The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors.
The 660-kilometer discontinuity, which separates Earth's upper and lower mantle, has been detected routinely on a global scale in underside reflections of precursors to SS shear waves. Here, we report observations of this discontinuity in many different regions, using precursors to compressiona...
| Main Authors: | , , , |
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| פורמט: | Journal article |
| שפה: | English |
| יצא לאור: |
2006
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| _version_ | 1826286994520539136 |
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| author | Deuss, A Redfern, SA Chambers, K Woodhouse, J |
| author_facet | Deuss, A Redfern, SA Chambers, K Woodhouse, J |
| author_sort | Deuss, A |
| collection | OXFORD |
| description | The 660-kilometer discontinuity, which separates Earth's upper and lower mantle, has been detected routinely on a global scale in underside reflections of precursors to SS shear waves. Here, we report observations of this discontinuity in many different regions, using precursors to compressional PP waves. The apparent absence of such precursors in previous studies had posed major problems for models of mantle composition. We find a complicated structure, showing single and double reflections ranging in depth from 640 to 720 kilometers, that requires the existence of multiple phase transitions at the base of the transition zone. The results are consistent with a pyrolite mantle composition. |
| first_indexed | 2024-03-07T01:51:58Z |
| format | Journal article |
| id | oxford-uuid:9a698503-ba89-4231-b384-3ad363c12ef6 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:51:58Z |
| publishDate | 2006 |
| record_format | dspace |
| spelling | oxford-uuid:9a698503-ba89-4231-b384-3ad363c12ef62022-03-27T00:21:09ZThe nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:9a698503-ba89-4231-b384-3ad363c12ef6EnglishSymplectic Elements at Oxford2006Deuss, ARedfern, SAChambers, KWoodhouse, JThe 660-kilometer discontinuity, which separates Earth's upper and lower mantle, has been detected routinely on a global scale in underside reflections of precursors to SS shear waves. Here, we report observations of this discontinuity in many different regions, using precursors to compressional PP waves. The apparent absence of such precursors in previous studies had posed major problems for models of mantle composition. We find a complicated structure, showing single and double reflections ranging in depth from 640 to 720 kilometers, that requires the existence of multiple phase transitions at the base of the transition zone. The results are consistent with a pyrolite mantle composition. |
| spellingShingle | Deuss, A Redfern, SA Chambers, K Woodhouse, J The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors. |
| title | The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors. |
| title_full | The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors. |
| title_fullStr | The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors. |
| title_full_unstemmed | The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors. |
| title_short | The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors. |
| title_sort | nature of the 660 kilometer discontinuity in earth s mantle from global seismic observations of pp precursors |
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