A collection of repeat photography of glaciers from the National Snow and Ice Data Center (NSIDC). The photos are taken years apart at or near the same location, and at the same time of year. These images illustrate how dramatically glacier positions can change even over a relatively short period in geological time: 60 to 100 years. Background essay and discussion questions are included.

The NOAA Sea Level Trends map illustrates U.S. regional and some international trends in sea level, with arrows representing the direction and magnitude of change. Students can investigate sea level changes around the U.S. and some worldwide using an interactive map interface with supporting data plots and tables.