Meteorology in Tunnel - Effect of barometric pressure changes on extensometer observations

隧道气象学 - 气压变化对引伸计观测的影响

• 批准号: 16540381
• 负责人: IMANISHI Yuichi
• 金额: $ 1.6万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540381/
• 关键词: extensometer; adiabatic changes; heat transfer; 精密観測; 気圧変化

One of the main sources of observational noise for 100 meter quartz tube extensometers in Matsushiro Seismological Observatory, Matsushiro, Nagano, Japan is the effect of air temperature changes on the quartz tubes. The temperature changes, in turn, are caused by adiabatic compression/expansion of the inside air due to atmospheric pressure changes. In this study, we performed continuous observation of temperature, humidity and pressure in order to understand exactly what are going on inside the tunnel. The main results are :1. Air pressure and temperature are in very good correlation. Most of the observed temperature changes are caused by pressure changes.2. Temperature changes are approximately proportional to pressure changes, and the coefficient of proportionality varies systematically with frequency. The coefficient is almost constant at periods shorter than 2 hours, whereas it becomes smaller as the period gets longer.3. Relative humidity inside the tunnel is always higher than 90%, and does not change throughout a year. We could not verify whether temperature changes accompany humidity changes or not.4. The coefficient of the proportionality (0.05K/hPa) at the shorter periods is closer to the theoretical value for humid air (0.042K/hPa), rather than that for dry air (0.085K/hPa).5. The frequency dependence of the pressure effect is very well explained by a theoretical model which takes into account adiabatic changes of the air and heat transfer between air and surrounding rocks.These results lead to a conclusion that temperature changes inside the tunnel are predictable from pressure records and that precise observations of pressure as well as temperature enable us to remove observational noise from extensometer records. However, there still remains unexplained facts, including that the observed proportionality favors a humid air model rather than a dry air model.

日本长野松下地震观测站100米石英管伸缩仪观测噪声的主要来源之一是气温变化对石英管的影响。温度的变化反过来又是由大气压力变化引起的内部空气的绝热压缩/膨胀引起的。在这项研究中，我们对温度、湿度和压力进行了连续观察，以准确了解隧道内发生的事情。主要研究结果如下：1.气压与温度具有很好的相关性。观测到的大部分温度变化是由压力变化引起的。温度变化与压力变化近似成正比，比例系数随频率系统变化。在短于2小时的时段内，该系数几乎不变，而随着时段的延长，该系数变小。隧道内相对湿度始终高于90%，全年不变。我们无法证实温度变化是否伴随着湿度变化。短周期的比例系数(0.05K/百帕)更接近湿空气的理论值(0.042K/百帕)，而不是干燥空气的理论值(0.085K/百帕)。压力效应的频率依赖性可以用一个理论模型很好地解释，该模型考虑了空气和周围岩石之间空气和热传递的绝热变化。这些结果得出的结论是，隧道内的温度变化是可以从压力记录中预测的，并且对压力和温度的精确观测使我们能够从引伸仪记录中去除观测噪声。然而，仍然有一些无法解释的事实，包括观察到的比例倾向于湿空气模式而不是干燥空气模式。

项目成果

Parameters of the fluid core resonance inferred from superconducting gravimeter data

• DOI: 10.1016/j.jog.2004.07.016
• 发表时间: 2004-10
• 期刊: Journal of Geodynamics
• 影响因子: 2.3
• 作者: Tadahiro Sato;Y. Tamura;Koji Matsumoto;Y. Imanishi;H. McQueen

The first absolute gravity measurements in Indonesia

印度尼西亚首次进行绝对重力测量

• 发表时间: 2004
• 期刊: Journal of Geodynamics Vol.38, Nos.3-5
• 作者: Fukuda;Y.;T.Higashi;S.Takemoto ・他
• 通讯作者: S.Takemoto ・他

A network of superconducting gravimeters detects submicrogal coseismic gravity changes

• DOI: 10.1126/science.1101875
• 发表时间: 2004-10-15
• 期刊: SCIENCE
• 影响因子: 56.9
• 作者: Imanishi, Y;Sato, T;Okubo, S
• 通讯作者: Okubo, S

Hydrological effects on the superconducting gravimeter observation in Bandung

• DOI: 10.1016/j.jog.2005.08.030
• 发表时间: 2006
• 期刊: Journal of Geodynamics
• 影响因子: 2.3
• 作者: M. Abe;S. Takemoto;Y. Fukuda;T. Higashi;Y. Imanishi;Sachiko Iwano;S. Ogasawara;Yuki Kobayashi;S. Dwipa;D. S. Kusuma

Combination of temporal gravity variations resulting from superconducting gravimeter (SG) recordings, GRACE satellite observations and global hydrology models

• DOI: 10.1007/s00190-005-0014-8
• 发表时间: 2006-01
• 期刊: Journal of Geodesy
• 影响因子: 4.4
• 作者: J. Neumeyer;F. Barthelmes;O. Dierks;F. Flechtner;M. Harnisch;G. Harnisch;J. Hinderer;Y. Imanishi;C. Kroner;B. Meurers;S. Petrovic;C. Reigber;R. Schmidt;P. Schwintzer;Heping Sun;H. Virtanen