The ISC-GEM Global Instrumental Earthquake Catalogue is a global homogenised catalogue of more than 20.000 earthquakes that cover more than 110 years of earthquake history. The catalogue can be used for global hazard assessment and serves a starting point for compilation of more detailed regional catalogues.
An archive of 994 earthquakes and a catalogue of 827 earthquakes was developed by identifying, collecting and critically organising the best and most recent information available for earthquakes in the time-window 1000-1903 and magnitude equal to or higher than 7.
By combining the expert opinions of scientists worldwide, a suite of GMPEs has been selected that can be used at global level for hazard assessment. Three or four GMPEs were selected for each tectonic regime (subduction zones, active crustal regions, stable continental regions) and one for component substitution.
A homogenous global database of active faults that integrates currently available national and regional databases worldwide is being assembled following recognized standards defined by earthquake geologists worldwide. A capture tool will allow geologists to feed (new) fault data for use in the OpenQuake platform and after quality control for upload into the database.
The global geodectic strain rate model is numerical model that is based on almost 6.000 GPS stations worldwide plus 1200 in China that measure plate motion, as well as 14.000 from literature. The model is of great relevance to improve understanding of seismicity as strain rate is a proxy for earthquake potential. The GEM Global Geodetic Strain Rate Model is a significant improvement from the model that was developed in 2004.
There are two working groups active at the moment working on hazard-related issues:
The Powell working group
Brings together experts who work on a wide range of topics relevant for development of PSHA input models. The group provides an opportunity for discussing and working on challenging and disputed problems related to seismicity occurrence, such as the maximum magnitude concept or the definition and characterisation of earthquake occurrence.
A working group on Tectonic Regionalisation
An interdisciplinary group of experts working together on the definition of a regionalistation scheme/methodology which, for each point on the globe, can provide a corresponding set of GMPEs and magnitude scaling relationships.