posted 08/22/00

Magnitude 2.5 Earthquake Centered North of New York City Recorded at Lamont
Columbia University, New York City

Map of Greater New York area
with known earthquakes prior to 1975.
note: up to 1975 only mag 3+ are shown; after 1975 mag 2+

The blue star at top of map is the location of the magnitude 2.5 earthquake of Tuesday morning, 1:46 AM EDT, August 22, 2000, in Putnam County, New York.

 On Tuesday morning, August 22, 2000 Lamont's seismographs recorded a minor earthquake felt near Carmel, in Putnam County, New York.

The epicenter was located approximately 4 km (approx. 2.5 miles) northeast of the town of Carmel. An earthquake of this size would not be expected to cause damage. The shaking would have been short and sharp. People were awakened mainly because of the loud noise as if their oil burner had exploded or there was a truck collision on a road near their house.

Seismograms of the Quake and Map of Stations

The previous earthquake widely felt in the New York City area occured in October of 1985 and was centered near the northern border of the city of Yonkers (large blue dot on the map above) and was magnitude 4.1. Ten months prior to this earthquake there was a magnitude 2.2 earthquake at the same location and five months prior to the magnitude 4.1 there were magnitude 1.4 and 1.8 quakes.

The largest earthquakes known in the Greater New York Metropolitan area were of approximately magnitude 5. They occured in 1737, 1783, and 1884. They were felt from Maine to Virginia and caused chimneys to fall from Connecticut into New Jersey.

With the last magnitude 5 earthquake in 1884, we are now in the longest known period without a magnitude 5 earthquake in the vicinity of New York City.

An earthquake occurred in 1994 near Reading, Pennsylvania (magnitude 4.7) and caused damage in the millions of dollars. This earthquake was found by a Lamont team to have been triggered by a rock quarry. The seismicity began in May 1993, 6 months after the quarry was abandonned and flooded; the main shock occured January 1994.

Lamont-Doherty Earth Observatory of Columbia University has monitored earthquakes in the New York City area since the 1960s and operates a network of seismic stations in cooperation with the US Geological Survey. Recordings from the Lamont seismic network can be observed near real-time by visiting the website: http://www.ldeo.columbia.edu/~wykim/LCSN/lcsn.html.

Lamont researchers were instrumental in the development of the seismic building code for New York City. It went into effect on February 21, 1996.

Currently Lamont researchers contribute to a study of the expected losses from future larger earthquakes in the NYC Metropolitan area. More about this at:
http://www.nycem.org/techdocs.asp and
http://www.nycem.org/techdocs/siteCondsYr1/default.asp.

About The Earth Institute
The Earth Institute at Columbia University is the world's leading academic center for the integrated study of Earth, its environment and society. The Earth Institute builds upon excellence in the core disciplines — earth sciences, biological sciences, engineering sciences, social sciences and health sciences — and stresses cross-disciplinary approaches to complex problems. Through research, training and global partnerships, it mobilizes science and technology to advance sustainable development, while placing special emphasis on the needs of the world's poor. For more information, visit www.earth.columbia.edu.