Atmospheric resonant oscillations by the 2014 eruption of the Kelud volcano, Indonesia, observed with the ionospheric total electron contents and seismic signals
Atmospheric resonant oscillations by the 2014 eruption of the Kelud volcano, Indonesia, observed with the ionospheric total electron contents and seismic signals
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DOI：
10.1016/j.epsl.2015.11.029
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发表时间：
2016-01
影响因子：
5.3
通讯作者：
Yuki Nakashima;K. Heki;A. Takeo;M. N. Cahyadi;A. Aditiya;K. Yoshizawa
中科院分区：
文献类型：
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作者：
Yuki Nakashima;K. Heki;A. Takeo;M. N. Cahyadi;A. Aditiya;K. Yoshizawa
火山爆发产生的声波在近场常被观测为次声波。它们中的一部分向上传播并扰动电离层，可以用全球导航卫星系统（GNSS）接收器的总电子含量（TEC）数据进行观测。在这里，我们报告了2014年2月13日印度尼西亚东爪哇克卢德火山普林尼式喷发后，通过区域GNSS网络观察到的TEC变化。利用6颗GNSS卫星探测到TEC的显著扰动，小波分析表明谐波振荡开始于2016：25 UT，持续时间为202.5 h。TEC时间序列的振幅谱在3.7mHz、4.8mHz和6.8mHz处显示出峰值。普林尼火山喷发激发出了低层大气中波长范围很宽的长波驻波。然而，地震仪记录的地面运动的振幅谱，在离散波周期的频率分量。只有在这些离散的波周期和水平波长对上才满足大气和固体地球之间的共振振荡条件，因此，从大气驻波到固体地球瑞利波的有效能量传递发生在离散的周期上，并导致简谐地震动。
Acoustic waves from volcanic eruptions are often observed as infrasound in near fields. Part of them propagate upward and disturb the ionosphere, and can be observed with Total Electron Content (TEC) data from Global Navigation Satellite System (GNSS) receivers. Here we report TEC variations after the 13 February 2014 Plinian eruption of the Kelud volcano, East Java, Indonesia, observed with regional GNSS networks. Significant disturbances in TEC were detected with six GNSS satellites, and wavelet analysis showed that harmonic oscillations started at ∼16:25 UT and continued for ∼2.5 h. The amplitude spectrum of the TEC time series showed peaks at 3.7 mHz, 4.8 mHz and 6.8 mHz. Long-wavelength standing waves with a wide range of wavelength trapped in the lower atmosphere are excited by the Plinian eruption. Amplitude spectra of the ground motion recorded by seismometers, however, had frequency components at discrete wave-periods. The condition for the resonant oscillations between the atmosphere and the solid Earth is satisfied only at these discrete wave-period and horizontal wavelength pairs, therefore efficient energy transfer from the atmospheric standing waves to the solid Earth Rayleigh waves occurred at discrete periods and resulted in the harmonic ground motion.