bluuebunny/crossref_metadata_2025_split huggingface dataset:
The reactions of CCl2FO2 with NO and NO2 and the thermal decomposition of CCl2FO2NO2
Authors: Simonaitis R. , Glavas Sotiris , Heicklen Julian 
Published: February 2008

CCl2FO2 radicals are produced in the stratosphere from the oxidation of CCl2F radicals produced from the photodissociation of CCl3F. The reactions of CCl2FO2 with NO and NO2 have been studied by steady state photolysis at 1 atm and 286‐305°K. The reactions are with k3/k4 = 0.58 ± 0.10 over this temperature range. The thermal decomposition of CCl2FO2NO2 via the back reaction −4 was studied at 274‐305°K and 1 atm total pressure (mainly N2).The Arrhenius expression obtained for the thermal decay is In the stratosphere CCl2FO2NO2 will be produced from reaction 4 and since its thermal lifetime at 220°K exceeds 1 year it could play a role in the stratospheric chlorine budget if it is sufficiently stable to photodissociation.
Hypocenter for the 1979 Imperial Valley Earthquake
Authors: Archuleta Ralph J. 
Published: February 2008

Using P‐and S‐wave arrival times with the laterally varying P‐wave velocity structure derived from analysis of a refraction survey of the Imperial Valley, a hypocenter is ascertained for the October 15, 1979, Imperial Valley earthquake:Latitude 32° 39.50′N,Longitude 115° 19.80′W,Depth 8.0 km,Time 23:16:54.40 GMT.
Global distributions of cirrus clouds determined from Sage data
Authors: Woodbury Gerard E. , McCormick M. P. 
Published: February 2008

An analysis using SAGE data for the period February 1979 to April 1980 was performed to determine the spatial extent and frequency of cirrus clouds over a large portion of the earth's surface. These results should be of interest to, among others, both the researchers concerned with global monitoring and modeling of the earth's radiation budget and climate and to reentry vehicle designers concerned about anomalous aerodynamic effects or damage due to the ice particles found in cirrus clouds. A by‐product of the study reveals the statistics of tropospheric observational opportunities for a limb‐sounding satellite sensor by determining the percentage of times of successful penetration to 7 km.The results of the analysis showed that optically thick cirrus clouds are found most often in the mid‐latitudes and over the tropics with distinct minima near the ± 20 to 30° latitude bands. Thin cirrus clouds (as defined in this paper), on the other hand, occur much less often than the optically thick cirrus clouds. A comparison of the optically thick cirrus clouds observed by SAGE was made zonally with surface‐based observations and was found to generally agree. The percentage of tropospheric observational opportunities down to 7 km was as high as 60 percent in the upper latitudes but fell to about 30 percent in the tropics.
Late Paleozoic remagnetization of the Trenton Limestone
Authors: McCabe Chad , Van der Voo Rob , Ballard Martha M. 
Published: February 2008

Samples of the Middle Ordovician Trenton Limestone were collected from 8 sites in Quebec, Ontario, and New York State for paleomagnetic study. Stepwise thermal demagnetization reveals a very well defined characteristic magnetization that has a corresponding paleomagnetic pole at 53.0° N, 126.9° E (K=97.7, A‐95=2.7°). This pole is not at all close to other Ordovician poles from cratonic North America but is near Late Carboniferous and Early Permian ones, indicating that the Trenton was remagnetized in the Late Paleozoic. An earlier paleomagnetic investigation of the Trenton gave a pole that did not appear to be Late Paleozoic in age. However, we demonstrate that this earlier study failed to isolate the ancient characteristic magnetization.Rock magnetic experiments and analyses of magnetic extracts show that the carrier of magnetization is Fe3O4 that does not contain Ti or other elements in solid solution that would indicate a detrital source. The magnetite and its associated remanence appear to have a diagenetic origin.
MAGSAT scalar anomaly map of India and a part of Indian Ocean‐magnetic crust and tectonic correlation
Authors: Mishra D. C. , Venkatraydu M. 
Published: February 2008

Magnetic scalar anomaly maps over India and a part of the Indian ocean are prepared from the MAGSAT data using an average of the observed field in a grid of 1°×1°. The MAGSAT scalar anomaly map thus obtained is characterised by ‘highs’ over the Indian shield and large ‘lows’ over the Himalayas centered over Tibet Plateau. A NE‐SW magnetic trend emanating from NE India and spreading almost over the entire peninsular shield is the single most prominent feature of the map which might be related to the stress system or deepseated structural trends associated with plate motion. The Deccan Traps are reflected by ’nosing’ of the magnetic contours. The Shillong massif is characterised by a separate anomaly which deflects the NE‐SW magnetic trend referred to above. A magnetic crustal map prepared from this MAGSAT scalar anomaly, using the principles of harmonic inversion, yields a thickness of 30 km under the cambay basin and the western part of the Narmada‐Son lineament for a magnetization of 2A/m suggesting a higher subsurface thermal gradient in this area and therefore a tectonically active region.A maximum thickness of 40‐42 km is found under the regions of Aravallis, Singhbhum and south of the Narmada‐Son Lineament, which are Precambrian stable cratons. Major lineaments and faults are reflected as variations in the thickness of the magnetic crust along these lines.The Himalayas are chaaracterised by an average thickness of 35‐36 km with a thickening of 2‐4 km under the Tibet plateau and Shillong massif. The MAGSAT anomaly in the northern part of the Indian ocean can be accounted for by a thickening of 8 km in the magnetic crust.The center of this crustal thickening derived from the MAGSAT anomaly after appropriate correction for the inclination of the earth's magnetic field in this region coincides with the wellknown Indian ocean gravity and geoid lows.
Paleomagnetism of Silurian‐Ordovician sediments from the Valley and Ridge Province, northwest Georgia
Authors: Morrison Jean , Ellwood Brooks B. 
Published: February 2008

The remanent magnetism (RM) for 93 specimens has been determined in 34 independently oriented samples from 20 sites at Ringgold Gap, Georgia, in the Valley and Ridge Province of the Southern Appalachians. Lithologies sampled include Middle Ordovician through Silurian fossiliferous limestones and hematitic sandstones and siltstones. The section is confined within a single thrust slice. Thermal demagnetization results indicate that hematite is the dominant RM carrier although detrital magnetite has also been identified optically in some specimens.Both normal and reversed polarities are present and the resulting paleopole is 28°N, 142°E (α95 = 7.3°). This pole falls within the cluster of published Lower Paleozoic Valley and Ridge poles but rather than clarifying the distribution of poles it augments the scatter. Three factors are thought to contribute to this scatter: (1) unresolved components of rotation, possibly introduced during folding and thrust faulting, which result in declination anomalies, (2) true vertical axis tectonic rotations during deformation, and (3) insufficient knowledge of the timing of magnetization. In light of these uncertainties, caution should be exercised in constructing a Lower Paleozoic apparent polar wander path with paleopoles from the Valley and Ridge Province.
Observation of several chlorine nitrate (ClONO2) bands in stratospheric infrared spectra
Authors: Zander R. , Rinsland C. P. , Farmer C. B. , Brown L. R. , Norton R. H. 
Published: February 2008

Four of the most prominent and sharpest infrared absorption features of chlorine nitrate at 780.2, 807.7, 809.4 and 1292.6 cm−1 have been observed in a series of infrared solar spectra obtained at an unapodized spectral resolution of 0.01 cm−1, using the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument from on‐board Spacelab 3.A quantitative analysis of the ν4 Q branch at 780.2 cm−1 has provided insight into the concentration of ClONO2 between 19 and 40 km altitude. While the mean profile deduced from 3 sunset occultations near 30° N latitude exhibits a shape close to that predicted by model calculations, its conconcentrations in the 20 to 32 km altitude range are, however, about 30% larger, reaching a peak concentration of 9 × 108 molecules/cm³ at 25 km. The concentrations above 32 km, deduced from one sunrise occultation at 47° S, are even larger than the corresponding sunset values at 30° N latitude. Some of these discrepancies may be caused by the rather large uncertainty in the assumed Q branch strength.The results reported here constitute a significant input towards understanding the chemistry prevailing in the stratosphere as well as for model calculations predicting the secular evolution of our atmosphere.
The origin of the power‐law component in auroral electron spectra
Authors: Stasiewicz K. , Lundin R. , Hultqvist B. 
Published: February 2008

Electron and ion data from the particle experiment onboard the VIKING spacecraft are examined in order to determine the origin of the power‐law component in auroral electron spectra. It is observed that at altitudes of ≈1 Re electron spectra peaked at a few keV are accompanied by a power law population in the energy range 10‐1000 eV that is usually thought to be composed of degraded primaries and secondary electrons of ionospheric origin.However, the presence of an ion beam at an energy of 1 keV flowing out of the ionosphere indicates the existence of a potential barrier between the location of the satellite and the ionosphere which would prevent secondary electrons of ionospheric origin from reaching the satellite altitude. Moreover, the angular characteristics of the low energy electrons indicate that this population moves downward and cannot be attributed to secondary and backscattered electrons coming out of the ionosphere. The spectral index k=1.7‐2 of the distribution function f ⧜ E−k for the power‐law electrons supports earlier theoretical findings that this population is formed in the auroral acceleration region by a combined action of a parallel electric field and waveparticle interactions.
A new transient tracer: Measured vertical distribution of CCl2FCClF2 (F‐113) in the North Pacific Subarctic Gyre
Authors: Wisegarver David P. , Gammon Richard H. 
Published: February 2008

The first quantitative marine measurements of trichlorotrifluoroethane (F‐113) were made in the North Pacific subarctic gyre in July of 1986, using a modification of the analytical procedure developed for the transient tracers F‐11 and F‐12 (Gammon et al., 1982; Wisegarver and Cline, 1985). The measured mixed layer concentration was 0.29±0.02 pM/L; the corresponding atmospheric mixing ratio was 35±1 pptv (Rasmussen scale).Below a subsurface maximum both F‐11 and F‐113 were found to fall off exponentially with increasing depth, F‐113 reaching effective blank levels first. The significance of adding F‐113 to the existing suite of measurable oceanic transient tracers rests in the possibility of age‐dating water masses by their (F‐113/F‐11) ratio with near annual resolution for the period since 1977.
Rupture extent of the 1978 Miyagi‐Oki, Japan, earthquake and seismic coupling in the northern Honshu Subduction Zone
Authors: Tichelaar Bart W. , Ruff Larry J. 
Published: February 2008

Underthrusting at subduction zones can cause large earthquakes at shallow depths, but is always accommodated by aseismic creep below a certain depth. This transition depth is referred to as the depth of seismic coupling and can be directly observed in a subduction zone as the lower depth extent of significant moment release of the deepest large underthrusting earthquakes. In 1978, a large (Ms=7.5) earthquake occurred off the coast of Miyagi Prefecture in northern Honshu. Its focal mechanism represents underthrusting of the Pacific plate beneath Honshu. Since the hypocenter is located 150 km landward from the trench and there are no other large interplate earthquakes further landward from the trench axis, this event defines the maximum depth of the coupled zone.The lower limit of significant moment release of the Miyagi‐Oki earthquake is obtained by analysis of the long‐period P waves. The deconvolved source time function consists of a dominant single pulse with peak moment release at 12 s and a total duration of 18 s. The rupture extent of this dominant pulse does not extend deeper than 40 km, thus the transition from coupled to uncoupled in northern Honshu occurs at or above 40 km depth.
Pioneer and Voyager observations of the solar wind at large heliocentric distances and latitudes
Authors: Gazis P. R. , Mihalov J. D. , Barnes A. , Lazarus A. J. , Smith E. J. 
Published: February 2008

The Pioneer 10, 11 and Voyager 2 spacecraft are well suited for exploring spatial gradients in the distant solar wind. Between 1984 and 1986 Pioneer 11 and Voyager 2 were located at nearly the same heliocentric distance (≃20 AU) and longitude but were widely separated in latitude; Pioneer 11 was at a heliographic latitude of ≥15° while Voyager 2 was near the solar equator. Pioneer 10 was located near the solar equator but at a considerably greater heliocentric distance (≃40 AU). IMP observations at 1 AU provide an inner heliosphere baseline.Prior to mid‐1985, Pioneer 11 and Voyager 2 observed nearly identical solar wind structures. The characteristics and arrival times of these structures were similar at both spacecraft.After day 150 of 1985 this situation changed dramatically. The velocity structure at Voyager 2 became flatter. The velocities seen at Voyager 2 also fell with respect to Pioneer 11; the difference in velocities observed by the two spacecraft grew to 200 km s−1 by late 1986. In late 1985 Pioneer 10 observed a change in the solar wind similar to that observed at Voyager 2. These changes in the solar wind at low latitudes may be related to a change which occurred in the coronal hole structure in early 1985.
Effects of near source seafloor topography on long‐period teleseismic P waveforms
Authors: Okamoto Taro , Miyatake Takashi 
Published: February 2008

In the study of the shallow earthquakes in the subduction zones, reverberations inside the water layer near the source are known to affect very significantly the far field body waveforms. The usual correction is to take a horizontally layered model as the near source structure, but it is not realistic for the trench geometry. Therefore finite‐difference simulation combined with far‐field ray‐theory is employed in order to examine the effects of the realistic non‐flat seafloor topography.As a realistic trench model the Japan trench is selected. The response of the structure near the source is calculated by two‐dimensional finite‐difference simulation. Then teleseismic P waveforms are calculated by using reciprocal theorem. Our results suggest that (1) around the trench bottom, effects of non‐planar structure are remarkable and the realistic seafloor cannot be approximated by any model of planar structure, however, (2) effects of the continental slope are well approximated by a model of planar dipping seafloor of appropriate dip. Therefore, the near source structure must include the realistic seafloor topography, or the waveform analyses may lead to spurious subevents in a later stage of rupture process and mislocation of events. Our results also show that present knowledge about the seafloor topography is enough to incorporate the complicated geometry.
Fault‐zone attenuation of high‐frequency seismic waves
Authors: Blakeslee Sam , Malin Peter , Alvarez Marcos 
Published: February 2008

We have developed a technique to measure seismic attenuation within an active fault‐zone at seismogenic depths. Utilizing a pair of stations and pairs of earthquakes, spectral ratios are performed to isolate attenuation produced by wave‐propagation within the fault‐zone. This empirical approach eliminates common source, propagation, instrument and near‐surface site effects. The technique was applied to a cluster of 19 earthquakes recorded by a pair of downhole instruments located within the San Andreas fault‐zone, at Parkfield California. Over the 1‐40 Hz bandwidth used in this analysis, amplitudes are found to decrease exponentially with frequency. Furthermore, the fault‐zone propagation distance correlates with the severity of attenuation. Assuming a constant Q attenuation operator, the S‐wave quality factor within the fault‐zone at a depth of 5‐6 kilometers is 31 (+7,−5).If fault‐zones are low‐Q environments, then near‐source attenuation of high‐frequency seismic waves may help to explain phenomenon such as fmax. Fault‐zone Q may prove to be a valuable indicator of the mechanical behavior and rheology of fault‐zones. Specific asperities can be monitored for precursory changes associated with the evolving stress‐field within the fault‐zone. The spatial and temporal resolution of the technique is fundamentally limited by the uncertainty in earthquake location and the interval time between earthquakes.
Form and behavior of radium, uranium, and thorium in central Pennsylvania soils derived from dolomite
Authors: Greeman Daniel J. , Rose Arthur W. , Jester William A. 
Published: February 2008

In a pair of well‐ and poorly‐drained soils developed on Ordovician carbonate rocks in Central Pennsylvania, the distribution with depth and chemical form of 238U, 232Th, and 226Ra have been compared to soil properties. Concentrations range from 3.3 to 8 ppm U and 6.3 to 11 ppm Th in the soils. Although radium is in equilibrium with U at depth in both soils, in surficial A‐horizons Ra is well in excess of U (165–180%). Ra and U are enriched 10X‐12X over the bedrock. Th is enriched, along with Al and Fe, by 20X.Progressive selective extractions for U, Th, and Ra in soil show half the radium occurring in pedogenic phases, chiefly in the organic fractions (24% of total Ra). By contrast, <1% of the U and Th occurs in any of the organic fractions; up to 80% occurs in the silt and clay fractions with a significant occurrence in the Fe‐oxides, up to 50% for Th.Ra and chemically similar Ba are cycled by vegetation but Ra is retained in soil, bound in humified soil organic matter while Ba is not. Radon emanation of these soils (8–27%) can be almost entirely attributed to highly emanative Ra bound in organic matter. In these soils the action of vegetation leads to high soil gas radon by maintaining high Ra concentration and enhancing its emanating power.
Discrete phase changes within nonlinear steepened magnetosonic waves: Comet Giacobini‐Zinner
Authors: Tsurutani Bruce T. , Smith Edward J. , Buti B. , Matsumto Hiroshi , Brinca Armando 
Published: February 2008

In this letter, we will illustrate the intricate complexities of nonlinear wave evolution and briefly discuss their consequences. We will show examples of nonlinear steepened magnetosonic waves that have subintervals without phase rotation (linearly polarized) and other subintervals with discrete, rapid phase rotation. Some specific features are: 1) the trailing (∼half) portion of the wave sometimes has no phase rotation and is simply compressive; 2) just behind the leading adge of the wave front where there is a sharp rotation (called a partial rotation), there is often a second region with no phase change; 3) between these two regions is an interval with a distinct phase change; 4) in the examples shown in this paper, the distinct phase changes have right‐hand polarizations in the spacecraft frame; 5) the magnetosonic wave appears to split into two parts with time; the right‐hand rotation is located where the splitting occurs.Possible explanations for the right‐hand rotation will be explored. One plausible explanation is that a right‐hand wave is generated through the decay instability of a magnetosonic wave, i.e., a magnetosonic wave propagating towards the sun decays into a sound wave and a magnetosonic wave propagating away from the sun. If right‐hand daughter waves are actually present, this will have important consequences. Even though these waves are present only ∼ 10% (or less) of the time, this may allow significant wave‐particle interactions to make the self‐consistent second‐order Fermi acceleration mechanism of energetic cometary ions feasible.
An estimate of the amount of material removed from the Martian fretted terrain
Authors: Dimitriou Andrew 
Published: February 2008

Three models are proposed for the former extent of a continuous heavily cratered plateau within the present area of fretted terrain between 270°W and 360°W. To the south and west, each model area limit is well constrained by the northern boundary of the unfretted heavily cratered plateau. The northern limit of each model is defined by the gradational northern limit of fretted terrain. The eastern limits are distinct for each model. Model 1 assumes a once continuous plateau was dropped to the north along NW‐trending normal boundary faults in the Ismenius Lacus SE subquadrangle. Model 2 includes model area 1 and places the former limit of the plateau 400 km farther east along a trace subparallel to the present plateau margin in this subquadrangle. Model 3 includes model area 2 and uses the rim of the proposed Borealis basin in Casius SW subquadrangle [Wilhelms and Squyres, 1984] as the eastern limit of the former plateau.The estimates for the amount of material removed vary from 1.04 ± 0.60 × 106 km3 for model 1 through 1.53 ± 0.80 × 106 km3 for model 2 to 1.99 ± 1.01 × 106 km3 for model 3. This implies that this area of fretted terrain is not a significant source of sediment for the northern lowlands of Mars.
Pioneer 11 Saturn encounter
Authors: Northrop T. G. , Opp A. G. , Wolfe J. H. 
Published: February 2008

Pioneer 11, later named Pioneer Saturn, reached its point of closest approach to Saturn on September 1, 1979. Pioneer Saturn carried 11 operating scientific instruments. The 2.293‐GHz telemetry carrier was also used for a radio occultation experiment and a celestial mechanics experiment. The Pioneer Saturn scientific instruments, objectives, and principal investigators are listed in Table 1.Pioneer Saturn was launched April 5, 1973. The objectives of Pioneer Saturn and its companion spacecraft, Pioneer 10, were to penetrate the asteroid belt and to explore the environment of Jupiter. Following the successful encounter with Jupiter by Pioneer 10, Pioneer Saturn was targeted to encounter Jupiter on a trajectory that propelled the spacecraft back across the solar system to be the first spacecraft ever to encounter Saturn, nearly 5 years later.
Dedication to Special Issue Honoring George Kennedy
Authors: Boettcher Art , Newton Robert C. 
Published: February 2008

This volume of the Journal of Geophysical Research was intended to be dedicated to Professor George C. Kennedy of the Institute of Geophysics and Planetary Physics, University of California, Los Angeles (UCLA), to commemorate his 60th birthday. However, George died of cancer on March 18, 1980, and this volume must now commemorate his career.On September 19 and 20, 1979, the Institute hosted a conference at UCLA to celebrate George's birthday, and most of the papers presented there, together with others by former coworkers, appear in this issue. All of the authors appreciate this opportunity to honor a man who made so many significant contributions to geochemistry and geophysics.