approved of the following summary of the conclusions reached in the work being made available in advance of the publication of the Memoir.
Pre‐history of the Earth's magnetic field
Authors: Johnson E. A. , Murphy Thomas , Torreson O. W.
Published: February 2008

Summary

In order to determine the origin and nature of the Earth's magnetic field and to test the various hypotheses which have been advanced to explain the field, it is desirable to determine the history of this field throughout geologic time and to investigate more carefully its spatial variations, both inside and outside the Earth's surface. This research is concerned with the determination of the history of the Earth's field as it can be deduced from the present polarization of crustal material. Unconsolidated fresh‐ and salt‐water sediments have been investigated. These sediments are in the form of clays and offer one of the simplest types of polarization, since the clays can be redeposited under laboratory conditions. A particularly lengthy investigation of the polarization of glacial varves has been made, together with measurements on core samples of sediments from the Pacific. From a study of anomalous deposits in the glacial clays, the geologic stability of the polarization of these clays has been established over geologic time. From the measurements of the glacial clays, it is concluded that the Earth's field has not changed substantially in direction or intensity during the last 15,000 years. From measurements of the Pacific cores, it is tentatively concluded that the direction and intensity of the Earth's magnetic field has probably remained substantially constant during the last million years. A much more complete investigation is necessary to verify these tentative conclusions. It would be desirable to extend the measurements to periods of the order of one billion years. These results are consistent with the “fundamental” theory proposed by Schuster, Babcock, and Blackett, but do not provide positive evidence to support this theory.
Revitalizing a fertile plain: A case study in simulation and systems analysis of saline and waterlogged areas
Authors: Fiering Myron B
Published: February 2008

This paper describes the application of systems analysis and digital computer simulation to the control of waterlogging and salinity in West Pakistan. The details of the project are not nearly so important here as the nature of the systems approach and the demonstration of digital computer applicability to civil engineering problems. The history of waterlogging and salinity of agricultural lands in West Pakistan is the by‐product of a truly remarkable system of crop irrigation which has been employed in increasing intensity over a period of some 3000 years. During the early part of this century British hydraulic engineers initiated the barrage system of irrigation and began to divert large quantities of water from the mighty Indus River and the five great tributaries that drain the Punjab region of the subcontinent. The economic and technologic aspects of the remedy, a well field of truly heroic proportions, are discussed; the role of the digital computer is seen to be essential to the concept and thrust of an operations research solution.
Derivation of the velocity profile from a statistical model of turbulence
Authors: Matalas N. C. , Conover W. J.
Published: February 2008

A statistical model of turbulence for two‐dimensional uniform flow in open channels is developed, and this model is used to derive the vertical velocity profile. This profile is defined by a three‐parameter hyperbolic function, with two parameters reflecting the effect of bed roughness and fluid viscosity on the shape of the profile. The third parameter is the mean velocity in the vertical. The hyperbolic function is fitted to velocity data for water in natural channels, a laboratory flume, and air in a wind tunnel. A brief comparison of the hyperbolic function with the logarithmic function is given.
Intraparticle transport of sulfonated alkylbenzenes in a porous solid: Diffusion with nonlinear adsorption
Authors: Weber Walter J. , Rumer Ralph R.
Published: February 2008

Molecular diffusion is one of several phenomena contributing to establishment of rates of transfer of adsorbed materials from the exterior sites of a porous adsorbent to surfaces bounding inner pore spaces. For many applications of adsorption and ion exchange the rate of intraparticle transport in turn governs the over‐all rate of removal of solute from solution. The present work represents an approach to partial characterization of intraparticle transport kinetics by separation and evaluation of component molecular diffusion parameters. Data have been collected for rates of adsorption in several dilute, aqueous, single‐solute experimental systems, each comprised of a linear‐chain sulfonated alkylbenzene in micromolar concentration as the adsorbate and porous granular carbon as the absorbent. From measurements of rate of removal of solute from bulk solution for each system, and from separate measurements of adsorption isotherms, values for the corresponding coefficients of molecular diffusion have been calculated by numerical integration of the conservation of diffusing mass equation, incorporating an expression for simultaneous adsorption according to the nonlinear Langmuir monolayer model for adsorption. Calculated values for the coefficients of diffusion for the respective solutes, of the order of 10−5−10−7 square centimeter per second, derived from measurements in the experimental systems, agree with values cited in the literature for the same and similar solutes measured in aqueous solution. This accordance indicates that the postulated model for intraparticle transport may be valid for description of the rate‐limiting process in agitated nonflow systems similar to those from which the experimental data have been derived. The technique further permits reduction of experimental data to a common parameter to facilitate system‐to‐system comparisons.
Laboratory evaluation of a numerical flood routing technique for channels subject to lateral inflows
Authors: Ragan Robert M.
Published: February 2008

As a result of advances in high speed digital computers, considerable interest has been shown in the use of a numerical solution of the complete equations of free surface flow to synthesize the unsteady channel and overland flow conditions that occur during a period of runoff. The advantage of this approach is that it provides a logical description of the phenomenon of local inflows entering along a stream flowing at either subcritical or supercritical velocities. This paper shows the feasibility of the approach by comparing the hydrographs and water surface profiles obtained from a numerical solution of the equations with those produced by introducing time varied and spatially varied lateral inflows along the length of a 72‐foot‐long experimental flume. One of the practical problems found with the numerical technique was a sensitivity to errors in the value of the Manning n used to describe the channel roughness. The difficulties imposed by this sensitivity are discussed and compared with the problems associated with traditional routing methods. (Key words: Flood routing; hydraulics; computers, digital; synthesis.)
Recreational benefits of water resource development
Authors: Merewitz Leonard
Published: February 2008

Although the major concern of the federal government is with the character of the facilities provided, the calculation of the efficiency benefits of recreational investment is an appropriate part of the process of design of water resource systems. Recreation is a purpose of water resource development that should be considered in project evaluation. A demand curve was simulated for recreation at the Lake of the Ozarks, Niangua Arm. Using distance as a proxy for price, the consumers' surplus implied by the demand curve was measured. Cross‐sectional variations in associated costs simulated price variations for recreation, a nonmarket commodity. The pilot calculation ascertained what basic data are required. A knowledge of a county's population, population density, distance from the site, and mean income of residents was useful in predicting the demand from a county. Factors such as mobility and the availability of alternative recreational opportunity did not appear to be useful in the forms in which they were available. Some relevant considerations in the design of the sample survey are indicated.
A new approach for estimating transmissibility from specific capacity
Authors: Hurr R. Theodore
Published: February 2008

Transmissibility estimated from specific capacity is subject to error, because the effects of duration of pumping and specific yield are not evaluated. Rearrangement of the Theis equation provides a mathematical relation for evaluating drawdown during nonequilibrium conditions and delayed yield from storage at any time after pumping begins. This relation is obtained from type curves of u plotted against u[W(u)] where u[W(u)] is equal to 1.632 × 10−2 [(Sy) r2s/Qt]. The only term that needs to be assumed is specific yield. The error of the estimated transmissibility will be 30 to 40% of the error made in assuming the apparent specific yield for u = 10−2 and 10 to 15% for u less than 10−4. The curves presented in the paper were used to construct a transmissibility map of the valley‐fill aquifer in the Arkansas River valley of Colorado. The map was the foundation for an analog‐model analysis of the aquifer system. The transmissibilities estimated from the type curves correlate well with transmissibilities determined from aquifer tests and estimated from test‐hole logs.
A note concerning the eddy transfer coefficients of momentum and water vapor under near‐adiabatic conditions
Authors: Harbeck G. Earl
Published: February 2008

Data from the Lake Hefner evaporation study of 1950–1951 were used to compute Km, the eddy transfer coefficient for momentum, and Ke, the eddy transfer coefficient for water vapor. For approximately adiabatic conditions the two coefficients were found to be almost exactly equal.
Snow accumulation in a Manzanita Brush Field in the Sierra Nevada
Authors: Wilken Gene C.
Published: February 2008

Some physical features of greenleaf manzanita (Arctostaphylos patula), a dominant species in a brush field in the snow zone of the Sierra Nevada west side, are described and presented diagrammatically and related to snow accumulation under different storm conditions. Initially snow penetrates open manzanita canopies, but intercepted snow soon forms a nearly solid surface. The low sturdy shrubs support heavy weights of snow without bending or breaking, but side branches depress with sufficient loading. Such deformation increases surface roughness of the brush field. Voids or open spaces make up a large part of newly deposited brush field snowpacks but tend to disappear in interstorm periods of consolidation, suggesting that brush fields can fill from the ground up to form fairly solid packs. (Key words: Brush fields; snow accumulation; Sierra Nevada)
Excess benefit
Authors: Tullock Gordon
Published: February 2008

The recent discussion of the ‘Economic Basis for Effluent Charges and Subsidies’ [Whippie, 1966] has tended to ignore one important bit of that economic base. Governments need money, and the return from charges on externality is a possible source of such funds. When I say that this has been ignored I am not criticizing Dr. Whipple. Economists, like everyone else, sometimes keep ideas in watertight compartments.
Thermal prospecting for ground water
Authors: Cartwright Keros
Published: February 2008

Theoretical consideration of the thermal properties of unconsolidated deposits suggests that a shallow aquifer might form a heat sink that influences and modifies the temperature effects of heat originating at the land surface and within the crust. The unconsolidated water‐yielding deposits apparently are not of the same temperature as the material surrounding them. If the shallow aquifer is nonuniformly distributed, it should produce a temperature anomaly in the surface soil. The size of the anomaly resulting from a shallow aquifer would depend on the thermal properties and thickness of the overburden and on temperature differences between the surface and the aquifer.
The effects of entrapped air and barometric fluctuations on the drainage of porous mediums
Authors: Norum D. I. , Luthin J. N.
Published: February 2008

A theory was developed for transient drainage of porous mediums taking into consideration the air that is entrapped within the flow region. The theory is based on the soil moisture diffusion equation with modifications made to include the effect of the entrapped air and the effect of changes in pressure due to barometric fluctuations. The theory was tested on a one‐dimensional flow sand model, and the results were compared with results obtained from a numerical solution of the developed equation. The theory and experiments show that barometric fluctuations have little effect on a draining column containing entrapped air when the column is open to the atmosphere at both ends. However, when the column is closed at the bottom, an increase in atmospheric pressure lowers the position of the water table, whereas a decrease in atmospheric pressure raises the water table. Both the experiments and the developed theory show a much greater change in the position of the water table with atmospheric pressure than a previous steady‐state theory.
The permeability of a porous medium determined from certain probability laws for pore size distribution
Authors: Brutsaert Wilfried
Published: February 2008

An equation derived for the permeability of a porous medium based on the general principles of the series‐parallel model contains a double integral which is solved for several continuous probability laws describing the distribution of the sizes of the interstices of the porous medium. The agreement between calculated results and available experimental data is satisfactory.
Watershed Simulation by Stream Path Analogy
Authors: Onstad C. A. , Brakensiek D. L.
Published: February 2008

The surface runoff hydrograph at the outlet of a watershed is the result of distributed inputs being modified by flowing through the watershed surface drainage networks. In this study a model is proposed by which an outflow hydrograph is synthesized by routing input through a simulated drainage system. The simulated flow system is developed from a flow net. Overland flow is routed through stream tubes formed by pairs of stream lines constructed normal to the contour lines (equipotentials) of the watershed to an intersection with an appropriate surface channel. Channel flood routing is then performed down to the outlet, with the calculated overland flow from each stream tube as lateral input. Optimization of the system parameters is studied with respect to factors calculated from hydrograph moments. By comparison with visual judgments the hydrograph lag and shape factor were found to be possible criteria for optimization.
Some Factors Affecting Baseflow
Authors: Singh Krishan P.
Published: February 2008

For a shallow aquifer and a fully penetrating stream, the ideal baseflow curve does not plot as a straight line on semilog paper, and its recession rate continuously decreases with time. For a deep aquifer and a shallow‐entrenched stream, the ideal baseflow generally decays exponentially, and its recession rate decreases with increasing stream entrenchment. In the case of loss from evapotranspiration, the baseflow curves steepen progressively with time, and the stream may become influent. In the case of gain from confined aquifers, the baseflow curves become flatter. The recharge results in shifting of the baseflow curves upward in magnitude or laterally in time. The baseflow peak occurs at about 0.75T from the beginning of recharge to the aquifer, where T denotes the effective duration of recharge. The lag between the total flow peak and the baseflow peak depends on rainfall, soil, and basin factors. The variability of these factors precludes the notion of a constant lag.