The improved empirical fragility model addresses statistical dependence among observations of seismic performances, which arises from common but unknown factors influencing the observations. The proposed model accounts for this dependence by explicitly including common variables in the formulation of the limit state for individual components. Additionally, the fact that observations of the same...

Advanced finite-difference methods for seismic modeling Yang Liu1,2 and Mrinal K Sen2 State Key Laboratory of Petroleum Resource and Prospecting (China University of Petroleum, Beijing), Beijing, 102249, China The Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences, The University of Texas at Austin, 10100 Burnet Road, R2200 Austin, TX 78758, USA E-mail: wliuyang@vi...

Seismicity time properties of the Etna Volcano (Italy) are investigated through a systematic pattern recognition analysis. Mean Hypothesis Testing (MHT) has been applied to a long time database of instrumental data recorded from 1981 to 1996 to identify relevant correlation among seismic patterns, main seismogenic volumes and the eight flank eruptions occured in the same period. Time evolution ...

This paper should be understood as a tutorial in multifractals and their analysis via wavelets, in view of possible applications in geophysics. It is elaborated how a description of the well log measurement through wavelets provides a new way of modeling re ection of waves in a material which is dependent on frequency. The wavelet analysis has the potential to provide an explanation for the inc...

Current rising energy demand/supply ratio trends are forecast to continue into the foreseeable future. As a consequence, effective and efficient seismic surveying and processing techniques are required now more than ever. Unfortunately those outside of organizations with the resources to develop their own processing and/or visualization packages, or license proprietary third-party ones, must ma...

This paper compares performance of a hidden Markov model (HMM) and a hybrid HMM/ANN model in seismic events modeling. Observation variables are assumed to follow a Poisson distribution. Parameters of the discrete-time two-state models are estimated on the basis of data on seismic events that were recorded in Poland from 1991 to 1995. Then, on the basis of the estimation results, the most likely...

It has been hypothesized that much of the crustal deformation attributed to the Laramide orogeny of the southwest North American Cordillera was caused by dynamic effects induced by the flat subduction of a large oceanic plateau that was embedded within the Farallon plate. Previous studies have identified within the North American mantle a seismic velocity anomaly that plausibly represents the r...

The high water storage capacity of minerals in Earth's mantle transition zone (410- to 660-kilometer depth) implies the possibility of a deep H2O reservoir, which could cause dehydration melting of vertically flowing mantle. We examined the effects of downwelling from the transition zone into the lower mantle with high-pressure laboratory experiments, numerical modeling, and seismic P-to-S conv...

Low seismic velocity regions in the mantle and crust are commonly attributed to the presence of silicate melts. Determining melt volume and geometric distribution is fundamental to understanding planetary dynamics. We present a new model for seismic velocity reductions that accounts for the anomalous compressibility of silicate melt, rendering compressional wave velocities more sensitive to mel...

Detailed seismic modeling and imaging of Earth’s deep interior is providing key information about lower-mantle structures and processes, including heat flow across the core-mantle boundary, the configuration of mantle upwellings and downwellings, phase equilibria and transport properties of deep mantle materials, and mechanisms of core-mantle coupling. Multichannel seismicwave analysismethods t...