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Wabush Lake is one of the few very well-constrained source-to-sink sedimentary systems in the world that exhibits near-continuous turbidity currents. In this system, approximately 20 million tons of mine tailings are delivered each year to a 40 km 2 lake. Multibeam bathymetric surveys of this lake were carried out between 1999 and 2011. In addition, a program of extensive sampling and seismic surveys, an airborne LiDAR survey and a photogrammetric survey were carried out during this period. The objective of this study was to determine the evolution through time of this anthropic source-to-sink system, from the point where sediments exit the slurry pipelines at the head of the system to the distal end and bottom of the Lake. The total volume of the Lake is around 1 × 10 9 m 3 . Analysis of subaerial and subaqueous datasets allows the evaluation of disposal strategies on the delta topset and on tailings accumulation. Disposal strategies influence the dynamics of the channels on the topset, thus in turn affecting the accumulation of tailings throughout the lake, as well as the shoreline advancement rate. Subaqueous erosional channels present on the bed of the Lake influence the depositional pattern of tailings as well as their granulometric distribution. These erosional channels are created by the shoreward migration of knickpoints. In some places, this migration can be documented over multiple surveys. Finally, sequential analysis of the 1999, 2004, 2006, 2008 and 2011 surveys has allowed detailed documentation of the infilling of the Lake, including the migration of sediment depocenters, the mechanism of emplacement and the progressive infilling of a series of minibasins. [ABSTRACT FROM AUTHOR]

Wabush Lake is one of the few very well-constrained source-to-sink sedimentary systems in the world that exhibits near-continuous turbidity currents. In this system, approximately 20 million tons of mine tailings are delivered each year to a 40 km 2 lake. Multibeam bathymetric surveys of this lake were carried out between 1999 and 2011. In addition, a program of extensive sampling and seismic surveys, an airborne LiDAR survey and a photogrammetric survey were carried out during this period. The objective of this study was to determine the evolution through time of this anthropic source-to-sink system, from the point where sediments exit the slurry pipelines at the head of the system to the distal end and bottom of the Lake. The total volume of the Lake is around 1 × 10 9 m 3 . Analysis of subaerial and subaqueous datasets allows the evaluation of disposal strategies on the delta topset and on tailings accumulation. Disposal strategies influence the dynamics of the channels on the topset, thus in turn affecting the accumulation of tailings throughout the lake, as well as the shoreline advancement rate. Subaqueous erosional channels present on the bed of the Lake influence the depositional pattern of tailings as well as their granulometric distribution. These erosional channels are created by the shoreward migration of knickpoints. In some places, this migration can be documented over multiple surveys. Finally, sequential analysis of the 1999, 2004, 2006, 2008 and 2011 surveys has allowed detailed documentation of the infilling of the Lake, including the migration of sediment depocenters, the mechanism of emplacement and the progressive infilling of a series of minibasins. [ABSTRACT FROM AUTHOR]

Since 1964, the Iron Ore Company of Canada has deposited iron tailings resulting from mining operations into Wabush Lake, Western Labrador, Canada. This activity has resulted in a continuous hyperpycnal flow flowing over the lake floor. Bathymetric surveys were carried out between 1999 and 2008 as part of the overall environmental Iron Ore Company of Canada plans to maintain safe disposal strategies of tailings into the lake. Here, this dataset is used to study the evolution of different channels present in Wabush Lake and their link with knickpoints found at the head of most of these channels. The channels show notable evolution from one survey to the next. Some knickpoints and channels may be followed throughout more than one survey; the evolution of these knickpoints is the process responsible for the creation of erosional channels. The context in which they appear, as well as the evolution of some of the subaqueous channels is analysed. Cyclic steps and sediment waves are also found in the lake. These rhythmic bedforms, also created by the passage of turbidity currents, are analysed. Sediment waves found in Wabush Lake show values for both wavelength and wave height that are approximately one order of magnitude smaller than most of those found in the marine environment. [ABSTRACT FROM AUTHOR]