Values for core 94BC28 (88.87°N, 140.18°E) are from Darby et al. [1997]; values for PS1230 (78.9°N, 4.8°W)are from Darby [2003]. While the northern Canadian Islands are the largest source or one of the largest in all three cores, there is a significant shift from northern Ellesmere Island to Ellef Ringnes Island from the older ACEX (87.52°N, 136.11°E) record to the more recent record. Note that Ellef Ringnes Island and northern Ellesmere Island are included in the northern Canadian Islands, and the Kara Sea also includes the northern Kara Sea.