I was sipping my coffee this morning — actually the mug was sitting on the nightstand next to my bed — when there was a shudder. The dark liquid formed a miniature wave against the side of the white porcelain and I knew. I KNEW!

The time on the clock read 7:02.

Later it was confirmed that a magnitude 5.6 earthquake was recorded at 7:02 a.m. Saturday, with an epicenter close to Pawnee, Okla., some 300 miles distant. That’s a pretty powerful shudder for middle America.

As a high school student in Seattle many moons ago, I felt a few tremors; dishes shook occasionally in the cabinets. West Coast residents get used to them. And who doesn’t know that the tectonic plates below the earth’s surface are constantly shifting?

Then there was the time in Acapulco when I awoke in the middle of the night. The hotel windows rattled and the accompanying rumble made it seem like a tropical storm was blowing in off the bay. That time, the shaking lasted long enough for us to check both the windows and the door to the interior atrium. When we saw other tourists running, we dared to think earthquake. Hotel staff, as it turned out, were unfazed and simply went about their routine duties. And so we returned to bed.

Earthquakes don’t strike in the middle of vacationland, we thought. As it turned out, they did quite regularly. But they were rarely reported, so as not to scare away the tourists. Or so we were told later that day as we sat on the beach sipping our margaritas.

Today, because it was odd to see the coffee sloshing in the cup, I researched earthquakes.

As it turns out, today’s little episode in Pawnee was just that. A small shake in the worldwide scheme of things. In earthquake terminology it was a “modest” temblor, but  it is also the largest quake to be recorded in the past seven days in the area that includes the United States, Canada and Mexico. The list is long, and earthquakes have been felt in Wyoming, Nevada, California, Tennessee, Alaska and Hawaii, not to mention quite a few others in Oklahoma. The event near Pawnee is termed a cluster, and the shocks might continue for a while, according to all reports. The most surprising fact is that they are routine, rather than cause for alarm.

In total, 245 quakes of magnitude 2.0 or greater have been recorded in seven days. Surprised? I certainly was. Worldwide, during the same seven-day period, there have been a handful of others of the magnitude of the Pawnee quake or greater, notably in New Zealand, New Guinea and Indonesia, but at least 245 incidences of 4.0 or greater. One week in the history of earthquake reporting. Two days ago, New Zealand felt a 7.2 earthquake, and a tsunami warning was issued.

What do these shakers portend for “the big one?” Not much, according to the U.S. Geological Survey (USGS). Today may have been a relatively unusual day for moderate temblors around the globe, but the number of measurable earthquakes annually is around 20,000, or 55 each day. Who knew? USGS experts report that a temporary uptick or decrease in “seismicity is part of the normal fluctuation of earthquake rates.”

As it turns out, what the disaster movies have been feeding us is fiction, in capital letters. Not to make light of serious earthquakes; they can and do occur, and they will no doubt continue to cause damage and loss of life. But, as we learn more about them and as our buildings become more structurally sound, the devastation will also, hopefully, be reduced. Major worries are the damage from collapsing buildings in highly populated areas, and the resulting tsunamis that a shaking earth causes in the world’s oceans.

Also, as it turns out, earthquakes in Oklahoma are not at all uncommon. Actually, the state overtook California’s number two spot for earthquake frequency in 2014, a position it held into 2015. Alaska retains its Number One position — a dubious distinction. But we’ll just have to wait and see the rankings at the end of this year.

If you’re interested in a scientific journey into the world of earthquakes, you might want to read this National Geographic article from 2006. It’s long, but worth it!