Locked History Actions


Request for Comments, QuakeML Basic Event Description, Version 1.0

RFC_BED_1.0 QuakeML 1.0 RFC Overview

Event, Origin

This is the Request for Comments page for the QuakeML elements Event and Origin. Please add comments which are related to these aspects of QuakeML at the bottom of the page. Please also give your name and the submission date.


Open Issue- Alternate Specification for ConfidenceEllipsoid

The current specification for ConfidenceEllipsoid makes sense if it is considered to be a three dimensional analog of the two dimensional error ellipse specification provided by minHorizontalUncertainty, maxHorizontalUncertainty, and azimuthMaxHorizontalUncertainty attributes of the OriginUncertainty element. That is, the two dimensional representation could be used for fixed depth origins and the three dimensional representation for free depth origins.

However, I was thinking about the confidence ellipsoid as an alternative to the two dimensional error ellipse that is used by the IMS1.0 format. What I recommend is to make ConfidenceEllipsoid simpler, more complete, and more suitable for both two and three dimensional use by having it contain the maximum, intermediate, and minimum ellipse/ellipsoid axes. Each axis would be represented exactly as they would for the principle axes of a moment tensor except that the azimuth, plunge, and length would be of type float rather than RealQuantity.

That is, ConfidenceEllipsoid would have the attributes:

semiMajorAxis          ErrAxis   1
semiIntermediateAxis   ErrAxis   0..1
semiMinorAxis          ErrAxis   1

and ErrAxis would be a new complex type with the attributes:

azimuth                float     1   (in degrees)
plunge                 float     1   (in degrees)
length                 float     1   (in km)

For two dimensional use, the semiIntermediateAxis would be omitted and, of course, the plunges would be zero. This is consistent with NEIC usage and the shape of the error ellipsoid can be seen at a glance without doing any computation.

Ray Buland, 2008-02-01 (transferred from old trac Wiki by FabianEuchner)

  • Forced location, depth, OriginTime ?

How can we report that the depth and/or location and/or OriginTime has been forced by the geophysicist in the location process? This is different than my previous remark as here the location is not reported but used in the location and residuals are computed.

  • Ground Truth events

Here is a reference paper on GT events that it may be interesting to add in the RFD. "Epicentre accuracy based on seismic network criteria" de Bondár, I., Myers, S. C., Engdahl, E. R., & Bergman, E. A. GJI 2004, Vol. 156 (3), pp. 483-496

  • Time Error ?

In GSE2.0 format, the time error is reported (beneath the origin time). It is different from the RMS. Where can it be reported in the QuakeML format ?

  • TimeCorrection ?

What is the "TimeCorrection" that appear in the definition of Arrival element ? Static time correction ?

G. Mazet-Roux; EMSC 17/03/2008

  • EventType enumeration

Add SNOW_AVALANCHE = snow or ice avalanche to the EventType enumeration - it seems that we have much more recordings of these events than e.g. of meteor impacts

Add INDUCED_EARTHQUAKE (?) - this somehow does not fit the concept of the other entries telling exactly what induced the earthquake, but it would allow to label a broad variety of phenomenons as what they really are.

Philipp Kästli; SED August 8, 2008