I may be the grandson of a California seismologist, but before yesterday, my only direct experience of an earthquake was the day when a rake fell over on my front porch. There was nothing around that could have pushed it, so it had to be an earthquake, and of course, it was. But on that occasion, I didn’t actually feel the floor move. It was a different story yesterday. For ten or twenty seconds, the building I was in rumbled as if the air conditioner on the roof had gone wonky. Then the shaking grew until it was like an airplane taking off. Everyone agreed it could only be an earthquake. I ducked under the nearest desk for a moment, then joined the more sensible people who were already heading for the exits.
At the time, I guessed the magnitude was 6, and immediately realized that I wasn’t qualified to make that guess. But for a novice, I wasn’t too far off — it was 5.9 at the epicenter two states away. It surprised me to learn how far the earthquake extended. It was also felt in Atlanta and Boston. On the other hand, many people who were in shorter buildings on harder ground barely felt anything.
Geologists have always told us that much of the eastern half of the United States is on the same plate, and an earthquake anywhere east of Missouri has the potential to reach north to the Great Lakes and east to the Atlantic coast. A major earthquake in this zone, something we expect about every 500 years, could affect not just half the population of the country, but about three fourths of the federal government all at once. A moderate earthquake that struck during severe winter weather could be just as damaging. There is roughly a 1 in 10 chance of one of these two scenarios happening in the next 25 years. It is not a great chance, but not insignificant either. It presents a potential continuity problem for the federal government and the country. Where I was, and in many East Coast cities, the cellular network was largely unavailable for the better part of an hour. Imagine what might happen if it had been all utilities taken out for a few days across the same region.
Engineers know about this possibility, of course, and have been telling us for years that bridges and new buildings should be earthquake-resistant in design and that more of our utilities should be underground, where they are better protected from disasters of all kinds. I am sure these considerations will be taken a little more seriously now that so many people have personally experienced an East Coast earthquake.