April earthquakes centered in Adams Center awaken a sense of wonder

Apr. 29—WATERTOWN — Nerves frayed, questions arose, dishes rattled, some pets skedaddled and rumblings echoed in Northern New York with the two recent earthquakes emanating from the Adams Center area — or, as one Times reader suggested, from "Adams EpiCenter."

There were several aftershocks reported, the most recent late Monday morning; a small rumble coming in at 1.8 on the Richter magnitude scale, devised in 1935 by American seismologist Charles F. Richter.

That made a total of 10 aftershocks since the original one that registered 3.6 and raised questions Sunday afternoon. Quakes in the 2.5 to 3 magnitude range usually are the smallest felt by people.

In terms of being notable in the world of earthquakes, only Sunday's 3.6 quake was of official "significance." The U.S. Geological Survey says "significant events" relating to quakes are determined by a combination of magnitude, the number of "Did You Feel It?" responses and pager alert levels.

Sunday's 3.6 quake was the only "significant" quake worldwide for April 23, according to the USGS. The National Earthquake Information Center, part of the USGS, locates about 20,000 earthquakes around the globe each year, or approximately 55 per day.

An earthquake is caused by a sudden slip on a fault. Tectonic plates are always slowly moving, but can get stuck at their edges due to friction. When the stress on the edge overcomes the friction, an earthquake occurs that releases energy in waves that travel through the Earth's crust and cause the shaking that we feel.

In the north country, such science has been of no great shakes for most residents. But that changed on April 14 when a 2.6-magnitude quake, centered a mile west of Adams Center, was reported by the U.S. Geological Survey.

Sunday's 3.6 quake, also centered in Adams Center, has been followed by nearly a dozen smaller quakes, also centered near Adams Center, mostly too small to feel. It's all taking place in an area where there had been very limited earthquake activity. So what's going on?

"There's a bit of an increase in seismicity along what seismologists call the St. Lawrence seismic zone," said Geoffrey A. Abers, chair of Earth and atmospheric sciences at Cornell University, Ithaca.

The zone, he said, roughly follows the St. Lawrence Seaway. "These are earthquakes that are normally magnitude 2 or 3, or even smaller," Mr. Abers said. "This one, (Sunday's) at 3.6, was just big enough that people could feel it."

And also hear it. People reported that Sunday's quake resembled the echoes of a sonic boom or a rumbling train passing by their homes. That is rather unusual, said Mr. Abers, a geophysicist who uses the tools of earthquake seismology to understand the forces, material cycles and deep structure of the Earth.

"It's been documented in a few places," Mr. Abers said. "The frequencies of the seismic signals get high enough through this kind of rock that it's in the range that people can hear. It's not as common as in California where the rocks are absorbing a lot more of the high frequency signals. The ground shakes a lot but it takes more to get into the audible range. It's interesting, but there's certainly been past examples of people hearing earthquakes."

Two days after Sunday's significant quake in Adams Center, there was an odd coincidence.

On Tuesday morning, 197 miles east of Adams Center, and nearly in an exact parallel line from the Adams Center epicenter, there was a 2.9 quake in New Hampshire centered in Center Sandwich at 9:49 a.m. No damage was reported, according to WMUR-9.

But Mr. Abers doesn't think there are greater forces at work in those two quakes.

"I think that's just coincidental," he said. "There are quakes of this size that happen in the U.S. and eastern Canada a few times a year."

There was also a quake Feb. 6, centered near Buffalo, that shook Western New York. That one registered a 3.8 magnitude.

"Very generally, there seems to be a belt of seismicity along the St. Lawrence Seaway and the first couple of Great Lakes," Mr. Abers said. "It's not very strong, but every now and then there's like a 5.1 in the Massena/Plattsburgh area."

A 1944, a 5.8 earthquake centered near Massena is one of the strongest quakes in recorded state history, according to the National Earthquake Information Center, Golden, Colorado.

According to Cornell University, New York's biggest earthquakes have occurred in the Adirondack Mountains: In 1983, an event that measured 5.1 occurred near the town of Newcomb, and in 2002 a 5.3 event occurred in Ausable Forks.

"The rocks underneath all of us in upstate New York are very old and they've had a long and complex history," Mr. Abers said. "So, there's a lot of faults down there and a lot we at least don't know about. As you get up close to the border in the St. Lawrence, you can start to see granites, but everywhere south of there, you see flat-lying sedimentary rocks."

Common sedimentary rocks include sandstone, limestone and shale.

"These are all 400-million-year-old rocks, but underneath them, there are much older rocks that have faults in them and it's very hard to learn about them because they don't move very much," Mr. Abers said. "They just sat there for most of the last billion years."

"But every now and then," he added, "stresses slowly build up over geologic time and every now and then, one of them goes."

'A LOT OF QUESTIONS'

It's not known if the recent quakes in Adams Center are indicative of more to come. Earthquakes cannot be predicted.

"We don't have a good physical mechanism that would say, 'Oh, this happened, and expect more big ones,'" Mr. Abers said. "We also don't really understand what's driving these quakes. There's still a lot of questions."

The February earthquake in Turkey and Syria that has caused a humanitarian disaster originated from a known active seismic zone, Mr. Abers said.

"We don't have anything like that on that scale in the eastern U.S.," Mr. Abers said. "California — yes. That's a different story."

To measure earthquakes, the USGS oversees a series of seismographs across the U.S.

"They try to record every earthquake bigger than about a magnitude of 2 1/2 ," Mr. Abers said. "In Watertown, you're close enough to Canada where the Canadian national network provides a lot of information about earthquakes on the U.S. side. And then there's the Northeast Regional Network operated by a consortium of universities and coordinated by Columbia University in the past. They all coordinate and share data."

Mr. Abers estimated that there are probably a couple of dozen seismographs for the networks within 100 or 200 miles of Watertown.

"Some of them might be on a school campus and some are in more remote places," he said. "The sensors themselves vary in size and shape but they're usually like a small cylinder that's buried in the ground so they detect really small ground motions."

According to USGS, the largest recorded earthquake in the United States was a magnitude 9.2 that struck Prince William Sound, Alaska, on Good Friday, March 28, 1964.

The largest recorded earthquake in the world was a magnitude 9.5 in Chile on May 22, 1960.

QUAKES IN NNY

Northern New York has a notable history of earthquakes, although nothing on the magnitude of major humanitarian disasters such as the Feb. 6 one that hit southeast Turkey and the northwest region of Syria, killing more than 50,000 and affecting 18 million others. However, if more people were around here in 1663, a quake that shook the East likely would have been a major disaster.

We can thank the late Lt. Col. Albert M. Skinner of Watertown for our region's early earthquake history. In 1944, following a big earthquake that hit Northern New York, Lt. Col. Skinner, "a student of weather conditions in this area," wrote an article in the Watertown Daily Times about the north country and its quake history. At the time, he was working for the Office of Civilian Defense in Washington, D.C. He noted that seismological investigations were assigned to the U.S. Coast and Geodetic Survey, the first scientific agency of the U.S. government, in 1925. His local survey was assembled by "widely scattered" information regarding earthquakes in the publication "Earthquake History of the United States," published in 1938.

Among the major NNY earthquakes Lt. Col. Skinner documented: — Feb. 5, 1663: A quake with the epicenter near Trois-Rivières, Quebec, was probably felt in all of eastern Canada and northeastern U.S.

"Its intensity was probably 10 at its epicenter," Lt. Col. Skinner wrote. "It occurred so early in colonial history that accounts are far from definite. Many of them are quite lurid and tell of mountains being thrown down and of great forests sliding into the St. Lawrence."

To measure earthquakes before the 1930s, the events were given a number based on damage and where people felt tremors. — March 12, 1853: "A shock of intensity 7" occurred in the northern part of New York state. — Dec. 18, 1867: A shock lasting 25 seconds was felt in Vermont, Canada and NNY. In Ogdensburg, it woke people up. — Oct. 20, 1870: A shock of 8 or 9, centering in Canada, was most strongly felt along the St. Lawrence River between Montreal and Quebec. — Dec. 25, 1903: A quake with an intensity of 5 centered in Madrid affected 1,500 square miles. — April 28, 1913: A 7-8 intensity shock, centered near Potsdam, was felt over an area of 3,000 square miles. — May 22, 1917: A shock covered 15,000 square miles in the St. Lawrence River Valley. — March 18, 1928: A shock centered in Saranac Lake was felt at Malone. Sounded like "artillery fire." Dishes fell from shelves.

—March 10, 1937: A shock of 4-5, centered in the Canton area.

From the Times files, the following are highlights of reports from more recent earthquakes, most from the Massena area:

—Sept. 5, 1944: At 12:39 a.m. Labor Day, severe shock shakes Earth in Massena; measures 6.0 on Richter scale; causes structural damage in excess of $1 million; 2,800 chimneys broken or toppled; called strongest quake in state history at the time by Carl Stover, National Earthquake Information Center, Golden, Colorado, in 1981.

"In Watertown, the effects of the earthquake inspired wonderment and fear in residents who were awakened by the sway of their beds. Rattling windows and dishes were widespread," the Times reported. — Aug. 6 and 7, 1950: "At 8 p.m. and midnight, two quakes; plates fastening WMSA radio tower to ground loosened; no major structural damage elsewhere, although 332-foot tower swayed violently during tremors." — Sept. 29, 1961: At 2:40 a.m. Rooseveltown customs collector claims house shaken; no confirmation from seismological equipment in Montreal. — March 30, 1964: At 4:10 a.m., series of three quakes awakens Massena; third shock most severe; houses shook for several seconds; no confirmation from seismological equipment. — Oct. 9, 1969: At 8:08 p.m., measured 4.0 on Richter scale; Massena-Cornwall area; household windows rattled; slightly shook tower at Ottawa International Airport. — April 20, 1961: At 8 a.m., brief, sharp tremor rumbled Robert Moses Power Dam but caused no structural damage. — Oct. 25, 1951: Village of Massena residents awakened by rumbling noises from two quakes; Fordham University seismologist William Lynch says no quake measured by equipment. — July 4 weekend, 1981: Several tremors felt throughout St. Lawrence and Franklin counties; most severe reached 3.0 on Richter scale; no structural damage. — March 2, 1982: It was a tremor that at first, only one person seemed to notice. Claims by Michael Becker of Alexandria Bay that he had been awakened by a small quake were at first refuted but later supported by seismology experts. — Oct. 7, 1983, a strong tremor measuring 5.2 with its epicenter about 9 miles north of Blue Mountain Lake shakes the north country. — Oct. 11, 1983: A 4.2 quake centered near Ottawa was felt in St. Lawrence and Jefferson counties.

At the time, Frank A. Revetta, geology professor at SUNY Potsdam, told the Associated Press: "Why this is acting up right now, I don't know. It's very odd." Earthquakes, he said, weren't nearly so well understood as those in California, where faults surface and are easily mapped. — Aug. 9, 1988, a quake centered 6 miles north of Massena rumbles at 3.4 on the scale. — Nov. 25, 1988, an earthquake rumbled through the Adirondacks and the St. Lawrence River valley. It lasted more than two minutes and measured 6 on the Richter scale. Its epicenter was in Quebec's Charlevoix region, about 95 miles north of Quebec City. — Oct. 19, 1990, a moderate earthquake centered about 70 miles north of Ottawa rattled dishes and windows throughout St. Lawrence and Franklin counties, but didn't affect most of Jefferson County. — April 17, 1992, the epicenters of two earthquakes that shook part of the north country were in the middle of the St. Lawrence River. Quakes occurred at 9:38 p.m. and 10:11 p.m. about 25 kilometers apart in the St. Lawrence River between Massena and Cornwall, Ontario. The first registered 2.4 on the Richter scale and the second quake registered 2.5. — Nov. 16, 1993, an earthquake registering 4.1 on the Richter scale shook the Montreal area before dawn and was felt as far away as Vermont and Northern New York. No injuries were reported. The quake's epicenter was 15 miles south-southeast of Montreal. — Jan. 18, 1994, a quake at 1:45 a.m. and registered 3.0 on the Richter scale. It woke several people up in Malone, Chateaugay and Burke in Franklin County. It was pinpointed directly below Chateaugay, a small village 15 miles east of Malone.

—March 2, 1995, an earthquake rumbled through a remote region of the Adirondack Mountains near Tupper Lake. It registered about 3 on the Richter scale and the focal point of the temblor was 15 miles north of Tupper Lake and 20 miles northwest of Saranac Lake. — March 14, 1996, an earthquake that rumbled through a remote area of Quebec was felt in the north country. The quake took place at 5:42 a.m. and registered 4.5 on the Richter scale. The epicenter was in a remote area about 55 miles northwest of Montreal. — July 31, 1997, a quake centered near Glenfield and Greig in Lewis County registers between 3.0 and 3.4 in magnitude on the Richter scale. — July 10, 1997, an earthquake with a magnitude of 2.9 was felt in Massena. The epicenter was six miles west of Cornwall, Ontario, just across the St. Lawrence River from Massena. No damage was reported. — June 9, 1998, a small earthquake centered near the Canadian border rattled parts of Northern New York. There were no reports of significant damage or injuries. The epicenter was near Malone. The quake had a preliminary magnitude of 3.4, Canadian officials said. A quake of magnitude 3.5 can cause slight damage. — April 20, 2000, a minor earthquake hit parts of eastern New York from the Adirondacks to the Mohawk Valley. The tremor was recorded at about 4:45 a.m., with the epicenter in the town of Newcomb in Essex County, about 95 miles north of Albany. The National Earthquake Information Center says the quake registered 3.7.

-Nov. 6, 2012: A temblor measuring 4.2 on the Richter scale occurred 31 miles east of Ottawa along the Ottawa River just after 4 a.m. Its effects were felt as far away as Potsdam and Massena. — Jan. 16, 2013: A 2.4-magnitude temblor strikes at 8:46 a.m. Wednesday, centered 11 miles northeast of Saranac Lake. — Nov. 28, 2015: A magnitude 3.3 quake centered near Rooseveltown was felt through most of St. Lawrence County and in large portions of Ontario and Quebec, Canada. — March 21, 2018: A magnitude of 2.7 quake occurred at a depth of 3.11 miles, about 15.5 miles outside Malone. — Jan. 13, 2020: A magnitude 3.28 quake, centered in Ormstown, Quebec, was felt around Northern New York. — July 15, 2021: A quake centered roughly 5 miles northwest of the village of Massena near the western tip of Croil Island on the St. Lawrence River was felt around St. Lawrence County and southern Ontario. — July 29, 2022: A magnitude 2.5 quake centered in St. Regis Falls felt as far away as Saranac Lake. — Feb. 20, 2023: A 2.1-magnitude quake centered near the intersection of Route 37 and Haverstock Road in Massena. — Mid-to-late-April, 2023: The tremors of Adams Center.