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在1996年12月和1997年1月,3个宽频带地震台被布设在埃里伯斯火山最高处的平顶上,它们距离火山口中心分别为0.7,1.4和1.9km,火山口内是熔岩湖。在埃里伯斯火山的斯特隆博利爆发以前检测到有显著能量的地震和声能,其频带为1～6Hz。新的观测数据表明有明显的附加信号,其频谱的峰值靠近7.7,11.4和20.4s。爆发前约1.5s开始出现几乎完全相似的具有膨胀初动的甚长周期信号,并持续了150s。所有3个台站都记录到了甚长周期波形,表明地震图基本是受震源控制的。质点运动分析表明,甚长周期源的初始矩心大约在几百米深,在约15s内迁移到更深的位置。与爆发事件伴随的甚长周期信号可能出现一种重复的非破坏性谐振,表明在岩脉开放型火山近顶峰处的岩浆系内存在非线性液流激发机制。
In December 1996 and January 1997, three wideband seismic stations were laid flat on top of the highest point of the Erepith volcano, 0.7, 1.4 and 1.9 km from the center of the crater respectively, and lava lake. Seismic and acoustic energies of significant energy were detected before the Stroboli explosion in the Ereboros volcano at a frequency of 1 to 6 Hz. New observational data indicate significant additional signals with peaks in the spectrum near 7.7, 11.4 and 20.4 s. Approximately 1.5 s before the onset of an almost completely similar very long period signal with an initial onset of expansion continued for 150 s. Very long period waveforms were recorded at all three stations, indicating that the seismogram was basically under source control. The particle motion analysis shows that the initial centroid of the very long-period source migrates to a deeper position in about 15s with a depth of a few hundred meters. A very repetitive non-destructive resonance may occur with the very long-period signal accompanying the outbreak, indicating the presence of a nonlinear flow excitation mechanism within the magma near the dikes of the dikes.