Melt water release from North American glacial lakes that caused the 8.2ka event: possible magnitude of a single or two-staged event

• Main Author: Macdonald, Alexander
• Other Authors: Faculty of Science & Technology.
• Format: Thesis
• Language: English
• Published: University of plymouth 2012
• Subjects: Ice Sheet
• Online Access: http://hdl.handle.net/10026.2/1796

Many studies indicate that the 8.2 ka cooling event was caused by a freshwater outburst from the ice dammed lakes formed from the retreating Laurentide ice sheet. Although many results indicate that this outburst occurred in two pulses, some studies conclude only one outpouring event. Sea level will have risen due to this input of water. This study attempts to add to the amount of available data to establish whether sea level rose in two events. The data was collected from the Solway Firth region of the British Isles. It used modern and fossil foraminifera data to create a transfer function and recreate past salt marsh surface elevations. This data can be used to establish paleo-sea level. Two sites were used for this study. One indicates one abrupt sea level rise event, with a minute peak present thereafter. The second core clearly indicates two meltwater pulse events. These occur post 8947-8403 ka and pre 7973-8295 ka which are similar dates to previous studies. Magnitudes produced in this study vary, with a figure of the meltwater outburst at Priestside Flow of ~0.5x1014 m3 which is significantly lower than previous studies. This may be due to only one clear outburst event recorded in the sampled core. Drumburgh Moss shows a potential meltwater outbursts of 4.5x1014 m3 or 9.7x1014 m3 which are similar to figures produced in previous studies.