The Morris Area High School eighth grade class has been studying earthquakes and focused some of that study on local earthquakes. They learned that Stevens County had two earthquakes, one in 1975 and another in 1993. They requested memories from people in the area who experienced the quakes and got a few responses.
Pam Gades, of Morris, did a college paper on the earthquake and documented the earthquakes in the county. Some of the following information is from her report.
The earthquake in 1975 registered 4.6 on the Richter scale and occurred at 9:54 a.m. on July 9. The epicenter of the 1975 quake was calculated to be 6 – 10 miles west, and 2 to 3 miles south of Morris. A team from the United States Geological Survey was in Morris the next day to set up seismographs in the hope of measuring aftershocks.
Damage in Stevens County was confined to cracked plaster, items falling off shelves and pictures dropping off walls.
The earthquake was recorded on a homemade seismograph by Dennis Myers, the manager of the A&W Drive-in in Morris. Myers had built a seismograph when he was stationed with the Navy in California. He brought it with him to Morris when he was discharged early in 1975. The machine, a coffee can for a drum, powered by the motor of a clock, with a 19 cent pen to record ground shock intensity, showed a reading for the quake of 4.7.
The students received one memory from the day from Jan Freese. This is what she recalled:
“After a shopping trip into town, I had just driven into the ground floor garage of our hillside home and walked up the flight of steps to my first floor kitchen. I walked around my portable dishwasher sitting in the middle of the room to the kitchen sink and started washing my hands when I began to feel a strange vibration under my feet. As it got stronger, I realized I felt the need to steady myself with one hand on the dishwasher and the other on the sink counter. As I did so, glancing towards the dining room window, the tops of a row of poplar saplings on the side of the road caught my eye as they were being whipped back and forth while my brain was asking if there might be some huge farm equipment going by on the highway. I ran into the living room to look but found nothing there. As I turned to run back, I noticed some movement of the dining room ceiling chandelier, but then what caught my attention was the sound of all the dishes and glassware dancing in the wall hung china cabinet. As everything began to subside, I realized I was talking out loud to myself asking the question that had been going through my brain, “Was this an earthquake? in Minnesota?”
“Later that day my husband came home to tell me his experience of the day. He’d been on a second story also, but he was in the East Elementary School, a brick and block building. He’d removed a small window in preparation for its replacement, so was seated on the bottom of the empty window frame and the question going through his head was should he jump in or should he jump out, all of which depended on which way the wall might lean the most. Thankfully he was able to keep a firm grip on the window frame long enough for things to subside before that decision had to be made.”
The second earthquake in Stevens County took place on June 4, 1993, which was also the Morris High School graduation night. The most prominent memory was from those attending the graduation and listening to the class speaker as he addressed the sudden shifting in the gymnasium.
Jeremy Lopez was the student speaking as the earthquake hit. His comments immediately after were “I don’t know how I can say anything after that.” The earthquake occurred midway through his speech. The tremor caused noise, shaking and unforgettable memories for those attending the graduation.
This earthquake was recorded at 4.1 on the Richter Scale. The epicenter was determined to be in Traverse County, about 25 miles northwest of Morris or about four miles north of Graceville.
The epicenter of an earthquake is the spot on the surface of the earth directly above the rupture, or slippage along a fault line. There is a fault line in Minnesota that stretches from Big Stone or Traverse County to Duluth. 17 of the recorded Minnesota earthquakes have occurred along that line with the largest being the 1975 quake in Stevens County and a 1917 quake near Staples.
Stevens County sits directly on that line which is more like a ‘zone’ and it is estimated that earthquakes can occur along it every 15 to 20 years. During the late 1800s earthquakes occurred in Minnesota at 5 to 10 year intervals. Aftershocks are usually a smaller magnitude than the original earthquake, and it’s hard to feel an earthquake below magnitude 4.
At the time of the 1993 earthquake, there were two theories about why earthquakes occur in this area. One is that the earth is still slightly rebounding from the weight of the last ice age. The other theory is plate tectonics or that North America is moving to the west, away from the Atlantic Ridge, also known as a continental drift. That movement sets up subtle stress in the earth’s crust that can pop loose with an earthquake.
No matter the reason or when they might occur, there is always the possibility of an earthquake in this area. It has been several years since the last one so there may soon be another on the horizon. So if you feel the earth moving under your feet, it is not just the lyrics of a song, it just might be a rare Minnesota earthquake.