Seasonal variability in turbidity currents in Lake Ohau, New Zealand and their influence on sedimentation

Cossu, R., Forrest, A. L., Roop, H. A., Dunbar, G. B., Vandergoes, M. J., Levy, R. H., Stumpner, P. and Schladow, S. G. (2015) Seasonal variability in turbidity currents in Lake Ohau, New Zealand and their influence on sedimentation. Marine and Freshwater Research, 67 11: 1725-1739. doi:10.1071/MF15043


Author Cossu, R.
Forrest, A. L.
Roop, H. A.
Dunbar, G. B.
Vandergoes, M. J.
Levy, R. H.
Stumpner, P.
Schladow, S. G.
Title Seasonal variability in turbidity currents in Lake Ohau, New Zealand and their influence on sedimentation
Journal name Marine and Freshwater Research   Check publisher's open access policy
ISSN 1323-1650
1448-6059
Publication date 2015-01-01
Year available 2015
Sub-type Article (original research)
DOI 10.1071/MF15043
Open Access Status Not yet assessed
Volume 67
Issue 11
Start page 1725
End page 1739
Total pages 15
Place of publication Clayton, VIC, Australia
Publisher CSIRO Pubishing
Language eng
Formatted abstract
Layers of sediment that are deposited on the floor of Lake Ohau, New Zealand, offer a means to reconstruct past climate conditions in the Southern Hemisphere at subdecadal and annual resolution. A robust understanding of the modern physical processes that control the influx and dispersal of sediment in the lake is required to reconstruct climate from these sedimentary archives. In this study, water temperature and velocity measurements collected during 2012–13 were analysed to determine the primary physical processes that influence sediment transport in the lake. Sediment input from river inflow occurs throughout the year but exhibits strong seasonal variation. Large inflow events (Q > 500 m3 s–1) that follow strong summer rainstorms trigger high-concentration turbidity currents, which are the main agents for sediment delivery and deposition. During winter, smaller turbidity currents also occur after rain events and contribute to annual sediment accumulation. In addition, large internal waves were observed during the summer and may influence sedimentation. In conclusion, several processes including river inflow, internal waves and convectively driven flows control sediment deposition and accumulation in the Lake Ohau system. We utilise these observations to establish a conceptual model to explain the observed infill stratigraphy in Lake Ohau and guide interpretation of the longer sedimentary record.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Civil Engineering Publications
 
Versions
Version Filter Type
Citation counts: Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Fri, 19 Feb 2016, 07:13:57 EST by Jeannette Watson on behalf of School of Civil Engineering