2.4.1 Summary record

 

To save space no decimal points are used. Use the FORTRAN format for reading the summary record given below.

 

Item

Column Nos.

Format for Reading

Origin Time:

KDATE - year, month, day (e.g. 19981231)

1

8

i8

KHRMN - hour, minute (e.g. 2358)

9

12

i4

KSEC - (seconds)

13

16

F4.2

LAT (degrees)

17

18

i2

N or S

19

A1

LAT (minutes)

20

23

F4.2

LON (degrees)

24

26

i3

E or W

27

A1

LON (minutes)

28

31

F4.2

DEPTH (km) [If negative, reset to ᆔ]

32

36

F5.2

PREFERRED MAGNITUDE

37

38

F2.1

NO - Number of P, S, and S-P readings used in the solution

39

41

i3

GAP - Largest azimuthal separation in degrees between stations as seen from the epicenter (deg.)

42

44

i3

D1 - Distance to closest station used in solution (km)

45

47

F3.0

RMS (s)

48

51

F4.2

Azimuth of axis 1 of error ellipsoid (deg)

52

54

i3

Dip of axis 1 (deg)

55

56

i2

SE - length of ellipsoid semi-axis 1 (km)

57

60

F4.2

Azimuth of axis 2 of error ellipsoid (deg)

61

63

i3

Dip of axis 2 (deg)

64

65

i2

SE - length of ellipsoid semi-axis 2 (km)

66

69

F4.2

Average XMAG

70

71

F2.1

Average FMAG

72

73

F2.1

Processing state (not used by HYPOELLIPSE)

74

A1

 

 

* - More data available to be added
P - Preliminary, but location not finalized
F - Final location determine
G - National Earthquake Information Center (NEIC) solution
A - NEIC solution obtained from USGS/UAGI
N - Not of principal interest
I - Insufficient data to determine a hypocenter

SE - length of ellipsoid semi-axis 3 (km)

75

78

F4.2

Quality - either error-ellipsoid quality or HYPO quality depending upon QUALITY OPTION record. (See 2.2.3.4) [In reformatted NEIC data this column contains the depth quality indicator.]

79

A1

MAGTYP - F, X, A, or K to indicate which type of magnitude is entered in columns 37ᆺ. (See 2.2.3.3 and 2.2.17)

80

A1

NSWT - Number of S-phase arrivals used in solution.

81

82

i2

/ or \
The primary SUMMARY record is always first and has a "/" in column 83. If an archive file has more than one SUMMARY record, the second and any subsequent records will have a "\" in column 83.

83

A1

First 4 characters of INSTRUCTION record

84

87

A4

Month earthquake was run

88

89

i2

Year earthquake was run

90

91

i2

Event type

92

A1

E or blank

local or regional earthquake

S

artificial source such as seismic line or shot

T

teleseism

O

other non-earthquake (e.g. sonic boom or lightning)

R

regional (poor coverage; use solution from another organization)

C

calibration signal

N

nuclear explosion

A

volcano tectonic (VT)

G

glacial event

B

volcano long-period (LP)

Q

quarry or mine explosion

X

emergent, low frequency near volcano,

F

false trigger

V

volcano tremor burst or eruption

I

Augustine volcano shore-ice event

H

volcano VT-LP hybrid

+

continuation of previous event

For type T, R, or N, do not compute the hypocenter location, but instead compute the azimuth and apparent velocity across the network.

Once the event type has been placed on the SUMMARY record of an earthquake in archive format, it will be transferred to succeeding SUMMARY records generated by later runs of HYPOELLIPSE.

Fixed location indicator, from column 19 of INSTRUCTION record or imposed by SELECT DELAY option (2.2.3.6)

93

i1

Sequence number

94

98

A5

S-P time at closest station used in solution. Blank if either P or S is not used. Set to 9999 if S-P .GE. 100.

99

102

F4.2

ZUP - Computed with GLOBAL OPTION.

103

104

F2.0

ZDN - Computed with GLOBAL OPTION.

105

106

F2.0

Vp/Vs - Computed slope of Ts vs Tp. Only computed if TEST(49) is not equal 0.

107

110

F4.2

Number of readings weighted out due to Jeffrey's, truncation, or boxcar weighting.

111

112

i2

DEPTH (km) [Allowed to be negative]

113

117

F5.2

 

 

The ARCHIVE-PHASE FILE may be used as a HYPOELLIPSE input phase file. In that case, the starting location, depth, and origin time will be taken from the first SUMMARY record associated with the event unless overridden by a location, depth, or origin time on the INSTRUCTION record (section 2.2.6.3). The format specification for reading an ARCHIVE ARRIVAL TIME record is as follows:

 

Item

Col. Nos.

Format

Station code

1

4

A4

Any two alphanumeric symbols to describe P phases. (See 2.2.6.2)

5

6

A2

First motion direction of P arrival

7

A1

c, C, u, or U

Compression

d, D

Dilatation

+

Questionable compression

-

Questionable dilatation

n, N

Noisy

.or Blank

Not readable

z, Z

Nodal, and not clearly up or down

P-weight-code

8

F1.0

0 or blank

Full weight

1

Partial weight

2

Partial weight

3

Partial weight

4, 5, 6, 7, 8

No weight

9

Use S-P interval (see 2.2.9)

If the P phase is a secondary arrival refracted along the bottom of the Ith layer, type the value of I here. If event is in the (I + 1)th layer, a direct wave calculation will be made. Below that, the weight is reset to zero.

9

i1

Year, month, day, hour, minute (e.g. 9812312358)

10

19

i10

Seconds of P arrival

20

24

F5.2

Distance (km)*

25

28

F4.1

AZM - Azimuth from epicenter to station (degrees)*

29

31

F3.0

Seconds of S arrival

32

36

F5.2

S remark

37

39

A3

S-weight-code

40

F1.0

AIN - Angle of ray leaving hypocenter (degrees)*

41

43

F3.0

Maximum peak-to-peak amplitude. Values from .001 to 9,999 are entered as positive. Negative entries are multiplied by ᆞ,000 to allow for values of 10,000 to 9,990,000.

44

47

F4.0

Period of maximum amplitude (s). If left blank, the standard period as specified in the station list will be used

48

50

F3.2

P travel-time computed*

51

54

F4.2

P standard error*

55

57

F3.2

D, B, M, J, X, R, G, or * weight-code (See 2.3.7 for definition)*

58

A1

Instrument Period (S=short, L=long, B=broad)

59

A1

Instrument Gain (H=high, L=low)

60

A1

Siemens gain state: 0 = high; 1 = low (gain times 1/4)

61

i1

A1VCO gain range state.
0 = high; 1 = gain times 1/10; 2 = gain times 1/500

62

i1

Remark (Recorder location in column 63, e.g. F=Fairbanks)

63

64

A2

Corrected first-motion symbol

65

A1

Time correction (s)

66

70

F5.2

F-P time interval (s) for FMAG

71

75

F5.0

P:RES - Residual of P arrival (s)*

76

80

F5.2

S standard error*

81

83

F3.2

D, B, M, J, X, R, G, or "*" weight-code*

84

A1

S:RES - Residual of S arrival (s)*

85

89

F5.2

P delay*

90

92

F3.1

S delay*

93

95

F3.1

P elevation delay*

96

98

F3.1

System response code*

99

100

i2

XMAG*

101

102

F2.1

FMAG*

103

104

F2.1

Polarity source code**

105

A1

P-arrival source code**

106

A1

S-arrival source code**

107

A1

Amplitude source code**

108

A1

Coda-duration source code**

109

A1

Number of satellite hops (NHOP) in telemetry path, each producing a delay of 0.27 s. (If the P-arrival and S arrival sources are not the same, then NHOP is set according to the P-arrival source.) *

110

i1

 

 

* These items are added to the original ARRIVAL TIME record, but are not used in subsequent runs of HYPOELLIPSE

** See 4.2.2.2 for a listing of source codes.

 

Use of Polarity Source Code by HYPOELLIPSE:

STATION records have two fields for keeping track of station polarity (see 2.2.5), the Polarity-Reversal-Indicator in column 34 and the Tape-Polarity-Reversal-Indicator in column 48, and these two indicators do not always agree. The Polarity-Reversal-Indicator is used in correcting the observed first motion unless the polarity source code is S, in which case the Tape-Polarity-Reversal-Indicator is used.