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 ≥ 2.0 occurring in the Groningen area of the Netherlands. Earthquake information, waveform data and automatically processed strong motion data are provided by the KNMI. Real-time RRSM processing started in September 2015, while past events have been processed separately in order to provide a complete database back to 2013.
The Nederland RRSM is based in the European RRSM, developed by ODC and ETH within the NERA and EPOS projects.
Key features of the RRSM:
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:
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. The KNMI declines any responsibility from any improper use of the information therein represented.
All waveform data within the RRSM are subject to this disclaimer.
Although the RRSM stands for a high-quality automatic processing of strong motion parameters, the reliability of this data strongly depends on the magnitude of the earthquake. The bigger the earthquake, the better the reliability of the parameters. In addition, the special nature of the seismicity in Groningen (induced and shallow earthquakes), makes the Nederland RRSM a product still in research and development.
Raw waveform data and basic station information are available from the KNMI network.
The RRSM database is populated via a strong motion processing module "scwfparam" which is integrated in SeisComP (SC).
The RRSM "scwfparam" processing is triggered after an earthquake is published by the KNMI.
Earthquake data is being processed if it meets the following criteria:
Note: After the data gathering and filtering are done, only the stations that exceed certain STA/LTA threshold are further processed. This can result in situations where events which its magnitude is bigger or equal than 2.0 does not appear in this interface, because any station has been finally processed.
Waveform data are collected from accelerometer stations of the Groningen's network within 150km maximum epicentral distance. The length of the requested time windows is 60 seconds. The corner frequencies of the filter depend on the magnitude:
| Magnitude | Filter frequencies |
|---|---|
| ≥ 2 | 0.5 Hz – 80% Nyquist |
| ≥ 3 | 0.3 Hz – 80% Nyquist |
| ≥ 5 | 0.1 Hz – 80% Nyquist |
| ≥ 7 | 0.05 Hz – 80% Nyquist |
In addition, a post-deconvolution filter (0.05 Hz – 40Hz, order 4) is applied in the frequency domain to get rid of noise blown up by the process as well as possible distortions in the original signal.
Each earthquake is reprocessed after some time to ensure all available data to be included. Current scheduling is:
The database is filled with data since 2013.
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 different request types:
After submitting the search criteria, the list (and map) of earthquakes / waveforms are shown. 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 wavefoms from KNMI FDSN web services.
Note: Only the most recently processed strong motion data is shown for each event.
The adaptation of the European RRSM interface for Netherlands has been carried by the KNMI. The European RRSM interface has been designed and implemented by Orfeus Data Center (ODC) and ETH Zurich, using funding from NERA and EPOS. The waveform processing tool "scwfparam" within SeisComP 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.
SeisComP 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: data ownership acknowledgement
Other websites related to the Nederland RRSM Interface.
KNMI: https://www.knmi.nl/
KNMI Seismic & Acoustic Data Tools: http://rdsa.knmi.nl/
ORFEUS: https://orfeus-eu.org/
EPOS (European Plate Observing System): https://www.epos-eu.org/
European Rapid Raw Strong Motion (RRSM) interface: https://www.orfeus-eu.org/rrsm
SeisComP scwfparam module: https://www.seiscomp.de/doc/apps/scwfparam.html
