A seismotectonic model for the 300-kilometer-long eastern tennessee seismic zone

Area of Science:

• Earth Sciences
• Seismology
• Geophysics

Background:

• A regional seismic network has monitored microearthquakes in eastern Tennessee for ten years.
• Understanding seismic activity patterns is crucial for assessing regional tectonic stress and crustal dynamics.

Purpose of the Study:

• To identify and characterize zones of seismic activity in eastern Tennessee.
• To analyze the release of seismic strain energy within the region.
• To investigate the relationship between seismicity and underlying crustal structures.

Main Methods:

• Analysis of ten years of microearthquake data from a regional seismic network.
• Calculation of seismic strain energy release, normalized by crustal area.
• Correlation of seismic activity with geological data on basement crustal blocks.

Main Results:

• A well-defined, linear zone of seismic activity was identified in eastern Tennessee.
• This zone exhibited the second highest seismic strain energy release east of the Rocky Mountains in the last decade (normalized by area).
• Seismicity is concentrating near the boundary between strong and weak basement crustal blocks.

Conclusions:

• The identified seismic zone represents a significant area of intraplate tectonic stress.
• The concentration of seismicity suggests that crustal block boundaries act as conduits or stress concentrators.
• These findings contribute to understanding the mechanisms driving seismicity in stable continental interiors.