Knowing the best 1Dmodel of the crustal and uppermantle structure is useful not only for routine hypocenter determination, but also for linearized joint inversions of hypocenters and 3D crustal structure, where a good choiceof the initialmodel canbevery important.Here,we tested thecombinationof a simpleGA inversionwith the widely used HYPO71 program to find the best three-layer model (upper cru...

S U M M A R Y The geographical distribution of the (1981–2005) seismicity in southern California forms a ±150 km broad zone adjacent to the Pacific–North America plate boundary, ranging from depths of ∼1–∼30 km, with the bulk of the focal depths in the range of 2–12 km. The distribution of the seismicity that includes both mainshock–aftershock sequences and background events is affected by both...

Global compilations indicate that the geochemistry of arc magmatism is sensitive to Moho depth. Magmatic products are prevalent throughout the history of Cordilleran orogenesis and can be employed to constrain the timing of changes in crustal thickness as well as the magnitude of those changes. We investigate temporal variations in crustal thickness in the United States Cordillera using Sr/Y fr...

High-quality seismic data obtained from a dense broadband array near Kimberley, South Africa, exhibit crustal reverberations of remarkable clarity that provide well-resolved constraints on the structure of the lowermost crust and Moho. Receiver function analysis of Moho conversions and crustal multiples beneath the Kimberley array shows that the crust is 35 km thick with an average Poisson’s ra...

[1] The Hoggar swell in Algeria is one of the significant massifs of northwest Africa. The paucity of high‐ resolution geophysical studies of the crust and mantle beneath the massifs is mostly responsible for the heated debates about the depth of the source region of the Cenozoic volcanism and the closely related uncertainty about the mechanism that formed and maintains the high elevation of th...

The formation of the lunar farside highlands has long been an open problem in lunar science. We show that much of the topography and crustal thickness in this terrain can be described by a degree-2 harmonic. No other portion of the Moon exhibits comparable degree-2 structure. The quantified structure of the farside highlands unites them with the nearside and suggests a relation between lunar cr...

Seismic structure beneath the contiguous U.S. was imaged with multimode receiver function stacking and inversion of Rayleigh wave dispersion and ellipticity measurements. Crust thickness and elevation are weakly correlated across the contiguous U.S., but the correlation is ~3–4 times greater for separate areas east and west of the Rocky Mountain Front (RMF). Greater lower crustal shear velociti...

Cheng, Lui & Li inverted surface-wave phase-velocity maps from ambient noise to obtain crustal thickness for eastern Tibet and western Yangtze Craton. They applied a three steps procedure: in a first step, they collected the phase velocity maps and extrapolated the phase velocities into group velocities. In a second step, they performed a joint inversion of phase and group velocities using neur...

Cheng, Lui & Li inverted surface-wave phase-velocity maps from ambient noise to obtain crustal thickness for eastern Tibet and western Yangtze Craton. They applied a three steps procedure: in a first step, they collected the phase velocity maps and extrapolated the phase velocities into group velocities. In a second step, they performed a joint inversion of phase and group velocities using neur...