Today, we set off in search of a glacier, but not just any glacier though, Emmons Glacier, the glacier with the largest surface area in the lower 48 states. It slowly creaks down the north-eastern side of Mt. Rainier here in Washington State. Seeing the glacial-carved geology of a place like Mt. Rainier, which also has its amazing volcanic origins, is great evidence of the power of glaciers to change a landscape. It’s also an opportunity to consider the changes that are happening to glaciers as climate changes. Even though there was some unseasonably early snow the last few days, we assumed we would be able to do it. Hopefully, there wouldn’t be too much snow, and we could make it.
The trail up to Emmons Glacier is called Glacier Basin Trail and is one of the climbing routes up to the top of Mt. Rainier. It starts from the White River Campground in Mt. Rainier National Park. Emmons Glacier is the White River’s source. The river flows all the way down to Tacoma and gets its name from the white colored water, filled with fine chalky glacial till. There had been about 4-5 inches of snow recently, and the huge Douglas fir, hemlocks, and cedars along the river were covered with snow. It was starting to warm up, close to 34 degrees, so some big chunks of snow would fall from the tree limbs creating mini-avalanches in the forest.
The hike up along the trail follows an old wagon trail to a copper mine that was used in the late 180-s and early 1900s. After a while the trails ascends quickly and then gets flat for most of the rest of the way. Along the trail you can see the big U-shaped glacial valley that the White River flows down through. Up ahead, the the snowy fog, the Emmons Glacier is flowing down. It’s a little hard to see at first though, because everything is covered with snow.
So, we arrived at the Emmons Glacier Trail which branches off to the left. We had to cross a log bridge. It was difficult as the narrow log was covered with deep slippery snow. Luckily, holding the one handrail tight, we each crossed safely. Here was the perfect spot to see where two different glaciers used to be. Less than 100 years ago, the Emmons Glacier was at this spot. Up to the right is a different glacier, the Inter Glacier. They had carved out these u-shaped glacial troughs, and as they melted away, the river took their place. Some climate change and warming of the Earth is natural. The Earth’s average temperature gets warmer and colder in cycles. The Earth is naturally in a warming period after the last ice age ended about 10,000 years ago. However, human created pollution is causing temperatures to get hotter, faster, making glaciers melt away faster too.
Glaciers are heavy. As they move down a mountain, they carve into the rock and create rock debris called moraine. The moraine that is deposited on the sides is called lateral moraine. After we crossed the Inter Glacier creek, we had to climb up the lateral moraine, and hike some more, in order to finally see Emmons Glacier. From the top of the moraine, far in the distance, we could see the foot of the glacier. The foot, snout, or terminus, is where the glacier ends and usually melts into a creek or river.
The ice here at the foot of the glacier is blueish because it is so old. Pressure from the snow above, over hundreds and thousands of years, turns the snow below into thick, dense, blueish ice. At the base of the foot is a cave where the melt water that starts the White River comes from. When there is no fresh snow, this part of the glacier is covered with rocky debris, making it look more like rock than moving ice. Glaciers naturally move down the mountain, slowly creeping down the mountain, usually moving just inches each day, but sometimes moving as much as 3 feet. Many scientists study these glaciers to understand how glaciers change landscapes and how human activity changes glaciers.
Learn more about glaciers and glacial geology here: https://www.bbc.co.uk/bitesize/guides/zftycdm/revision/3