Description of the Updated Earthquake Catalog for Stable Continental Regions

The database is organized as an ASCII table. The following is a description 
of the 36 fields of the database.

Field 1:
Date, consisting of 8 characters: year, month, day.
Example: An event that occurred on January 26th, 2002 is indicated as 
20020126

Field 2:
Field indicating whether an event was recorded instrumentally or derived 
from historical documents
hist = historical event
instr = instrumentally recorded event
hist/instr or instr/hist = event parameters determined from combination of 
instrumental recording and historical documentation

Field 3:
Lattitude (degrees north of equator)

Field 4:
Longitude (degrees east of Greenwich)

Field 5:
Origin time, consisting of max 8 characters: hour, min, sec.
Example: If an event occurred at 08:52:24, its origin time is indicated as 
85224

Field 6:
Continent (Stable Continental Region) in which event occurred. One of the 
following:

AF = Africa
AU = Australia
CH = China
EU = Eurasia (Europe and Russia)
IN = India
NA = North America
SA = South America

Field 7:
Depth in km

Field 8:
Moment Magnitude estimate

Field 9:
Uncertainty estimate for Moment Magnitude

Field 10:
Body wave Magnitude estimate (mb)

Field 11:
Surface wave Magnitude estimate (Ms)

Field 12:
Local Magnitude estimate (ML)

Field 13:
factor a of the Seismic Moment expression: Mo = a x 10**b Nm

Field 14:
factor b of the Seismic Moment expression: Mo = a x 10**b Nm

Field 15:
Quality estimate of seismic moment
A, B, C, D, or - (no quality estimate).

Field 16:
Calculated Seismic Moment in Nm. Calculated either from Moment Magnitude 
estimate, or taken from Fields 13 and 14 if assigned relatively good quality 
(Field 15)

Field 17:
Strike of nodal plane 1 (degrees)

Field 18:
Dip of nodal plane 1 (degrees)

Field 19:
Rake of nodal plane 1 (degrees)

Field 20:
Strike of nodal plane 2 (degrees)

Field 21:
Dip of nodal plane 2 (degrees)

Field 22:
Rake of nodal plane 2 (degrees)

Field 23:
Quality estimate of focal mechanism
A, B, C, D, or - (no quality estimate).

Field 24:
Dip direction P-axis

Field 25:
Dip P-axis

Field 26:
Dip direction T-axis

Field 27:
Dip T-axis

Field 28:
Dip direction B-axis

Field 29:
Dip B-axis

Field 30:
Stress regime according to Zoback [1992] classification

Field 31:
azimuth Shmax according to Zoback [1992] classification

Field 32:
I = independent event (mainshock)
D = dependent event (either fore- or aftershock)
P = possibly dependent event

Field 33:
date main event associated with this dependent event

Field 34:
type of event (tectonic or non-tectonic)
tect. = tectonic event
deep min. = event associated with deep mining
mining = event associated with mining
reservoir = event associated with water reservoir
oil field = event associated with activity oil field

Field 35:
Tectonic association:
r = rifts
pm = rifted continental margins (passive margins)
not = non rifted crust
pr = possible rifts
e = Europe, outside rifts but likely to be rifted crust (part of pr 
category)
ppm = possible rifted continental margins

Field 36:
* = event taken from Centennial catalog [Engdahl and Villasenor, 2002]
** = event time, location and depth taken from Centennial catalog [Engdahl 
and Villasenor, 2002]
*** = changes in location/ depth/ magnitude/ seismic moment/ focal mechanism 
taken from EPRI [1994] that were not yet included in Triep and Sykes [1996]
^ = focal mechanism taken from Bent [2002, pers. comm]
^^ = magnitude taken from Bakun and Hopper [2003]
~ = magnitude and seismic moment taken from Johnston [1996]

Fields 1, 3-5, 7, 10-14, 17-22 were taken directly from source catalogs, 
which were:
events historical through 1994: Triep and Sykes [1996], unless indicated 
otherwise in field 36
1994 -2000: ISC bulletin [2001], unless indicated otherwise in field 36
2001-2002: NEIC bulletin
1990-2002: Harvard CMT catalog (focal mechanisms, seismic moment)

Quality assigments (fields 15 and 23) were taken directly from (or for more 
recent events according to criteria given in) Triep and Sykes [1996]

Information for fields 2, 9, 24-29, 32, 33, and 34 was taken directly from 
the EPRI [1994] earthquake datasheets or determined in this study for the 
more recent events.
In field 9, uncertainty estimate was altered for historical events (now 
often estimated 1.0 M units), based on recent studies (see accompanying 
paper [Schulte and Mooney, 2004] for discussion)

Moment Magnitude (field 8) taken from source catalogs if available, or 
calculated from regressions EPRI [1994] and Johnston [1996].

For references see accompanying text.