Earthquakes in an Aseismic Region: Local Seismic Network Results for Central New York An AVF Investigation

Twelve seismographs were deployed on or near the campus of Cornell University in the fall of 2015 to record seismic activity in an area under consideration for development of geothermal wells. This area is notable for its lack of recorded and historic seismic activity. The CorNET network operated from October 15, 2015 until November 2, 2016. Preliminary examination of the recorded seismograms has identified 90 events, 64 of which are likely to be earthquakes in central New York. The magnitudes of these events are all less than m = 3.7. However, only four of these likely earthquakes were located within Tompkins County, within which the proposed drill sites lie. The lack of apparent alignment of these events suggests that none of the geological faults known or suspected near the campus are active at present. None of these local events are reported in the national and regional catalogs produced by permanent networks operating in the area, supporting the speculation that the apparent aseismicity of the Ithaca area is an artifact of the detection limits of conventional networks rather than complete lack of natural seismic events. No events were found in the immediate vicinity of the proposed drilling sites for Earth Source Heating. Although the locations of events well beyond the limits of the CorNET array are poorly constrained, most occur within the Finger Lakes region to the northwest of the array. Additionally, 13 events were detected that seem to occur near an active salt mine. Some of these events display a distinctive waveform and temporal clustering, suggesting that they are artificial events rather than tectonic.Cornell University Atkinson Center for a Sustainable Futur