The ground motion attenuation relations have been proposed on an empirical basis and widely been used for ground motion prediction in convenient and efficient way. The accuracy of the predictions, however, is not so high given an earthquake magnitude and distance, the uncertainty of the relations has, say, 0.5 or more in a natural logarithmic standard deviation, which significantly governs the ...

[1] Available records of the magnetic indices Dst and ap together with standard observatory recordings of 1-min field levels were examined for the period preceding the earthquake of October 1989, centered near Loma Prieta, California. The magnetic records showed that the Fraser-Smith et al. (1990) report claiming the existence of a 100-s (ultralow frequency) geomagnetic field precursor signal a...

Fuzzy logic techniques have been widely used in civil and earthquake engineering applications in the past four decades. However, no thorough research studies were conducted to use them for deriving attenuation relationships for peak ground accelerations (PGA). This paper is an attempt to fill this gap by employing a fuzzy approach with fuzzy sets for earthquake magnitude and distance from sourc...

Most instruments used in seismological practice to record ground motion are pendulum seismographs, velocigraphs, or accelerographs. In most cases it is assumed that seismic instruments are only sensitive to the translational motion of the instrument’s base. In this study the full equation of pendulum motion, including the inputs of rotations and tilts, is considered. It is shown that tilting th...

[1] We have developed a systematic nonlinear inversion method for estimating rupture propagation and the underlying dynamic parameters for large historical earthquakes. The rupture modeling is carried out using a three-dimensional finite-difference method, and the inversion is implemented by a neighbourhood algorithm, minimizing the misfit between computed and observed near-fault seismograms. W...

For seismic resistant design of critical structures, a dynamic analysis, based on either response spectrum or time history is frequently required. Due to the lack of recorded data and randomness of earthquake ground motion that might be experienced by the structure under probable future earthquakes, it is usually difficult to obtain recorded data which fit the necessary parameters (e.g. soil ty...

S U M M A R Y W phase is a long period phase arriving before S wave. It can be interpreted as superposition of the fundamental, first, second and third overtones of spheroidal modes or Rayleigh waves and has a group velocity from 4.5 to 9 km s−1 over a period range of 100–1000 s. The amplitude of long period waves better represents the tsunami potential of an earthquake. Because of the fast gro...

Earthquake-induced increases in streamflow, producing ;0.7 km3 of total excess water, were documented after the 1999 (Mw 5 7.5) Chi-Chi earthquake in central Taiwan. Analysis of stream gauge data and well records suggests that the excess water originated in the mountains. We propose that the extensive high-angle fractures formed during the earthquake allow rapid release of water from mountains ...

The Hartley transform, a real-valued alternative to the complex Fourier transform, is presented as an efficient tool for the analysis and simulation of earthquake accelerograms. This paper is introduced a novel method based on discrete Hartley transform (DHT) and radial basis function (RBF) neural network for generation of artificial earthquake accelerograms from specific target spectrums. Acce...

A leading cause of death from natural disasters over the last 50years is witnessed by none other than earthquake occurrences which have a negative economic impact on world and claimed thousands lives years, causing devastation to properties. In this paper, novel Ensemble Earthquake Prediction Method (EEPM) proposed implemented produce strong learner (ensemble method) having better accuracy in p...