Automated Seismic Moment Tensor Determination by Using On-line Broadband Seismic Waveforms

Seismic moment tensor and b value variations over successive seismic cycles in laboratory stickslip experiments

The formation of fault damage due to slip under high normal stresses can rarely be monitored under in situ conditions. To advance our understanding of microfracture processes, we investigated stick-slip events on Westerly granite samples containing the following: (1) a planar saw cut fault and (2) a fault developed from a fresh fracture surface. We examined temporal changes of seismic moment te...

Analysis of seismic waveforms using full-bridge voltage source inverter

The current research talks about a designed accelerometer system which is able to measure every type of mechanical vibration. The applied vibration in this survey is called seismic wave. Then the measured wave by this novel system is transf ormed to a specif ic function using spline interpolation. This explicit function can be used as a reference signal in the technique PWM to be made in curren...

Group features of small seismic waveforms

This paper demonstrates several group features observed from small seismic waveforms and distinguishes abnormal group features that preceded destructive major shocks from normal ones. Important group features discussed in this paper include direction of seismic wave’s first motion, amplitude ratio, half period of the first motion, frequency components of earthquakes, and linearity of seismic wa...

Universality of the Seismic Moment-frequency Relation

We analyze the seismic moment-frequency relation in various depth ranges and for different seismic regions, using Flinn-Engdahl’s regionalization of global seismicity. Three earthquake lists of centroid-moment tensor data have been used: the Harvard catalog, the USGS catalog, and the HUANG et al. (1997) catalog of deep earthquakes. The results confirm the universality of the b-values and the ma...

Broadband Seismic Methods for Towed-streamer Acquisition