Introduction
The RRSM portal allows users to query earthquake information, peak ground motion parameters, response spectral amplitudes and to select and download earthquake waveforms within minutes after an earthquake with magnitude ≥ 3.5 occurring in the European-Mediterranean region. Earthquake information is provided by the EMSC and all on-scale seismic waveform data available from ORFEUS EIDA is considered for fully automated processing. Realtime RRSM processing started in June 2014. Offline reprocessing was carried out for all M ≥ 4.5 events that occurred since January 2005, and all M ≥ 3.5 events since January 2012.
The RRSM is the first European system that delivers strong motion products close to realtime for earthquake scientists and earthquake engineers.
Key features of the RRSM:
- It uses all relevant, unrestricted waveform data from the European Integrated waveform Data Archive (EIDA), which is predominantly broadband but includes substantial sets of continuous strong motion data - EIDA consists of high quality waveform data and station metadata, based on international seismological standards.
- EIDA consists of high quality waveform data and station metadata, based on international seismological standards.
- It facilitates discovery and dissemination of peak ground motion parameters, earthquake information and related products, in near-realtime, and download of the raw, unprocessed event waveforms.
- It uses fully automated processing software ("scwfparam") which is open source and integrated in SeisComP3.
- It provides additional and independently derived data compared to those provided by traditional strong motion datasets.
- It processes all available (and relevant) on-scale waveforms in the vicinity of the earthquake, not only ‘strong-motion’ data recorded by accelerometers.
- It provides a simple and user-friendly web interface to query data, in addition to state-of-the-art webservices.
The RRSM target community
The RRSM is significantly different from traditional dissemination systems of strong motion earthquake data in Europe, which have been characterised for decades by (large) delays in availability of reviewed, processed data. The RRSM concept reflects the current status in seismic monitoring where data users require rapid access to raw waveform data and metadata and do not necessarily rely on delayed processed waveforms.
With this background, the RRSM is particularly targeted towards rapid data access for:
- Seismologists and strong-motion data analysts.
- Earthquake and geotechnical engineers.
- International earthquake response agencies.
- The educated general public.
Data gathering and processing
Raw waveform data and basic station information are available from the European Integrated waveform Data Archive (EIDA). The ORFEUS Data Center (ODC) is a primary EIDA node.
The RRSM database is populated via a strong motion processing module "scwfparam" which is integrated in SeisComP3 (SC3).
The RRSM "scwfparam" processing is triggered by an earthquake alert dissemination by the EMSC. These alerts are typically available 5-20 minutes after earthquake origin time.
Earthquake data is being processed if it meets the following criteria:
- Magnitude (any scale) ≥ 3.5
- Location is within the greater European region (27° ≤ lat ≤ 81°, -32° ≤ lon ≤ 51°)
Waveform data are collected from seismic stations within magnitude dependent maximum epicentral distance. The length of the requested time windows as well as the corner frequencies of the filter depend also on the magnitude:
| Magnitude | Stations within | Filter frequencies | Requested time window |
|---|---|---|---|
| ≥ 3.5 | 100 km | 0.3 Hz - 0.8 * Nyquist | 70 s |
| ≥ 4.0 | 125 km | 0.3 Hz - 0.8 * Nyquist | 85 s |
| ≥ 4.5 | 150 km | 0.3 Hz - 0.8 * Nyquist | 100 s |
| ≥ 5.0 | 175 km | 0.2 Hz - 0.8 * Nyquist | 115 s |
| ≥ 5.5 | 200 km | 0.2 Hz - 0.8 * Nyquist | 125 s |
| ≥ 6.0 | 225 km | 0.2 Hz - 0.8 * Nyquist | 140 s |
| ≥ 6.5 | 250 km | 0.1 Hz - 0.8 * Nyquist | 155 s |
| ≥ 7.0 | 300 km | 0.05 Hz - 0.8 * Nyquist | 175 s |
| ≥ 7.5 | 400 km | 0.05 Hz - 0.8 * Nyquist | 205 s |
Disclaimer: Spectral ordinates computed at frequencies lower than the low-cut should not be used. Please see Akkar and Bommer (2006) for more details.
Each earthquake is reprocessed after some time to ensure all available data in EIDA to be included. Current scheduling is:
- Immediately upon receiving alert
- 5 minutes after origin time
- 15 minutes after origin time
- 1 hour after origin time
- 3 hours after origin time
- 6 hours after origin time
- 1 day after origin time
- 2 days after origin time
The database is filled with data since January 1st, 2005.
Only the stations and streams that match the RRSM quality criteria are show in this interface. For instance, tables and charts only display data within certain limits:
- 0.001 cm/s2 ≤ PGA ≤ 980.6 cm/s2
- 0.0001 cm/s ≤ PGV (broadband) ≤ 1.3 cm/s
- 0.0001 cm/s ≤ PGV (others) ≤ 100 cm/s
The webinterface
The user interface allows users to access both raw waveform data and peak ground-motion values as well as response spectral ordinates of engineering interest.
The RRSM Interface supports following request types:
- Select Events: search earthquakes by time, magnitude and location; get stream and peak-motions fulfilling the criteria.
- Select Peak-Motions: search waveforms (earthquake-station combinations) by peak-motion criteria, station location, distance and magnitude; get stream and peak-motions fulfilling the criteria.
- Combined Selection: search earthquakes by peak motion criteria; get stream and peak-motions fulfilling the criteria.
After submitting the search criteria, the earthquakes/waveforms are shown in the Results page. From there, the user can navigate through the Event detail page and/or the Station detail page.
Peak ground-motion values are shown on all page levels. The interface provides plots of peak amplitude versus distance for a selected earthquake, and response spectra for selected stations. In addition, the user can select a set of events/stations/streams to download raw waveforms using standard FDSN EIDA webservices.
Notes
- Only the most recently processed strong motion data is shown for each event.
- Most of the features of this interface, as well as WedDC3 (for waveform download) requires JavaScript enabled.
- Users are encouraged to report issues here: https://github.com/EIDA/rrsm/issues
Disclaimer
The information provided by this portal has been automatically processed and it is intended only for research usage. The results are NOT reviewed by a seismologist. ORFEUS declines any responsibility from any improper use of the information therein represented.
All waveform data within the RRSM are subject to the EIDA disclaimer (http://orfeus-eu.org/data/eida/acknowledgements/).
Acknowledgments
The RRSM interface was designed and implemented by ORFEUS Data Center (ODC) and ETH Zurich, using funding from NERA and SERA. The waveform processing tool "scwfparam" within SeisComP3 was designed by ETH Zurich and implemented by Gempa GmBH. Funding for "scwfparam" development came from ETH Zurich, GNS New Zealand and Geoscience Australia. Details on "scwfparam" processing options can be found here.
SeisComP3 is an earthquake monitoring software developed by GFZ Potsdam and Gempa GmbH, largely used in Europe and worldwide.
The data user is kindly requested to provide proper reference to the data suppliers: http://orfeus-eu.org/eida/eida_acknowledgement.html
Where appropriate, citing the RRSM reference journal article is appreciated: https://pubs.geoscienceworld.org/ssa/srl/article/87/4/977/314137/Introducing-the-European-Rapid-Raw-Strong-Motion
Data format and usage
Mini-SEED data can be read in Matlab by means of a variety of scripts prepared by Matlab users and available on the Web. One example is the miniSeedToolbox, that uses the IRIS libmseed library to read and write Mini-SEED formatted files in Matlab. If Matlab and the miniSeedToolbox are properly installed on your computer, this sample script can be used as a starting point for reading and displaying Mini-SEED data files.
A powerful tool for Mini-SEED data visualisation and basic processing is PQLII, free software available from IRIS Passcal. Further, the reader is invited to evaluate the variety of free software resources provided by Passcal here.
Other free software tools that can deal with Mini-SEED are Geopsy and Obspy.
As to data conversion, the reader is referred to the exhaustive list of tools provided by ORFEUS and IRIS. This list includes software packages for conversion from Mini-SEED to ascii and SAC, the standard package for seismic data processing in many regions, in particular the US.
rdseed
In particular, rdseed can be used to convert SEED volumes into SAC compatible data.
As exhaustively documented in the rdseed manual, several options can be used when reading SEED volumes. In particular, the
-d read data from tape
option can be used to read the waveforms from full SEED data and subsequently convert into different formats:
-o specify output format (1=SAC, 2=AH, 3=CSS, 4=miniSEED, 5=SEED [default=1])
When Mini-SEED data are used, the user should specify that station configuration and responses be taken from another SEED volume, for example a data-less SEED volume. The environment variable ALT_RESPONSE_FILE should be defined with its value being the path name of the SEED volume (be it full or data-less SEED) from which responses should be taken. If Mini-SEED is being used, enter the Mini-SEED file name into the rdseed prompt as you would a normal seed volume, as following:
rdseed -d -f yourminiseedfile -o 1 -g yourdatalessfile
The following files can be used as 'fake' data-less for rapid conversion into sac:
- strong-motion.dless
- broadband.dless
- short-period.dless
The user should modify the station and network name using e.g. PDCC.
Note on start/end time of the requested waveforms
Users might be interested in processing waveform data with start and end time that exactly match the start / end time of the requested time windows. Time sichronisation tipically does not occur automatically because - as SEED format is block-oriented - it is possible to have incomplete blocks in the waveforms retrieved from ArcLink.
One possibility is to sychronise the waveforms later in SAC, using the SYNCHRONIZE command.
Another possibility is to fill in the incomplete blocks with padding, so that the data starts and ends as close as possible to the specified time. qmerge for example has an option -T: Exact trim -- trim data to closest specified time. Default is to trim to nearest inclusive block boundary.
Links
Other websites related to the RRSM Interface.
European Station Book interface: http://orfeus-eu.org/stationbook/
Engineering Strong Motion (ESM) interface: https://esm-db.eu
NERA project: http://nera-eu.org/
SERA project: http://sera-eu.org/
EIDA data access: http://orfeus-eu.org/data/eida/
SeisComP3 scwfparam module: https://docs.gempa.de/seiscomp3/current/apps/scwfparam.html
SeismicPortal: http://seismicportal.eu/
Disclaimer The peak-motion and spectral values provided through the RRSM Interface result from fast high-quality automatic processing of velocity and acceleration waveforms, without any human interaction. Please help us clearing severe mistakes if any, by sending your feedback at rrsm@knmi.nl
RRSM Interface ©2018 ODC/ETH