Seismic image and velocity models were obtained from a newly conducted seismic survey around the Integrated Ocean Drilling Program (IODP) Japan Trench Fast Drilling Project (JFAST) drill site in the Japan Trench. Pre-stack depth migration (PSDM) analysis was applied to the multichannel seismic reflection data to produce an accurate depth seismic profile together with a P wave velocity model alo...

The Nevada Seismic Array (NVAR) is a small-aperture seismic array designed for monitoring an eventual nuclear test ban treaty. In spite of the 4 km aperture, large amplitude variations are recorded due to the complicated local geology. This study takes advantage of the collocated infrasound and seismic sensors to discuss the use of air-to-ground coupled waves to characterize the shallow geologi...

Methodologies for calculating surface-wave velocities and the associated displacement/stress eigenfunctions and Green’s functions have been well established for many decades. However, to our knowledge, no one has ever documented a quantitative evaluation of these properties for commonly used empirical scalings. For example, it is currently not possible to take a given power-law dependence of sh...

Love and Rayleigh wave phase velocities increase systematically with increasing age of oceanic lithosphere up to 150 Ma. The rates of increase differ between oceans and vary for different age intervals. Modeling of lithospheric age–phase velocity relations indicates that the high velocity seismic lid thickens and the velocities in the sub-lithospheric low velocity Ž . zone LVZ increase with age...

In many real-life situations, we have several types of uncertainty: measurement uncertainty can lead to probabilistic and/or interval uncertainty, expert estimates come with interval and/or fuzzy uncertainty, etc. In many situations, in addition to measurement uncertainty, we have prior knowledge coming from prior data processing, prior knowledge coming from prior interval constraints. In this ...

Many techniques have been proposed in recent years for in situ soil characterization, and among them, acoustic methods have been revealed to be particularly promising. These methods are based on measurements of the propagation velocities of seismic, sonic, and ultrasonic waves. However, in granular and porous mediums, velocities depend on the state of the saturation of the soil in a complex and...

An ever present goal of seismic processing and inversion is to extract meaningful geology information from seismic data. The simplest possibility is to invert for seismic impedances, or, considering density constant, invert for velocities. Here I use a micro genetic algorithm program to achieve this goal. I use a real sonic log to compute a synthetic seismic trace and then use that trace as inp...

We collected SH-wave seismic reflection data over a shallow aquifer in southwestern British Columbia to investigate the use of such data in hydrogeologic applications. We used this data set in developing a methodology that uses cone penetrometer data as an integral part of the inversion and interpretation of the seismic data. A Bayesian inversion technique converts the seismic amplitude variati...

Reconstructing past ocean-climate environments and heat transport requires proxies from which these conditions can be quantified. This is particularly important for the evaluation of numerical palaeoclimate models. Here we present new evidence for a reduced North Atlantic Current (NAC) at the termination of the third last glacial, for which palaeocurrent information was previously unavailable. ...

Results of study of anomaly behavior of amplitudes, phase velocities and gradients of ULF electromagnetic disturbances (F = 0.002 – 0.5 Hz) before and during a seismic active period are presented. Investigations were carried out in Japan (Izu and Chiba peninsulas) by two groups of magnetic stations spaced apart at a distance ∼140 km. Every group (magnetic gradientometer) consists of three 3comp...