bluuebunny/crossref_metadata_2025_split huggingface dataset:
Displacement analysis of the GPS station of Sampali, Indonesia
Authors: Lee Eun Soo , Lee Young Wook , Park Jung Hyun 
Published: August 2014

Abstract
The displacement of the SAMP GPS station located in Medan City, Indonesia, is analyzed by means of an on-line point positioning method, the Canadian Spatial Reference System-Precise Point Positioning (CSRS-PPP). Based on the comparison of the results obtained with those from previous studies, we propose that CSRS-PPP can be applied to analyses of the displacement of a GPS station. Previous studies have focused solely on the “Sumatra-Andaman Islands Earthquake of December 26, 2004”; in contrast, we provide here an in-depth analysis of the crustal movements at the SAMP station for an expanded period of 2.5 years. CSRS-PPP, an Internet data processing service of the Department of Natural Resources Canada (NRCan), was used to process the data obtained at the SAMP station from January 2004 to July 2006. The data show a clear displacement in the southwestern direction from December 26, 2004 to March 28, 2005 when two major earthquakes occurred. However, after the midpoint of 2005, the data show displacement at a regular speed. In particular, the “Sumatra-Andaman Islands Earthquake (M
w = 9.0) of December 26, 2004” led to a displacement of 0.1387 m (dn = −0.0122 m, de = −0.1382 m) to the southwest. The earthquake (M
w = 8.7) that occurred on March 28, 2005 led to a displacement of 0.1921 m (dn = −0.1400 m, de = −0.1315 m) to the southwest. Starting from December 26, 2004, displacement to the southwest continued. From April 2005, however, the speed of the displacement gradually slowed down. The dn variation shows a displacement at a regular rate (−55.69 mm/year) from April 28, 2005 to July 2006, while the de variation shows a displacement at a regular rate (−23.66 mm/year) from July 5, 2005 to July 2006.
Evaluation of dehydration mechanism during heating of hydrous asteroids based on mineralogical and chemical analysis of naturally and experimentally heated CM chondrites
Authors: Nakato Aiko , Nakamura Tomoki , Kitajima Fumio , Noguchi Takaaki 
Published: August 2014

Abstract
Based on the evidence derived from spectroscopic observation and meteorite analysis, some hydrous asteroids were heated and dehydrated for a certain period of time after aqueous alteration. In order to reproduce the dehydration processes, we experimentally heated Murchison CM chondrite at 600°C for 1 h (600°C/1 h), 600°C/96 h, 900°C/1 h, and 900°C/96 h under controlled oxygen partial pressures. The experimental products were compared with Belgica (B-)7904 CM chondrite, a meteorite from a dehydrated asteroid in terms of characteristic mineralogical and compositional properties. B-7904 shows properties intermediate between the two experimental products heated at 900°C/1 h and 900°C/96 h. In addition, the presence or the absence of some temperature-sensitive minerals in B-7904 suggests that it experienced heating at a temperature higher than 700°C but lower than 890°C. The duration of heating, based on the diffusion time needed to achieve the Fe-Mg zoning profile in olivine in B-7904, was estimated to be between 10 and 103 days at 700°C and between 1 to 102 h at 890°C. The obtained durations are much shorter than those expected from the internal heating model which requires prolonged heating over million years. Therefore, it is unlikely that the short-lived radionuclide of 26Al is a heat source for the dehydration of B-7904. Instead, short-duration local heating, such as that from impacts or solar radiation, is a more promising heat source.
Latitudinal dependence of the solar wind density derived from remote sensing measurements using interplanetary Lyman α emission from 1999 to 2002
Authors: Nakagawa Hiromu , Fukunishi Hiroshi , Watanabe Shigeto , Takahashi Yukihiro , Taguchi Makoto , Lallement Rosine 
Published: August 2014

Abstract
The interplanetary Lyman α backscattered emission is an effective tool for remote sensing of the global structure of the solar wind proton flux. This paper reports an attempt to derive the latitudinal dependence of the solar wind density by combining the interplanetary Lyman α measurements of the Nozomi spacecraft for the period 1999–2002 with the solar wind speed data derived from interplanetary scintillation measurements. This approach successfully revealed the slow and dense solar wind over the poles during the period of the solar maximum. Data on the polar solar wind density indicate a significant growth from the middle of 2000, and the polar values of solar wind density are close to those of the equatorial values as a result of the disappearance of the coronal hole. A marked density depletion occurred in the middle of 2001, which can be ascribed to the development of fast winds from the polar coronal hole. To evaluate the remote sensing method, we considered solar wind density data from in situ measurements obtained by the Ulysses spacecraft. We conclude that our method basically agrees with in situ measurements, although we found a significant (a factor of 2) difference between these in the middle of 2001.
Three dimensional configuration of earthward fast plasma flow in the near-Earth plasma sheet
Authors: Kondoh Koji , Ugai Masayuki , Shimizu Tohru 
Published: August 2014

Abstract
The earthward short-term (1-min. order) fast flow event (Flow Burst) and the long-term (10-min. order) fast flow event (Bursty Bulk Flow) observed in the near-Earth plasma sheet are examined using three dimensional MHD simulations on the basis of spontaneous fast reconnection model. It is well known that these fast flow events are closely related to the magnetic substorms. On the other hand, it is considered that these fast flow events are caused by the magnetic reconnection in the near-Earth magnetotail. The time profiles of plasma quantities in these events observed by in-situ satellites are quite different in each event. Above Flow Burst and Bursty Bulk Flow events are often examined separately due to the large difference in time scale. In this paper, these differences are interpreted by the three-dimensional position of satellite relative to the X-line and the reconnection jet channel, and the simulation results are directly compared with the results of in-situ satellite observations using the virtual satellites located in simulation domain.
Frequency-dependent attenuation of S-waves in the Kanto region, Japan
Authors: Yoshimoto Kazuo , Okada Mariko 
Published: August 2014

AbstractApparent, scattering, and intrinsicS-wave attenuations (QS−1,Qscat−1andQint−1) of the upper lithosphere in the Kanto region of Japan were measured in the 1- to 32-Hz frequency range using Multiple Lapse Time Window Analysis (MLTWA) for 115 borehole seismograms of local earthquakes. A new set of time windows for MLTWA, in which multiple isotropic scattering is assumed, was proposed and employed to estimate the frequency dependence ofS-wave attenuation parameters. Scattering attenuation was found to dominate intrinsic attenuation in theS-wave attenuation mechanism at low frequencies (<;2 Hz), whereas the opposite relation was observed at high frequencies. The transition is caused by the different frequency dependences ofQscat−1(∝f−1.5) andQint−1(∝f−0.7) at this frequency. Interestingly,Qscat−1is almost frequency independent at frequencies >8 Hz, which implies the self-similar nature of short-wavelength heterogeneities in the upper lithosphere. In terms of the upper lithosphere of the Kanto region, these results may indicate that the random heterogeneities characterized by the Gaussian autocorrelation function with a fractional fluctuationε≈ 10% and a correlation lengtha≈ 2 km are superimposed on the weak background self-similar heterogeneity.
Prehistorical archaeomagnetic directions from Hungary in comparison with those from south-eastern Europe
Authors: Márton P. 
Published: August 2014

Abstract
Since the beginning of the modern archaeomagnetic investigations in Hungary in the nineteen seventies, some directional data of various prehistorical ages have also accumulated beside a larger body of the historical results. These are presented here and compared with 1) coeval directional results which are available from south-eastern Europe, as well as 2) the predictions of geomagnetic field directions for Hungary of the global geomagnetic field model, CALS7K.2. The comparison with the south-eastern European data has lead to new archaeomagnetic dates for one of the studied archaeological features which are thought to be an improvement to the presently accepted radiometric dates.
An analysis of the infrasound signal from the Miyagi-Oki earthquake in Japan on 16 August 2005
Authors: Che Il-Young , Lee Hee-Il , Jeon Jeong-Soo , Kang Tae-Seob 
Published: August 2014

AbstractFollowing the 16 August 2005 Miyagi-Oki earthquake in Japan, coherent atmospheric infrasonic waves were observed at regional distances (1200–1500 km) using three seismo-acoustic arrays on the Korean Peninsula. A source-location procedure was applied to the distinct long-duration infrasonic signals to construct earthquakegenerated infrasound source regions on the Japanese island arc. The results showed that the long-duration infrasonic signal was attributable to extensive seismic ground motions on land areas from the southwestern through to the northeastern part of the island arc as well as regions close to the earthquake epicenter. In many coherent infrasonic signals, an effect of seismic ground motions in sedimentary basins could be identified as a source of infrasound radiation from the large earthquake. These observations and interpretations were confirmed using predictions of possible infrasound arrival azimuth variation by converting real seismological data from the dense Japanese seismic network.
Variation process in stiffness inferred by nonlinear inversion during mainshocks at Kushiro Port vertical array site
Authors: Thabet Mostafa , Nemoto Hiroo , Nakagawa Koichi 
Published: August 2014

AbstractIn the present study, a set of three strong motions accompanied by 21 before and after mainshock motions from liquefied soil at the Kushiro Port vertical array site have been obtained.S-wave velocity variation is estimated using a new proposed nonlinear GA inversion technique. This inversion technique is reproductive in assessment forS-wave velocities due to its direct link with the simulation FEM program and matching technique between the observed and simulated waveforms. Layers (6 ∼ 23 m depth) have been found to be responsible for liquefaction at the Kushiro Port site. Stiffness degradation due to liquefaction could be predicted by applying the inversion technique on the horizontal components of the mainshocks at different time-windows and then multiplying the weighting functions by the nonlinear simulated ground motions. These weighting functions were applied to delete the misfit time window of the nonlinear simulated ground motions when these were compared to the observed records. Finally, stacking was applied for the weighted nonlinear simulated ground motions. A strong degree of liquefaction is concluded during the Kushiro-Oki (1993) and the Hokkaido Toho-Oki (1994) earthquakes, whereas a low degree of liquefaction was detected to have occurred during the Tokachi-Oki (2003) earthquake due to high increase of rigidity following a trend that resembles a consolidation curve.
Substorm onset dynamics in the magnetotail as derived from joint TC-1 and Cluster data analysis
Authors: Wang H. , Lühr H. , Ma S. Y. , Ridley A. J. 
Published: August 2014

Abstract
This study investigates two substorm onset events with favorable constellations of spacecraft, TC-1 and Cluster, separated by several Earth radii. The substorms have been identified in both auroral regions. One is believed to be triggered by a northward turning of the interplanetary magnetic field (IMF), while the other occurs under generally southward IMF. For both events, Cluster was located tailward of TC-1, but observed the dipolarization at earlier time for one event while at later time for the other. The timing difference of dipolarization at different positions could be explained by the earthward or tailward propagation of the field disturbances in the radial direction. The earthward dipolarization front was found in one case to bounce back and forth at TC-1. The earthward propagation was accompanied by a fast earthward plasma flow for the 21 September 2005 event. The event analysis suggests that substorms can be quite different from case to case due to differences in the solar wind condition and magnetotail configuration.
Postseismic slip associated with the 2007 Chuetsu-oki, Niigata, Japan, Earthquake (M 6.8 on 16 July 2007) as inferred from GPS data
Authors: Iinuma Takeshi , Ohta Yusaku , Miura Satoshi , Tachibana Kenji , Matsushima Takeshi , Takahashi Hiroaki , Sagiya Takeshi , Ito Takeo , Miyazaki Shin’ichi , Doke Ryosuke , Takeuchi Akira , Miyao Kayo , Hirao Akihiko , Maeda Takahiro , Yamaguchi Teruhiro , Takada Masamitsu , Iwakuni Makiko , Ochi Tadafumi , Meilano Irwan , Hasegawa Akira 
Published: August 2014

AbstractPostseismic crustal deformation associated with the 2007 Chuetsu-oki Earthquake, which occurred on 16 July 2007 with a magnitude of 6.8 at the southeastern rim of the Sea of Japan, near the coast of Mid-Niigata Prefecture, Central Japan, are detected by GPS observations. We analyzed continuous GPS data from the sites of the Geographical Survey Institute of Japan (GSI) and another dense temporary network, which we established just after the main shock to reveal spatio-temporal evolution of postseismic slip for 50 days after the main shock by geodetic inversion methods. Four models of faults are configured following Ohtaet al.(2008, this issue), and these are optimized based on ABIC (Akaike’s Bayesian Information Criterion). The results of the inversion analysis show that the postseismic slip on the faults occurred at a downdip and updip extension of the coseismically slipped portion. The slip in the shallower portion decayed to be negligible within 2 weeks, and the slip in the deeper portion was still large after the slip in the shallower portion had almost terminated.
Electrodynamics of the vertical coupling processes in the atmosphere-ionosphere system of the low latitude region
Authors: Abdu M. A. , Brum C. G. M. 
Published: August 2014

Abstract
Dynamical, electro-dynamical and electrical coupling processes originating from upward propagation of atmospheric waves, and magnetosphere-ionosphere interaction are responsible for the large degree of variabilities observed in the low latitude ionosphere. One of the most outstanding aspects of its phenomenology is related to the sunset electrodynamical processes responsible for the evening enhancements in zonal and vertical electric fields and the associated spread of F/plasma bubble irregularity development. Recent observational results have provided evidence of significant contribution to their quiet time variability arising from thermospheric wind patterns, upward propagating planetary waves and possibly sporadic E layers. This paper provides an overview and some new results on planetary wave coupling with the equatorial F region, the E layer conductivity as key connecting mechanism, a possibly interactive role by sporadic E layers, and the resulting day-to-day variability in the evening prereversal electric field enhancements with consequences on spread F development.
Reflection and refraction of acoustic waves at poroelastic ocean bed
Authors: Vashishth A. K. , Sharma M. D. 
Published: August 2014

AbstractOcean bottom is considered as a plane interface between non-viscous liquid and anisotropic dissipative poroelastic solid. The dissipation comes from the viscosity of pore-fluid as well as the anelasticity of the porous frame. Biot’s theory is used to derive a system of modified Christoffel equations for the propagation of plane harmonic waves in a porous medium. The non-trivial solution of this system is ensured by a determinantal equation. This equation is solved into a polynomial equation of degree eight, whose roots represent the vertical slowness values for the waves propagating upward and downward in a porous medium. The eight, numerically obtained, slowness values are identified with the four waves propagating towards (or away from) the boundary in the porous medium. Incidence of acoustic wave through the liquid at the interface results in its reflection and the refraction of four attenuating waves in the poroelastic medium. The energy partition among the reflected and refracted waves is calculated at the interface. Conservation of energy is obtained except in the case of partially opened surface pores of the porous medium. Energy refracted to the dissipative porous medium is expressed through an energy matrix. The four diagonal elements of this matrix represent the energy shares of the four inhomogeneous waves and the sum of all the off-diagonal elements of this matrix represents the interaction energy. Few significant results are extracted from the observations in the numerical examples studied. These results represent the effect of anisotropic symmetries, anelasticity, wave-frequency, opening, configuration and flow-impedance of pores, on the energy shares of reflected and refracted waves.
Multi-year temperature measurements of the middle atmosphere at Chatanika, Alaska (65°N, 147°W)
Authors: Thurairajah Brentha , Collins Richard L. , Mizutani Kohei 
Published: August 2014

Abstract
Over an eight-year period (1997–2005) Rayleigh lidar temperature measurements of the stratosphere and mesosphere (40–80 km) have been made at Poker Flat Research Range, Chatanika, Alaska (65°N, 147°W). The Rayleigh lidar measurements have been made between mid-August and mid-May. These measurements have yielded a total of approximately 904 hours of temperature measurements of the middle atmosphere over 116 nights. The seasonal evolution of the middle atmosphere shows an annual cycle with maximum in summer below 60 km and a reversal of the cycle with minimum in summer above 60 km. The monthly mean stratopause has a highest temperature of 273 K at an altitude of 47.5 km in May and a lowest temperature of 243 K at an altitude of 54.7 km in January. However, nightly stratopause temperatures in January and December are sometimes warmer than those in May and August. An elevated stratopause (>65 km) is observed on 5 occasions in 41 observations in January and February. The Chatanika measurements are compared with five other Arctic data sets and models. The upper stratosphere at this site is slightly colder than the zonal mean as well as sites in Greenland and Scandinavia with the largest differences found in January. We discuss the wintertime temperatures in the upper stratosphere and lower mesosphere in terms of the position of the polar vortex and the increased occurrence of stratospheric warming events during the 1997–2005 observation period.
A new instrument for the study of wave-particle interactions in space: One-chip Wave-Particle Interaction Analyzer
Authors: Fukuhara Hajime , Kojima Hirotsugu , Ueda Yoshikatsu , Omura Yoshiharu , Katoh Yuto , Yamakawa Hiroshi 
Published: August 2014

Abstract
Wave-particle interactions in a collisionless plasma have been analyzed in several past space science missions but direct and quantitative measurement of the interactions has not been conducted. We here introduce the Wave-Particle Interaction Analyzer (WPIA) to observe wave-particle interactions directly by calculating the inner product between the electric field of plasma waves and of plasma particles. The WPIA has four fundamental functions: waveform calibration, coordinate transformation, time correction, and interaction calculation. We demonstrate the feasibility of One-chip WPIA (O-WPIA) using a Field Programmable Gate Array (FPGA) as a test model for future science missions. The O-WPIA is capable of real-time processing with low power consumption. We validate the performance of the O-WPIA including determination of errors in the calibration and power consumption.
Application of GOCE data for regional gravity field modeling
Authors: Janák Juraj , Fukuda Yoichi , Xu Peiliang 
Published: August 2014

Abstract
In principle, every component of a disturbing gravity gradient tensor measured in a satellite orbit can be used to obtain gravity anomalies on the Earth’s surface. Consequently, these can be used in combination with ground or marine data for further gravity field modeling or for verification of satellite data. Theoretical relations can be derived both in spectral and spatial forms. In this paper, we focus on the derivation of a spatial integral form in the geocentric spherical coordinates that seems to be the most convenient one for regional gravity field modeling. All of the second partial derivatives of the generalized Stokes’s kernel are derived, and six surface Fredholm integral equations are formulated and discretized. The inverse problems formulated for particular components clearly reveal different behaviors in terms of numerical stability of the solution. Simulated GOCE data disturbed with Gaussian noise are used to study the performance of two regularization methods: truncated singular value decomposition and ridge regression. The optimal ridge regression method shows slightly better results in terms of the root mean squared deviation of the differences from the exact solution.
The effect of distribution of stations upon location error: Statistical tests based on the double-difference earthquake location algorithm and the bootstrap method
Authors: Bai Ling , Wu Zhongliang , Zhang Tianzhong , Kawasaki Ichiro 
Published: August 2014

AbstractIn this letter, we investigate the effect of station distribution (including the number and azimuthal gap of stations) upon location error based on the field data observed at Northern California Seismic Network (NCSN) using a double-difference earthquake location algorithm and a bootstrap method. The earthquakes relocated by all 117 stations are set as reference and the error of location is defined as the RMS of the difference to the reference. We find that the location error has a nonlinear relationship with the distribution of stations. The results may be used as guidelines for building seismic network.
Mass-redistribution-induced crustal deformation of global satellite laser ranging stations due to non-tidal ocean and land water circulation
Authors: Takiguchi Hiroshi , Otsubo Toshimichi , Fukuda Yoichi 
Published: August 2014

Abstract
The effect of the non-tidal ocean load (NTOL) and the continental water load (CWL) on crustal deformation are calculated for global satellite laser ranging (SLR) stations and on 4°×4° grids (only over the land). For the regions most severely affected, the peak-to-peak displacements due to the NTOL are found to be as large as 3 mm for the horizontal components and 10 mm for the vertical component. The peak-to-peak displacements due to the CWL reach 3 mm for the horizontal components and 15 mm for the vertical component. We apply the time series of NTOL and CWL to precise SLR analysis. The LAGEOS orbit analysis reveals that the Estimating the Circulation and Climate of the Ocean (ECCO) model makes the root mean square (RMS) of the range residual 0.2% smaller, and that the CWL makes it 0.8% smaller, compared with the case where loading displacement is neglected. On the other hand, with the NTOL derived from Topex/Poseidon altimetry data, the SLR orbit fit is not improved.