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  • This dataset contains the number of earthquakes, incident-parameters and trend-parameters from the earthquakes in the KNMI catalogue that took place on the Groningen gas field. The number of earthquakes are categorized by year and magnitude. The incident-parameters are the maximum PGA and PGV values of the last earthquake with magnitude >= 2.0 processed by KNMI's RRSM system. The trend-parameters (number of earthquakes and maximum earthquake density) are computed following the definition by SodM. Disclaimer: New earthquakes are assigned to the Groningen gas field by means of an automatic procedure, based on the location. It is possible that, after manual analysis, the quake is nevertheless attributed to another source of induced seismicity, as a result of which the list of earthquakes belonging to the Groningen gas field may change.

  • This dataset represents expected location uncertainty of seismic events, when using sensors from the Netherlands seismic network and sensors just across the boarder in Belgium and Germany. The computation has been done over a grid covering the Netherlands, with a fixed source depth of 3 km. For each scenario event, the location probability density function has been determined, both as function of depth and as function of the horizontal coordinates. The assumption has been made that these probability density functions can be approximated as being (multivariate) normal distributions, such that they can be described with standard deviations. The uncertainty in the horizontal plane is parameterized with σ1 (S1), σ2 (S2) and θ (T). S1 is the standard deviation in the direction with maximum uncertainty, which occurs at a certain angle (T) with north. S2 is the standard deviation in the perpendicular direction with minimum uncertainty. In the vertical direction, the probability density function is computed at the most likely epicenter. The corresponding uncertainty is parameterized with SZ. Additionally, the azimuthal gap (AG) has been computed and is included in the dataset. This parameter describes how well the azimuthal coverage of stations is for event location. Details are described in the following technical report: https://cdn.knmi.nl/knmi/pdf/bibliotheek/knmipubTR/TR405.pdf.

  • KNMI manages and provides access to a metadata inventory which contains information about KNMI seismic networks, stations and their instruments. Such information varies over time, for instance when new stations are deployed in a seismic network, when a new instrument is added to a station, or when orientations of sensors are estimated. The Inventory ChangeLog aims to inform stakeholders and users of the KNMI data about such changes.

  • This dataset contains the location (epicentre), origin time (UTC), magnitude, depth [km] and type of all the earthquakes in and around the Netherlands. The location of the epicentre has an uncertainty of approx. 1 kilometer (horizontal). The type of earthquake distinguishes between natural (tectonic) earthquakes and induced earthquakes. The seismic network of the KNMI consists of geophones in boreholes (up to 300 m depth), accelerometers, and "broadband" seismometers.

  • The main seismic-network assessment parameter is magnitude of completeness, which has been computed over a grid covering the Netherlands. This parameter describes the spatial variation of the minimum magnitude for which almost every earthquake can be located. The location of an earthquake can be determined if the earthquake signal is detected on at least three sensors. Detection has been modeled using expected signal-to-noise levels. Noise levels are the actually recorded noise levels at stations from the Netherlands seismic network, and stations just across the border in Belgium and Germany. The signal levels have been modeled for sources at 3 km depth, using a newly calibrated P-wave ground-motion prediction equation. Details are described in the following technical report: https://cdn.knmi.nl/knmi/pdf/bibliotheek/knmipubTR/TR405.pdf.

  • This dataset contains images of scanned analog seismograms for historical earthquakes. They belong to the old instrumentation of the following KNMI seismic stations in the Netherlands: De Bilt (DBN), Epen (ENN), Heerlen (HEE), Ravensbos (RSB), Witteveen (WIT) and Winterswijk (WTS). The different parts of the name of the images correspond to: station code, channel code, instrument code, time of the first minute of the seismogram, time of the end of the seismogram (approximate) and version number. The complete description of the stations, their instrumentation and the channel codes can be found in the following report: http://bibliotheek.knmi.nl/knmipubTR/TR245.pdf

  • Hazard maps published by the KNMI. The last version (v4) has been published on June 15, 2017. Previous versions were originally published in June 2016 (v2), October 2015 (v1) and December 2013 (v0). The hazard map shows surface peak ground acceleration (PGA, period T = 0.01 s) in the unit of [g] (9.82 m/s^2). The hazard map is calculated for the province of Groningen in the northern part of the Netherlands. The technical reports explain the specifications of the different versions of the hazard maps: http://www.knmi.nl/kennis-en-datacentrum/publicatie/probabilistic-seismic-hazard-analysis-for-induced-earthquakes-in-groningen-2013, http://www.knmi.nl/kennis-en-datacentrum/publicatie/probabilistic-seismic-hazard-analysis-for-induced-earthquakes-in-groningen-update-2015, http://www.knmi.nl/kennis-en-datacentrum/publicatie/probabilistic-seismic-hazard-analysis-for-induced-earthquakes-in-groningen-update-june-2016, http://cdn.knmi.nl/system/readmore_links/files/000/000/408/original/20170615_Technisch_rapport_hazardkaart_Groningen_2017.pdf Seismic hazard map 2017 (v4) which provides the spectral accelerations for specific locations and return-periods: http://rdsa.knmi.nl/hazard/

  • ShakeMaps of Peak Ground Acceleration (PGA, in units of %g), Peak Ground Velocity (PGV, in units of cm/s), and Pseudo-Spectral Acceleration (PSA, in units of %g). The KNMI publishes ShakeMaps for induced earthquakes with magnitude bigger than 2.0 in the province of Groningen. A ShakeMap is a representation of the actual ground shaking produced by an earthquake. The ShakeMap represents a combination of automatically recorded strong motion values, in the accelerometer stations around the epicenter of the earthquake, with the Ground Motion Prediction Equations (GMPE), for the places where there are no stations around. This GMPE is specially developed for Groningen (V7). More information about ShakeMaps can be found at: http://www.knmi.nl/kennis-en-datacentrum/achtergrond/shakemaps-voor-groningen