Citation

Sivakumar R, Ghosh S. Nat. Hazards 2017; 86(2): 711-740.

Copyright

(Copyright © 2017, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s11069-016-2713-2

PMID

unavailable

Abstract

The phenomenon of earthquake is the major seismic event occurring in the subsurface rupture zone. In the recent years, specifically active tectonic zones are more important due to its frequent occurrences of earthquakes. The main aim of the present research is to determine the threshold energy by studying the relationship between various geomechanics parameters and to develop seismic energy anomaly based on threshold energy for the assessment of deviated energy. To achieve this goal, subsurface geomechanics parameters such as energy, pressure, force and acceleration were studied to understand the correlation of the above parameters with magnitude and hypocentral distance for the determination of threshold energy. In addition, geospatial and geotectonic databases were generated in GIS platform. Further, the seismic energy anomaly model was developed on the basis of threshold energy for the assessment of deviated energy from threshold and also compared with geological formation and tectonic features through transect chart. The correlation between geomechanics parameters indicates that the earthquake magnitude depends on subsurface energy, pressure, force, acceleration and hypocentral distance. The threshold determination study represents that the threshold energy increases with the increase in hypocentral distance. The threshold energy has been classified as least intensity, strong, disastrous, catastrophic and great catastrophic threshold which varies at different hypocentral distances. It defines that if the concentration of energy exceeds the value of 41.26 yottajoule or 4.126 × 1025 J energy at 10 km depth, people can feel the earthquake while 41.26 yottajoule or 4.126 × 1025 J kinetic energy is considered as least intensity threshold at 10 km depth. The seismic energy anomaly model represents the positive and negative energy anomaly. Positive energy anomaly shows that the kinetic energy accumulation exceeds in many parts of the study area, while negative energy anomaly illustrates the deficit in energy which observes in very few places in the study area. The transect chart depicts that the positive seismic energy anomaly is recognized where the concentration of kinetic energy exceeds its threshold limit to induce high-magnitude earthquake and tectonic influences are also significant. Similarly, negative seismic energy anomalies were observed where the concentration of kinetic energy is not sufficient to trigger a strong earthquake and tectonic influences are also not remarkable. The present study can be useful to develop threshold energy-based early warning system of earthquake by the simulation model in future.

Language: en