Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra Delta
Abstract The contribution of subsidence to relative sea level rise in the Ganges‐Brahmaputra delta (GBD) is largely unknown and may considerably enhance exposure of the Bengal Basin populations to sea level rise and storm surges. This paper focuses on estimating the present‐day subsidence induced by...
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| Format: | Article |
| Language: | English |
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Wiley
2018-02-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1002/2017GL076388 |
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| author | M. Karpytchev V. Ballu Y. Krien M. Becker S. Goodbred G. Spada S. Calmant C. K. Shum Z. Khan |
| author_facet | M. Karpytchev V. Ballu Y. Krien M. Becker S. Goodbred G. Spada S. Calmant C. K. Shum Z. Khan |
| author_sort | M. Karpytchev |
| collection | DOAJ |
| description | Abstract The contribution of subsidence to relative sea level rise in the Ganges‐Brahmaputra delta (GBD) is largely unknown and may considerably enhance exposure of the Bengal Basin populations to sea level rise and storm surges. This paper focuses on estimating the present‐day subsidence induced by Holocene sediment in the Bengal Basin and by oceanic loading due to eustatic sea level rise over the past 18 kyr. Using a viscoelastic Earth model and sediment deposition history based on in situ measurements, results suggest that massive sediment influx initiated in the early Holocene under a strengthened South Asian monsoon may have contributed significantly to the present‐day subsidence of the GBD. We estimate that the Holocene loading generates up to 1.6 mm/yr of the present‐day subsidence along the GBD coast, depending on the rheological model of the Earth. This rate is close to the twentieth century global mean sea level rise (1.1–1.7 mm/yr). Thus, past climate change, by way of enhanced sedimentation, is impacting vulnerability of the GBD populations. |
| format | Article |
| id | doaj-art-b9d704d76c7e41648ef2d01424ef0bd1 |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2018-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-b9d704d76c7e41648ef2d01424ef0bd12025-08-20T02:31:40ZengWileyGeophysical Research Letters0094-82761944-80072018-02-014531433144210.1002/2017GL076388Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra DeltaM. Karpytchev0V. Ballu1Y. Krien2M. Becker3S. Goodbred4G. Spada5S. Calmant6C. K. Shum7Z. Khan8LIENSs UMR 7266 CNRS University of La Rochelle La Rochelle FranceLIENSs UMR 7266 CNRS University of La Rochelle La Rochelle FranceLIENSs UMR 7266 CNRS University of La Rochelle La Rochelle FranceLIENSs UMR 7266 CNRS University of La Rochelle La Rochelle FranceDepartment of Earth and Environmental Sciences Vanderbilt University Nashville TN USADipartimento di Scienze Pure e Applicate University of Urbino “Carlo Bo” Urbino ItalyLEGOS UMR5566/CNRS/CNES/IRD/UPS Toulouse FranceSchool of Earth Sciences Ohio State University Columbus OH USAInstitute of Water Modelling Dhaka BangladeshAbstract The contribution of subsidence to relative sea level rise in the Ganges‐Brahmaputra delta (GBD) is largely unknown and may considerably enhance exposure of the Bengal Basin populations to sea level rise and storm surges. This paper focuses on estimating the present‐day subsidence induced by Holocene sediment in the Bengal Basin and by oceanic loading due to eustatic sea level rise over the past 18 kyr. Using a viscoelastic Earth model and sediment deposition history based on in situ measurements, results suggest that massive sediment influx initiated in the early Holocene under a strengthened South Asian monsoon may have contributed significantly to the present‐day subsidence of the GBD. We estimate that the Holocene loading generates up to 1.6 mm/yr of the present‐day subsidence along the GBD coast, depending on the rheological model of the Earth. This rate is close to the twentieth century global mean sea level rise (1.1–1.7 mm/yr). Thus, past climate change, by way of enhanced sedimentation, is impacting vulnerability of the GBD populations.https://doi.org/10.1002/2017GL076388Ganges‐Brahmaputra deltaland subsidencesediment loadingrelative sea level change |
| spellingShingle | M. Karpytchev V. Ballu Y. Krien M. Becker S. Goodbred G. Spada S. Calmant C. K. Shum Z. Khan Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra Delta Geophysical Research Letters Ganges‐Brahmaputra delta land subsidence sediment loading relative sea level change |
| title | Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra Delta |
| title_full | Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra Delta |
| title_fullStr | Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra Delta |
| title_full_unstemmed | Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra Delta |
| title_short | Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present‐Day Subsidence of the Ganges‐Brahmaputra Delta |
| title_sort | contributions of a strengthened early holocene monsoon and sediment loading to present day subsidence of the ganges brahmaputra delta |
| topic | Ganges‐Brahmaputra delta land subsidence sediment loading relative sea level change |
| url | https://doi.org/10.1002/2017GL076388 |
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