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Mount Shasta: The Medusa of Siskiyou County

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


For those of you who may or may not know me, I grew up in the Pacific Northwest. My childhood was spent in Siskiyou County, California. Siskiyou County is the “Atlantis” of the west coast. There is no place like it anywhere else. With mountains, valleys, rivers, lakes, and abundant wildlife; there is so much to explore. From caves to trails and parks, one can find almost anything to do. There are places to swim, ski, hike, fish, hunt, and just have fun. Needless to say, Siskiyou County is probably one of the largest natural playgrounds around.

Amongst this natural playground, lies a danger, a beauty, and a reminder that nature can prevail. Siskiyou County is the home to Mt Shasta. Mt Shasta is not only a mountain to many of the locals but it is one of the largest stratovolcanoes on the west coast. A stratovolcano is a large, steep-sided, symmetrical cone built of alternating layers of lava, ash, cinders, blocks, and bombs. It is also called a composite volcano. It is a type of cone volcano that is built up layer by layer over subsequent eruptions.

What exactly is a volcano? It is a vent, fissure, or rupture in the earth's crust through which molten lava and gases erupt or escape. Think of a volcano like a steam kettle. Pressure builds up inside the kettle from the boiling water. Once there is enough pressure from the boiling, steam is released. This is similar to what happens in volcano. Only in a volcano, there is more than steam that comes out. Earthquakes underneath volcanoes are caused by the movement of magma (liquid lava). The magma exerts pressure on the rocks until it cracks the rock.


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Shasta is possibly Indian or Russian and means “White Mountain”. The elevation of the mountain is 14,179 feet. It is the 46th highest mountain in the United States. It is part of the cascade mountain range. It also has four volcanic cones. The first ascent was August 1854 by Captain Elias Pearce. The volume of the mountain is 350 cubic kilometers and has a base diameter that is 17 miles.

Mt. Shasta is considered an active volcano. its last eruption was in 1786 which was over 220 years ago. It has erupted at least every 800 years but now, the activity may be changing. Recently, there has been recorded earthquake activity below the mountain. Yes, this can be cause for alarm.

It might, however, sound familiar. Another mountain, Mt St Helens, gave us the same experience.

Is Mt Shasta the next Mt St Helens? And if it is, are we prepared? Mt. Shasta is considered a “high threat”. This is simply because of the populated towns surrounding the mountain. If the mountain does erupt, it will be seen as far south as Sacramento. It has been known in previous eruptions to cause a landslide that reached from Weed, California to Yreka, California. That is a distance of about 28 miles long. It has been known to vent boiling clouds of fast-moving debris and hot gasses known as pyroclastic flows. Once the mountain erupts, it will probably have intermittent eruptions for years to come.

What can we do to prepare for such event? We can never be fully prepared for what nature has in store for us. As much as we examine data and patterns, we can never fully predict a natural event one-hundred per cent. But we can have emergency plans. These are plans like evacuation plans, storing up food , having flashlights available, and having backup plans for the unexpected.

Though we may “fear” such event, we must remember we only fear what we do not understand. With this in mind, we need to develop educational programs. Programs that can help people understand what a volcano is and what it does. Along with this, we need to educate about earthquakes; what they do and why they happen. The more we understand something like this, the more we can have an appreciation for what nature does and how it behaves.

For now, let us treasure the beauty of the mountain; but like the greek goddess, Medusa, remember beauty can also be deadly.

Images: Fall: Mt. Shasta, McCloud, and northern California; September 2012; Winter: Shasta Mountain Guides; Spring and Summer: Hike Mt.Shasta.

Joel Taylor grew up in Siskiyou County, California. He attended Yreka High School in Yreka, California. After that, he attended College of the Siskiyous in Weed, California and then transferred to Southern Oregon University in Ashland, Oregon where he graduated with a Bachelor's of Science in Physics. Since then, he has had his own tutoring and research company. He has also worked at the Maryland Science Center in Baltimore, Maryland. Joel is also a member of the American Physical Society and American Institute of Physics.

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