3. Quantifying Sediment Deposition Patterns of Lake Underflows Using a Novel Underflow Sediment Trap

Abstract

Lake underflow deposition is an important limnological process which greatly affects sediment deposition patterns and lake varve formation. Currently no feasible, cost‐effective device or method has been regularly utilized to quantify sediment deposition patterns. This study utilizes a novel underflow trap which was deployed at two locations at the bottom of a High Arctic lake subject to seasonal river inflow. It was found that a peak in lake bottom temperature departures, lake bottom turbidity, and river suspended sediment concentration are strongly associated with peak underflow deposition events. Furthermore, evidence shows that deposition amounts are greatly reduced as underflow distance increases. One year was also found to show a clear lag in deposition patterns between two distant stations. This method of quantifying underflow deposition is useful for determining deposition patterns over time and space. This knowledge is useful in monitoring the changes in the lake bottom waters, and for aiding in the reconstruction of past sediment deposition patterns.