bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mn−Cr ages of Fe-rich olivine in two Rumuruti (R) chondrites
Authors: Sugiura Naoji , Miyazaki Akiko 
Published: August 2014

Abstract
Mn−Cr systematics in olivine of two Rumuruti (R) chondrites was investigated. Mn/52Cr ratios up to 1800 and 1300, and δ53Cr of up to 25‰ and 7‰ were observed for NWA 753 and Sahara 99531, respectively. All data points of NWA 753 show a linear correlation between δ53Cr values and Mn/52Cr ratios on the isochron diagram. The inferred initial 53Mn/55Mn ratio for NWA 753 is (1.84 ± 0.42(2σ)) × 10−6. In the case of Sahara 99531, a positive correlation interpreted as an isochron for 53Mn/55Mn = 2.75 ± 1.55(2σ) × 10−6 was obtained for only one chondrule. Data from other chondrules in Sahara 99531 give an upper limit of 53Mn/55Mn = 0.49 × 10−6. The Mn−Cr ages of NWA 753 and a chondrule in Sahara 99531 are slightly older than that of the angrite LEW 86010 (Lugmair and Shukolyukov, 1998). Other chondrules in Sahara 99531 are at least 5 Ma younger than the LEW 86010. The Mn-Cr ages of olivine in R chondrites correspond to the time when olivine became a closed system either during slow cooling from the peak metamorphic temperature or during rapid cooling by impact excavation. In either case the olivine closure occurred earlier than the final assembly of the brecciated chondrites.
Study on mesosphere summer echoes observed by digital ionosonde at Zhongshan Station, Antarctica
Authors: Li Hai-Long , Wu Jian , Liu Rui-Yuan , Huang Ji-Ying 
Published: August 2014

Abstract
The irregular characteristics of E and Es layers are studied with data from 1995 to 2002 observed by a Digisonde Portable Sounder-4 (DPS-4) ionosonde at Zhongshan Station, Antarctica. Because they have much similar characteristics with Polar Mesosphere Summer Echoes (PMSE), two criteria are proposed to study PMSE at MF and HF bands in Southern hemisphere. The phenomena of irregular E and Es layer are called as PMSE-like or Polar Mesosphere Summer Echoes-Es (PMSE-Es) here. The occurrence rate variations of PMSE-Es show similarity to those of PMSE at multi-scales, such as seasonal, diurnal, and semidiurnal variation. Finally, the discrepancies between diurnal, semidiurnal and seasonal variation between PMSE and PMSE-Es are discussed respectively.
Energetic particle injections into the outer cusp during compression events
Authors: Delcourt D. C. , Malova H. V. , Zelenyi L. M. , Sauvaud J.-A. , Moore T. E. , Fok M.-C. 
Published: August 2014

Abstract
We investigate the dynamics of charged particles in the dayside magnetosphere in response to abrupt variations of the solar wind dynamical pressure. Using test particle simulations, we show that the electric field induced by the compression of the frontside magnetosphere may be responsible for prominent energization of plasma sheet ions as well as trapping at high latitudes. We demonstrate that, due to the short-lived character of the magnetic field line reconfiguration (on the time scale of a few minutes), the particle magnetic moment (first adiabatic invariant) may not be conserved during such events. Ions that are initially bouncing from one hemisphere to the other are found to experience nonadiabatic energization up to the hundred of keV range while being injected into the outer cusp. Such injections involve particles from limited portions of the dayside flux tubes. The energetic particles that are produced in the outer cusp during such events subsequently circulate about the field minimum at high latitudes without intercepting the equatorial plane, thus contributing to the high-energy populations that are observed in this region of space.
Examination of consistency of marine gravity with land gravity in and around the Japanese Islands using a helicopter-borne gravimeter
Authors: Segawa Jiro , Komazawa Masao , Kumar K. Vijay , Nakayama Eiji , Joseph E. John , Kusumoto Shigekazu , Onodera Ken-ei , Kuroishi Yuki 
Published: August 2014

Abstract
This paper reports a finding that marine gravity data around the Japanese Islands are inconsistent with nearby land gravity data. The comparison between land and marine gravity was made possible by the gravity measurements from the air using a helicopter-borne gravimeter (SEGAWA Model) developed by the present authors. The ground/sea truth gravity anomaly can be checked against the gravity from the air, though it is not free air gravity anomaly but gravity disturbance. The newly-developed airborne gravimeter first manufactured in 1998 shows a good performance with a 1–2 mgal average repeatability of measurement under a 90-knot flight speed. Thus we have found disagreements between ground truth and sea truth gravity anomalies on the basis of airborne gravity data in the areas in Japan where we have so far made measurements. Among them we will report the case in the area from Saitama and Ibaraki offshore to the Kashima-Nada Sea, p]Japan. Our conclusion about this area is that the past marine gravity data obtained by surface ship gravimeters involve systematic errors of more than 10 mgals. This kind of inconsistency between marine and land gravity is expected to be found in a number of other areas around the Japanese Islands.
Synthetic Aperture Radar Interferometry: Separation of atmospheric artifacts from effects due to the topography and the terrain displacements
Authors: Ballatore Paola 
Published: August 2014

Abstract
This paper reports the new concept of possibly applying independent component analysis (ICA) on Synthetic Aperture Radar (SAR) satellite images for separating atmospheric artifacts from effects due to topography and terrain displacements. Specifically, the FastICA algorithm is applied on simulations of SAR interferograms with the purpose of extracting the different independent sources. Results show the existence of significant correlations between estimated and original components, with correlation coefficients above 0.9 and statistical confidence level above 99.9%. These findings suggest that ICA might provide a useful tool in SAR data processing, with a specific crucial usefulness in cases of an absence of ground truth knowledge, as in the cases of insufficient meteorological information at specific observational times or in satellite monitoring of remote lands. Applications on real data show that the topographical component is automatically derived by the FastICA algorithm for whatever real data set. What is different is that the extraction of terrain displacements may require some a priori information for separating different kinds of landslides and that the use of possible semi-blind ICA/FastICA approach might be considered, dependent on the specific data set.
Numerical simulation of tsunamis generated by caldera collapse during the 7.3 ka Kikai eruption, Kyushu, Japan
Authors: Maeno Fukashi , Imamura Fumihiko , Taniguchi Hiromitsu 
Published: August 2014

Abstract
The relationship between tsunamis and scales of caldera collapse during a 7.3 ka eruption of the Kikai volcano were numerically investigated, and a hypothetical caldera collapse scale was established. Wave height, arrival time, and run-up height and distance were determined at some locations along the coastline around Kikai caldera, using non-linear long-wave equations and caldera collapse models using parameters showing the difference in geometry between pre- and post-collapse and the collapse duration. Whether tsunamis become large and inundations occur in coasts is estimated by the dimensionless collapse speed. Computed tsunamis were then compared with geological characteristics found in coasts. The lack of evidence of tsunami inundation at Nejime, 65 km from the caldera, suggests that any tsunamis were small; indicating that the upper limit of dimensionless caldera collapse speed was 0.01. On the other hand, on the coast of the Satsuma Peninsula, 50 km from the caldera, geological characteristics suggests that tsunamis did not inundate, or that even if tsunamis inundated the area, the traces of a tsunami have been eroded by a climactic pyroclastic flow or the tsunami itself and they have not been left. In numerical computations, when a dimensionless caldera collapse speed is more than 0.003, tsunami can inundate this area.
Long-distance traveling ionospheric disturbances caused by the great Sumatra-Andaman earthquake on 26 December 2004
Authors: Astafyeva Elvira I. , Afraimovich Edward L. 
Published: August 2014

Abstract
By using data from the GPS network, we observed exceptional intensive quasi-periodical perturbations of the total electron content (TEC) caused by the great Sumatra-Andaman earthquake on 26 December 2004. The time period of the variations was about 15 min, their duration was about 1 hour. The amplitude of the TEC oscillations exceeded the amplitude of “background” fluctuations in this range of periods by one order of magnitude, at a minimum. They were registered 2–7 hours after the main shock at a distance from 1000 to 5000 km, both on the northwest and northeast outward from the epicenter. The most probable source of the observed oscillations appeared to be a seismic airwave generated by the sudden vertical displacement of the Earth’s surface near the epicenter.
Early cretaceous absolute geomagnetic paleointensities from Córdoba Province (Argentina)
Authors: Ruiz Ruben Cejudo , Goguitchaichvili Avto , Geuna Silvana E. , Alva-Valdivia Luis M. , Solé Jesus , Morales Juan 
Published: August 2014

Abstract
We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks of Sierra Chica de Cordoba (Argentina). The new K-Ar isotopic ages of 5 samples range from 136 to 122 Ma. Twenty five samples from 7 individual flows yielded acceptable paleointensity estimates. The mean paleointensity values per flow are ranging from 53.0 ± 1.9 to 25.4 ± 2.6 μT and the corresponding Virtual Dipole Moments (VDMs) are ranging from 9.3±1.3 to 4.6±0.5 (1022 Am2). This corresponds to the mean value of 7.3±1.7×1022 Am2, which is compatible to the present geomagnetic axial dipole. Currently available selected paleointensity data from 80 to 130 Ma suggest that geomagnetic field strength frequently fluctuated before and during the Cretaceous Normal Superchron while the magnetic polarity maintained stable. The mean paleointensities derived from Córdoba lavas agree remarkably well with those obtained from the Paraná Magmatic Province (133–132 Ma). This reinforces the hypothesis about the unreliability of ‘Mesozoic Dipole Low’. Key words: Paleointensity, rock-magnetism, Early Cretaceous, South America.
Rock magnetic study of fluvial Holocene soil from Buenos Aires province (Argentina)
Authors: Vasquez Carlos A. , Nami Hugo G. 
Published: August 2014

Abstract
The magnetic characteristics of soils are widely used in environmental and paleoclimatic investigations for studying the several factors involved in the soil formation process. We propose here a new analytical tool that takes into account the variations in magnetic properties correlated with grain sizes and concentrations of ferrimagnetic minerals. This analytical tool is based on a mathematical model of well-established magnetic properties in samples of known grain sizes and was used in this study to determine changes in the grain size and concentration of ferrimagnetic minerals along a terminal Pleistocene/Holocene fluvial section located in the northeast of Buenos Aires province. These variations may reflect a humid period prevailing in the area and may be associated with climate changes that occurred in the Chaco-Pampean region during the Middle Holocene.
Estimations of the S-wave velocity structures in Chia-Yi City, Taiwan, using the array records of microtremors
Authors: Huang Huey-Chu , Wu Cheng-Feng 
Published: August 2014

AbstractShear-wave velocities (VS) have been widely used for the site characterization of earthquake ground motion. We report here our investigation of theS-wave velocity structures of Chia-Yi City, Taiwan using the array records of microtremors at seven sites. The dispersion curves at these sites were first calculated using the F-K method proposed by Capon (1969); theS-wave velocity structures in Chia-Yi City were then estimated by employing the surface wave inversion technique (Herrmann, 1991). At frequencies lower than about 1 Hz, the propagation directions are concentrated in the northwest and southwest quadrants. The generation of these may be attributed to the ocean waves of the Taiwan Strait. The harder site (CBA) has higher phase velocities, while the softer sites (CWB, SHP and YRU) have lower phase velocities, especially at frequencies between 1 and 5 Hz. The shallow velocity structures (0–1,500 m) can be roughly divided into four to five layers. The depth of the alluvium gradually increases from east to west and from north to south.
Sq and sfe currents at equatorial stations along the western and eastern African sectors
Authors: Rastogi R. G. 
Published: August 2014

Abstract
The paper describes the daily variations in the Sq and sfe induced ionospheric current at the equatorial stations of Addis-Ababa (Inclination: 1.0°; Declination: 1.5°) and M’Bour (Inclination: 9.0°; Declination: −9.3°). At Addis-Ababa, the diurnal SqH loop as well as sfe H currents aligned fairly well with the direction of declination. At M’Bour, the SqH as well as the sfe H vector were along the direction of about 30°W. Thus, in the region of an abnormally large declination at equatorial stations, the daily Sq current does not follow a direction normal to the declination.
Hypocenter distribution of the main- and aftershocks of the 2005 Off Miyagi Prefecture earthquake located by ocean bottom seismographic data
Authors: Hino Ryota , Yamamoto Yojiro , Kuwano Asako , Nishino Minoru , Kanazawa Toshihiko , Yamada Tomoaki , Nakahigashi Kazuo , Mochizuki Kimihiro , Shinohara Masanao , Minato Kouetsu , Aoki Gen , Okawara Nariaki , Tanaka Masayuki , Abe Masao , Araki Eiichiro , Kodaira Shuichi , Fujie Gou , Kaneda Yoshiyuki 
Published: August 2014

Abstract
The preliminary hypocenter distribution of the 2005 Off Miyagi Prefecture earthquake and its aftershocks is estimated using data from five ocean bottom and six onshore seismic stations located around the rupture area of the earthquake. The epicenter of the mainshock is relocated at 38.17°N, 142.18°E, and the focal depth is estimated to be 37.5 km. The aftershocks surrounding the mainshock hypocenter form several clusters that are concentrated along a distinct landward dipping plane corresponding to the plate boundary imaged by the previous seismic experiment. The strike and dip angles of the plane agree well with those of the focal mechanism solution of the mainshock. The size of the plane is about 20×25 km2 in the strike and dip directions, which is similar to that of the large coseismic slip area. The up-dip end of the planar distribution of the aftershocks corresponds to the bending point of the subducting oceanic plate, suggesting that the geometry of the plate boundary affects the spatial extent of the asperity of the 2005 earthquake
Source modeling of the 2005 off-shore Miyagi prefecture, Japan, earthquake (MJMA=7.2) using the empirical Green’s function method
Authors: Kamae K. 
Published: August 2014

AbstractA preliminary source model composed of asperities for the 2005 off-shore Miyagi prefecture, Japan, earthquake (MJMA=7.2) was estimated by the empirical Green’s function method. The source parameters for two asperities located on the fault plane were determined by comparing synthesized broad-band ground motions with observed ones at several stations. We concluded that the stress parameters of the asperities are very high (90 MPa for Asp-1,300 MPa for Asp-2) and that these values are nearly equal to those (73 MPa and 29 MPa) calculated by the Earthquake Research Committee (2005) in Japan for the off-shore Miyagi prefecture earthquake that is expected in the near future. However, the location of the asperities is not completely consistent with the expected event.
Imaging S-wave scatterer distribution in southeast part of the focal area of the 2005 West Off Fukuoka Prefecture Earthquake (MJMA 7.0) by dense seismic array
Authors: Matsumoto Satoshi , Watanabe Atsushi , Matsushima Takeshi , Miyamachi Hiroki , Hirano Syuichiro 
Published: August 2014

Abstract
Spatial distribution of S-wave scatterers in the SE part of the focal area of the 2005 West Off Fukuoka Prefecture Earthquake (M = 7.0) has been estimated using dense seismic array data. Waveforms of 22 natural earthquakes were analyzed in a frequency range of 16–24 Hz. It is difficult to estimate the inhomogeneous structure in this wavelength range with ordinary travel time tomography despite the importance of this parameter for understanding the earthquake-generating process. After filtering and gain recovery in the coda part, observed waveforms were semblance-enhanced slant-stacked into various directions from the array. This was followed by diffraction curve summation in order to image the scatterer distribution. The spatial distribution of scatterers thus imaged revealed that higher strengths were distributed at the SE-extension of the fault plane of the event, which corresponds to a region where the rupture process of the main shock stopped
Crustal structure of the southwestern margin of the Kuril arc sited in the eastern part of Hokkaido, Japan, inferred from seismic refraction/reflection experiments
Authors: Kurashimo Eiji , Iwasaki Takaya , Hirata Naoshi , Ito Tanio , Kaneda Yoshiyuki 
Published: August 2014

Abstract
Hokkaido Island in northern Japan is located at the intersection of the Kuril and Northeast Japan arcs. Eastern Hokkaido represents the southwestern margin of the Kuril arc that evolved as an oceanic island arc, but its crustal structure has remained unclarified. In the summer of 2000, a highly dense onshore-offshore integrated seismic experiment was conducted in order to reveal the entire crustal section covering from the Kuril Trench to the back-arc basin of the Okhotsk Sea crossing eastern Hokkaido. High-quality refraction/wide-angle reflection data collected for the onshore survey line delineated a detailed crustal structure of easternmost part of Hokkaido Island. Our seismic velocity model shows a good correlation with the surface geology along the profile. The notable feature of the velocity model is the existence of a 6.0-km/s layer beneath the onshore survey line. A reflective middle to lower crust is also found beneath eastern Hokkaido. These results indicate that the southwestern margin of the Kuril arc is in a matured state of oceanic island-arc crust.
An example of secondary fault activity along the North Anatolian Fault on the NE Marmara Sea Shelf, NW Turkey
Authors: Tur Huseyin 
Published: August 2014

Abstract
Seismic data on the NE Marmara Sea Shelf indicate that a NNE-SSW-oriented buried basin and ridge system exist on the sub-marine extension of the Paleozoic Rocks delimited by the northern segment of the North Anatolian Fault (NS-NAF), while seismic and multi-beam bathymetric data imply that four NW-SE-oriented strike-slip faults also exist on the shelf area. Seismic data indicate that NW-SE-oriented strike-slip faults are the youngest structures that dissect the basin-ridge system. One of the NW-SE-oriented faults (F1) is aligned with a rupture of the North Anatolian Fault (NAF) cutting the northern slope of the Ç0imarc0ik Basin. This observation indicates that these faults have similar characteristics with the NS-NAF along the Marmara Sea. Therefore, they may have a secondary relation to the NAF since the principle deformation zone of the NAF follows the Marmara Trough in that region. The seismic energy recorded on these secondary faults is much less than that on the NAF in the Marmara Sea. These faults may, however, produce a large earthquake in the long term.
On long-term trends in European geomagnetic observatory biases
Authors: Verbanac Giuli , Korte Monika , Mandea Mioara 
Published: August 2014

Abstract
We investigated the European geomagnetic observatory biases over 42 years, considered as contributions of the crustal field, and generally assumed to be constant in time. To estimate these biases, we compared observatory annual means to predictions given by the continuous CM4 model, and to four other core field models for different epochs. Solar-cycle related external fields are clearly present in the residuals. Although well-known, no suitable model to minimise them exists. We found that an empirical approach, taking advantage of the homogeneity of the external influences in the European region, can minimise these influences. Their reduction is better than when the external field description included in the comprehensive CM4 model is used. At several locations clear long-term trends remain after subtraction of the core field and minimisation of external fields. We investigated whether they are due to an insufficient description of the core field secular variation by the CM4 model, or to changes in induced lithospheric fields.
Site amplification and strong ground motion of the 2007 Noto Hanto, Japan, earthquake estimated from aftershock observation
Authors: Yoshimi Masayuki , Yoshida Kunikazu 
Published: August 2014

AbstractSite amplifications in the lowlands most affected by the 2007 Noto Hanto earthquake, Monzen, Anamizu, and Wajima, are examined using aftershock records observed at eight temporary seismic stations installed just after the mainshock and at two K-NET stations. The predominant frequencies of spectral ratios at alluvium sites in Anamizu and Wajima are approximately 1 Hz. Site amplifications at the alluvium sites are successfully reproduced from 1-D response analysis, except for that at ISK005 where 2-D or higher amplification effects are inferred to play a significant role. A source model composed of two asperities reproduces the ground motions of the mainshock using the empirical Green’s function method. The seismic moments of the asperities are 3.76×1018N m and 2.21×1018N m, respectively. Peak ground velocity (PGV) at alluvium sites during the mainshock are estimated to be 70–110 cm/s for Monzen, 50–110 cm/s for Anamizu, and 60–70 cm/s for Wajima.
Estimation of the lunar reflectance by ground-based observation using a tunable liquid-crystal filter telescope
Authors: Saiki Kazuto , Saito Kimiko , Okuno Hideaki , Suzuki Akiko , Yamanoi Yuta , Hirata Naru , Nakamura Ryosuke 
Published: August 2014

Abstract
Lunar reflectance data are useful not only for lithological identification of the lunar surface but also for radiometric calibration and determination of exposure time for optical sensors of lunar probes. To gain data on lunar reflectance, we acquired multi-band images (five bands: 650, 750, 900, 950, and 1000 nm) of the lunar surface and those of some standard stars using a liquid-crystal tunable filter (LCTF) telescope located on the peak of Mt. Haleakala (Hawaii, USA). The data obtained indicate that the reflectance data of Clementine UV/VIS is too high and that the correction factor is 0.59±0.06 at 950 nm. Our new reflectance data are available to the public at the web site of one of authors (K.S.). We report here our method of deriving the lunar reflectance images from the ground-based observation with a hyperspectral telescope for the users of our reflectance data. The results suggest that ground-based observation is more suitable for the radiometric calibration of the sensor of a lunar probe than laboratory data.