Sea-level and sediments
Mass redistribution on the continental shelf, both with respect to meltwater from ice sheets and sediments being transported by rivers into the ocean, over time and space is of interest especially to stratigraphers and paleoclimate researchers. During the last deglaciation, ice sheets melted to raise sea level, with the shoreline moving landward on the continental shelf. In the first chapter of this dissertation, I have explored the partitioning of meltwater coming from the North American and the Antarctic ice sheets during the last phase of this deglaciation. I show that the north American ice sheet was the major contributor of meltwater to the global oceans about 9000-7000 years ago. In the next chapter, I have looked at fundamental questions about transport of sediments into the deep ocean during sea-level lowstands and the factors behind formation and progradation of the shelf edge, using the distinctly different western and eastern shelves of southern Africa. In the last chapter, I have field-tested the signal shredding theory using a seismic volume from the Mississippi delta and show that preservation potential of different relative sea level signals of varying amplitude in the strata are different, which is dependent also on the internal dynamics of the largest sediment transport system present locally. This dissertation presents research that advances our understanding of paleo sea level, source to sink sediment transport and stratigraphy.