Kvantifiering av strukturell och käll heterogenitet i vulkaner med användning av utspridda seismiska vågor
Tidsperiod: 2018-07-01 till 2021-06-30
Projektledare: Ka Lok Li
Bidragstyp: Bidrag för anställning eller stipendier
Budget: 3 150 000 SEK
Volcanic eruptions are dangerous natural phenomena, and if “unexpected”, can cause huge economic loss and loss of human life. Eruptions can be “unexpected” if they exhibit ambiguous precursory signals because of a lack of understanding of the physical mechanisms at work at a given volcano. Such a lack of understanding inhibits our ability to forecast eruptions. Hence, the purpose of this work is to better understand precursory seismic signals on volcanoes, in terms of their underlying physical mechanisms. This will be achieved by improving imaging of both volcano sources and volcano structures using data from recent deployments of dense seismic networks. To obtain better images of the heterogeneous volcanic structures, I will develop a new “coda wave envelope” inversion method, which exploits the scattered seismic waves generated by highly variable volcanic rock. For better “imaging” volcano sources, I will draw on Time Reversal Imagery (TRI) techniques used in medicine and recently adopted in earthquake seismology, where real data are used as inputs to numerical simulations and “back propagated” to their “point” of origin. These methods will be developed and tested using 3D full wavefield numerical simulations in realistic volcano models in which the host institution abroad has expertise. I expect better combined structural and source imagery to impact hazard estimation on volcanoes through a better physics-based understanding of source processes.