Malawi Seismogenic Source Model: v1.1

The Malawi Seismogenic Source Model (MSSM) is a geospatial database that documents the geometry, slip rate and seismogenic properties (ie earthquake magnitude and frequency) of active faults in Malawi. Each geospatial feature represents a potential earthquake rupture of 'source' and is classified based on its geometry into one of three types: section fault multi-fault Source types are mutually exclusice, and so if incorporated into a PSHA, they should be assigned relative weightings. The MSSM is the first seismogenic source database in central and northern Malawi, and represents an update of the South Malawi Seismogenic Source Database (SMSSD; Williams et al., 2021a) because it incorporates new active fault traces (Kolawole et al., 2021; Williams et al., 2021b; 2022 - MAFD), new geodetic data (Wedmore et al., 2021) and a statistical treatment of uncertainty, within a logic tree approach. The seismogenic sources in this model are adapted from the faults in the Malawi Active Fault Database (Williams et al., 2021b; 2022). Prior to publication please cite this database using the following two references: Williams, J. N., Wedmore, L. N .J., Fagereng, Å., Werner, M. J., Biggs, J., Mdala, H., Kolawole, F., Shillington, D. J., Dulanya, Z., Mphepo, F., Chindandali, P., Wright, L. J. M.., Scholz, C. A. Geological and geodetic constraints on the seismic hazard of Malawi's active faults: the Malawi Seismogenic Source Model (MSSM). Manuscript submitted to Natural Hazards and Earth System Sciences Williams, Jack N., Wedmore, Luke N. J., Fagereng, Åke, Werner, Maximilian J., Biggs, Juliet, Mdala, Hassan, Kolawole, Folarin, Shillington, Donna J., Dulanya, Zuze, Mphepo, Felix, Chindandali, Patrick R. N., Wright, Lachlan J. M., & Scholz, Christopher A. (2021). Malawi Seismogenic Source Model [Data set]. Zenodo. https://doi.org/10.5281/zenodo.5599616 Database Design and File Formats The MSSM is a geospatial database that consists of two separate components: A 3D geometrical model of fault seismogenic sources in Malawi The mapped trace of each source in a GIS vector format, with associated source attributes (Data Table). Each fault is associated with a source in the 3D geometrical model that is listed in a comma-separated-values (csv) file. The sections, faults and multi-faults that make up the individual seismogenic sources are described in separate geospatial files that describe the map-view geometry and metadata that control each sources earthquake magnitude and frequency for seismic hazard purposes. The sections, faults and multi-faults in this database are provided in a variety of GIS vector file formats. GeoJSON is the version of record, and any changes should be made in this version before they are converted to other file formats using the script in the repository that uses the GDAL tool ogr2ogr (the script is adapted from https://github.com/cossatot/central_am_carib_faults/blob/master/convert.sh - we thank Richard Styron for making this publicly available). The other versions available are ESRI ShapeFile, KML, GMT, and GeoPackage. List and brief description of the fault geometry, slip rate estimates and earthquake source attributes in the GIS vector format files that make up the MSSM. Attribuge Type Description Notes MSSM_ID integer Unique numerical reference ID for each seismic source ID 00-300 is section rupture ID 300-500 is fault rupture ID 600-700 is a multi-fault rupture name string Assigned based on previous mapping or local geographic feature. For sections and faults, the name of the fault (flt_name) and larger multi-fault (mflt_name) system they are hosted on are given respectively. basin string Basin that source is located within. Used in slip rate calculations class string intrarift or border fault length (Ls) real number straight-line distance in km between fault tips; sum of Lsec for segmented faults; sum of Lfault for multi-faults measured in km to 1 decimal place. Must be greater than 5 km (except for linking sections). area integer Calculated from Ls multiplied by Eq. 1 or based on fault truncation. measured in km2 strike integer Azimuth of straigth line between the fault tips. azimuth is