A couple years later, in 1982, I sat down at my electric typewriter in the upstairs office early in the morning to start a column. I flipped the switch to turn on the typewriter, and the house began to shake again. “Wow!” I thought. “This piece is gonna be a good one!”

Here in New England our reactions to local earthquakes, though nervous, are usually tinged with humor. That’s because we can afford it; elsewhere, it’s not so funny. The recent quakes in Haiti, which toppled most of Port-au-Prince and killed over 100,000 people, and another over the weekend near Santiago, Chile, were far more destructive. After Pat Robertson’s take on the cause of the Haitian quake – the result of a pact with the Devil – it’ll be interesting to see how he explains the damage to a city named after one of the first Christian martyrs.

The fact is that most earthquakes are, if not predictable, at least foreseeable. Since World War II, when scientists began to develop vastly more sensitive instruments to measure almost any phenomenon, geologists’ knowledge of the earth’s dynamics has expanded exponentially. My geology textbooks from the early 1950s, for example, speak of the orogenies that formed the Appalachian and Rocky Mountains, but offer no speculations about the causes. The theory of continental drift was postulated as early as 1928, but without measurable evidence didn’t make it into undergraduate texts until recently.

Now we know, because we can measure the movement, that the earth’s crust floats around on its molten core much like the scum on a pot of boiling beans. The crust is fractured into many chunks (tectonic plates) that rub up against each other (Haiti), pull away from each other (Iceland), or slide under and over each other (Chile). On those lines along which the plates meet are what are called hotspots – areas of thin or disrupted crust where molten rock, or magma, always under pressure from the weight pushing down on it, can squirt to the surface,as relatively benign lava flows, or more violently as volcanoes.

We once spent a night at Carney Park, the United States Sixth Fleet’s recreational area in Pozzuoli, Italy. I couldn’t help but notice that, for all its green soccer and baseball fields, it was pretty obviously a volcanic caldera, the crater of a (in this case, allegedly extinct) volcano. When we got home, I looked it up. Turns out that the city and its harbor are located on top of a magma dome that swells and shrinks irregularly. The ruins of ancient Roman temples on the waterfront routinely rise and fall as much as three feet in a matter of months. There is allegedly a plan to evacuate everybody in the event of a sudden increase in the daily tremors that keep the town jumping, but people are often loath to leave the devil they know for one they don’t. An Italian geologist is quoted by [ital] National Geographic [ital] as saying, “I would not sleep in Pozzuoli.”

California is a prime example of living in the shadow of an impending and certain calamity. Its earthquakes are of the type called “transformation” quakes, in which one plate slides horizontally past another, releasing the tremendous potential energy stored as the strain along the fault increased. A structural geologist I once asked about the worst-case scenario on the San Andreas Fault remarked that he couldn’t rule out the possibility of the land on the west side of the fault slipping beneath the sea. I suggested for years to my old school roommate in California that he move to the east side, or at least garage his Pierce-Arrow there. Instead, he sold the car.

Here in New England we’re justified in not worrying much about earthquakes – though, as conservative bloggers on the Web often assert, New England is not without its faults. (Sorry) I spoke this morning with Richard Birnie, a retired Dartmouth Earth Sciences professor and my favorite geologist for his enthusiasm and his ability to explain the inscrutable writing of scientific papers in language comprehensible to metaphor-prone dubs like me. He confirmed that there are several geologic faults running through our area: the Lake George basin, for example, which has several; and the Connecticut River Valley. But most of our quakes are the result of the readjustment of magma intrusions beneath the crust. We have lots of those. The Adirondacks are a massive intrusion of magma under pressure; Mount Ascutney is the granite core of a large volcano that probably never erupted; Mount Desert, Maine, is the result of several dome-shaped intrusions, one of which collapsed after its magma chamber drained, leaving a fascinating ring around the edges and a mass of chocolate chip cookie dough-looking rock in the middle. Two 5.5-magnitude quakes near Ossipee, New Hampshire, that in 1940 destroyed chimneys, moved a few old houses, and broke furniture were the result of an adjustment of the roots of an ancient volcano beneath the town.

Living on the dynamic surface of the earth gets more exciting the more you know about it. If you don’t want to get upset about the possibility of earthquakes and massive eruptions, please don’t check out the roughly 1100-mile-square Yellowstone caldera, site of a huge super-eruption in the past, still seething with geysers and hotspots, and, ominously, beginning to bulge upward under pressure from beneath. And you thought chronic Congressional gridlock was a problem?