Mount Van Halens

On May 18th 1980, everything the United States knew about volcanic eruption was put to the test when the most destructive volcano in history erupted in Washington, Mount St. Helens. I chose to write over the topic of Mount St. Helens due to its indelible historic significance as well as acknowledging the possibility of re-eruption in the later years.

Following the discovery of volcanoes, geologists study the characteristics and properties in order to accurately label and determine its geological category. For instance, volcanoes are typically categorized by their size or activity and then classified based on the “explosiveness and pose of danger to life” (Brantley). More specifically, known as composite, shield and dome volcanoes. Mount St. Helens falls under the composite volcano category (stratovolcano), based on its steep features and layer composition meaning the levels of ash, variety of lava and distance of the semifluid lava upon eruption. This volcano is located in Skamania County, Washington, where the nearest town is 18 kilometers away from the bottom of the mountain, and in the Pacific Northeast Region of the United States. Being located in that specific region, Mt. St. Helens sits on top two tectonic plates , Juan de Fuca an oceanic plate and the North American continental plate creating the Cascadia Subduction zone, meaning the oceanic plate slides below the continental plate (Akpan).

The eruption that took place in May of 1980 surpassed all previous examples of violent volcanic eruptions in the United States. With approximately fifty seven deaths from inhaling hot ash and numerous accounts of injury throughout the eruption process this event will forever be remembered (Taylor). Researchers and geologists also need to consider the long-term health ramifications of involvement and shear proximity to the blow such as: chronic lung cancer, contractions of respiratory problems, bronchitis and asthma. Over 97 patients tested positive for lung cancer from the general area according to the US Library of Medicine National Institutes of Health writers Baxter, Ing, Falk. Not only did the eruption itself have astronomical repercussions for health related events but also in an environmental aspect. For instance, this prompted the largest landslide known to date (Taylor). It generated so much sound that hundreds of miles away heard the blow, shockwaves radiated, ash circulated 15 miles into the air, and ecosystems, entire forests, ice caps, all destroyed. What I found most startling during research, was the VEI index of Mt. St. Helens, coming in as a 5 on the 8 level scale (USGS). This was due to the severe impact of the actual blow but in fact did not produce a large amount of magma upon the surface.

I mentioned previously that volcanoes are divided into categories depending on the amount activity it undergoes such as: active, dormant, or extinct. Mount St. Helens to this day remains an active volcano, meaning that at any point can begin the eruption process again. The most recent activity deriving from the volcano occurred in the period of 2004-2008. Surprisingly, prior to the eruption there were very few instances of earthquakes surrounding the mountain, which is often the largest indicator of reawakening state. Although, this eruption was not nearly as detrimental or adverse as the one in 1980-86 immense consequences were reaped. For example, in late October lava and volcanic ash flared out the top of the mountain in sporadic sequences for a thirty-six month period. This demolished the preexisting dome presence of the mountain and left behind an “area footprint of approximately 127 acres” and until it later settled forming another dome 460 meters high (USGS).

Works Cited:

1. https://www.livescience.com/27553-mount-st-helens-eruption.html
2. https://www.pbs.org/newshour/science/explosives-reveal-mount-st-helens-cold-heart
3. https://volcanoes.usgs.gov/volcanoes/st_helens/st_helens_geo_hist_100.html
4. https://www.theatlantic.com/photo/2015/05/the-eruption-of-mount-st-helens-in-1980/393557/
5. https://www.ncbi.nlm.nih.gov/pubmed/6870351
6. https://pubs.usgs.gov/gip/msh/comparisons.html