Insane amount of data openly available. But:

• heterogeneous distribution
• various instrument types
• mixed quality
• with lots of errors

Outline

• Seismograph networks and datacenters
• FDSN naming conventions
• Waveform data, meta-data and file formats
• Downloading seismological data
• Software tools & Pyrocko
• Data management with Pyrocko Squirrel (Hack-along)
• Looking at waveforms with Pyrocko Snuffler (Tutorial)

Seismograph networks and datacenters

Global seismograph networks

GSN - Global Seismographic Network (IRIS/USGS)
152 Stations (2023) - Network codes: II, IU, CU, IC

Global seismograph networks

GEOSCOPE - French global network of broad band seismic stations. (IPGP) - 33 Stations (2023) - Network code: G

Global seismograph networks

GEOFON - GEOFOrschungsNetz
122 Stations (2023) - Network code: GE

Coordination

International Federation of Digital Seismograph Networks

• Assigns network codes.
• Standardises exchange formats.
• Provides network and datacenter citation information

Data centers / pools

IRISDMC

ds.iris.edu/ds

• Seattle, USA
• Continuous recordings from thousands of stations worldwide.

Data centers / pools

ORFEUS EIDA

www.orfeus-eu.org/data/eida

• Distributed federation of European seismic datacenters
• Continuous recordings from thousands of stations in Europe.
• GEOFON (GFZ) is operating one of 12 EIDA nodes.

Data centers / pools

Regional datacenters

www.fdsn.org/datacenters

• But the list is incomplete...
• And growing!

Seismic stations

Available through FDSN from AUSPASS, BGR, ETHZ, GEOFON, GEONET, ICGC, INGV, IPGP, IRIS, KNMI, KOERI, LMU, NCEDC, NIEP, NOA, NORSAR, NRCAN, ORFEUS, RESIF, SCEDC and USP.

1950

Seismic stations

Available through FDSN from AUSPASS, BGR, ETHZ, GEOFON, GEONET, ICGC, INGV, IPGP, IRIS, KNMI, KOERI, LMU, NCEDC, NIEP, NOA, NORSAR, NRCAN, ORFEUS, RESIF, SCEDC and USP.

2023: 10004 stations

FDSN naming conventions

FDSN naming conventions

"NSLC" codes are used to identify waveform channels, example:

IU.SDV.10.BHZ

Band code

From SEED reference manual, Appendix A

Instrument and component code

From SEED reference manual, Appendix A

Waveform data, meta-data and file formats

Data model and file formats

Data model and file formats

Data model and file formats

Data model and file formats

Data model and file formats

Mini-SEED

• Binary format
• File is a sequence of equal length records
• Record length typically 1024 or 4096 bytes, others possible
• Records are self-contained (include their own header)
• Streamable
• File may contain data from multiple channels/stations
• Supported data types: int32, int64, float32, float64
• Supports compression for int32

Downloading seismological data

Acquisition protocols

FDSN web services

Implemented by most datacenters nowadays.

Practical: FDSN web services

1. Go to https://service.iris.edu/fdsnws/station/1
2. Investigate station GE.BOAB
   
   • https://service.iris.edu/fdsnws/station/1/query?network=GE&station=BOAB
3. Experiment with the level parameter.
   
   • .../query?network=GE&station=BOAB&level=network
   • .../query?network=GE&station=BOAB&level=station
   • .../query?network=GE&station=BOAB&level=channel
   • .../query?network=GE&station=BOAB&level=response
4. When was it installed?
   1999-11-11
5. How many station epochs are defined for its BHZ channel?
   three: 1999-11-11 ... 2003-12-31, 2004-01-01 ... 2008-01-14, and 2008-01-15 ... ongoing

Summary

• Data model standardized by FDSN
• Most common data formats: Mini-SEED and StationXML
• Downloadable through FDSN web services

→ How can we control this data mammoth?

Software tools & Pyrocko

An incomplete list of tools
to process / visualize seismograms

Pyrocko - software for seismology

pyrocko.org

Applications

• Snuffler: a waveform browser and workbench
• Cake: classical ray theory
• Fomosto: a Green's function management tool
• Squirrel: dataset acquisition and management
• Sparrow: 3D visualization of geospatial data

Library

• Waveform processing
• Waveform database functionality
• Data acquisition
• Event data handling
• Online catalog access
• Real-time data processing
• Synthetic seismogram synthesis

Pyrocko - project history

Data management with Pyrocko Squirrel

(Hack-along ceremony)

squirrel
squirrel template --help
squirrel template
squirrel template bgr-gr-lh.dataset
squirrel template bgr-gr-lh.dataset > bfo.dataset.yaml
gedit bfo.dataset.yaml  # add to query_args: "station: 'BFO'"
squirrel update --help
squirrel update --dataset bfo.dataset.yaml
squirrel nuts --help
squirrel nuts --dataset bfo.dataset.yaml
squirrel update --dataset bfo.dataset.yaml --responses
squirrel nuts --dataset bfo.dataset.yaml
squirrel nuts --dataset bfo.dataset.yaml --style summary 
squirrel nuts --dataset bfo.dataset.yaml --style yaml 
squirrel coverage --dataset bfo.dataset.yaml

squirrel stationxml --help
squirrel stationxml --dataset bfo.dataset.yaml
squirrel stationxml --dataset bfo.dataset.yaml --codes '*.BFO.*.LHZ'
squirrel stationxml --dataset bfo.dataset.yaml --codes '*.BFO.*.LHZ' --level station
squirrel stationxml --dataset bfo.dataset.yaml --codes '*.BFO.*.LHZ' > bfo.xml

squirrel response --help
squirrel response --dataset bfo.dataset.yaml
squirrel response --dataset bfo.dataset.yaml --codes '*.BFO.*.LHZ' --level=stages 
squirrel response --dataset bfo.dataset.yaml --codes '*.BFO.*.LHZ' --plot
squirrel response --dataset bfo.dataset.yaml --codes '*.BFO.*.LHZ' --plot --show-breakpoints 

squirrel update --dataset bfo.dataset.yaml --promises --tmin '2023-02-05' --tmax '2023-02-27'
squirrel summon --dataset bfo.dataset.yaml --tmin '2023-02-05' --tmax '2023-02-27'
squirrel nuts --dataset bfo.dataset.yaml
squirrel coverage --dataset bfo.dataset.yaml
squirrel coverage --dataset bfo.dataset.yaml --tmin 2023-02-01 --tmax 2023-03-01
squirrel snuffler --dataset bfo.dataset.yaml

squirrel check --dataset bfo.dataset.yaml
squirrel check --dataset bfo.dataset.yaml -v
squirrel check --dataset bfo.dataset.yaml -vv
                    

Looking at waveforms with Pyrocko Snuffler

(Tutorial)

Snuffler - a seismogram browser and workbench

Snuffler tutorial

Workout complete ✓

• Know how seismological data is structured.
• Can download seismograms and metadata.
• Can investigate seismic datasets.
• Can visualize seismograms.

Next step towards moment tensor inversion:
→ Green's functions and synthetic seismograms