Tracking the Photographic History of the Environment

Scientists have been using photography to document the history of glaciers and other natural features for some time. But not everything has been formally doucmented. Yet there's a significant number of historic photographs that can be used to document changes since they were taken, if the original location can be determined - something that's much easier with modern digital photography and mapping techniques. 

And Canada has a big part to play in this research.

Unlike most of Europe and the U.S., Canada was still largely terra incognita in the late 19th century. Eager to build railways opening up the land to mining and settlement, the government sought to map thousands of miles of rugged terrain at an unprecedented rate. Laying down chains to measure distance on the ground — the standard surveying technique of the period — was far too laborious, and it was practically useless for plotting elevation in a mountainous region. As the government grew impatient, a surveyor named Edouard Deville proposed trying out a method invented in his native France: With the help of an optical device called a theodolite, which measures angles, a surveyor could translate a comprehensive set of panoramic photographs into an accurate topographic map.

 Deville and his successors succeeded, charting most of Canada between the 1880s and the first decades of the 20th century. Once their maps were complete, the photos were no longer needed. The heavy glass-plate negatives were set to be destroyed, but they ended up misfiled in an Ottawa warehouse (perhaps intentionally diverted by a far-sighted civil servant). Higgs’ grad students found them while investigating gaps in the Jasper prints, exploring equivalent photos from a neighboring park. The whole collection numbered 120,000 images, neatly preserved in 300 large boxes.

Higgs couldn’t let the opportunity pass him by, and he immediately started retaking some of the photos. “We’ve done around 8,000 repeat images over the past 20 years,” he says. The large-format film camera has been retired, supplanted by digital photography. Google Earth and GPS technologies get the photographers to the right spot, typically within a meter of where the original surveyor once looked through his lens. On the ground, the rephotographers — mostly students now — often see remnants of the original surveys, including fabric from century-old flags.