The Canadian earthquake felt over a wide area of the northeastern United States should get people to pay more attention to making essential buildings in the region earthquake-proof, a geologist said Saturday. ``Earthquakes in New England are relatively infrequent but they do occur,'' said Dr. John Ebel, a seismologist at the Weston Observatory at Boston College in Newton. ``With that in mind, we need to be sure that critical facilities are made to stand up to earthquakes. Ebel said Massachusetts is one of the few states in New England that have a seismic provision required in the construction of major structures like tall buildings and hospitals. New York state recently required that some structures meet earthquake codes, Ebel said. Nuclear power plants in the region are constructed to withstand earthquakes, Ebel said. Friday's quake, centered 95 miles north of Quebec City, registered 6.0 on the Richter scale, according to U.S. and Canadian seismic monitors. Less than 12 hours later, two aftershocks had been recorded and more were expected, although no damage was reported, state officials said Saturday. Geophysicist Dick Holt at the Weston Geophysical Laboratory said aftershocks could register up to 5.0 on the Richter scale. The main tremor was felt in the northeastern United States from Michigan to Washington, D.C. ``One lady called us and said she had whitecaps in her fish tank and her chandelier was shaking,'' said Pennsylvania state police Cpl. Clifford Williams, near Erie, Pa. There was no structural damage reported, although authorities were told of broken windows in Maine, shelves and dishes falling in Rhode Island, and several intravenous bottles knocked over and broken at a Wilkes-Barre, Pa., hospital. Police in some areas were swamped with calls while other people never felt a thing. In Ohio, as an example, police in Columbus, about in the center of the state, said several people called to report feeling the tremor, but officials in Youngstown, closer to the quake epicenter, were not aware of the quake. People in Cleveland reported feeling buildings move. But a few miles away, seismic monitoring equipment at the Perry nuclear power plant did not detect the quake, said Todd Schneider, a spokesman for Cleveland Electric Illuminating Co. In New York City, firefighters were sent to 40 separate locations in Manhattan where tremors were reported but no damage was found, said fire Lt. Kenneth Murphy. People in other buildings on the granite island didn't notice the quake. In Massachusetts, several people felt the tremor Friday night. ``We ran out of our house. Our lampshade was shaking. We were shaking,'' said Carol Dalessandro, 40, of Wakefield. At the Top of the Hub restaurant on the 52nd floor of the Prudential Center in Boston, about 120 people were dining when the earthquake struck. ``It was enough to make you feel queasy,'' said maitre d' Stephen Brown. ``The entire dining room felt it. Everyone felt they were becoming dizzy or faint. They all sort of smiled and looked at each other. No one felt panicked or anything.'' The Richter scale is a measure of ground motion as recorded on seismographs. Every increase of one number means a tenfold increase in magnitude. An earthquake measuring 5 on the Richter scale can cause considerable damage, a 6 reading severe damage, and a 7 is a major earthquake. The strongest earthquake in Canada this century was recorded off the coast of British Columbia in 1949 and measured 8 on the Richter scale.