September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data
We provide a new set of complementary geodetic data for the 2005 rifting event of Afar (Ethiopia). Interferometric synthetic aperture radar and subpixel correlations of synthetic aperture radar and SPOT images allow us to deduce 3-D surface displacement unambiguously. We determine the geometry of th...
| Hlavní autoři: | , , , , , , , , , , , |
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| Médium: | Journal Article |
| Jazyk: | English |
| Vydáno: |
2012
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| Témata: | |
| On-line přístup: | https://hdl.handle.net/10356/95659 http://hdl.handle.net/10220/8648 |
| _version_ | 1826114680784945152 |
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| author | Grandin, R. Socquet, A. Binet, R. Jacques, E. de Chabalier, J. B. King, G. C. P. Lasserre, C. Tait, S. Delorme, A. Pinzuti, P. Klinger, Yann Tapponnier, Paul |
| author_facet | Grandin, R. Socquet, A. Binet, R. Jacques, E. de Chabalier, J. B. King, G. C. P. Lasserre, C. Tait, S. Delorme, A. Pinzuti, P. Klinger, Yann Tapponnier, Paul |
| author_sort | Grandin, R. |
| collection | NTU |
| description | We provide a new set of complementary geodetic data for the 2005 rifting event of Afar (Ethiopia). Interferometric synthetic aperture radar and subpixel correlations of synthetic aperture radar and SPOT images allow us to deduce 3-D surface displacement unambiguously. We determine the geometry of the dike and neighboring magma chambers and invert for the distribution of opening of the dike, as well as slip on rift border faults. The volume of the 2005 dike (1.5–2.0 km3) is not balanced by sufficient volume loss at Dabbahu and Gabho volcanoes (0.42 and 0.12 km3, respectively). Taking into account the deflation of a suspected deep midsegment magma chamber simultaneously to dike intrusion produces a smoother opening distribution along the southern segment. Above the dike, faults slipped by an average 3 m, yielding an estimated geodetic moment of 3.5 × 1019 Nm, one order of magnitude larger than the cumulative seismic moment released during the earthquake swarm. Between Dabbahu and Ado'Ale volcanic complexes, significant opening occurred on the western side of the dike. The anomalous location of the dike at this latitude, offset to the east of the axial depression, may explain this phenomenon. A two-stage intrusion scenario is proposed, whereby rifting in the northern Manda Hararo Rift was triggered by magma upwelling in the Dabbahu area, at the northern extremity of the magmatic segment. Although vigorous dike injection occurred during the September 2005 event, the tectonic stress deficit since the previous rifting episode was not fully released, leading to further intrusions in 2006–2009. |
| first_indexed | 2024-10-01T03:43:06Z |
| format | Journal Article |
| id | ntu-10356/95659 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:43:06Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | ntu-10356/956592020-09-26T21:27:22Z September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data Grandin, R. Socquet, A. Binet, R. Jacques, E. de Chabalier, J. B. King, G. C. P. Lasserre, C. Tait, S. Delorme, A. Pinzuti, P. Klinger, Yann Tapponnier, Paul DRNTU::Science::Geology::Volcanoes and earthquakes We provide a new set of complementary geodetic data for the 2005 rifting event of Afar (Ethiopia). Interferometric synthetic aperture radar and subpixel correlations of synthetic aperture radar and SPOT images allow us to deduce 3-D surface displacement unambiguously. We determine the geometry of the dike and neighboring magma chambers and invert for the distribution of opening of the dike, as well as slip on rift border faults. The volume of the 2005 dike (1.5–2.0 km3) is not balanced by sufficient volume loss at Dabbahu and Gabho volcanoes (0.42 and 0.12 km3, respectively). Taking into account the deflation of a suspected deep midsegment magma chamber simultaneously to dike intrusion produces a smoother opening distribution along the southern segment. Above the dike, faults slipped by an average 3 m, yielding an estimated geodetic moment of 3.5 × 1019 Nm, one order of magnitude larger than the cumulative seismic moment released during the earthquake swarm. Between Dabbahu and Ado'Ale volcanic complexes, significant opening occurred on the western side of the dike. The anomalous location of the dike at this latitude, offset to the east of the axial depression, may explain this phenomenon. A two-stage intrusion scenario is proposed, whereby rifting in the northern Manda Hararo Rift was triggered by magma upwelling in the Dabbahu area, at the northern extremity of the magmatic segment. Although vigorous dike injection occurred during the September 2005 event, the tectonic stress deficit since the previous rifting episode was not fully released, leading to further intrusions in 2006–2009. Published version 2012-09-27T02:54:58Z 2019-12-06T19:19:12Z 2012-09-27T02:54:58Z 2019-12-06T19:19:12Z 2009 2009 Journal Article Grandin, R., Socquet, A., Binet, R., Klinger, Y., Jacques, E., de Chabalier, J. B., et al. (2009). September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data. Journal of geophysical research, 114. 0148-0227 https://hdl.handle.net/10356/95659 http://hdl.handle.net/10220/8648 10.1029/2008JB005843 en Journal of geophysical research © 2009 American Geophysical Union. This paper was published in Journal of Geophysical Research and is made available as an electronic reprint (preprint) with permission of American Geophysical Union. The paper can be found at the following official URL: [http://dx.doi.org/10.1029/2008JB005843]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. application/pdf |
| spellingShingle | DRNTU::Science::Geology::Volcanoes and earthquakes Grandin, R. Socquet, A. Binet, R. Jacques, E. de Chabalier, J. B. King, G. C. P. Lasserre, C. Tait, S. Delorme, A. Pinzuti, P. Klinger, Yann Tapponnier, Paul September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data |
| title | September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data |
| title_full | September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data |
| title_fullStr | September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data |
| title_full_unstemmed | September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data |
| title_short | September 2005 Manda Hararo-Dabbahu rifting event, Afar (Ethiopia) : constraints provided by geodetic data |
| title_sort | september 2005 manda hararo dabbahu rifting event afar ethiopia constraints provided by geodetic data |
| topic | DRNTU::Science::Geology::Volcanoes and earthquakes |
| url | https://hdl.handle.net/10356/95659 http://hdl.handle.net/10220/8648 |
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