Recursos de colección

Hokkaido University Collection of Scholarly and Academic Papers (130.615 recursos)

HUSCAP (Hokkaido University Collection of Scholarly and Academic Papers) contains peer-reviewed journal articles, proceedings, educational resources and any kind of scholarly works of Hokkaido University.


Mostrando recursos 1 - 8 de 8

  1. 2003年十勝沖地震(Mw8.0)前後の北海道太平洋沿岸5観測点の地殻変動連続記録について

    笠原, 稔; 山口, 照寛; 高田, 真秀; 一柳, 昌義; 岡山, 宗夫
    Secular and short term strain variations before and after the 2003 Tokachi-Oki earthquake, Mw8.0, recorded at five continuous crustal movement stations located along the Pacific coast are reported. There is no obvious forerunner movement at all stations. However, clear co-seismic and post-seismic strain changes are recorded at all stations. Strain data are digitized by 18 bits with 1 Hz sampling rate so that the complete strain seismogram of Mw8.0 event were recorded at MYR station nearest the source of the event. Strain seismograms recorded at all stations in Hokkaido are also reported.

  2. Poissonの関係式を用いた北海道北部地域における重力・磁気異常の地下構造解析

    梶原, 崇憲; 茂木, 透
    The Poisson's equation expresses a linear relationship between the gravity and magnetic potentials arising from a body with uniform density and magnetization contrast. The equation was extended to multi body case by repeatedly applying it within a small uniform body called the moving window. The moving-window Poisson's (MWP) analysis technique was proposed by Chandler et al. (1981) to apply to general complex structures. The correlation coefficient between the total magnetic intensity anomaly reduced to the pole and vertical derivative of the gravity anomaly, and the magnetization-to-density ratio were obtained by the MWP analysis. We investigated the profiles of these parameters...

  3. 北海道北部地域の重力測定

    本多, 亮; 茂木, 透
    The northern part of Hokkaido (Dohoku region) is recognized as the boundary region between the Okhotsk and Amurian plates. In this region, strain concentration is reported based on triangulation and GPS observations. However, there had not been observed any inland earthquakes larger than MJMA 6 in Dohoku region, until the 2004 Rumoi-Nanbu earthquake (MJMA 6.1) occurred. There may be a possibility of occurrence of intraplate large earthquake in the future. The mechanism of the earthquakes observed in the region is strikeslip and thrust type, owing to the east-west compression. In case the thrust type earthquake had been rupturing recurrently, it...

  4. 地球電子放射線帯内側領域における動径拡散係数

    小松, 研吾; 渡部, 重十
    The radiation belts are the region that energetic charged particles are trapped by Earth’s magnetic field. The radiation belts have been observed by a lot of satellites and researched by theoretical approach since the discovery of it. The electron radiation belt is separated into two regions called the outer belt and the inner belt by the slot region in which the flux is very small. It is well known that the outer belt flux vary by several orders of magnitude associated with geomagnetic disturbances (e.g., Baker et al., 1994) and the exact mechanism of such variations has been a puzzle...

  5. 数値モデル計算によるマグマ貫入に伴う地熱系発達過程の研究

    佐波, 瑞恵; 茂木, 透; 西田, 泰典; 橋本, 武志; 田村, 慎
    Cooling of intruded magma, development and decay of hydrothermal systems are investigated by model calculations for various combination of parameters such as hydraulic permeability of the intruded magma and its surroundings. Dependence of the pressure gradient on the hydrothermal systems is also investigated to inspect the effect of the potential flow of the groundwater along the topography. In the case that the horizontal pressure gradient is smaller than buoyancy, the hydrothermal system develops just above the intruded magma, while the greater pressure gradient as well as high permeability of surroundings carries the hydrothermal system to downstream. We applied these examinations...

  6. 北朝鮮核実験による地震波形記録

    吉澤, 和範
    Seismic waves generated by a nuclear test carried out by North Korea on October 9, 2006 were observed throughout the Japanese islands. Clear arrivals of Pn waves, which traveled below the Moho discontinuity underneath the Japan Sea, were recorded by the Japanese broad-band seismic network, F-net, deployed by National Research Institute for Earth Science and Disaster Prevention (NIED). We analyzed the waveforms of the nuclear event observed at F-net stations as well as some global seismic stations in East Asia. Apparent path-average velocity of Pn waves and their maximum amplitudes are estimated from vertical component seismograms of the F-net stations....

  7. 火山岩塊の運動再考 (4) : 浅間火山1938年および有珠火山1977年噴火における放出火山岩塊の解析

    鈴木, 建夫; 新井田, 清信; 西田, 泰典; 大島, 弘光; 室伏, 誠
    Spatial distribution of volcanic blocks, as well as landing distance from a crater, landing angle and diameter of the blocks has been well investigated on and around the crater in cases of the 1938 Asama and the 1977 Usu eruptions by some researchers. Then, this paper reproduces detailed kinematic aspects of the eruptions so as to interpret the above-mentioned field data, on the basis of a generalized ballistic equation of ejected volcanic blocks proposed by the present authors. Calculations are made for combination of various parameters, such as air resistance to the blocks, direction of the wind, orientation dependence of...

  8. 火山岩塊の運動再考 (3) : 放出火山岩塊に対する風の効果と岩塊の初速度についてのモデル計算

    鈴木, 建夫; 新井田, 清信; 西田, 泰典; 大島, 弘光; 室伏, 誠
    From the volcano-energetics point of view, it is very important to evaluate the velocity, direction and distribution of ejected volcanic blocks. However, in most cases, it is hard to measure directly such quantities during the eruption. Therefore, the volcanic blocks landed on and around the crater have been investigated to reproduce dynamic aspects of eruption after the eruption. In the present paper, ballistic curves of the volcanic blocks are numerically analyzed for various combination of parameters, such as direction of the explosion principal axis of ejection, velocity and direction of the wind, air resistance to the block and dependence of...

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