It is generally agreed that there were three minima in the Little Ice Age, beginning about 1650, about 1770, and 1850, each separated by slight warming intervals.
The Maunder Minimum is the name given to the period roughly from 1645 to 1715, when sunspots become exceedingly rare, as noted by solar observers of the time.
It is named after the solar astronomer Edward W. Maunder (1851–1928) who discovered the dearth of sunspots during that period by studying records from those years.
During one 30-year period within the Maunder Minimum, for example, astronomers observed only about 50 sunspots, as opposed to a more typical 40,000–50,000 spots.In the mid-17th century, glaciers in the Swiss Alps advance, gradually engulfing farms and crushing entire villages.
The River Thames and the canals and rivers of the Netherlands often freeze over during the winter, and people skate and even hold frost fairs on the ice.
