Extracting earthquake induced Lagrangian ground displacements and their implication for source inversion analysis

Seismographs are crucial for understanding a variety of aspects of earthquake-inflicted property damage and human suffering. However, strong ground motion records are often missing or very sparsely available especially in the developing countries, discouraging all attempts for rational rehabilitations. Something that should not be forgotten in talking about rehabilitations is that a large earthquake often causes long lasting geotechnical problems, in which terrain changes are to be thoroughly studied. A method is presented here to extract Lagrangian ground displacements from an available set of aerial/satellite data capturing sub-aerial topography. Its application to the Mid-Niigata Prefecture Earthquake, a well recorded and documented seismic event, has shown good correlation with the field measurements and/or observations. An inversion analysis is carried out with the predetermined static ground surface displacements to determine the spatial distribution of slips on fault rupture planes for known fault geometry.

► A method is proposed to extract Lagrangian components of ground displacement.
► The outcomes of the method are consistent with the field measurements/observations.
► Source inversion analysis with predetermined static ground displacements is presented.