Earthquakes are associated with the West Coast, but they can happen in New York. While the state is situated far from the boundaries of the North American tectonic plate, it is not immune to seismic activity. New York is located in a region of intraplate seismicity, meaning earthquakes occur within the stable interior of the continent. Understanding this geological setting, the history of past tremors, and the current risk assessment is important for residents.
History of Notable Seismic Activity
Historical records confirm that New York and the surrounding region have experienced significant earthquakes. The largest event centered within the state occurred on September 5, 1944, near the New York-Canada border, registering a magnitude of 5.9. This quake caused extensive damage in the northern town of Massena, including the destruction of a school gymnasium and damage to nearly all chimneys.
The New York City metropolitan area has also been struck by damaging tremors. On August 10, 1884, a magnitude 5.2 earthquake with an epicenter likely near Coney Island or Far Rockaway was felt from Virginia to Maine. This event caused widespread reports of cracked plaster, broken windows, and fallen chimneys throughout New York City and surrounding areas. A similar magnitude 5.2 event struck the region in 1737, also damaging chimneys.
Upstate New York features other zones of historical activity, particularly in the Adirondack Mountains and Western New York. Notable Adirondack quakes include the magnitude 5.3 tremor in Au Sable Forks in 2002 and a magnitude 5.1 event near Newcomb in 1983. Most recently, a magnitude 4.8 earthquake in April 2024, centered in New Jersey, was felt across the entire New York metropolitan area, serving as a reminder of the region’s persistent seismic potential.
Why Earthquakes Occur Far from Plate Boundaries
New York’s seismic activity is classified as intraplate, meaning tremors happen far from the edges of the North American tectonic plate. The mechanism for these inland earthquakes involves the reactivation of ancient, buried faults that were formed hundreds of millions of years ago. These faults are deep scars in the Earth’s crust, remnants of continental assembly and failed rifting events that occurred long before the modern continental configuration.
These old faults represent zones of weakness susceptible to movement. The necessary force comes from the immense tectonic stresses transmitted across the entire North American plate. This stress originates primarily from the continuous push of plate creation at the Mid-Atlantic Ridge, which forces the continent westward.
The force accumulates over long periods, eventually causing subtle slippage along these weaknesses. The rock structure in the Eastern United States is significantly older, denser, and colder than the rock found in the seismically active West. This difference allows seismic waves to travel much farther and more efficiently before dissipating. Consequently, an earthquake of a given magnitude in New York can be felt over an area up to ten times larger than a comparable quake in California.
Current Seismic Hazard and Frequency
While major earthquakes are rare, minor seismic events are a regular occurrence throughout New York State. Hundreds of small tremors, mostly below magnitude 2.0 and often unfelt, are recorded annually by monitoring networks. The main seismic zones are concentrated around New York City, the Adirondacks, and the western part of the state.
The risk for a moderate to large event is statistically low but present. Seismologists estimate the New York City area has a 5 to 25 percent chance of experiencing a damaging earthquake over a 100-year period. A magnitude 5.0 or greater earthquake in the metropolitan area is estimated to occur, on average, once every 100 years.
The potential for impact is compounded by the region’s population density and aging infrastructure. Many New York City buildings were constructed before modern seismic design provisions were adopted in 1995. Significant fault zones, such as the Ramapo fault which extends from New Jersey into southeastern New York, are capable of generating a moderate to large earthquake, possibly reaching magnitude 6 or 7. This combination of low-frequency events and high structural vulnerability elevates the overall seismic risk for the state.
Preparing for a Low-Frequency Event
Given the low-frequency but high-impact potential of a moderate earthquake, preparedness is important. The primary safety protocol during shaking is Drop, Cover, and Hold On. This involves dropping to the floor, taking cover under a sturdy piece of furniture like a desk or table, and holding on until the shaking stops.
If inside a high-rise building, stay away from windows and exterior walls, and avoid using elevators. Securing household objects beforehand can significantly reduce injury risk. Residents should anchor tall, heavy furniture, such as bookcases and cabinets, to wall studs and store heavy or breakable items on lower shelves.
An emergency supply kit should be maintained with non-perishable food, water, a first-aid kit, and necessary medications for at least three days. These steps address the immediate dangers posed by falling objects and can sustain a household through the initial aftermath and potential aftershocks.