Amidst the Oregon Cascade mountain fires of last fall, something novel occurred. A glacier was discovered, a mass of ice in motion covering 30 football fields. A field team from the Oregon Glaciers Institute (OGI) recently located and conducted the initial survey of this new glacier on the northern flank of South Sister Mountain.
This glacier is not new in a sense that it is recently formed but rather because it was simply missed during the mapping efforts over the last hundred years. It has never been noted, described or mapped, with the U.S. Geological Survey and Forest Service maps showing bare ground where glacial ice exists today, as well as in the past.
Peter Clark, a professor at Oregon State University, states: “This is a very intriguing find. While OGI is conducting much needed documentation on the decay or disappearance of glaciers in Oregon and the attendant consequences, their discovery of a hitherto unknown and active glacier in the continental USA highlights the critical nature of this work. How many glaciers remain? What is their fate?”
Mapping efforts during the mid-20th century relied heavily on aerial photographs to identify features that would be included in topographic maps. It is likely that this glacier was not clearly visible in air photos due to its positioning in a shaded high mountain cirque and therefore was never mapped. The glacier probably formed during the Little Ice Age before 1850. Undoubtedly, this glacier had been seen by a select few mountaineers exploring the remote side of the mountain. However, this knowledge was never passed on to the U.S. government or glacier scientists.
OGI President Anders Carlson, Ph.D. commented that “despite more than a century of exploring the Oregon High Cascades by mountaineers and government scientists, we know very little about our own backyards. The age of discovery is not over, even here in Oregon!”
Glaciers are an important part of the mountain environment and factor heavily into the supply of freshwater streams and groundwater during the warm summer months when glaciers typically undergo some degree of melting. In particular, ranchers and farmers use glacier meltwater as an irrigation source while the near freezing meltwater cools streams for fish spawning as well as cool forests to reduce fire risk. In short, these glaciers act as natural reservoirs, or mountain water towers. This previously unmapped glacier can now be added into what is known about Oregon’s water resources.
OGI co-founder and head of field operations Aaron Hartz noted that “as snowpack and glaciers decline, so too will water flowing out of the mountains into the forest and fields below. This decline will lead to drier mountain forests and increased risk of fire.”
OGI has been working in recent months to document the condition of Oregon’s remaining glaciers. Their fieldwork has also shown that many mapped glaciers in Oregon are now only remnants and are essentially dead ice bodies, meaning the ice is no longer flowing and deforming under their own weight. Glaciers hang in the balance of accumulating winter snow and summer melt. When summer melt exceeds snow accumulation, glaciers decline in mass. OGI’s goal for the coming summer and years is to set up a proper glacier monitoring network that will inform on glacier changes and their attendant consequences. This will allow for projections of future glacier viability to determine if, or when, they may disappear from Oregon’s high Cascade summits.