A varve is one year pressed into two thin bands: a pale summer layer of diatom bloom and algae, settling over a dark winter layer of fine clay dropped through still, ice-covered water. Glacial lakes lay one couplet down every year — count the couplets and you have read a calendar no one wrote.
Warmer years melt more and bloom harder, so their summer band is thick; cold years are thin. The bands ARE the climate record.
click the core to deposit a year · drag the climate slider · press play to run · sound is opt-in