WTNH News Channel 8 / News / 1999

	Connecticut Quake Predicted (MIDDLETOWN-AP)_ An active fault line has been discovered in Connecticut, and scientists say their evidence suggests the state is due for an earthquake. Three Wesleyan University scientists, working in marshes in Branford, said they inadvertently uncovered evidence of the fault's activity while studying long-term sea level trends. They believe the fault, long thought to be dormant, is responsible for a pattern of earthquakes that have occured about every 200 years in Connecticut over the past 1,200 years. The pattern suggests Connecticut could be due for another earthquake any time now, one that could reach a magnitude of five on the Richter Scale. That is strong enough to jiggle furniture, topple objects off shelves, crack some foundations and damage chimneys. "There are earthquakes that occur in Connecticut, particularly in the New Haven area. That is what our evidence suggests," said William G. Thompson, one of the researchers. "People should know that. The discovery resulted from research conducted by Thompson, a geologist, Joop Varekamp, a geochemist; his wife, Ellen Thomas, a paleoceanographer. "I think the layperson's view is that we live on the East Coast, and we don't have to worry about earthquakes. But although we don't have the same frequency as the West Coast -- they are fewer and farther between -- it doesn't mean they are off the chart," Thompson said. "They can happen, and they will happen." Jelle Zeilinga de Boer, the Harold Stearns Professor of Earth Science at Wesleyan who has done extensive earthquake research in Connecticut, said that any quake that might occur most likely would not be life-threatening because of the nature of the Earth's crust in the East. It is geologically old and comparatively stable, criss-crossed by so many small cracks that any slippage along a fault line is confined, keeping damage to the lower end of the scale, he said. The scientists, in research supported by the Connecticut Sea Grant program, stumbled upon the evidence while analyzing ancient buried sediments from marshes beside the Farm River in Branford and Kelsey Island in Long Island Sound. Analyzing organic and fossil remains from those sediments, the researchers can determine what sea levels were at a given time. Though the two sites are little more than a mile apart, the sediment histories didn't match. "The rate of sea level rise on Kelsey Island was way too fast," Varekamp said. "It appeared to be sinking way too fast." Aware that the two sites happened to be on either side of the fault line -- a segment of a mostly north-south fault that forms the eastern edge of the Connecticut River Valley -- Thompson wondered if earthquakes caused the level of the island marshes, on the south side, to drop below the level of the Farm River marshes, on the north side. After extensive radio-carbon-dating work last summer, Thompson became convinced that was the case. The scientists found that the level of the island marsh had dropped more than 3 feet since 815 B.C. The sediment analysis and carbon dating indicated a series of earthquakes occurred about every 200 years during the past 1,200 years, each one preceeded by a slight upwelling in the island marsh -- which is common in areas with active faults. Varekamp, Thomas and Thompson noted that seven small quakes have occurred in a path between Branford and Greenwich in recent decades, probably involving the same fault line that runs between the two marshes they studied. The most recent substantial earthquake in Connecticut occurred about 200 years ago, possibly centered in East Haddam, the researchers said. If the pattern of tremors they identified were to continue, another earthquake could come any year now. Sediment analysis indicates an upwelling is in fact occurring, such as those that occurred before the previous quakes. "It is really unbelievable," de Boer said of their findings. "They've got the cat by the tail." Today's News Page. WTNH Home Page. ©1999 WTNH/WTNH-DT A LIN station.

Connecticut Quake Predicted
(MIDDLETOWN-AP)_ An active fault line has been discovered in Connecticut, and scientists say their evidence suggests the state is due for an earthquake.

Three Wesleyan University scientists, working in marshes in Branford, said they inadvertently uncovered evidence of the fault's activity while studying long-term sea level trends.

They believe the fault, long thought to be dormant, is responsible for a pattern of earthquakes that have occured about every 200 years in Connecticut over the past 1,200 years.

The pattern suggests Connecticut could be due for another earthquake any time now, one that could reach a magnitude of five on the Richter Scale. That is strong enough to jiggle furniture, topple objects off shelves, crack some foundations and damage chimneys.

"There are earthquakes that occur in Connecticut, particularly in the New Haven area. That is what our evidence suggests," said William G. Thompson, one of the researchers. "People should know that.

The discovery resulted from research conducted by Thompson, a geologist, Joop Varekamp, a geochemist; his wife, Ellen Thomas, a paleoceanographer.

"I think the layperson's view is that we live on the East Coast, and we don't have to worry about earthquakes. But although we don't have the same frequency as the West Coast -- they are fewer and farther between -- it doesn't mean they are off the chart," Thompson said. "They can happen, and they will happen."

Jelle Zeilinga de Boer, the Harold Stearns Professor of Earth Science at Wesleyan who has done extensive earthquake research in Connecticut, said that any quake that might occur most likely would not be life-threatening because of the nature of the Earth's crust in the East. It is geologically old and comparatively stable, criss-crossed by so many small cracks that any slippage along a fault line is confined, keeping damage to the lower end of the scale, he said.

The scientists, in research supported by the Connecticut Sea Grant program, stumbled upon the evidence while analyzing ancient buried sediments from marshes beside the Farm River in Branford and Kelsey Island in Long Island Sound. Analyzing organic and fossil remains from those sediments, the researchers can determine what sea levels were at a given time.

Though the two sites are little more than a mile apart, the sediment histories didn't match. "The rate of sea level rise on Kelsey Island was way too fast," Varekamp said. "It appeared to be sinking way too fast."

Aware that the two sites happened to be on either side of the fault line -- a segment of a mostly north-south fault that forms the eastern edge of the Connecticut River Valley -- Thompson wondered if earthquakes caused the level of the island marshes, on the south side, to drop below the level of the Farm River marshes, on the north side.

After extensive radio-carbon-dating work last summer, Thompson became convinced that was the case. The scientists found that the level of the island marsh had dropped more than 3 feet since 815 B.C. The sediment analysis and carbon dating indicated a series of earthquakes occurred about every 200 years during the past 1,200 years, each one preceeded by a slight upwelling in the island marsh -- which is common in areas with active faults.

Varekamp, Thomas and Thompson noted that seven small quakes have occurred in a path between Branford and Greenwich in recent decades, probably involving the same fault line that runs between the two marshes they studied.

The most recent substantial earthquake in Connecticut occurred about 200 years ago, possibly centered in East Haddam, the researchers said. If the pattern of tremors they identified were to continue, another earthquake could come any year now. Sediment analysis indicates an upwelling is in fact occurring, such as those that occurred before the previous quakes.

"It is really unbelievable," de Boer said of their findings. "They've got the cat by the tail."

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