Basaltic magma becomes more viscous, solid-like (elastic), and non-Newtonian (shear-thinning, non-zero yield stress) as its crystal content increases. However, the rheological effects on bubble bursting and airwave excitation are poorly understood. Here we conduct laboratory experiments to investigate these effects by injecting a bubble of volume V into a refractive index-matched suspension consisting of non-Brownian particles (volumetric fraction \(\phi\)) and a Newtonian liquid. We show that depending on \(\phi\) and V, airwaves with diverse waveforms are excited, covering a frequency band of \(f = {\mathcal {O}}(10-10^4)\) Hz. In a suspension of \(\phi \le 0.3\) or in a suspension of \(\phi = 0.4\) with a V smaller than critical, the bubble bursts after it forms a hemispherical cap at the surface and excites a high-frequency (HF) wave (\(f \sim 1-2 \times 10^4\) Hz) with an irregular waveform, which likely originates from film vibration. However, in a suspension of \(\phi = 0.4\) and with a V larger than critical, the bubble bursts as soon as it protrudes above the surface, and its aperture opens slowly, exciting Helmholtz resonance with \(f = {\mathcal {O}}(10^3)\) Hz. Superimposed on the waveform are an HF wave component excited upon bursting and a low-frequency (\(f = {\mathcal {O}}(10)\) Hz) air flow vented from the deflating bubble, which becomes dominant at a large V. We interpret this transition as a result of the bubble film of a solid-like \(\phi = 0.4\) suspension, being stretched faster than the critical strain rate such that it bursts by brittle failure. When the Helmholtz resonance is excited by a bursting bubble in a suspension whose surface level is further below the conduit rim, an air column (length L) resonance is triggered. For L larger than critical, the air column resonance continues longer than the Helmholtz resonance because the decay rate of the former becomes less than that of the latter. The experiments suggest that a bubble bursting at basaltic volcanoes commonly excites HF wave by film vibration. The Helmholtz resonance is likely to be excited under a limited condition, but if detected, it may be used to track the change of magma rheology or bubble V, where the V can be estimated from its frequency and decay rate.

随着其晶体含量的增加，玄武岩岩浆变得更加粘稠、固体状（弹性）和非牛顿（剪切稀化、非零屈服应力）。然而，对气泡破裂和电波激发的流变学影响知之甚少。在这里，我们进行实验室实验，通过将体积为V的气泡注入由非布朗粒子（体积分数\(\phi\)）和牛顿液体组成的折射率匹配悬浮液中来研究这些影响。我们表明，根据\(\phi\)和V，具有不同波形的电波被激发，覆盖\(f = {\mathcal {O}}(10-10^4)\) Hz 的频带。在\(\phi \le 0.3\)或在悬浮液中的\（\披= 0.4 \）与V比临界越小，泡沫破裂它形成在所述表面并且激励的高频（HF）波（半球形帽后\（F \ SIM 1- 2 \times 10^4\) Hz) 具有不规则波形，这可能源于薄膜振动。然而，在\(\phi = 0.4\)和V大于临界值的悬浮液中，气泡一旦突出到表面上方就会破裂，其孔径缓慢打开，激发与\(f = {\数学 {O}}(10^3)​​\) Hz。叠加在波形上的是突发时激发的 HF 波分量和低频 ( \(f = {\mathcal {O}}(10)\)Hz) 从放气气泡排出的气流，在大V 时变得占主导地位。我们将这种转变解释为固体状\(\phi = 0.4\)悬浮液的气泡膜，其拉伸速度比临界应变速率快，因此它因脆性破坏而破裂。当悬浮液中的爆裂气泡激发亥姆霍兹共振时，该悬浮液的表面水平进一步低于导管边缘，就会触发气柱（长度L）共振。对于L大于临界值，气柱共振比亥姆霍兹共振持续的时间更长，因为前者的衰减率变得小于后者的衰减率。实验表明，在玄武岩火山爆发的气泡通常通过薄膜振动激发高频波。亥姆霍兹共振很可能在有限条件下被激发，但如果被检测到，它可用于跟踪岩浆流变学或气泡V的变化，其中V可以从其频率和衰减率估计。