Use freqwrt to turn the mineos frequency file into a binary file for other codes Use efnwrt to combine radial and spheroidal modes Mineos has some instabilities, most involving the performance of the Mode Counter. This routine counts the number of eigenvalues of the differential operator in the chosen frequency interval. Sometimes it gets confused.
Noted problems:
1) if the desired freq interval for spheroidal modes is too big, the mode counter will get lost, and the program will find exotic overtones instead of e.g. fundamentals. The most common problem occurs if the freq range is specified from 0 to f0, as mineos hunts for the core mode 1S1 near zero freq. Instead, specify 0.25 to f0 as the freq range. Also, f0 cannot go much past 40 mHz without more instability - pemasseig, etc is a composite of calculations from 0.25-40 mHz and 40-100mHz. Use efnwrt2 to make the composite.
2) Toroidal calculations go into semi-infinite loops as the 1T branch approaches the frequency cutoff f0, so that the modes are never done. The solution is to guess the l-cutoff for the fundamental branch, increase f0 and limit the calculation using lmax. For instance, to calc pemasteig, etc, to 100 mHz, I took f0=120 mHz, and lmax=1020, then discarded the excess modes with efnwrt3.
3) When running mineos on sph modes, all overtones, from 0.25 to 40 mHz, the code gets hung at l=20.
steps:
> run mineos for radial modes --> radeig
> run mineos for spheroidal modes --> spheig
> run mineos for toroidal modes, but use lmax as mode limit, let fmax be larger --> toreig
> strip model off mineos ascii freq file output - no header line
> write "torf,radf,sphf" binary files with freqwrt (input # of radial knots, rad/tor:2; sph:6)
> use efnwrt3 to trim toroidal files
> use efnwrt to combine radial and spheroidal files
> use efnwrt2 to splice freq intervals if necessary
model files: (/data/g1/park/Mineos or /data/d8/park/Modes) *needs updating*
pema (165 knots) - model with an ocean
pemass (207 knots) - pema, spline interpolated in upper mantle & crust
premiss (218 knots) - isotropic prem, spline interpolated in upper mantle & crust
premi_gj (218 knots) - isotropic prem modified to be isotropic part of PA5 model of Gaherty and Jordan, spline interpolated in upper mantle & crust
a1066m (160 knots) - old dependable model without an ocean
a1066mss (215 knots) - a1066m, spline interpolated in upper mantle & crust
a1066mssC (215 knots) - a1066m, spline interpolated in upper mantle & crust, with a continental crust (New Hampshire) grafted onto the top 35 km
free-oscillation files: (/data/g1/park/Mineos) *needs updating*
spheignl, spheigd - a1066m, all sph modes to 10 mHz, includes radial modes
toreignl, toreigd - a1066m, all tor modes to 10 mHz
pemasseig,pemassnl - pemass, first 5 sph branches to 100 mHz, no radial modes
pemasteig,pemastnl - pemass, first 5 tor branches to 100 mHz
a66ss20t_eig,a66ss20tnl - a1066mss, all tor modes to 20 mHz
a66ss20s_eig,a66ss20snl - a1066mss, all sph modes to 20 mHz
a66ssC20t_eig,a66ssC20tnl - a1066mssC, all tor modes to 20 mHz
a66ssC20s_eig,a66ssC20snl - a1066mssC, all sph modes to 20 mHz
must use modes with the correct model: pemasseig needs pemass, not pema
c**** program minos ****
c This program uses one input and two output files
c The input file contains the model
c The output files are 1) a model listing + a summary of mode properties
c 2) a file for the eigenfunctions
c The program asks for some control info from the screen (see below)
c
c structure of model file
c card 1 : title (80 chars) (20a4 format)
c card 2 : ifanis,tref,ifdeck (unformatted)
c ifanis=1 for anisotropic model, 0 for isotropic
c tref=ref period(secs) of model for dispersion correction.
c if tref is .le. 0. no correction is made
c ifdeck=1 for card deck model, 0 for polynomial model
c *** card deck model ***
c n=no of levels,nic=index of solid side of icb,noc=index of
c fluid side of mcb.note that n must be .le. 223
c card 4-n: r,rho,vpv,vsv,qkappa,qshear,vph,vsh,eta (f8.0,3f9.2,2f9.1,2f9.2,f9
c if isotropic vp=vpv,vs=vsv and vph,vsh,eta are unspecified.
c if the q model is not specified then no disp. correction is made.
c s.i. units are used,e.g. radius in metres and velocities in m/s.
c *** polynomial model ***
c card 3 : nreg,nic,noc,rx (unformatted)
c nreg is the number of regions in the model,nic and noc as before
c and rx is the normalising radius for the polynomials.
c card 4 : nlay,r1,r2 (unformatted)
c nlay is the number of levels to be used in the region extending
c from radius r1 to r2 (in kms).
c 5 sets of coefficients are required for each region of an isotropic
c model and 8 sets for an anisotropic model.each polynomial can be
c up to a quartic in r/rx ( 5 coefficients) and are ordered thusly:
c rho,vpv,vsv,qkappa,qshear,vph,vsh,eta. the coeffs are given in the
c usual mixed seismological units (rho in g/cc,vel in km/s etc.)
c conversion to s.i. is done by the program.
c model
c
c The following models are available
c 1066a is in a1066m (g+d 1975)
c 1066b is in b1066m ( " )
c pema is in pemam (d+h+l 1975)
c prem (anisotropic) is in aniprm (d+a 1981)
c prem (isotropic) is in isoprm ( " )
c
c Control parameters (from screen)
c eps,wgrav
c eps controls the accuracy of the runge-kutta integration scheme.
c the relative accuracy of an eigen frequency will be 2-3 x eps.
c It also controls the precision with which a root is found and
c the minimum relative separation of two roots wit h the same angular
c order.It is safe to set eps=1.d-7.
c wgrav is the frequency in millihertz above which gravitational terms
c are neglected-this gives about a factor of 3 increase in speed.
c jcom
c jcom=1 radial modes, 2 toroidal modes, 3 spheroidal modes,
c 4 inner core toroidal modes.
c lmin,lmax,wmin,wmax,nbran
c lmin - lmax defines the range of angular orders to be computed.
c if jcom=1 this is ignored. wmin - wmax defines the frequency range
c to be computed (in millihertz)
c Nbran specifies the number of mode branches to be computed (0 will
c cause all branches to be computed otherwise the nbran lowest
c frequency branches will be computed)
c
c Model listing
c This is an ascii file which lists the model and mode properties
c i.e. frequency in rad/sec and millihz,period,group velocity in km/s,
c q and a parameter which is the ratio of kinetic to potential energy
c minus 1 .This should be small ( of order eps )if the eigenfunction is
c accurate and if there are enough radial knots in the model to allow
c quodratures to be done accurately. (You will probably see some degradation
c in this parameter for strongly exponential modes such as Stoneley modes )
.
c
c Eigenfunction file
c this is a fixed record length binary file with an entry for each mode
c written as
c write(ioeig) (abuf(i),i=1,nvec)
c where nvec is 5+6*npts for spheroidal modes and 5+2*npts for toroidal
c and radial modes. The first five words of abuf are n,l,frequency,q and
c group velocity. The rest of abuf contains w(1..npts) and wp(1..npts)
c for toroidal modes and u(1..npts),up(1..npts),v(1..npts),vp(1..npts),
c p(1..npts) and pp(1..npts) for spheroidal modes. These are as in
c Woodhouse and Dahlen 1978 except that w,wp,v and vp must be divided
c by sqrt(l*(l+1)). the normalisation is such that
c frequency**2 times integral(rho*w*w*r*r) is 1 for toroidal modes
c frequency**2 times integral(rho*(u*u+v*v)*r*r) is 1 for spheroidal modes
c The model has been normalised such that a density of 5515 mg/m**3 = 1 ;
c pi*G=1 where G is the grav constant (6.6723e-11) and the radius of the
c earth (rn=6371000 m) is 1. these normalizations result in
c acceleration normalisation = pi*G*rhobar*rn
c velocity normalisation = rn*sqrt(pi*G*rhobar)= vn
c
c program minosa - see notes to program minos
c io is identical except that this version reads a file with
c jcom while each following line consists of n,l,freq,weps where
c freq is a guess in millihz of the frequency of the mode and weps
c is a guess of the precision of the frequency estimate in microhz.
c The program loops through this file until an eof is encountered.
c TGM
back to seismology roadmap