Warning to read seismic data

Users Mailing List Archive
1

Hi everyone

I try to read de seismic data and the obspy issued this:

UserWarning: Record contains a fractional seconds (.0001 secs) of 16910 - the maximum strictly allowed value is 9999. It will be interpreted as one or more additional seconds.
category=UserWarning)

I would like to understand what does it mean that.

I appreciate your cooperation and assistance

Thanks

2

Presumably it means that the value 16910 will be interpreted as 1.6910 seconds

3

Hi Edwar, inside the fixed section of the mSEED header there is two bytes that specify the fraction of a second (0.0001) of the record starttime. In the mSEED manual it is defined that this value can be between 0 - 9999, so between 0 and 1 second respectively. However, in this file the value is almost 17000 and will be interpreted as 1.7 seconds by ObsPy and used in the record starttime.

https://github.com/obspy/obspy/pull/1531

Best,
Mathijs

4

Hi all,

actually, very likely your files are totally valid MiniSEED files and
you're seeing this warning due to a very minor bug in ObsPy. Reading the
data is not at all affected by this bug though, only this warning is
shown when it shouldn't be, really.

Long story:
During reading MiniSEED at some point the endian has to be
determined/guessed and when the wrong endian is trialed first, this
warning is shown on trying to read the file with the wrong endian. The
file afterwards gets read with correct endian, though.

This is a known issue on current stable ObsPy version and will be fixed
in the next bug fix release, see:
https://github.com/obspy/obspy/pull/1988

If you want to be certain whether you see this warning because of this
minor bug or if there actually is some minor issue with the data file,
you could try the code branch form this PR to check.

cheers,
T