A SEISMIC HAZARD STUDY OF THE MASSENA AREA, NORTHERN NEW YORK
On September 5, 1944, an earthquake of intensity VIII on the Modified Mercalli Scale shook the Massena-Cornwall area. This magnitude six earthquake caused $2,000,000 in damage, mostly to chimneys and cracked brick walls. Studies of the destructive effects of the earthquake with the geology indicated the most destructive effects were found on structures built on the Massena (Leda) clay. This is a marine clay deposited in the Champlain Sea and occurring at Massena, NY, Cornwall, and Ottawa, Canada. Large-scale (1:24,000) maps of the Massena area have been drawn to show the distribution of this clay. The scale of the maps make them practical for residents in the area to determine the location of their houses or structures relative to the clay. Maps of the Ottawa area also show the distribution of the Leda clay.