Clarendon-Linden Fault has shaken earth locally on several occasions

Posted 2 October 2023 at 12:28 pm

The Medina Daily-Journal, August 12, 1929, reported on an earthquake.

By Catherine Cooper, Orleans County Historian

“Illuminating Orleans” – Vol. 3, No. 32

Tremors were felt all over Western New York early on a Monday morning, August 12, 1929, and even registered on the official seismograph at Georgetown University. The greatest damage was reported from the Attica area where the quake measured 4.9. Walls and chimneys were damaged, the cost of repairs was estimated at $20,000.

This earthquake was attributed to the Clarendon-Linden Fault, a tectonic feature of Western New York, which runs north-south from Lake Ontario, west of Rochester, through Batavia and Attica to the Pennsylvania border. Geologists believe that it extends into Lake Ontario in a partially buried bedrock ridge known as the Scotch Bonnet Rise.

The fault is named for the Town of Clarendon in Orleans County and Linden, a hamlet of the Town of Bethany in Genesee County. Since 1929, numerous smaller earthquakes have been attributed to this system, including a 2.6 earthquake on March 29, 2020, which had an epicenter in Medina.

The first published reference to this fault was written by George H. Chadwick and was published in the 1920 Geological Society of America Bulletin #31. Previously, D.H. Williams, a geologist with the Dominion Natural Gas Company, was the first to recognize the existence of the fault in the East Bethany – East Alexander area of Genesee County.

In 1975, Arthur Van Tyne prepared a detailed report on the Clarendon-Linden Structure of Western New York. He noted that three main faults ran north-south and that two subsidiary faults parallel the central major fault, the Clarendon- Linden fault. This report was responsible for the 1975 decision to discontinue proposals to locate nuclear power plants along the Lake Ontario shoreline in Niagara and Orleans counties.

Articles about earthquakes invariably end with a paragraph speculating on the possibility or probability of future occurrences. Geologists generally “hedge their bets” with ominously portentous statements indicating that seismic risk in this area is “not negligible.” Geologist Walter Mitronovas explained it thus:

“Compared to the states of Alaska and California, New York State has a considerably lower earthquake hazard. This does not necessarily imply the absence of larger destructive earthquakes: it implies only that earthquakes of all sizes will be less frequent”

(From information compiled in 1982 by former Town of Clarendon Historian, Alan J. Isselhard.)