Earthquakes endanger New York more than previously believed
the main gas, oil and power transmission lines all cross the parallel active faults, making them particularly vulnerable to being cut. Lerner-Lam, who was not involved in the research, said that the identification of the seismic line near Indian Point “is a major substantiation of a feature that bears on the long-term earthquake risk of the northeastern United States.” He called for policymakers to develop more information on the region’s vulnerability, to take a closer look at land use and development, and to make investments to strengthen critical infrastructure.
“This is a landmark study in many ways,” said Lerner-Lam. “It gives us the best possible evidence that we have an earthquake hazard here that should be a factor in any planning decision. It crystallizes the argument that this hazard is not random. There is a structure to the location and timing of the earthquakes. This enables us to contemplate risk in an entirely different way. And since we are able to do that, we should be required to do that.”
New York earthquakes’ facts and figures
- Existing U.S. Geological Survey seismic hazard maps show New York City as facing more hazard than many other eastern U.S. areas. Three areas are somewhat more active — northernmost New York State, New Hampshire and South Carolina — but they have much lower populations and fewer structures. The wider forces at work include pressure exerted from continuing expansion of the mid-Atlantic Ridge thousands of miles to the east; slow westward migration of the North American continent; and the area’s intricate labyrinth of old faults, sutures and zones of weakness caused by past collisions and rifting.
- Due to New York’s past history, population density and fragile, interdependent infrastructure, a 2001 analysis by the Federal Emergency Management Agency ranks it the 11th most at-risk U.S. city for earthquake damage. Among those ahead: Los Angeles, San Francisco, Seattle and Portland. Behind: Salt Lake City, Sacramento, Anchorage.
- New York’s first seismic station was set up at Fordham University in the 1920s. Lamont-Doherty Earth Observatory, in Palisades, New York, has operated stations since 1949, and now coordinates a network of about 40.
- Dozens of small quakes have been felt in the New York area. A 17 January 2001 magnitude 2.4, centered in the Upper East Side — the first ever detected in Manhattan itself — may have originated on the 125th Street fault. Some people thought it was an explosion, but no one was harmed.
- The most recent felt quake, a magnitude 2.1 on July 28, 2008, was centered near Milford, New Jersey. Houses shook and a woman at St. Edward’s Church said she felt the building rise up under her feet—but no damage was done.
- Questions about the seismic safety of the Indian Point nuclear power plant, which lies amid a metropolitan area of more than 20 million people, were raised in previous scientific papers in 1978 and 1985.
- Because the hard rocks under much of New York can build up a lot strain before breaking, researchers believe that modest faults as short as 1 to 10 kilometers can cause magnitude 5 or 6 quakes.
- In general, magnitude 3 quakes occur about 10 times more often than magnitude fours; 100 times more than magnitude fives; and so on. This principle is called the Gutenberg-Richter relationship.
