Is there a nascent plate boundary in the Northern Indian Ocean?
The northern Indian Ocean has been widely recognized as an area of broadly distributed deformation within the composite India‐Australia‐Capricorn plate, hosting several diffuse boundary zones and a diffuse triple junction. The occurrence, along reactivated fracture zones, of the exceptionally large...
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2020
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| Online Access: | https://hdl.handle.net/10356/143675 |
| _version_ | 1811686586115424256 |
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| author | Coudurier‐Curveur, Aurélie Karakaş, Ç. Singh, S. Tapponnier, P. Carton, H. Hananto, N. |
| author2 | Earth Observatory of Singapore |
| author_facet | Earth Observatory of Singapore Coudurier‐Curveur, Aurélie Karakaş, Ç. Singh, S. Tapponnier, P. Carton, H. Hananto, N. |
| author_sort | Coudurier‐Curveur, Aurélie |
| collection | NTU |
| description | The northern Indian Ocean has been widely recognized as an area of broadly distributed deformation within the composite India‐Australia‐Capricorn plate, hosting several diffuse boundary zones and a diffuse triple junction. The occurrence, along reactivated fracture zones, of the exceptionally large (Mw = 8.6 and Mw = 8.2) 2012 Wharton Basin strike‐slip earthquakes, however, questions whether this composite plate is breaking apart along a discrete boundary. Using recent bathymetric and seismic data, we analyze the most prominent fracture zone (F6a), whose structural trace is particularly well expressed. We identify 60 kilometric‐scale pull‐apart basins with geometric properties (length/width ratios) similar to those observed along continental strike‐slip plate boundaries. Four of the pull‐aparts formed above narrow, subvertical faults extending into the oceanic crust. Within the broad Wharton deformation zone, the significant slip rates (0.8 to 2.5 mm/yr) and unusually large coseismic displacements recorded along F6a suggest that it may be a nascent plate boundary. |
| first_indexed | 2024-10-01T05:02:46Z |
| format | Journal Article |
| id | ntu-10356/143675 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:02:46Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1436752020-09-26T21:30:08Z Is there a nascent plate boundary in the Northern Indian Ocean? Coudurier‐Curveur, Aurélie Karakaş, Ç. Singh, S. Tapponnier, P. Carton, H. Hananto, N. Earth Observatory of Singapore Science::Geology Wharton Basin Reactivated Fracture Zones The northern Indian Ocean has been widely recognized as an area of broadly distributed deformation within the composite India‐Australia‐Capricorn plate, hosting several diffuse boundary zones and a diffuse triple junction. The occurrence, along reactivated fracture zones, of the exceptionally large (Mw = 8.6 and Mw = 8.2) 2012 Wharton Basin strike‐slip earthquakes, however, questions whether this composite plate is breaking apart along a discrete boundary. Using recent bathymetric and seismic data, we analyze the most prominent fracture zone (F6a), whose structural trace is particularly well expressed. We identify 60 kilometric‐scale pull‐apart basins with geometric properties (length/width ratios) similar to those observed along continental strike‐slip plate boundaries. Four of the pull‐aparts formed above narrow, subvertical faults extending into the oceanic crust. Within the broad Wharton deformation zone, the significant slip rates (0.8 to 2.5 mm/yr) and unusually large coseismic displacements recorded along F6a suggest that it may be a nascent plate boundary. Ministry of Education (MOE) National Research Foundation (NRF) Published version This research was partly supported by the Singapore National Research Foundation and Ministry of Education under the Earth Observatory of Singapore Research Center of Excellence initiative. The bathymetric data were acquired during the MIRAGE 1 (Marine Investigation of the Rupture Anatomy of the 2012 Great Earthquake, https://doi.org/10.17600/16003200) experiment in the Wharton Basin. The seismic profiles were acquired during the MEGATERA (Mentawai Gap— Tsunami Earthquake Risk Assessment) experiment (http://www.marine-geo. org/tools/search/entry.php?id= FK150523). We thank Qin Yanfang for processing of the four seismic lines used in this work. The morphologic analyses were performed using the ENVI software, and the maps and figures designed using Adobe Illustrator. This work comprises Earth Observatory of Singapore contribution No. 286. 2020-09-16T06:36:19Z 2020-09-16T06:36:19Z 2020 Journal Article Coudurier‐Curveur, A., Karakaş, Ç., Singh, S., Tapponnier, P., Carton, H. & Hananto, N. (2020). Is there a nascent plate boundary in the Northern Indian Ocean?. Geophysical Research Letters, 47(7). doi:10.1029/2020GL087362 0094-8276 https://hdl.handle.net/10356/143675 10.1029/2020GL087362 7 47 en Geophysical Research Letters © 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. application/pdf |
| spellingShingle | Science::Geology Wharton Basin Reactivated Fracture Zones Coudurier‐Curveur, Aurélie Karakaş, Ç. Singh, S. Tapponnier, P. Carton, H. Hananto, N. Is there a nascent plate boundary in the Northern Indian Ocean? |
| title | Is there a nascent plate boundary in the Northern Indian Ocean? |
| title_full | Is there a nascent plate boundary in the Northern Indian Ocean? |
| title_fullStr | Is there a nascent plate boundary in the Northern Indian Ocean? |
| title_full_unstemmed | Is there a nascent plate boundary in the Northern Indian Ocean? |
| title_short | Is there a nascent plate boundary in the Northern Indian Ocean? |
| title_sort | is there a nascent plate boundary in the northern indian ocean |
| topic | Science::Geology Wharton Basin Reactivated Fracture Zones |
| url | https://hdl.handle.net/10356/143675 |
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