GSE2 - Mismatching checksums

Users Mailing List Archive
1

Dear collegues!

I received a bunch of GSE2 files, each of them for one earthquake event, containing several traces.

I wrote an obspy script to convert each trace to mseed format (read gse2 into a stream and write each trace to mseed).

The following warning appears when reading the files:

"Checksum differs only in absolute value. If this file " + \

"was written with ObsPy GSE2, this is due to a bug in " + \

"the obspy.io.gse2.write routine (resolved with [3431]), " + \

“and thus this message can be safely ignored.”

But reading works fine in this case.

Some of the GSE2 files cannot be read by Obspy at all. I receive the following error (example):

ChksumError: Mismatching checksums, CHK -7224649 != CHK 231752008

Does anyone know more about this error and if there is a way to force Obspy to read those files into a a stream object?

Thank you and best regards

Franz Reiter

PhD student

University of Innsbruck

Institute for Geology

2

Dear Franz,

you can ignore the warning if your GSE2 files were written with a very
old ObsPy version. The files with checksum mismatches seem to be broken.
However the GSE2 checksum is known to have issues - some GSE exporting
programs wrote for years wrong checksum values. That is the reason ObsPy
also offers a very handy verify_chksum parameter for the read function,
see link below for more information.

https://docs.obspy.org/packages/obspy.io.gse2.html#module-obspy.io.gse2

Cheers,
Robert