I planned our route for the remainder of Hanna’s visit, before we departed Palmer. The Matanuska Glacier was only an hour east and on the way to our next stop in Valdez. I reserved a 2-hour glacier tour for 10 AM, and we headed out under mostly sunny skies. As had become routine, the scenery was amazing, and we took advantage of periodic pullouts for pictures. Hanna was in the passenger seat, while I sat prepared to take photos through the back seat windows. Suddenly, she screamed, “a glacier,” and we each sat awestruck by our first glimpse of Matanuska from about 5 miles away and several hundred feet below us. Stunning!
We descended into the Matanuska River Valley and exited onto the glacier access road. Conveniently, there sat the Arctic Cup coffeeshop, but we were running too late to stop. We were greeted by an unexpected and unnerving traffic sign. The access road was unpaved, steep, and riddled with potholes. Suddenly, towing an RV on this road didn’t seem wise; however, we had no choice. It was an agonizingly slow, bumpy mile to the Visitor Center and controlled entrance gate. Check-in went smoothly, and we were advised not to worry about missing our reserved time slot. The remaining 2-mile drive to the equipment and tour-guide assignment building was scenic but even slower and bumpier.
We had no idea where to park, but a tour guide walked out to greet us and directed MFI to the east side of the building. We couldn’t have asked for a better parking spot or more ideal location for showing off Arthur Air Stream (refer to feature photo). The equipment and tour assignment building was large, had registration tables in front of equipment storage, contained a convenient bank of toilets and wash basins, and provided folding tables where assigned teams received pre-tour instructions from their guides. I took two pictures of the glacier face before we descended and started the tour.
We crossed a pontoon footbridge, which spanned a lake of glacial summer melt below the face, and stopped at a station of picnic tables where we each donned crampons. Once properly equipped, our guide trained us how to safely stand and walk up and downhill without tripping. We were required to practice before continuing the tour.
Ideally, our group was only nine people, not including the young guide from Ecuador. There were the three of us, a couple with two pre-ten-year-old boys, and two other young women. The boys were poor listeners, so the guide spent a fair amount of time explaining to and showing them the dangers we all faced while hiking across a glacier. The biggest concerns were falling or slipping into a crevasse, or stepping into what looked like a small puddle of water only to discover it was filled with glacial silt, which acted as quicksand and could be very deep. Walking single-file was the most important rule to follow.
The glacier ice came in three colors: white (clear), blue, and black. Our guide stopped beside a wall of sun-weathered ice to give us a chance to use his pick-axe and detach diamond-esque chunks. These chunks were entrained with lots of air, which gave them their prism-like clarity. The more familiar and common color was blue. Blue ice occurs when tons of snow, ice, and rocks create pressures that squeeze most air bubbles from the ice and make it dense. The dense structure absorbs the longer red and yellow wavelengths of light, while reflecting the shorter blue wavelengths. The longer distance the light is transmitted and scattered, the bluer it appears. Finally, the pressures become great enough to squeeze all air bubbles from the ice, such that, no light escapes, and the ice looks black. Our guide exposed this black ice for us by pouring water to clear away the floating silt. The ponds, lakes, visible glacier, and mounds of rock we saw around us, all sat atop black ice up to 15 meters thick.
We stopped at another spot along this same type of wall, where the guide used his pick-axe to start the flow of fresh water. He demonstrated how easy it was to find a reliable hydration source and encouraged us to taste the pure natural flavor of glacial water. It was remarkably better than the treated water we consume daily.
I think most readers are familiar with the term glacial moraine, where “moraine” refers to the soil and rocks ground up and carried by the movement of a glacier over time. There are four types: lateral, medial, ground, and terminal. A lateral moraine occurs at the outer edges of the glacier where it erodes valley walls. A medial moraine is one or more long narrow ridges of soil and rock formed when glaciers intersect. The ground moraine refers to the thick unseen layer of soil and rock being crushed beneath the glacier and only becomes visible once the glacier melts. The terminal moraine forms at the glacial face or terminal where we toured. We saw mounds of lateral and terminal moraine, as well as, the ends of medial ridges as they became exposed at the terminus. We certainly didn’t expect the terminus to look so… well… dirty.
Once we climbed to a clear view of the face, our guide talked about the visible scree lines (moraine tails) and the tall blocks or columns of ice called seracs, which form and eventually collapse or calve.
The guides conducted so many tours that they knew in advance, depending on the participants of each group, where they wanted to go and what they wanted to highlight. One of the go-to sites was an ice cave. We were each offerred the opportunity to stand at the mouth and have our pictures taken. But with permission, I wanted to go in further. Listen closely at the begginning of the video and you’ll hear our guide comment, “Mister Adventurous. This is sick“!
Our guide also took time to explain how glaciers are able to move large boulders, not just rocks. As the ice on the downhill side of a boulder melts, the rock drops. Then on the uphill side, as melt water flows beneath the rock and then freezes, the differential created allows the boulder to move during the next melt. According to our guide, University of Alaska students taking courses in Glaciology come to Matanuska because of its accessibility, select boulders, and monitor their movement as part of course studies. We don’t want you to think that glaciers only move soil and small rocks.
We experienced a variety of textures on the glacier. I took these pictures to share, yet again, the artistic talents of mother nature.
Also, I took many more pictures than what I’ve included in this blog. But here are a few more just because we thought they could expand your percetion of the tour.
Matanuska is the largest glacier accessible by car in the U.S. and it more than satisfied our bucket list item of “experiencing a glacier.” Yet as fantastic as it was, this satellite image of its full 27-mile length blew us away. I added a star on the small spot we toured. Sadly, as a result of climate change, Matanuska is in decline as indicated by receding and thinning measurements. Each year, it currently advances 80 meters but recedes 90. At its thickest, Matanuska is 300 meters deep, although in its basal region (where the glacial ice is in direct contact with bedrock) the thickness only varies between 3 to 15 meters. Matanuska is thinning at a rate of 0.3 meters annually. Gladly, as a result of its shear size and assuming all impacts remain unchanged, Matanuska should survive another 1,000 years.
