Institut des Sciences de la Terre, Université Joseph Fourier, CNRS, F-38041 Grenoble, France.
National Research Institute for Earth Science and Disaster Prevention, Tsukuba, Japan.
Science. 2014 Jul 4;345(6192):80-2. doi: 10.1126/science.1254073.
Volcanic eruptions are caused by the release of pressure that has accumulated due to hot volcanic fluids at depth. Here, we show that the extent of the regions affected by pressurized fluids can be imaged through the measurement of their response to transient stress perturbations. We used records of seismic noise from the Japanese Hi-net seismic network to measure the crustal seismic velocity changes below volcanic regions caused by the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki earthquake. We interpret coseismic crustal seismic velocity reductions as related to the mechanical weakening of the pressurized crust by the dynamic stress associated with the seismic waves. We suggest, therefore, that mapping seismic velocity susceptibility to dynamic stress perturbations can be used for the imaging and characterization of volcanic systems.
火山喷发是由于深部热火山流体积聚的压力释放而引起的。在这里，我们表明，可以通过测量它们对瞬态应力扰动的响应来对受加压流体影响的区域的范围进行成像。我们使用日本 Hi-net 地震网络的地震噪声记录来测量 2011 年矩震级（M(w)）9.0 东日本地震引起的火山地区下方的地壳地震速度变化。我们将地震时地壳地震速度的降低解释为与地震波相关的动应力对受压地壳的机械弱化有关。因此，我们建议，对动态应力扰动的地震速度敏感性进行成像和特征描述可以用于火山系统的成像和特征描述。
