A seismic source model, including logic-tree assessment of PSHA input parameters, was developed for northeastern Mozambique to support seismic design of of Anadarko Petroleum’s proposed Afungi LNG Facility.  The source model consists of 3-dimensional areal sources and well-constrained fault sources.  The fault sources are associated with the eastern arm of the East African Rift System, a tectonic plate boundary less than 100 km offshore to the east. Slip rates for the main faults are constrained by recent plate motion and geodetic models describing the relative motions between the Indian and African tectonic plates.

All of the faults within the 10-km radius have been interpreted as being associated with a regional gravitational failure of the Rovuma Delta and root into a subhorizontal detachment at a depth of -3.5 to 4.5 km.  These gravity-driven faults are therefore considered non-seismogenic (i.e. not capable of producing earthquakes having magnitudes greater than ~ M5.5).