The impacts of one hundred years of climate change at Okpilak Glacier

About 1907, Ernest Leffingwell travelled by dog team south from the arctic coast to explore the mountains and glaciers of the eastern Brooks Range in Alaska. In my opinion, Leffingwell deserves the title of 'Most Righteous Early Alaskan Arctic Scientist'. He had no real sponsorship or funding, he just decided to spend part of his life here making scientific investigations of this largely unknown region, even after all of his colleagues deserted him for warmer climates. Unlike his counterparts of the time who were mostly looking for glory and doing only enough science to support that, Leffingwell quietly wandered on his own, dedicating himself to a better understanding of this interesting place. I dont believe that anyone since then has made contributions with similar depth and breadth. His work remains largely unknown outside of his fan club, however, because his single publication is quite hard to find. But now it has now been digitized and is available online here, thanks to Alaska DGGS. I have also included a small photo collection there that I've acquired largely through the USGS photo library in Denver. This is a scratch page intended to give a sense of the photographic project I'm working on in the Okpilak valley to document the impacts of 100 years of climate change on the landscape there. As I get closer to completion, I'll revise it to be prettier and include more content.

Leffingwell managed to hike all the way back into Okpilak Valley, where he found the large Okpilak Glacier at nearly its maximum extent for the past few thousand years. His visit was just after the end of the Little Ice Age, a brief cold snap of several hundred years that ended at the end of the 19th century. Our dating methods indicate that 1890 is a good figure to use for the end of this cold snap. As you can see in the photos below, the glacier was nearly filling its moraine at that time. When Leffingwell visited, glaciology was not even a science yet, with just a few folks having even a basic understanding of their dynamics, and the concept of global ice ages was barely conceived of.

In spring 2004, I and my colleagues surveyed the surface elevation of Okpilak Glacier by skiing down it while carry high resolution GPS equipment. As part of this adventure, we also discovered all of Leffingwell's photo sites. Several other people had also discovered this particularly site, but no one I talked with (and I think that's everyone) claimed to have put up the cairn we found there, so we assume it was Leffingwell who erected it.

Click here to see a flash movie morphing between these two images.

I later visited the USGS photo library to learn more about Leffingwell and search for his photos. The first time I was there, I discovered that they have what seems to be the entire collection of his photos from this trip (though a few more may exist in the Dartmouth archives), many of which were not in his 1919 manuscript. While searching through them, I noticed several of them were actually part of a panorama he took from this same spot. The panorama was composed of both landscape and portrait shots, and probably the camera moved a little between shots. But I crudely stitched them together to form this image. (NOTE: If someone would like to try to stitch these for real, please let me know and I will send you the photos). We returned to the glacier in August 2004 when there was less snow and took this panorama from the spot. It easy to see the changes in the central hanging glacier and the main Okpilak Glacier to the right. But if you look closely, you will see enormous changes in ice cover on the mountains to the left and right. Glaciers like the ones seen here change in size basically only due to changes in climate, and our measurements here and nearby show that the rate of ice loss is increasing with time and our modelling shows that most of the ice in this region will be gone in the next 100-200 years, should the current climate trends continue as predicted.

This year (2007) I decided to invest some time and energy into becoming a better panoramic photographer. I had previously taken perhaps 50 panoramas from remote locations I've worked in, but these have always been hand-held with point and shoot cameras. Though they make pretty images, I quickly became aware of their weaknesses and started down the slippery slope of becoming a better panoramic photographer. In many ways, this is way more complicated than being a 'regular' photography, because all of the same rules of photographic exposure, composition, focus, etc apply, but in all directions. Similarly, the backend processing is quite an art form, with trying to adjust settings not just of one photos but potentially hundreds at a time, and dealing with lots of details with stitching, blending and displaying. I took 375 panoramas in August 2007; you can find some of them here or here in Google Maps or here in Google Earth. You can find more photos and a description of our trip here.

Anyway, I returned to the site in August 2007 to create a gigapixel panorama. Unfortunately, sometime in the previous three years, the original photo site and its cairn had subsided down the cliff, so it was no longer possible to duplicate the original photo exactly. I picked a new spot not far away that seemed safe enough to work from and that might last long enough for someone to repeat this new one. The image I created here consists of 504 photos stitched together. The photos were taken with a Nikon D2xs digital SLR camera, a Nikkor 18-200mm zoom lens set at 200mm, a Seitz Roundshot motordrive, a Really Right Stuff nodal mount, an Acratech levelling head and a Gitzo 01 carbon fiber tripod. It took me about 200 hours in a 2 week period to get this far, which is a 2 gigapixel version of a potential 6 gigapixel final result. At the moment I'm plagued by some annoying computer issues which prevent the full stitch from saving, and I still have some exposure blending cleanup other photographic work to do, but I'm saving that for the final image. In the meantime, I think you'll get the general idea of the coolness of the final result from this one. Note that there are two ways to view this image from this page: the Zoomify format in the window below and using HDView using the link below that.

This is a 2 gigapixel panorama from the Leffingwell site, shown in the Zoomify format; the full resolution image is 6 gigapixel. NOTE: you may see a popup blocker message at the top of your page -- you must click it and allow the popup, otherwise you may just get an empty box here. Once displayed, use the controls beneath the viewer or your mouse to zoom and pan.

Click here to see this image in HDView. HDView requires a manual software download from Microsoft, and it currently only works on Windows. But it is a far superior view in terms of it's full screen viewer, seamless zoom, and its dynamic range adjustments. You can learn more about HDView here.

After I returned from the field, I returned to the USGS photo library to see whether I could track down Leffingwell's original negatives. I heard a rumor that they might be there, but previously I had only come across some prints made from them. After some exploring, and leg-work by Colleen the librarian, we discovered an entire storage room that no one there apparently knew about (it took several days to track down a key after we found it) inside of which we found file cabinets filled with negatives, glass plates, and the like. Sure enough, we also found Leffingwell's negatives (or copies of them anyway). So now we're in the process of having these scanned in as high resolution as possible, to match the gigapixel imagery resolution as closely as possible. If anyone knows where the true originals may be, please let me know, I'd be happy to pay to have them scanned at ridiculous resolution and help with archiving costs.

In the near future, I hope to do some time-lapse panoramas and do some photo overlays with a new digital elevation model that we hope to create soon. Our studies of ice volume change will also be coming out soon, and I'll post a link here.