Radiographic imaging of magma dynamics in a volcanic conduit provides detailed information about ascent and descent magma, the flow rate, diameter inflation deflation due to volatile expansion release. Here we report first radiographic observation along utilizing atmospheric (cosmic ray) muons (muography) with dynamic imaging. Time sequential images show that top column ascends right beneath crater floor through which eruption was observed. In addition visualization this inflation, sequence...

In conventional muography observations using two detectors for muon tracking, the accidental coincidence of vertical electromagnetic showers generates identical trajectories to tracks. Although has favorable properties, which allow direct density measurements inside a volcano, measured is lower than actual value due these fortuitous trajectories. We performed Usu and confirmed that, in comparison with use detectors, background noise levels were reduced by more one order magnitude seven...

Abstract. Muography offers us a tool to observe hazardous erupting volcanoes remotely. However, practical muographic observations of from distance are difficult; therefore, various have been performed in the vicinity (< 1.5 km) volcano peaks suppress background noise and enhance images. In this study, we created image directly beneath caldera floor Shinmoe-dake Japan by locating our muography telescope 5 km peak. The began erupt on 19 January 2011 and, less than 1 month, ejected lava...

近年,宇宙線ミュー粒子を用いた探査が注目されており,河川堤防の内部構造可視化への有効性が認められている.一方で,従来の最小二乗法によるトモグラフィ解析手法は解の初期値依存性をもち,堤防内部の密度分布を定量的に評価ができない.そこで本研究では,Moore Penrose逆行列と観測誤差の影響を抑えるTikhonovの正則化法,パラメータを決定するMorozovの相反原理を導入した新たな解析手法を提案する.その結果,実際の地盤密度と解析値は概ね一致し,本手法の有効性が示された.また観測波線間隔が解析格子スケールの1/4以下である時,地盤内部の構造や空洞の位置を推定できることを明らかにした.

Abstract. Muography offers us a tool to observe hazardous erupting volcanoes remotely. However, practical muographic observations of from distance are difficult; therefore, various have been performed in the vicinity (< 1.5 km) volcano peaks suppress background noise and enhance images. In this study, we created image directly beneath caldera floor Shinmoe-dake Japan by locating our muography telescope 5 km peak. began erupt on 19 January 2011, less than one month, ejected lava almost...

In the recent decade, a nondestructive investigation method, muon radiography, has been developing and applied to volcanoes, pyramids, blast furnaces, World Heritage, etc. With this technique, we can measure density distribution inside target object by cosmic-ray muons. Measured cosmic-raymuon intensities be converted density-related information. To muons, for example, there are methods using scintillators or nuclear emulsions (high-sensitive photographic films). When scintillators, detect...

In recent years, it has been conducted to survey cavities in underground of roads using multichannel vehicle towed type GPR equipment. Enormous data can be acquired quickly, although engineers visually check the cavity judgment from data. There are disadvantages such as differences among or costly. We focused on machine learning technology with remarkable leap last few years and studied a method automatically process solve these problems. examined processing detect diffraction pattern caused...

本研究では,従来の物理探査ではカバーできない探査深度・分解能で探査できる宇宙線ミュー粒子を利用した探査を河川堤防に対して行った.観測データより,堤防の幾何形状を捉えることが出来た.また,トモグラフィ解析を行い,堤防内部の密度分布を1m×1mの分解能で推定した.さらに省スペース省人力を目的に開発された半導体小型検出器の河川堤防への導入に向け,性能比較試験として同一構造の二つの検出器の観測実験を行った.筐体温度が急激な変化を起こすことなく,かつ筐体温度差が±1℃以内に抑まる場合,二つの検出器は同等の観測が行えることを明らかにした.

The relationship between soil volumetric water content and permittivity is empirically formulated. applied to moisture meters. This method performed by measuring the propagation time called TDR. In this study, we estimated dielectric dispersion curve in frequency domain using step ground penetrating radar. We proposed a accurately obtain directly from frequency-domain data without converting time-domain waveforms. conducted experiment with changing level tank containing silica sand. As...