The Seismic & Acoustic Data Portal provides easy access to raw waveform data and station metadata of the seismic network in The Netherlands. It offers also an user-friendly interface to view all the earthquakes published by KNMI.

Note: This portal is mainly intended for event-related waveform data. If you are interested in continuous waveform data, please take a look at the FDSN DataSelect Web Service.



Getting started

The portal allows you to create requests which combine the stations' locations with earthquake lists provided by KNMI or other agencies (see the Help page). In this case the event time and coordinates are used to compute approximated arrival times ("onset times") for the P or S wave of the selected earthquakes at the selected stations.

Citation information

The data user is kindly requested to provide proper reference to the data supplier. This can be done by citing the Royal Netherlands Meteorological Institute (KNMI) and including the DOI of the networks. Example citations look like:

Seismic network NL https://doi.org/10.21944/e970fd34-23b9-3411-b366-e4f72877d2c5

KNMI (1993): Netherlands Seismic and Acoustic Network. Royal Netherlands Meteorological Institute (KNMI).
Other/Seismic Network. 10.21944/e970fd34-23b9-3411-b366-e4f72877d2c5

Seismic network NA https://doi.org/10.21944/dffa7a3f-7e3a-3b33-a436-516a01b6af3f

KNMI (2006): Caribbean Netherlands Seismic Network. Royal Netherlands Meteorological Institute (KNMI).
Other/Seismic Network. 10.21944/dffa7a3f-7e3a-3b33-a436-516a01b6af3f


Terms of use

The data is provided as Open Data (Open and Anonymous), under the license Creative Commons Attribution 4.0 International (CC BY 4.0).

Data ownership acknowledgement

See Citation information section.

Quality of the data

The KNMI take the greatest care to ensure that the data and metadata are accurate and of the highest possible quality. Users of this data tool assume all responsibility and risk for use of the data. In no event shall KNMI be liable for any damages caused by, but not limited to, absence of data, or erroneous data.

Misuse of the data

Users of the data agree not to misuse or add to without permission, or misrepresent the data provided in any way. Data provided through this data tool is free of use and cannot be reused in unaltered form for commercial use. The user cannot claim ownership of the data. Please inform us of any misuse of data from this data.


The Seismic & Acoustic Data Portal is based on the WebDC3 software, which has been developed by the Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum (GFZ) for EIDA in 2013.

The customisation for Netherlands has been carried by the Royal Netherlands Meteorological Institute (KNMI) in 2015.

This service uses OpenStreetMap data, which is available under the Open Database License.

Data format and usage

The types of data you can request are:

Waveform data

We offer you the choice of downloading Full SEED and Mini-SEED volumes.

Information about Full SEED and Mini-SEED can be found in IRIS (here and here), as well as the well-known libmseed library.

Very useful free software tools that can deal with Mini-SEED are Obspy and Geopsy. Other useful tools to view what it is inside a Mini-SEED file or to select specific data are miniSEED Inspector and dataselect, respectively.

Mini-SEED data can also be read in Matlab by means of a variety of scripts prepared by Matlab users and available on the Web. Another 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.

As to data conversion, the reader is referred to the exhaustive list of tools provided by ORFEUS and IRIS, as well as the mentioned Obspy. 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. For instance, rdseed can be used to convert SEED volumes into SAC compatible data.

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 synchronization typically does not occur automatically because - as SEED format is block-oriented - it is possible to have incomplete blocks in the waveforms retrieved from ArcLink.

Station metadata

You can also download Dataless SEED and Inventory XML. These formats contain only the station and stream information. They contain information like coordinates, names, codes and instrument responses for certain stations or networks.

Dataless SEED files can be decoded by Obspy and rdseed programs. Inventory XML files can be imported by the SeisComP3 software. An inventory XML file is a plain text file that can be inspected by any text editor, but it is recommended that you use a real generic XML parser to extract the desired information from it. A handy tool that allows you to convert XML files to a more linear format is Dan Egnor's xml2.