Week 4 - Volcanoes: Mount Rainier

Image courtesy of Stan Shebs

                For this week’s travel post, I chose to write a segment on an active volcano that exists only an hour and a half away from my own house: Mount Rainier. I have actually visited this mountain multiple times, and did not previously realize that it was considered an active volcano. Although its last eruption was in 1894, the USGS does consider the volcano active but dormant.

            Mount Rainier is quite large, with a summit elevation of 14,411 feet. According to Mount Rainier’s history, the height of the mountain is due in part to multiple eruptions and subsequent cooling of lava flows. Defined as a composite volcano (or stratovolcano), this mountain was primarily formed via “sluggish, intermittent lava flows and explosive eruptions of ash and rock” (APN Media, 2008).

            In addition to the general composition of the mountain, there is additional evidence of past eruptions in the surrounding area. Approximately 5,700 years ago, an eruption that occurred at Mount Rainier caused a large portion of the mountainside to collapse and crumble downward. Massive amounts of rock, mud and debris flowed down the northeast face of the mountain, and created a 125 square mile mud slide called the Osceola Mudflow. Presently, the cities of Sumner, Auburn, Kent and Puyallup are all built on top of this historic flow.

            Mount Rainier is predicted to erupt again, and is considered to be one of our nation’s most dangerous volcanoes. This is due largely to its location within such a densely populated region, but the predicted eruption hazards are significant as well. The primary safety concern involves Rainier’s icy mountain top, which – if melted during an eruption – would result in “rapidly flowing slurries of mud and boulders known as lahars” (Driedger & Scott, 2008). Additionally, the volcanic ash from an eruption can disrupt local flight operations and endanger airborne aircraft.

            While Rainier is predicted to erupt again, there is no telling how soon. The USGS states that an eruption of Mount Rainier can only be predicted days to months before the eruption occurs, so it is important to prepare ahead of time. Overall, it was fascinating to learn that such a dangerous landform exists only an hour and a half away from my house! Personally, I trust that the local experts have prepared my region properly for this kind of potential disaster, so I am not overly concerned about pending eruptions.

References

APN Media. (2008). Mount Rainier National Park - History and Culture. Retrieved from http://www.ohranger.com/mt-rainier/mount-rainier-history

Driedger, C. L., & Scott, W. E. (2008). Mount Rainier - Living Safely With a Volcano in Your Backyard. Retrieved from https://geology.com/usgs/rainier/