| Title | Impact of anthropogenic subsidence on relative sea-level rise in the Fraser River delta |
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| Author | Mazzotti, S ;
Lambert, A; Van der Kooij, M; Mainville, A |
| Source | Geology vol. 37, no. 9, 2009 p. 771-774, https://doi.org/10.1130/G25640A.1 |
| Image |  |
| Year | 2009 |
| Alt Series | Earth Sciences Sector, Contribution Series 20070553 |
| Publisher | Geological Society of America |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | British Columbia |
| NTS | 92G/02; 92G/03 |
| Area | Fraser River; Fraser River delta; Delta; Richmond |
| Lat/Long WENS | -123.2000 -122.9167 49.8500 49.0000 |
| Subjects | marine geology; sedimentology; deltas; deltaic sediments; deltaic deposits; sea level changes; sea level fluctuations; paleo-sea levels; floods; flood potential; erosion |
| Illustrations | location maps; plots |
| Program | Enhancing resilience in a changing climate |
| Released | 2009 09 01 |
| Abstract | Subsidence is a common cause of amplifi ed relative sea-level rise, fl ooding, and erosion in coastal environments. In particular, subsidence due to sediment consolidation can play a signifi cant role
in relative sea-level rise in large deltas. We use a combination of InSAR (interferometric synthetic aperture radar), leveling, and global positioning system data to map absolute vertical land motion in the Fraser River delta, western Canada. We show
that primary consolidation of shallow Holocene sediments is the main cause for the slow subsidence (-1 to -2 mm/a) affecting the delta lowlands. In addition, parts of the delta undergo increased anthropogenic subsidence. Rapid subsidence rates (-3 to
-8 mm/a) are associated with recent artifi cial loads and exhibit a fi rst-order exponential decrease with a time constant of ~20 years, consistent with the theory of consolidation. Assuming two sea-level rise scenarios of 30 or 100 cm by the end of
the twenty-fi rst century, natural subsidence will augment relative sea-level rise in the Fraser Holocene lowlands by ~50% or ~15%. Anthropogenic subsidence will augment relative sea-level rise by ~130% or ~40%, potentially raising it to as much as 1
- 2 m. In deltaic, lacustrine, and alluvial environments, anthropogenic sediment consolidation can result in signifi cant amplifi cation and strong spatial variations of relative sea-level rise that need to be considered in local planning. |
| GEOSCAN ID | 224814 |
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