We investigate the upper-crustal structure of the Rukwa–Tanganyika rift zone in East Africa, where the Tanganyika rift interacts with the Rukwa and Mweru-Wantipa rifts, coinciding with abundant seismicity at the rift tips. Seismic velocity structure and patterns of seismicity clustering reveal zones around 10 km deep with anomalously high Vp / Vs ratios at the rift tips, indicative of a localized mechanically weakened crust caused by mantle volatiles and damage associated with bending strain.
