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about Manhattan Earthquake 01/17/01

United States Earthquakes 1928-40
U.S. Department of Commerce
Environmental Science Services Administration
Coast and Geodetic Survey

July 18: 22:51 * Western Long Island, N. Y. Maximum intensity about IV. According to instrumental studies made by L. D. Leet of the Harvard Seismographic Station the focus was close to 40° 43' north 73° 42.5' west, a point very close to Floral Park, about 15 miles east of lower Manhattan. This point checks well with the center of the most strongly affected area which lay within a radius of about 8 miles of Floral Park. See map.

  A canvass made by the Coast and Geodetic Survey revealed that there were places within this area where the intensity was less than IV and quite a number of widely scattered points far beyond the epicentral area where it was reported as equivalent to IV. At Redding, Conn., 43 miles from the epicenter, a house was reported so furiously shaken that stones were loosened from the foundations and the lights went out temporarily. Such relatively high intensities at isolated distant points are believed due largely to resonance phenomena in local geological formations and in the structures themselves. In addition there is probably considerable variation of intensity because of the complex nature of the transmission of earthquake waves through the layered crust of the earth.

  There were no reports of seismic phenomena on Manhattan Island but it is rather likely that some isolated and very minor effects were not recognized as such or not reported. See "Earthquakes in North America, July-December 1937," by L. Don Leet, Bulletin of the Seismological Society of America, volume 28, No. 3, July 1938.

Intensity IV in New York: Bayside, Douglaston, Far Rockaway, Flushing, Freeport, Long Beach, Mineola, Ocean Bay Park, Rockaway Beach, Rockville Center, Scarsdale, Woodmere. In Connecticut: Norwalk and Redding ( See preceding note) . In New Jersey: Sandy Hook.

Intensity III and under in New York: Amityville, Baldwin, Bay Shore, Brooklyn, East Rockaway , Glen Cove, Jamaica, Jones Beach, Lloyd Harbor Light Bay, Port Jefferson, Queens, Richmond Hill, Rower Shoal Light Station, Westhampton Beach, Valley Stream. In Connecticut: Bridgeport, East Haven, Fairfield, Greenwich, Hartford, New Canaan, Stamford. In New Jersey: Maplewood, Trenton.

Not felt in New York: Aquebogue, Central Islip, East Hampton, Greenport, Mamaroneck, Manhattan, Mattituck, Montauk, Northport, Patchogue, Port Chester, Riverhead, Rocky Point, Yaphank. In Connecticut: Ansonia, Guilford, New Haven, Saybrook, South Norwalk, West Haven

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