Teleseismic spectral and temporal M0 and Ψ∞ estimates for four French explosions in southern Sahara

Estimates for explosion moment M , and reduced displacement potential, Ψ∞, are made for four French explosions at Taourirt Tan Afella Massif in southern French Sahara using data from the long-range seismic measurement network and the EKA and YKA arrays. Preparatory to determining moments, attenuation, t⋆, estimates are made for each station, and the source region t⋆ values of 0.30 to 0.35 sec are found for the southern Sahara test site. This source region attenuation level is consistent with the “hot spot” hypothesis for the Ahaggar plateau in northern Africa. Consequently, the attenuation bias between Ahaggar and the Nevada Test Site should be small. Both spectral estimation and broadband temporal deconvolution methods are used for estimation of the explosion moments. The deconvolution estimates of static moment are found to be consistent with the spectral estimation methods. Deconvolved seismograms for the explosions EMERAUDE, RUBIS, SAPHIR, and GRENAT show evidence of strong anisotropic free surface interaction that may be due to scattering or spall from the steep topography of the Taourirt Tan Affela Massif test site.