A renewed forward and inversion python package calculating effective elastic thickness

Abstract:

Elastic thickness (Te) is a mechanical property of Earth lithosphere and important to understand the lithospheric evolution of an area. The approach is to calculate the flexural response caused by a load on an elastic plate, which has a specific elastic thickness. In its simplest case, the load is caused by topography/bathymetry and sedimentary loads. In addition, crustal density variations can also be considered for load calculation. In a second step, several forward calculated flexural responses are compared to a pre-calculated crustal root from gravity inversion by a rolling window. For each window the RMS error is calculated and the best Te value is selected. The result is a map of best fitting elastic thickness values. These can be interpreted as geological clusters with same rigidity properties. These can be also linked to temperature and age of the lithosphere, because cold and old areas are also rigid areas compared to hot and young lithosphere.

The presented software package can be easily used in Python to calculate a gravity inverted Moho depth in a first step and use this as input for the inversion of elastic thickness.

Test calculations are shown over Africa and compared to existing lithospheric thickness models and regionalization/classifications of the crust.