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Updated: May 2, 2026
07:58
Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt
Published on: August 7, 2017
8.9K
Multiple seismic reflectors in Earth's lowermost mantle.
Xuefeng Shang1, Sang-Heon Shim, Maarten de Hoop
1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139.
Summary
Earth's deep mantle is more complex than previously thought. Seismic wave analysis reveals multiple reflectors, suggesting intricate structures and compositional variations beyond the D″ region.
Area of Science:
- Geophysics
- Seismology
- Earth Science
Background:
- The lowermost mantle (D″ region) is characterized by seismic heterogeneity.
- A key interface, often linked to the postperovskite phase transition, is located 150-300 km above the core-mantle boundary.
Purpose of the Study:
- To investigate the structure of Earth's lowermost mantle using seismic wave analysis.
- To reconcile seismic observations with current models of the D″ region and postperovskite transitions.
Main Methods:
- Analysis of ScS and SKKS seismic waves probing the lowermost mantle.
- Interpretation of multiple reflectors beneath Central America and East Asia.
Main Results:
- Seismic data reveal multiple reflectors in the lowermost mantle, inconsistent with a single isochemical postperovskite transition.
- Observed structures can be partially explained by postperovskite transitions within differentiated subducted slab materials.
Conclusions:
- The lowermost mantle exhibits greater complexity than previously understood.
- Interfaces and compositional heterogeneity extend beyond the traditional D″ region definition.
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