Seismological Investigation of Atmospheric Oscillations Excited by Volcanic Eruptions

本研究旨在探讨1991年6月15日菲律宾皮纳图博火山大喷发后，世界各地地震台站记录到的一个周期约为230秒的新的异常长（至少2小时）地震波序列的含义。初步分析表明，这是由火山附近的大气振荡激发的瑞利波，这种振荡是由火山持续的热能通量引起的。如果这个结论是正确的，我们可以预期在新的nsf支持的全球地震台网（GSN）上观测到的其他火山爆发也会出现类似的振荡。声耦合瑞利波可用于主要火山爆发的探测、表征和定量，也可用于研究地球大气的特性。对来源的定量描述是可取的，因为它将使我们能够估计注入大气的物质的数量，从而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，而大型火山喷发发出的地震信号有可能产生关于羽流大小的快速估计。

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.