Multiple seismic reflectors in Earth's lowermost mantle
The modern view of Earth’s lowermost mantle considers a D″ region of enhanced (seismologically inferred) heterogeneity bounded by the core–mantle boundary and an interface some 150–300 km above it, with the latter often attributed to the postperovskite phase transition (in MgSiO[subscript 3]). Seism...
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| Format: | Article |
| Language: | en_US |
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National Academy of Sciences (U.S.)
2014
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| Online Access: | http://hdl.handle.net/1721.1/90329 https://orcid.org/0000-0003-1650-6818 |
| _version_ | 1811077318299353088 |
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| author | Shang, Xuefeng Shim, Sang-Heon de Hoop, Maarten van der Hilst, Robert D |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Shang, Xuefeng Shim, Sang-Heon de Hoop, Maarten van der Hilst, Robert D |
| author_sort | Shang, Xuefeng |
| collection | MIT |
| description | The modern view of Earth’s lowermost mantle considers a D″ region of enhanced (seismologically inferred) heterogeneity bounded by the core–mantle boundary and an interface some 150–300 km above it, with the latter often attributed to the postperovskite phase transition (in MgSiO[subscript 3]). Seismic exploration of Earth’s deep interior suggests, however, that this view needs modification. So-called ScS and SKKS waves, which probe the lowermost mantle from above and below, respectively, reveal multiple reflectors beneath Central America and East Asia, two areas known for subduction of oceanic plates deep into Earth’s mantle. This observation is inconsistent with expectations from a thermal response of a single isochemical postperovskite transition, but some of the newly observed structures can be explained with postperovskite transitions in differentiated slab materials. Our results imply that the lowermost mantle is more complex than hitherto thought and that interfaces and compositional heterogeneity occur beyond the D″ region sensu stricto. |
| first_indexed | 2024-09-23T10:41:03Z |
| format | Article |
| id | mit-1721.1/90329 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:41:03Z |
| publishDate | 2014 |
| publisher | National Academy of Sciences (U.S.) |
| record_format | dspace |
| spelling | mit-1721.1/903292024-05-15T08:25:14Z Multiple seismic reflectors in Earth's lowermost mantle Shang, Xuefeng Shim, Sang-Heon de Hoop, Maarten van der Hilst, Robert D Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Shang, Xuefeng van der Hilst, Robert D. The modern view of Earth’s lowermost mantle considers a D″ region of enhanced (seismologically inferred) heterogeneity bounded by the core–mantle boundary and an interface some 150–300 km above it, with the latter often attributed to the postperovskite phase transition (in MgSiO[subscript 3]). Seismic exploration of Earth’s deep interior suggests, however, that this view needs modification. So-called ScS and SKKS waves, which probe the lowermost mantle from above and below, respectively, reveal multiple reflectors beneath Central America and East Asia, two areas known for subduction of oceanic plates deep into Earth’s mantle. This observation is inconsistent with expectations from a thermal response of a single isochemical postperovskite transition, but some of the newly observed structures can be explained with postperovskite transitions in differentiated slab materials. Our results imply that the lowermost mantle is more complex than hitherto thought and that interfaces and compositional heterogeneity occur beyond the D″ region sensu stricto. 2014-09-24T19:48:35Z 2014-09-24T19:48:35Z 2014-02 2013-07 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/90329 Shang, X., S.-H. Shim, M. de Hoop, and R. van der Hilst. “Multiple Seismic Reflectors in Earth’s Lowermost Mantle.” Proceedings of the National Academy of Sciences 111, no. 7 (February 3, 2014): 2442–2446. https://orcid.org/0000-0003-1650-6818 en_US http://dx.doi.org/10.1073/pnas.1312647111 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) National Academy of Sciences (U.S.) |
| spellingShingle | Shang, Xuefeng Shim, Sang-Heon de Hoop, Maarten van der Hilst, Robert D Multiple seismic reflectors in Earth's lowermost mantle |
| title | Multiple seismic reflectors in Earth's lowermost mantle |
| title_full | Multiple seismic reflectors in Earth's lowermost mantle |
| title_fullStr | Multiple seismic reflectors in Earth's lowermost mantle |
| title_full_unstemmed | Multiple seismic reflectors in Earth's lowermost mantle |
| title_short | Multiple seismic reflectors in Earth's lowermost mantle |
| title_sort | multiple seismic reflectors in earth s lowermost mantle |
| url | http://hdl.handle.net/1721.1/90329 https://orcid.org/0000-0003-1650-6818 |
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