Andover Townsman, Andover, MA

November 7, 2013

A whole lot of shaking going on

Bill Dalton
The Andover Townsman

---- — I’ve been thinking about earthquakes. There were a couple late last year. The first was a 4.5 on the Richter scale, causing our dogs to bark and us to bolt from our chairs. We felt the house move. The second quake was smaller, but a bathroom cabinet fell from our wall.

My wife, who is from Berkeley, Calif., has experienced numerous earthquakes, the most famous being the “World Series” quake in 1989, which struck as the game was beginning in San Francisco. Fear was in the announcers’ voices as the stadium shook. The quake measured 6.9, but was especially dangerous because of its side-to-side motion. My wife was driving on a freeway and says that it was like being hit by ocean waves from opposite sides at the same time. She thought she’d lost a wheel, and when she pulled over to check, a pickup drove by and someone yelled, “It’s an earthquake, you idiot.” Fifty-seven people were killed.

The Richter scale is difficult for me to figure out. According to the U.S. Geological Survey, a 4.5 can be recorded by seismographs (earthquake-measuring instruments) around the world. Its website says, “Each whole number increase in magnitude represents a tenfold increase in measured amplitude …” The explanation gets confusing from there, so let me put it this way: each whole number is wicked worse than the preceding whole number.

Earthquakes aren’t rare here. In fact, in geologic time, we live in a place where earthquakes are common. We can expect a moderate to strong one because of our past history. In 1638 and again in 1663, there were major earthquakes. The first one struck before Andover was settled. However, early settlors in Newbury were terrified by the four-minute quake. It knocked them down, scared their farm animals and caused widespread destruction. Settlors probably had second thoughts about their recent move to the New World. The 1663 quake was more destructive because of its size — Canada to Mexico — and intensity. It destroyed or damaged almost every Boston building.

On Oct. 29, 1727, the Merrimack Valley was clobbered by an earthquake, and days of prayer ensued. It was the worst earthquake to hit New England since its settlement, although it was not part of the “worldwide convulsions” that had accompanied other New England earthquakes. (“Historic Storms of New England,” Sidney Perley, 1891, reprinted in 2001 by Memoirs Unlimited, Inc.)

Many other earthquakes were felt in New England, but the only one I’ll add to the list is the earthquake of 1755, which was described as very severe. Having occurred at 4 a.m., it caused a Rev. Sewall (a descendant of the repentant witch-baiter Samuel Sewall) to preach, “Lest coming suddenly he find you sleeping” (Perley). That sure made folks feel better.

In early New England days, smaller but noted earthquakes were frequent, perhaps as many as several a year. In the last 100 years, only three, possibly four, have been noticeably felt, with the most significant being an earthquake and aftershock centered near Lake Ossipee, N.H., in 1940. Both were estimated at 5.5, although the aftershock caused more damage. It was felt from Quebec to Rhode Island. In 1963, some folks in Andover were slightly shaken by a small quake centered in Somerville.

Closer to the present, earthquakes that could be felt have been rare. I have felt only three in my life, including the two last year, but that’s not necessarily good news. In fact, this region is considered to be overdue for a moderate to significant earthquake — remember, we are talking about geologic events, so “overdue” doesn’t necessarily mean “imminent.” It also means it could happen tomorrow, so keep your shoes near your bed and pick out a strong doorway for cover.

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Bill Dalton’s somewhat regular column is a continuing feature on the Opinion page in the Townsman. His email address is BillDalton@AndoverTownie.com.