GLACIER PHOTOGRAPHER TO DYNAMIC PROCESS INTERPRETER: COMBINING GROUND-, AERIAL-, AND SPACE-BASED IMAGERY TO DOCUMENT, VISUALIZE, AND COMMUNICATE MULTI-TEMPORAL GLACIER CHANGE

In 1965, while aboard a research icebreaker offshore of Antarctica, I photographed my first glacier. Returning home about two months later, the film was developed and printed and I finally got to examine what I had photograph during my first brief glacier encounter. For months afterward, I proudly showed others the small black-and-white print depicting the unknown Antarctic glacier. I am not sure how much I or others learned from the experience or how much geoscience was communicated.

Today, more than 50 years and 150,000 glacier photographs later, my approach is significantly different. Although I still ‘shoot’ glacier targets of opportunity, I now target specific glaciers from known ground- and aerial-based-locations with the goal of duplicating ‘fields-of-view’ that were imaged by me and others in earlier photographs from the same locations. I pair my photographs with these earlier images to generate time-series that can be qualitatively and quantitatively analyzed to identify similarities, differences, and amounts of change. I produce repeat photography ‘then-and-now’ pairs, spanning intervals from 2 to 120 years, and I supplement them with aerial- or spaced-based panchromatic and multispectral images to provide a regional context and to clarify and enhance details about glacier behavior and process. I complete the presentation with a descriptive narrative that summarizes the observed change. I have produced these multiple-source time series for more than 150 unique locations at more than 75 different glaciers.

Concentrating on southern Alaska, where the earliest ground-based glacier photographs date from the 1880s, the earliest aerial glacier photographs date from the late-1920s, and spaced-based glacier imagery dates from the 1960s, provides multiple opportunities to document century-, decadal-, and annual-scale glacier and landscape change. Combining imagery time series for entire geographic regions (i.e., Glacier Bay, Prince William Sound, or the Kenai Fjords) results in regional syntheses that reinforce the extent of similar changes impacting large geographic areas. Many of the repeat photography pairs are posted on a USGS website (https://www2.usgs.gov/climate_landuse/glaciers/repeat_photography.asp) and provided to the National Snow and Ice Data Center for public distribution.