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Background The State of Tennessee is locate in the Eastern United States (US) and is bordered in the West at its south-western point at approximately −90.3° long. by 35.0° lat. and in the East at its north-eastern point at approximate −81.6° long. by 36.6° lat. From this north eastern tip to the south-western tip the longitudinal and latitudinal distances are approximately 800 km by 200 km, making it a long, narrow state. As a result, the western part of the state includes the New Madrid Seismic Zone (NMSZ) discussed by other speakers at this workshop and the most active seismic zone in the contiguous US east of the Rocky Mountains. In addition, the eastern part of the state includes the East Tennessee Seismic Zone (ETSZ), possibly the second most seismically active zone in the contiguous US. Powell and Beavers (1) described the NMSZ as: “... having abundant evidence ... that the NMSZ generated at least three major earthquake sequences in the past (1450, 900, and 1811–1812 AD) with a 400–500 year recurrence interval.” The ETSZ as discussed by Powell and Beavers (1) receives little publicity and is virtually unknown to the general population. However, Powell and Beavers state: “Although the ETSZ generates approximately 50 recorded earthquakes each year, none has exceeded magnitude 4.6 in recorded history.” In their paper Powell and Beavers conclude the following: “It is evident that the ETSZ as currently understood represents a significant risk to the population and should be treated with more respect ... research needs to be conducted ... capable of producing a magnitude ...7.9. A magnitude 7.9 would be catastrophic to the region.” As just implied and discussed further below such an earthquake would result in significant losses. |
