teleseisms best practices

[Shiro, Brian]

Hi everyone,

I was wondering how you all handle teleseisms that get located by AQMS from time to time.  Do you keep them, delete them, or do something else?

In our case, when our network mis-locates a teleseism, we change the gtype to "T" and then save them to "I" state with a comment noting where in the world the event really was.  The notion is that we might go back and use the events to check our instrument responses and polarities.

The question was raised whether we should also manually edit the hypocentral parameters to match the actual earthquake parameters and either save it to "I" state 9to keep it from showing up in geographic searches in our region) or even to finalize it to "F" state to keep such incomplete events from the local catalog.

If we did finalize a teleseism with the authoritative event parameters entered and submit the solution over PDL, I presume it would be associated with the event's solution in Comcat as a contributed solution.  Would that be valuable to anyone as a means to see what stations in our network recorded the event and when (automated picks only)?  Would the ISC grab phase arrivals from such contributed non-authoritative solutions?

Or should we just delete them and get them off our radar completely?  I know that's basically what telestifle tries to do automatically.  There are other tools out there like Mustang that can more consistently use teleseisms to check for things like polarity issues at sites.

Thanks,
Brian

*********************************************

Brian Shiro
Seismic Network Manager
USGS Hawaiian Volcano Observatory

1-808-265-1415 (UTC-10 HST)

bsh...@usgs.gov

orcid 0000-0001-8756-288X

Mail: PO Box 1026, Hilo, HI 96721

Shipping: 29 Kuhio Street, Hilo, HI 96720

*********************************************

[Mitch Withers]

We have an archive of teleseisms from the period before we had the ability to archive all channels continuously at IRIS.  Now that we are archiving all channels,  we only spot check polarities and otherwise delete them.

--
You received this message because you are subscribed to the Google Groups "AQMS" group.
To unsubscribe from this group and stop receiving emails from it, send an email to anss-aqms+unsubscribe@googlegroups.com.
To post to this group, send email to anss...@googlegroups.com.
Visit this group at https://groups.google.com/group/anss-aqms.
For more options, visit https://groups.google.com/d/optout.

[Paul Friberg]

Brian,

Just for clarification: Telestifle does not delete events. It only supresses alarms for events that could match an incident teleseism at the network.

Cheers,

Paul

To unsubscribe from this group and stop receiving emails from it, send an email to anss-aqms+...@googlegroups.com.

To post to this group, send email to anss...@googlegroups.com.
Visit this group at https://groups.google.com/group/anss-aqms.
For more options, visit https://groups.google.com/d/optout.

--
You received this message because you are subscribed to the Google Groups "AQMS" group.

To unsubscribe from this group and stop receiving emails from it, send an email to anss-aqms+...@googlegroups.com.

To post to this group, send email to anss...@googlegroups.com.
Visit this group at https://groups.google.com/group/anss-aqms.
For more options, visit https://groups.google.com/d/optout.

--

===================================
Paul Friberg   p.fr...@isti.com
CEO/Seismologist
ISTI==Instrumental Software Technologies, Inc.
Phone 845.256.9290  FAX 845.256.9299   Mobile +1.914.489.4888

[Macbeth, Harold]

Brian,

In the past we would just delete Teleseisms, but there is a use for good impulsive teleseisms to do polarity checks on our network stations, in the past 4 years we began saving them for that purpose. 

We do not have another procedure to save or look at teleseisms.

And yes Paul is correct that telestifle only quiets the alarm response but take no action on the misslocated event itself. The Duty seismologist will either "cancel" through the DRP ( which will delete it off the web" or leave it to the Jiggle timers to deal with if it did not make it to the "recent event webpage" as a misslocated event. 

So here are the two ways we take care of teleseisms with the Jiggle staff...

- If we have a teleseism as a result of a network trigger then we just set the GTYPE to "T" which sets the ETPYE automatically to "earthquake" , the location has no LAT/LON or depth to begin with and the "bogus flag" is automatically set because it is a network trigger. So after that we just "finalize" with a remark stating the NEIC location/mag and if it a good candidate for polarity checks.

 

- If we have a teleseism that was misslocated with "binder" as a local event, then we manually set  by hitting the "clear" button. This clears the LAT/LON and Depth which sets the "bogus location flag". Again we set the GTYPE to "T" and finalize. We don't even bother to clear the binder picks as a time saver.

If that does not clear the event off of the recent events webpage... 

- Delete the event in Jiggle

- wait for the event to be deleted off the web.

- then "undelete" the same event in Jiggle and check to see that the GTYPE and ETYPE are "earthquake" and "T" respectively and that the LAT/LON are cleared. 

- re- finalize the same event. It will be set back to COMCAT but be off the  recent events webpage.  

--
You received this message because you are subscribed to the Google Groups "AQMS" group.
To unsubscribe from this group and stop receiving emails from it, send an email to anss-aqms+...@googlegroups.com.
To post to this group, send email to anss...@googlegroups.com.
Visit this group at https://groups.google.com/group/anss-aqms.
For more options, visit https://groups.google.com/d/optout.

--

______________________________________________________

Hal Macbeth 

U.S.Geological Survey

Earthquake Science Center

Earthquake Monitoring Project                      Office: 650-329-4705

Northern California Seismic Network              FAX: 650-329-4732

345 Middlefield Road MS-977                       Pager: 415-807-4585

Menlo Park, California 94025                email: mac...@usgs.gov

______________________________________________________

Earthquake & related info on the web:   http://quake.usgs.gov

[Shiro, Brian]

Hal,

Thanks again for sharing your insights and experience!

I think we'll just delete teleseisms going forward.  Meanwhile, I have a few thousand in the database to decide whether we keep them.

Brian