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calcMoMw: modified for calculating Mo and Mw using metric units. calcsourcespec: modified correction for attenutation using an exponential including Q(f).

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This commit is contained in:
Ludger Küperkoch 2015-12-11 15:53:35 +01:00
parent f29d285910
commit f6930618f2
1 changed files with 10 additions and 5 deletions
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15
pylot/core/analysis/magnitude.py
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@ -240,8 +240,8 @@ class M0Mw(Magnitude):
# call subfunction to estimate source spectrum
# and to derive w0 and fc
[w0, fc] = calcsourcespec(selwf, picks[key]['P']['mpp'], \
self.getinvdir(), az, inc, self.getQp(), \
self.getiplot())
self.getinvdir(), self.getvp(), delta, az, \
inc, self.getQp(), self.getiplot())
if w0 is not None:
# call subfunction to calculate Mo and Mw
@ -268,6 +268,7 @@ def calcMoMw(wfstream, w0, rho, vp, delta, inv):
'''
tr = wfstream[0]
delta = delta * 1000 # hypocentral distance in [m]
print("calcMoMw: Calculating seismic moment Mo and moment magnitude Mw for station %s ..." \
% tr.stats.station)
@ -278,7 +279,8 @@ def calcMoMw(wfstream, w0, rho, vp, delta, inv):
Mo = w0 * 4 * np.pi * rho * np.power(vp, 3) * delta / (rP * freesurf)
Mw = np.log10(Mo * 1e07) * 2 / 3 - 10.7 #after Hanks & Kanamori (1979), defined for [dyn*cm]!
#Mw = np.log10(Mo * 1e07) * 2 / 3 - 10.7 # after Hanks & Kanamori (1979), defined for [dyn*cm]!
Mw = np.log10(Mo) * 2 / 3 - 6.7 # for metric units
print("calcMoMw: Calculated seismic moment Mo = %e Nm => Mw = %3.1f " % (Mo, Mw))
@ -286,7 +288,7 @@ def calcMoMw(wfstream, w0, rho, vp, delta, inv):
def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, Qp, iplot):
def calcsourcespec(wfstream, onset, inventory, vp, delta, azimuth, incidence, Qp, iplot):
'''
Subfunction to calculate the source spectrum and to derive from that the plateau
(usually called omega0) and the corner frequency assuming Aki's omega-square
@ -302,6 +304,7 @@ def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, Qp, iplot):
Q = int(qu[0])
# A, i.e. power of frequency
A = float(qu[1])
delta = delta * 1000 # hypocentral distance in [m]
fc = None
w0 = None
@ -408,7 +411,9 @@ def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, Qp, iplot):
F = f[fi]
YY = Y[fi]
# correction for attenuation
YYcor = YY.real*Q**A
wa = 2 * np.pi * F #angular frequency
D = np.exp((wa * delta) / (2 * vp * Q*F**A))
YYcor = YY.real*D
# get plateau (DC value) and corner frequency
# initial guess of plateau
w0in = np.mean(YYcor[0:100])