Documenting More Than a Century of Kenai Fjords Glacier and Landscape Change
with Repeat Photography from the Research Vessel Endeavour
Bruce F. Molnia, Ph.D.
Our project will use systematic repeat photography to visually document the extent and magnitude of the southern Alaskan glacier and landscape change resulting from post-Little-Ice-Age climate change. The Kenai Fjords area of the Kenai Mountains, the location of our expedition, is one of Alaska’s most scenic fiord-rich marine basins. With nearly 2,000 m of relief, the Kenai Fjords area has a large number of temperate tidewater glaciers and former tidewater glaciers, as well as dozens of other valley and mountain glaciers.
Repeat photography is a technique in which a historical and a modern photograph, both having similar fields of view, are compared and contrasted to quantitatively and qualitatively determine their similarities and differences. In precision repeat photography, both photographs have the same field of view, ideally being photographed from the same location.
I have been documenting post-Little-Ice-Age glacier change for more than 50 years. Considering Alaska’s remoteness, its early glacier-covered landscape photographic record is extensive. I use this photographic record as a baseline to provide unequivocal, unambiguous, irrefutable, nonjudgmental, visual documentation of the reality and rapidity of glacier change.
As part of the process of documenting what these glaciers looked like in the past, I have collected more than 500 pre-20th century photographs, all postdating the 1867 purchase of Alaska from Russia, and more than 1,000 early 20th century photographs that depict Alaskan glaciers and landscapes. About 50 of these photographs are of the Kenai Fjords area.
Additionally, since 1968, I have personally taken more than 100,000 photographs of Alaskan glaciers and landscapes. Several thousand of these depict Kenai Fjords glaciers. While most are ground- or ship-based, many are oblique aerial photographs of the glaciers that are the subject of my repeat photography activities. Many of the 19th and early-20th century historical photographs record glacier terminus positions that are at or near that glacier’s Little Ice Age (LIA) maximum position. The newer photographs document retreat histories underway for more than a century. All provide conclusive visual evidence of former glacier positions and thicknesses. Coupled with identically located modern photographs, the cycle of glacier change and landscape and ecosystem development can be easily seen and documented.
What has surprised me most is that many of the photographs contained in the pairs that I produced present beautiful images of stark, remote landscapes that convey the majestic nature of this dynamic region with its unique topography and landscapes.
Since 2000, I have systematically performed ground-based, precision repeat photography at more than 70 Alaskan glaciers, revisiting about 225 unique historical-photo locations to document glacier and landscape change. Areas investigated include Glacier Bay and Kenai Fjords National Parks, Prince William Sound, the Copper River Basin, and Alaska’s coastal mountains.
The result is ground-based ‘then-and-now’ image pairs from more than 150 individual Alaskan locations that document glacier and landscape change at each site over time periods ranging from <25 to >136 years. About 45 of these locations are in the Kenai Fjords. Some glaciers have more than one historical photo location. Photographed Kenai Fjords glaciers include Aialik Glacier, Anchor Glacier, Bear Glacier, Exit Glacier, Holgate Glacier, Little Dinglestadt Glacier, Little Holgate Glacier, McCarty Glacier, Northwestern Glacier, Ogive Glacier, Porcupine Glacier, Reconstituted Glacier, Redstone Glacier, Southwestern Glacier, and Yalik Glacier.
Using the research vessel Endeavour, we will visit and reoccupy as many of these already photographed sites as possible during a week-long field expedition in August 2021. At each site, new ‘precision’ photographs will be made permitting the previously produced ‘then-and-now’ pairs to be updated and expanded to ‘then-and-now’ precision-repeat-photography triplets. GPS will be used to document the latitude, longitude, and elevation of every location from which a photo is made. Additionally, new photo pairs will be made at historical photograph locations that I have not yet visited and photographed. Some are sites with National Park Service photographs that post-date 1980. Others are sites that I photographed between 2000 and 2007.
My project consists of:
a historical photograph acquisition and selection phase;
a logistics and mission planning phase where an optimal ship’s track-line was created and a schedule will be prepared;
an expedition phase where identified sites will be visited and photograph and video acquired with supporting metadata;
a data processing phase in which new photo pairs and triplets will be produced; and
an image exploitation and interpretation phase where qualitative and quantitative analyses of collected data are performed;
a report preparation phase where annotated photo pairs and triplets, maps, supporting graphics, and descriptive text are prepared; and
an information dispersal phase where results are released, reports are distributed, and lectures are presented. Project products could easily be packaged into a large format, well-illustrated book, and/or a video presentation.
Our field team consists of myself and colleagues Kim Angeli and Shawn Dilles.
Our intended outcome is successfully conducting a field photography expedition that visits as many Kenai Fiords remote locations as possible, each of which results in the production of a new historical-and-modern (“then-and-now”) repeat photography pair depicting and documenting climate-driven glacier and landscape changes spanning more than 110 years.
At locations that I have previously photographed between 2000 and 2007, previously completed pairs will have a new 2021 image added, producing new then-and-now triplets. Following qualitative and quantitative analysis of each pair/triplet, I will write an annotated summary that describes the history of glacier change and landscape evolution for that location. The compendium of annotated photographic products, coupled with supporting aerial and space-based imagery and ground-based photography and video taken at each site and collected during transits from historic photo site to historic photo site will provide ample material for either a printed or video document summarizing both the expedition and the landscape evolution.
I use repeat photography of Alaskan glaciers and landscapes that have undergone significant change in response to post-Little-Ice- Age climate events to visually communicate the reality of climate change to peers, students, the media, policymakers, and the public, and to attempt to make difficult concepts understandable and knowable to the majority of society not trained in science. If a picture is worth 1,000 words, then a pair or triplet of photographs, all with the same field of view, spanning a century or more, and showing dramatic differences, should speak volumes to documenting that dynamic change is occurring over a very broad region of Alaska, especially the Kenai Fjords region.
Through analysis and interpretation of these photographs -- pairs and triplets of images taken more than a century apart from the exact same location -- the quantitative and qualitative information extracted documents Alaskan landscape evolution and glacier dynamics for the last century-and-a-quarter on local and regional scales and the landscape response to retreating glacier ice. I want people to see and understand that over periods of just decades, the photographed landscapes change from black and white to blue and green. White ice becomes blue water and dark rock becomes lush vegetation. I believe that this conveys the reality of the magnitude and rapidity of global change and provides a smooth transition to a discussion of the causes and future consequences of human activity.