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Magnitude 5.1 Au Sable Forks, New York

Saturday, April 20, 2002

Preliminary Earthquake Report

World Location

Regional Location

Magnitude 5.1
Date-Time 2002 04 20 10:50:47 UTC
Location 44.51N 73.51W
Depth 11.0 kilometers
Reference 20 km (15 miles) SSW of Plattsburgh, New York
25 km (15 miles) W of Burlington, Vermont
80 km (50 miles) WNW of MONTPELIER, Vermont
205 km (130 miles) N of ALBANY, New York
Remarks Some roads, bridges, chimneys and water lines damaged in Clinton and Essex Counties. Many buildings in the area had cracked walls and foundations, broken windows and small items knocked from shelves. Maximum intensity (VII) at Au Sable Forks. Felt from New Brunswick and Maine to Ohio and Michigan and from Ontario and Quebec to Maryland.
Tectonic Setting

This earthquake occurred in the northeastern part of New York State, an area that experiences moderate-sized but infrequent seismic activity. Although earthquakes occur on geologic faults, in the northeastern U.S. it is difficult to assign an earthquake to a particular fault because they rarely cause surface rupture.

The most recent nearby earthquake of note occurred 80 km to the southwest, a magnitude 5.1 event in 1983. The largest historic earthquake in the northeastern region of the U.S. and nearby parts of Canada had an estimated magnitude of 7. It occurred near Charlevoix, Quebec in 1663, 425 km to the northeast of this latest event.

The pattern of historic seismicity can be seen in the USGS publication, "Earthquakes in and near the Northeastern United States, 1638 - 1998."

Map of Mainshock & Aftershocks

Map of Mainshock & Aftershocks
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Map of Historical Seismicity

Map of Historical Seismicity
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Did You Feel It?
Report shaking and damage at your location. You can also view a map displaying accumulated data from your report and others.

Location Map

Historical Seismicity

Theoretical P-Wave Travel Times

Phase (Arrival Time) Data

Seismic Record Section

Seismic Hazard Map

Earthquake Information for New York

Lamont-Doherty Seismic Network Special Event Page

Press Release-April 23, 2002: The University of Memphis/FedEx Send Aftershock Studies Team to New York

Preliminary Earthquake Report
USGS, Menlo Park, CA
U.S. Geological Survey, Menlo Park, California
U.C. Berkeley Seismological Laboratory,
Berkeley, California