CMT_format_dek.pdf
(12/20/2011)
From:
http://www.ldeo.columbia.edu/~gcmt/projects/CMT/catalog/allorder.dek_explained
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This file contains a brief description of the format used in the ASCII
version of the Harvard (now Global) centroid-moment-tensor (CMT)
catalog. The original description of the CMT method can be found in:
Dziewonski, Chou, and Woodhouse, JGR, 86, 2825-2852, 1981.
Dziewonski and Woodhouse, JGR, 88, 3247-3271, 1983.
All of the moment-tensor solutions have been published in Physics of the
Earth and Planetary Interiors, and new solutions are published there as
quarterly or yearly reports. These reports also contain descriptions of
various enhancements to the original algorithm, including the incorporation
of laterally heterogeneous earth models and the use of broad-band data
for depth determination.
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B010177C 1/ 1/77 11:33:41.6 30.66 137.06 476.05.20.0SOUTH OF HONSHU, JAPAN
MLI BW: 5 14 45 MW: 0 0
0 DT=
4.3 0.7 30.62 0.07 136.80 0.10 476.5 4.8
DUR 1.8 EX 24 -0.32 0.05 0.80 0.08 -0.48 0.09 1.01 0.10 -0.36 0.08 0.40 0.07
1.41 29 354 -0.15 31 104 -1.26 45 230
1.34 33 32 -163 289 81 -59
C010277A 1/ 2/77 9:55:28.4 -10.17 118.99 19.05.86.3SUMBA ISLAND REGION
MLI BW: 5 12 45 MW: 5 15 135 DT=
8.8 0.3 -10.41 0.02 118.86 0.04 24.5 1.5
DUR 6.0 EX 25 2.48 0.09 -2.46 0.05 -0.02 0.07 1.81 0.20 0.06 0.16 -0.01 0.04
3.07 72 357 -0.02 1 89 -3.06 18 179
3.07 271 27
92 89 63
89
B010177C 1/ 1/77 11:33:41.6 30.66 137.06 476.05.20.0SOUTH OF HONSHU, JAPAN
1st line: event_id, date,origin time,latitude,longitude,depth, mb, MS, region
(all as reported by NEIS or ISC).
MLI BW: 5 14 45 MW: 0 0
0 DT=
4.3 0.7 30.62 0.07 136.80 0.10 476.5 4.8
2nd line: first three characters: MLI=epicenter info from NEIC Monthly listings;
PDE=from Preliminary listings; ISC=from ISC catalog.
Number of stations and total number of body-wave records used in the
inversion (5 and 14) and cut-off in seconds (45). Same for mantle
waves (0, 0 and 0). DT is the centroid time from the inversion
(4.3 seconds) measured from origin time; its standard error (0.7);
centroid latitude, longitude and depth, each with standard error.
DUR 1.8 EX 24 -0.32 0.05 0.80 0.08 -0.48 0.09 1.01 0.10 -0.36 0.08 0.40 0.07
3rd line: Assumed half duration (1.8 sec) [NOTE - this value is assumed and is
not a result of the inversion]; EX=exponent of all moment values that
follow (24 means all moments are 'value*10**24'); moment tensor
elements, each followed immediately by its standard error.
The coordinate system is r-up, s-South, e-East, and the 6 elements
are ordered Mrr, Mss, Mee, Mrs, Mre, Mse. See Aki and Richards for
conversion to other systems.
1.41 29 354 -0.15 31 104 -1.26 45 230
1.34 33 32 -163 289 81 -59
4th line: moment tensor expressed in its principal axis system;
eigenvalue (1.41), plunge (29) and strike (354) of eigenvector 1
-- repeated for 2 other axes. Scalar moment (1.34 -- to be multiplied
by 10**24). Strike (33), dip (32), and rake (-163) for best
double couple -- repeated for second nodal plane. Aki and Richards
convention for fault angles.
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Goran Ekstrom
ekstrom@ldeo.columbia.edu
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