Wind Driven Circulation Triggering Whiting Events in Lake Kivu

Session: 27. - Emerging Partnerships, Research, and Capacity in the African Great Lakes

Anthony Vodacek, Rochester Institute of Technology, vodacek@cis.rit.edu
Rob Uittenbogaard, Deltares, Rob.Uittenbogaard@deltares.nl
Robert Hecky, Editor, Journal of Great Lakes Research, rehecky@gmail.com
Gaetan Sakindi, Lake Kivu Monitoring Program, sgaetan16@gmail.com
Wim Thiery, ETH Zurich, wim.thiery@env.ethz.ch
Nicole van Lipzig, Catholic University Leuven, nicole.vanlipzig@kuleuven.be
Meinard Tiessen, Deltares, Meinard.Tiessen@deltares.nl

Abstract

Lake Kivu in Central Africa has been shown to be very dynamic with respect to carbonate deposition over the past few thousand years and the variation is linked to changes in hydrothermal inputs related to the local volcanism. One period of carbonate deposition started just four decades ago and is ongoing as recorded in sediment cores. One way carbonate deposition is demonstrated is through whiting events known to occur every few years in Lake Kivu. We use MODIS time series data to identify which years had whitings and to identify the spatial characteristics of the whitings. The recent whitings occurring during the MODIS data record have all originated in the same general time of year and location in the eastern side of the lake near Kibuye, Rwanda and spread to the remainder of the lake in a somewhat consistent pattern, revealing aspects of the surface circulation. These events can be linked to specific carbonate deposition layers in some cores. These patterns in the MODIS data compare favorably to surface circulation predicted using the Delf3D-FLOW and WAQ codes and provide evidence for change in seasonal wind driven circulation as the trigger for whitings.

1. Keyword
Africa

2. Keyword
hydrodynamic model

3. Keyword
remote sensing

4. Additional Keyword
Lake Kivu