Description: As human-induced climate change causes dramatic decreases in sea ice across the Arctic today, geologists ask: Has sea ice disappeared from the Arctic in the past? When climate warmed in the past, how did sea ice decline? Did it increase in some places and decrease in others? Was it an abrupt decline or slow? In this talk, I’ll summarize how diatoms in marine sediments can be used as tracers of past sea ice and then show how sea ice changed in the North Pacific and its marginal seas after the Last Glacial Maximum.

Intended audience: This talk will be offered at a general level, while also having fun with using the actual species names of diatoms. Ecologists, geologists, and Arctic enthusiasts may be interested.