The Rumble in Chino Valley: A Look at Arizona's Seismic Activity
Growing up in San Diego, California, the phrase "stop, drop, and cover" was as familiar to us as the ocean's tides. The ever-present threat of earthquakes was a constant companion, subtly shaping our daily lives. We were always prepared and ready. Whether it was finding a sturdy doorway or ducking under a robust desk, we knew the drill. We were taught about the 'triangle of life,' a survival theory suggesting that the space next to a large, sturdy object, like a desk, could form a triangular void if a building collapses, providing a safe haven. For the past three years, since my wife and I moved to Prescott (she's a native Prescottonian, so go ahead and stop shaking your fist), these earthquake preparedness drills have faded into the background of my mind. However, today's seismic event brought those memories, and the memories of two earthquakes I lived through in particular, rumbling back in a profound way.
The Northridge earthquake in California is etched into my memory like a deep fissure in the earth. I recall being jolted awake from a deep sleep, my heart pounding as I stumbled towards the nearest doorway. The ground beneath me was shaking so violently that walking was impossible. I had to squat in the doorway of my room, and I remember being awed at the raw power of Mother Nature. At the time, I would have thought that I was sitting on top of the epicenter of that quake, only to find out that it was over 100 miles away. That is true power. Even though I was a child and this was over twenty years ago, I can still vividly remember that strange feeling of waking up to the world shaking all around me.
Then there was the Easter Day earthquake, a stark reminder of our vulnerability as humans. At the time, I was living in a second-story apartment. The quake struck in the middle of the afternoon, just as I was stepping out of the shower. Fortunately, I had just put my boxers on, because I would not have hesitated to dash outside with or without them. I recall barely navigating the trembling staircase, with the metal handrail bending and flexing so much that it looked like it was made of rope. After making it downstairs, I found myself in an open area away from telephone poles and electrical lines, and I remember thanking God as I realized I was not the only one standing outside in the alley, surrounded by neighbors, in my underwear.
People had fled their homes without a second thought for their attire, their fear overriding any sense of modesty. Some were attempting to cover themselves with whatever they could find in the alley. It was a surreal scene, but it underscored the genuine fear that had gripped us all. We laughed about it afterward, our shared experience fostering a sense of community that was deeper than before. It was a stark reminder that when faced with the raw power of nature, all we truly have is each other.
Fast forward to today, July 23, 2023, when residents of Chino Valley, Arizona, experienced a 3.8-magnitude earthquake. The U.S. Geological Survey reported that the epicenter was in a neighborhood near Center Street and Railroad Avenue, occurring around 1:52 p.m. The quake was just over 3 miles deep into the earth, and more than 800 people submitted reports about feeling the earthquake. This event brings to light the seismic activity in the Chino Valley and the greater Prescott area, which are situated on significant local fissures. The largest of these is the Big Chino fault, running about 30 miles from Paulden up toward Seligman. Experts suggest that if it were to rupture along its entire length, it could potentially result in a magnitude 7 or larger event, significantly impacting Paulden, Chino Valley, and the City of Prescott. A smaller fault, known as the Little Chino, is closer to Chino Valley. It is believed to have caused a 6 or 6.5-magnitude quake about 10,000 to 15,000 years ago. However, little else is known about when another significant event might occur on this fault line.
The history of earthquakes in the Chino Valley and Prescott areas over the last fifty years reveals a moderate seismic risk. The largest earthquake within 30 miles of Chino Valley was a 4.9-magnitude event in 1976. The USGS database shows that there is a 21.84% chance of a major earthquake within 50km of Chino Valley within the next 50 years.
While stronger earthquakes are unusual in Arizona, the potential exists for them to cause damage to property and/or result in people being injured or killed. As such, residents are encouraged to take safety measures, such as securing items that may fall from walls or shelves and practicing the "drop, cover, and hold on" technique in the event of an earthquake.
The recent 3.8-magnitude earthquake serves as a reminder of the seismic activity that can occur in the Chino Valley and the greater Prescott area. It underscores the importance of understanding the geological features of the area, being prepared for potential seismic events, and taking appropriate safety measures.