Upper mantle velocity structure beneath southern Africa from modeling regional seismic data
نویسندگان
چکیده
منابع مشابه
Mantle discontinuities beneath Southern Africa
[1] Seismic velocity discontinuities within the top 1000 km of the Earth beneath southern Africa are imaged by stacking about 1300 source-normalized broadband seismograms recorded by the Southern African Seismic Experiment. The Moho, 410, and 660 kilometer discontinuities are clearly detected. The mean mantle transition zone thickness is 245 km, essentially the same as the global average, sugge...
متن کاملUpper mantle SH- and P-velocity structures and compositional models beneath southern Africa
We constrain SH and P wave velocity structures in the upper mantle beneath southern Africa, using triplicated phases recorded in the epicentral distance range of 11°–28° for one shallow event. We then explore thermal and compositional models appropriate for explaining the inferred seismic structures in the region. Both SH and P wave data suggest presence of a low velocity zone with velocity red...
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The exposed geology of the Australian continent is composed of an assemblage of crustal blocks that can be broadly grouped into the Precambrian western and central cratons and the Phanerozoic eastern province (Figure 1). Structural differences between the Precambrian shield and eastern Australia are inferred from surface-wave dispersion (Muirhead & Drummond 1991; Denham 1991) and teleseismic tr...
متن کاملUpper mantle structure beneath the Azores hotspot from finite-frequency seismic tomography
The Azores archipelago is a classic expression of a hotspot that has interacted with a mid-ocean ridge. A variety of geochemical studies and geophysical observations point to the influence of some sort of mantle plume on the formation of the Azores Plateau and the adjacent Mid-Atlantic Ridge (MAR), but the mantle structure beneath the Azores has not heretofore been imaged tomographically at a s...
متن کاملTectospheric structure beneath southern Africa
P-wave and S-wave delay times from the broadband data of the southern Africa seismic experiment have been inverted to obtain three-dimensional images of velocity perturbations in the mantle beneath southern Africa. High velocity mantle roots appear to extend to depths of at least 250 km, and locally to depths of 300 km beneath the Kaapvaal and Zimbabwe cratons. Thick roots are confined to the A...
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ژورنال
عنوان ژورنال: Journal of Geophysical Research: Solid Earth
سال: 1999
ISSN: 0148-0227
DOI: 10.1029/1998jb900058