Project Details
Description
Collaborative Research:AfricaArray - Imaging the African Superplume
The African Superplume is a large region of low seismic wave speeds in
the lower mantle under southern Africa that has long been recognized as
one of the most prominent features of the mantle. Above the African
Superplume lies the African Superswell, suggesting a geodynamic link
between lower mantle dynamics and geologic processes shaping the
African plate. The origin and nature of the African Superplume is
controversial. The initial interpretation of the low wave speed region
under southern Africa attributed it to a long-lived, hot mantle
upwelling. A number of seismic studies since then have suggested the
presence of chemical heterogeneity within the superplume.
What parts of the superplume anomaly are thermal vs. chemical (or both)
remains uncertain, as does its origin. In this project, the structure,
composition and origin of the African Superplume will be investigated
using the first 3 years of broadband seismic data from AfricaArray,
together with existing data, and concentrating on four types of
analyses; 1) tomographic imaging of the upper and lower mantle using
body wave travel times, 2) modeling waveforms of teleseismic body wave
phases that sample the Superplume, 3) jointly inverting receiver
functions and surface wave dispersion measurements for crust and
uppermost mantle structure, and 4) stacking and migrating receiver
functions to image topography on the 410 and 660 km discontinuities.
AfricaArrayis a new 10-year-long Pan-African training and research
initiative in geophysics, with an emphasis on seismology, set up by the
University of the Witwatersrand, the Council for Geoscience (South
African geological survey), and Penn State. AfricaArraywill provide the
U.S. geophysics community with important seismic data on earth
structure and processes for many years. AfricaArraywill greatly
strengthen scientific ties between the U.S. geophysics community and
earth scientists throughout Africa. Once established, AfricaArraywill
provide opportunities for promoting geophysics to U.S. minority groups,
as well as other students, through summer internships and a summer
geophysics field course (both in Africa).
This award is co-funded by NSF's Office of International Science and Engineering.
Status | Finished |
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Effective start/end date | 3/1/05 → 2/28/09 |
Funding
- National Science Foundation: $148,913.00