Get theoretical absolute arrival times from an event location (local network)

Users Mailing List Archive
1

Hi,

I would like to get the theoretical absolute arrival times for all the stations of my local network given an event location.

The idea would be locate the event using HYPOINVERSE or NLLOC and to compute all abso. arrivals on all stations (not only on the ones that were picked) by either fixing the location or giving a null weigth to all stations that have no picks.

Then read the event_file output and store the abso. arrivals in a obspy 'Pick' class.

Has anyone ever done that before?

Thanks a lot, cheers,

Ch.

2

Can’t say i have set out to do that, but it sounds like a bit like choosing a hypocenter and running a raypath calc through tau P or the like…maybe find the potential hypocenter points that provide the earliest and latest potential arrivals to provide a likely interval?

Look at Tau P, especially the obspy operability, and aside from that, likely not too daunting to code if need be.

Just a thought…that is where i would start, at least. Heed my advice at your own peril.

Robert

3

Hi Christian,

you can do exactly this with NonLinLocs Time2EQ. It produces you an .obs file that you can handle with obspy.

Wasja

4

There's also the obspy.taup module
(http://docs.obspy.org/packages/obspy.taup.html)… it's usually used for
larger scale cases (regional to global), so not sure how well it works
down to smaller scales with local-scale models…

cheers,
T

5

Hi Chrisitan,

you can best do this directly in NonLinLoc using Time2EQ [1]:

1. Invert for the Hypocentre with one set of stations

2. perform the forward calculation for all required stations.

Dirk

[1] http://alomax.free.fr/nlloc/soft6.00/Time2EQ.html

6

Thanks for the reply, I’ll try it with Time2EQ then, seems pretty straightforward this way.

Cheers,

Christian