Infrasonic harmonic tremor and degassing bursts from Halema'uma'u Crater, Kilauea Volcano, Hawaii
Infrasonic harmonic tremor and degassing bursts from Halema'uma'u Crater, Kilauea Volcano, Hawaii
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DOI：
10.1029/2010jb007642
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发表时间：
2010-11-30
影响因子：
3.9
通讯作者：
Swanson, Don
中科院分区：
文献类型：
--
作者：
Fee, David;Garces, Milton;Swanson, Don
基拉韦厄火山火山的Halema 'uma'u火山口的形成、演化、坍塌和随后的复活，产生了2008年至2009年初附近的次声阵列记录的充满活力和变化的脱气信号。经过25年的沉寂，2008年3月19日的一次放空爆破产生了清晰、复杂的声学信号。近连续谐波次声震颤之后，这一爆发，直到2008年12月4日，当一段时间的减少脱气发生。的震颤频谱表明，体积振荡和混响的一个浅的气体填充腔下面的通风口。主震颤峰值可以通过腔的亥姆霍兹振荡来维持，而次震颤峰值和泛音被解释为假设声共振。主要的震颤频率匹配的振荡频率的气体从通风口观察到的视频。震颤频谱和功率也与空洞的几何形状和动力学相关，2008年11月估计空洞深度约为219米，体积约为3 x 10（6）米（3）。观察到超过21种不同的脱气爆发，其具有延长的爆发持续时间和频率内容，与激发腔体共振的气体的瞬时释放一致。次声与地震活动的相关性表明，大气与地震激发过程之间存在一个开放系统。许多脱气爆发产生了非常长的周期（0.03 - 0.1赫兹）的次声，第一次记录在基拉韦厄，表明长时间的大气加速。基拉韦厄次声似乎是由岩浆中气体的出溶作用，以及这种气体与封闭它的管道和空腔的相互作用所控制的。
The formation, evolution, collapse, and subsequent resurrection of a vent within Halema'uma'u Crater, Kilauea Volcano, produced energetic and varied degassing signals recorded by a nearby infrasound array between 2008 and early 2009. After 25 years of quiescence, a vent-clearing explosive burst on 19 March 2008 produced a clear, complex acoustic signal. Near-continuous harmonic infrasonic tremor followed this burst until 4 December 2008, when a period of decreased degassing occurred. The tremor spectra suggest volume oscillation and reverberation of a shallow gas-filled cavity beneath the vent. The dominant tremor peak can be sustained through Helmholtz oscillations of the cavity, while the secondary tremor peak and overtones are interpreted assuming acoustic resonance. The dominant tremor frequency matches the oscillation frequency of the gas emanating from the vent observed by video. Tremor spectra and power are also correlated with cavity geometry and dynamics, with the cavity depth estimated at similar to 219 m and volume similar to 3 x 10(6) m(3) in November 2008. Over 21 varied degassing bursts were observed with extended burst durations and frequency content consistent with a transient release of gas exciting the cavity into resonance. Correlation of infrasound with seismicity suggests an open system connecting the atmosphere to the seismic excitation process at depth. Numerous degassing bursts produced very long period (0.03-0.1 Hz) infrasound, the first recorded at Kilauea, indicative of long-duration atmospheric accelerations. Kilauea infrasound appears controlled by the exsolution of gas from the magma, and the interaction of this gas with the conduits and cavities confining it.