sentences:  After growing gradually towards 4,000 years before present (BP) the glacier has been of near present size over the last 4,000 years, growing slightly larger over the last 2-2,500 years.Prior to the climate optimum and following the deglaciation the glacier melted some 10,000 years before present.The flat valley-shoulder that the lake is eroded into is locally known as a ""fly"".