Seismological Investigation of Atmospheric Oscillations Excited by Volcanic Eruptions

这项研究是为了调查1991年6月15日菲律宾皮纳图博火山大喷发后世界各地地震台记录的一种新的、异常长的(至少两个小时)地震波列的含义，它的周期约为230秒。初步分析表明，这是由火山附近的大气振荡激发的瑞利波，而大气振荡是由火山持续的热能通量引发的。如果这一结论是正确的，人们可以预期在NSF支持的新的全球地震网络(GSN)上观察到的其他喷发也会出现类似的振荡。声学耦合瑞利波可用于探测、描述和量化主要火山喷发以及研究地球大气层的性质。对污染源的定量描述是可取的，因为这将使我们能够估计注入到大气中的物质的数量，而这又使我们能够估计对环境的总体影响。火山羽流对空中交通构成了特别的威胁，大型火山喷发发出的地震信号有可能迅速估计出羽流的大小。

This research is to investigate the implications of a new, unusually long (at least two hours) seismic wave train having periods of about 230 sec that was recorded at seismic stations throughout the world following the major eruption of Mount Pinatubo in the Philippines on June 15, 1991. Preliminary analysis indicates that this was a Rayleigh wave excited by atmospheric oscillations near the volcano that were set off by continuous thermal energy flux from the volcano. If this conclusion is correct, one can expect similar oscillations for other eruptions observed on the new NSF-supported Global Seismic Network (GSN). Acoustically coupled Rayleigh waves can be used for detection, characterization and quantification of major volcanic eruptions and for study of the properties of the Earth's atmosphere. A quantitative description of the source is desirable as it would allow us to estimate the amount of material injected in to the atmosphere which in turn permits us to estimate the general impact on the environment. Volcanic plumes pose a particular threat to air traffic and the seismic signal emitted by large volcanic eruptions has the potential to yield rapid estimates about the plume dimensions.