obspy.io.nied.fnetmt - F-net’s moment tensors TEXT format support for ObsPy

This module provides read support for the moment tensor files (TEXT format) provided for the F-net broadband seismograph network operated by the National Research Institute for Earth Science and Disaster Prevention in Japan (NIED; http://www.fnet.bosai.go.jp/).

copyright:The ObsPy Development Team (devs@obspy.org)
license:GNU Lesser General Public License, Version 3 (https://www.gnu.org/copyleft/lesser.html)

Example

It works by utilizing ObsPy’s read_events() function.

>>> import obspy
>>> cat = obspy.read_events("/path/to/FNETMTCATALOG")
>>> print(cat)
1 Event(s) in Catalog:
2011-03-11T05:46:18.120000Z | +38.103, +142.861 | 8.7 Mw

The event will contain a couple of origins and magnitudes.

>>> print(cat[0])  
Event:  2011-03-11T05:46:18.120000Z | +38.103, +142.861 | 8.7 Mw

                   resource_id: ResourceIdentifier(id="smi:local/fnetmt/2011excpds/event")
                    event_type: 'earthquake'
           preferred_origin_id: ResourceIdentifier(id="smi:local/fnetmt/2011excpds/origin#MT")
        preferred_magnitude_id: ResourceIdentifier(id="smi:local/fnetmt/2011excpds/magnitude#MT")
  preferred_focal_mechanism_id: ResourceIdentifier(id="smi:local/fnetmt/2011excpds/focal_mechanism")
                          ---------
              focal_mechanisms: 1 Elements
                       origins: 2 Elements
                    magnitudes: 2 Elements

obspy.io.nied.knet - K-NET and KiK-net ASCII format support for ObsPy

This module provides read support for the ASCII format for waveforms from the K-NET and KiK-net strong-motion seismograph networks operated by the National Research Institute for Earth Science and Disaster Prevention in Japan (NIED; http://www.kyoshin.bosai.go.jp/).

KiK-net stations consist of one borehole and one surface sensor which are distinguished by their channel names:

Channel name Sensor type Sensor orientation
NS1 Borehole N
EW1 Borehole E
UD1 Borehole Z
NS2 Surface N
EW2 Surface E
UD2 Surface Z

K-NET stations only have one surface sensor with the following channel naming conventions:

Channel name Sensor orientation
NS N
EW E
UD Z
copyright:The ObsPy Development Team (devs@obspy.org)
license:GNU Lesser General Public License, Version 3 (https://www.gnu.org/copyleft/lesser.html)

Example

Reading K-NET/KiK-net files is handled by using ObsPy’s standard read() function. The format is detected automatically.

>>> from obspy import read
>>> st = read('/path/to/test.knet')
>>> print(st) 
1 Trace(s) in Stream:
BO.AKT013..EW | 1996-08-10T... - 1996-08-10T... | 100.0 Hz, 5900 samples

Note that K-NET/KiK-net station names are 6 characters long. This will cause problems if you want to write MiniSEED as it only allows 5 character station names. In this case you can opt to write the last 2 characters of the station name into the location field. This is possible because the location is encoded in the channel name (see table above).

>>> st = read('/path/to/test.knet',convert_stnm=True)
>>> print(st) 
1 Trace(s) in Stream:
BO.AKT0.13.EW | 1996-08-10T18:12... - 1996-08-10T... | 100.0 Hz, 5900 samples

Additional header entries from the K-NET/KiK-net file are written to a dictionary called ‘knet’:

>>> print(st[0].stats) 
         network: BO
         station: AKT0
        location: 13
         channel: EW
       starttime: 1996-08-10T18:12:24.000000Z
         endtime: 1996-08-10T18:13:22.990000Z
   sampling_rate: 100.0
           delta: 0.01
            npts: 5900
           calib: 2.3841857...e-06
         _format: KNET
            knet: AttribDict(...)
>>> print(st[0].stats.knet.stlo)
140.3213
>>> print(st[0].stats.knet.comment)
A dummy comment
The meaning of the entries in the ‘knet’ dictionary is as follows:
Name Description
evot Event origin time (UTC)
evla Event latitude
evlo Event longitude
evdp Event depth
mag Event magnitude
stla Station latitude
stlo Station longitude
stel Station elevation
accmax Maximum acceleration (after baseline removal)
duration Recording duration time [s]
comment Comment
last correction Time of last correction (Japanese standard time)

Modules

fnetmt obspy.io.nied.fnet - F-net moment tensor file read support for ObsPy
knet obspy.io.nied.knet - K-NET/KiK-net read support for ObsPy