[webservices] events without mags, depending on whether mag range is specified

Mon Apr 22 16:43:11 PDT 2013

Hi,

Prepare to be surprised.

Looking at the source of our PDE information there is no magnitude for the event you identified.  Here is a link to the PDE for February 2010:
ftp://hazards.cr.usgs.gov/pde/ehdf201002.dat

If you find the event line starting "GS 201002132325418733999N117186W" (aka 2013-02-13T23:25:41) you'll see that there is no magnitude information.

Furthermore, I found the event in the NEIC catalog search and it is listed as a M0.0:
http://comcat.cr.usgs.gov/earthquakes/eventpage/pde20100213232541870_8#summary

Spot checking a few of the other "mystery" events and the story is the same.

So there are events with no magnitudes.

Chad

On Apr 22, 2013, at 3:51 PM, Philip Crotwell <crotwell at seis.sc.edu> wrote:

> 
> Switching to xml output and adding includeallmagnitudes still shows no magnitudes. For example:
> http://service.iris.washington.edu/fdsnws/event/1/query?nodata=404&starttime=2010-01-14&endtime=2010-04-15&orderby=magnitude&limit=2500&maxlat=45.33&minlat=18.65&maxlon=-99.14&minlon=-129.72&includeallmagnitudes=true
> 
> Or directly
> http://service.iris.edu/fdsnws/event/1/query?eventid=2844489
> 
> Kind of surprising that a PDE-M event in 2010 would not have a magnitude.
> 
> Hopefully this is a database error, or bad data. It would be nice if clients did not need to be defense about the existence of magnitudes. But maybe you always have to be defensive. :(
> 
> Philip
>  
> 
> 
> On Mon, Apr 22, 2013 at 6:07 PM, Russ Welti <russ at iris.washington.edu> wrote:
> I am seeing a small, sometimes up to 2%, number of events served up with no mag values.
> 
> This in format=text, if that matters.
> 
> If I use minmag=0 and maxmag=9 and query
> service.iris.washington.edu/fdsnws/event/1/query?format=text&nodata=404&minmag=0&maxmag=9&starttime=2010-01-14&endtime=2010-04-15&orderby=magnitude&limit=2500&maxlat=45.33&minlat=18.65&maxlon=-99.14&minlon=-129.72
> 
> ...skipping to the last N lines of output:  all is good.
>> 2843778|2010-01-26T04:20:27|37.477|-121.79|7.8|NC|NEIC PDE|NEIC PDE-M||MD|2.0|NC|CENTRAL CALIFORNIA
>> 2843696|2010-01-24T07:30:35|37.86|-121.799|14.3|NC|NEIC PDE|NEIC PDE-M||MD|2.0|NC|CENTRAL CALIFORNIA
>> 2848695|2010-04-11T02:26:49|32.67|-115.887|8.4|PAS|NEIC PDE|NEIC PDE-M||ML|2.0|PAS|CALIF.-BAJA CALIF. BORDER REGION
>> 2843273|2010-01-15T12:36:10|37.57|-121.84|12.0|NC|NEIC PDE|NEIC PDE-M||MD|2.0|NC|CENTRAL CALIFORNIA
>> 2846259|2010-03-08T06:03:14|33.316|-116.376|7.3|PAS|NEIC PDE|NEIC PDE-M||ML|1.9|PAS|SOUTHERN CALIFORNIA
>> 2843226|2010-01-14T15:28:55|33.911|-118.471|10.4|PAS|NEIC PDE|NEIC PDE-M||ML|1.9|PAS|SOUTHERN CALIFORNIA
>> 2848014|2010-04-05T10:02:35|34.031|-117.516|11.4|PAS|NEIC PDE|NEIC PDE-M||ML|1.7|PAS|SOUTHERN CALIFORNIA
>> 2845037|2010-02-27T08:31:52|33.999|-117.181|9.0|PAS|NEIC PDE|NEIC PDE-M||ML|1.5|PAS|SOUTHERN CALIFORNIA
> 
> 
> But if I leave mag out entirely from that query
> 
> service.iris.washington.edu/fdsnws/event/1/query?format=text&nodata=404&starttime=2010-01-14&endtime=2010-04-15&orderby=magnitude&limit=2500&maxlat=45.33&minlat=18.65&maxlon=-99.14&minlon=-129.72
> 
> last few lines now include 5 "mystery" events:
>> 2843226|2010-01-14T15:28:55|33.911|-118.471|10.4|PAS|NEIC PDE|NEIC PDE-M||ML|1.9|PAS|SOUTHERN CALIFORNIA
>> 2848014|2010-04-05T10:02:35|34.031|-117.516|11.4|PAS|NEIC PDE|NEIC PDE-M||ML|1.7|PAS|SOUTHERN CALIFORNIA
>> 2845037|2010-02-27T08:31:52|33.999|-117.181|9.0|PAS|NEIC PDE|NEIC PDE-M||ML|1.5|PAS|SOUTHERN CALIFORNIA
>> 2844574|2010-02-16T09:21:28|34.007|-117.187|8.3|PAS|NEIC PDE|NEIC PDE-M|||||SOUTHERN CALIFORNIA
>> 2848951|2010-04-14T22:59:01|37.39|-121.78|0.0|NC|NEIC PDE|NEIC PDE-M|||||CENTRAL CALIFORNIA
>> 2844821|2010-02-23T05:57:26|38.83|-122.809|1.7|NC|NEIC PDE|NEIC PDE-M|||||NORTHERN CALIFORNIA
>> 2844760|2010-02-21T07:57:56|34.785|-118.927|11.8|PAS|NEIC PDE|NEIC PDE-M|||||SOUTHERN CALIFORNIA
>> 2844489|2010-02-13T23:25:41|33.999|-117.186|8.8|PAS|NEIC PDE|NEIC PDE-M|||||SOUTHERN CALIFORNIA
> 
> It affects me some, because when in certain tight loops, say drawing or sorting events, if I can assume they will have some valid magnitude I can keep that loop as fast as possible.
> 
> Currently I discard them at fetch time.
> 
> The workaround is of course to always specify a mag range even if it is 0-10, but I wonder if that is the intended side effect of specifying a range vs. not....
> 
> No mag range specified, 2 invalid events:
> <IRIS Earthquake Browser-18.jpg>
> 
> Specify a range 0-10 and the two bad ones are not served:
> <IRIS Earthquake Browser-19.jpg>
> 
> 
> 
> Thanks!
> Russ
> 
> 
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