A hot midmantle anomaly in the area of the Indian Ocean Geoid Low
Abstract We investigate the upper mantle seismic discontinuities at 410 and 660 km depth beneath the Indian Ocean Geoid Low (IOGL). To map the discontinuities' topography, we use differential travel times of PP and SS waves and their precursors. Our final data set consists of 37 events with Mw ...
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| Format: | Article |
| Language: | English |
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Wiley
2017-07-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1002/2017GL073440 |
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| author | Anne‐Sophie Reiss Christine Thomas Jac vanDriel Björn Heyn |
| author_facet | Anne‐Sophie Reiss Christine Thomas Jac vanDriel Björn Heyn |
| author_sort | Anne‐Sophie Reiss |
| collection | DOAJ |
| description | Abstract We investigate the upper mantle seismic discontinuities at 410 and 660 km depth beneath the Indian Ocean Geoid Low (IOGL). To map the discontinuities' topography, we use differential travel times of PP and SS waves and their precursors. Our final data set consists of 37 events with Mw ≥ 5.8, which densely cover our investigation area, also with crossing ray paths. We use array methods to detect the low‐amplitude precursor signals. The best quality data show a deepened 410 km discontinuity in the center of the IOGL as well as a mostly elevated 660 km discontinuity beneath the northern Indian Ocean, which we interpret as a hot anomaly currently residing in the mantle transition zone. We conclude that the largest negative geoid anomaly might be caused by a combined effect of hot material in the midmantle below the innermost IOGL and cold material below 660 km farther south. |
| format | Article |
| id | doaj-art-bc177ecd9d1d4ff8964f1ce1aa57d729 |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2017-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-bc177ecd9d1d4ff8964f1ce1aa57d7292025-08-20T01:51:46ZengWileyGeophysical Research Letters0094-82761944-80072017-07-0144136702671110.1002/2017GL073440A hot midmantle anomaly in the area of the Indian Ocean Geoid LowAnne‐Sophie Reiss0Christine Thomas1Jac vanDriel2Björn Heyn3Westfälische Wilhelms‐Universität Münster Münster GermanyWestfälische Wilhelms‐Universität Münster Münster GermanyUniversity College London London UKWestfälische Wilhelms‐Universität Münster Münster GermanyAbstract We investigate the upper mantle seismic discontinuities at 410 and 660 km depth beneath the Indian Ocean Geoid Low (IOGL). To map the discontinuities' topography, we use differential travel times of PP and SS waves and their precursors. Our final data set consists of 37 events with Mw ≥ 5.8, which densely cover our investigation area, also with crossing ray paths. We use array methods to detect the low‐amplitude precursor signals. The best quality data show a deepened 410 km discontinuity in the center of the IOGL as well as a mostly elevated 660 km discontinuity beneath the northern Indian Ocean, which we interpret as a hot anomaly currently residing in the mantle transition zone. We conclude that the largest negative geoid anomaly might be caused by a combined effect of hot material in the midmantle below the innermost IOGL and cold material below 660 km farther south.https://doi.org/10.1002/2017GL073440Indian Ocean Geoid Lowmantle discontinuitiesarray seismology |
| spellingShingle | Anne‐Sophie Reiss Christine Thomas Jac vanDriel Björn Heyn A hot midmantle anomaly in the area of the Indian Ocean Geoid Low Geophysical Research Letters Indian Ocean Geoid Low mantle discontinuities array seismology |
| title | A hot midmantle anomaly in the area of the Indian Ocean Geoid Low |
| title_full | A hot midmantle anomaly in the area of the Indian Ocean Geoid Low |
| title_fullStr | A hot midmantle anomaly in the area of the Indian Ocean Geoid Low |
| title_full_unstemmed | A hot midmantle anomaly in the area of the Indian Ocean Geoid Low |
| title_short | A hot midmantle anomaly in the area of the Indian Ocean Geoid Low |
| title_sort | hot midmantle anomaly in the area of the indian ocean geoid low |
| topic | Indian Ocean Geoid Low mantle discontinuities array seismology |
| url | https://doi.org/10.1002/2017GL073440 |
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