BEGIN:VCALENDAR
VERSION:2.0
PRODID:Linklings LLC
BEGIN:VTIMEZONE
TZID:Europe/Stockholm
X-LIC-LOCATION:Europe/Stockholm
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700308T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701101T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20210916T132454Z
LOCATION:Louis Favre
DTSTART;TZID=Europe/Stockholm:20210709T140000
DTEND;TZID=Europe/Stockholm:20210709T143000
UID:submissions.pasc-conference.org_PASC21_sess134_msa375@linklings.com
SUMMARY:Finite-Frequency Sensitivity of Waves probing Global Deep Earth St
 ructure using Spectral-Element and Adjoint Methods
DESCRIPTION:Minisymposium\n\nFinite-Frequency Sensitivity of Waves probing
  Global Deep Earth Structure using Spectral-Element and Adjoint Methods\n\
 nKoroni\n\nUsing spectral-element and adjoint methods, this study investig
 ates the sensitivity of seismic waves to structural and boundary parameter
 s of the earth. Understanding wave propagation effects on many body wave s
 eismic phases travelling through the earth is important for improving 3-D 
 mantle models. This study focusses on analysing the finite-frequency conte
 nt of traveltimes of phases which in theory interact with global discontin
 uities and specifically the core-mantle boundary, which separates the soli
 d mantle from fluid outer core. Using adjoint methods, we obtain Frechet d
 erivatives of selected time windows and illustrate the computed adjoint se
 nsitivity of traveltimes to structural parameters, i.e. compressional and 
 shear wave-speed,and to the surface of the global boundaries. The main res
 ults show wave interference for measurements in narrow time windows reveal
 ing complicated wave propagation effects, which are not predicted by commo
 n infinite frequency theory. Additionally, we observe strong trade-off bet
 ween boundary and structural parameters at the core-mantle boundary. For t
 he seismic phases that are considered in this study, that in theory are mo
 stly sensitive to boundary structure, we see that structural parameters ha
 ve actually an important non-linear impact on travel-times. This tradeoff 
 necessitates incorporating finite-frrequency Frechet derivatives in invers
 ions for boundaries and structure. The main conclusion is that the finite-
 frequency nature of the waves  leads to complex kernels. These kernel
 s however are important for understanding seismic observables, such as tra
 veltimes, and should be considered in an iterative full-waveform inversion
  scheme using spectral-element modelling and adjoint methods for better re
 solution and simultaneous inversion of structural and boundary interface p
 arameters.\n\nDomain: CS and Math, Physics, Solid Earth Dynamics
END:VEVENT
END:VCALENDAR