[webservices] event service questions

Philip Crotwell crotwell at seis.sc.edu
Wed May 23 12:48:01 PDT 2012


Hi

A couple of questions about the event web service.

1) What is the intended meaning of "includeallmagnitudes"? I appears
to me that it means include zero or one magnitude, but never includes
more than that. For example this query finds one origin and one
magnitude:

http://www.iris.edu/ws/event/query?minmag=5&starttime=2000-06-08T12%3A10%3A00&endtime=2000-06-08T13%3A00%3A00&includeallmagnitudes=yes&orderby=time

The same query except dropping the includeallmagnitudes gives one
origin with zero magnitudes.
http://www.iris.edu/ws/event/query?minmag=5&starttime=2000-06-08T12%3A10%3A00&endtime=2000-06-08T13%3A00%3A00&includeallmagnitudes=no&orderby=time

This is even true if you pick a particular magnitude type, like this.
It seems very weird to me to ask for events with a MW >= 5 and have
the returned xml not include any magnitude information at all.
Magnitude is just about as fundamental as location or time, and to
make it be an optional value seems strange.

http://www.iris.edu/ws/event/query?minmag=5&starttime=2011-06-06T12%3A10%3A00&endtime=2011-06-08T13%3A00%3A00&magtype=MW&preferredonly=yes&includeallmagnitudes=no&orderby=time

I looked with seismoquery near the 2000-06-08 event and if I am
reading the output correctly, there are several magnitudes for this
event in the ISC catalog. I also looked at a couple of other time
ranges to be sure, but it appears that you either get zero or one
magnitude depending on the value of includeallmagnitudes. I thought
that this option was to allow you to choose to either get just the one
"preferred" magnitude or to get all of them, but if you only ever get
one then this option seems pointless.

2) Similarly, the "preferredonly" option makes it sound like you can
get either just the preferred origin, or all of the origins for a
particular event, assuming that grouping information exists. Am I
misunderstanding the meaning of this? I have tried several time ranges
and have yet to see an event that had more than just the preferred
origin.

3) What is the effect of not choosing a catalog? I can think of two
meanings, either "all catalogs" or "only the preferred catalog". Both
of these seem valid choices, but it is not clear how to enact them.

4) Can I specify multiple catalogs? Putting two &catalog= items in the
URL gives back no events, so I guess not, or maybe it just takes the
last one.

thanks,
Philip


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