Evaluating the effectiveness of rolling impact compaction at a brownfield site with high and low frequency seismic surface waves and geotechnical testing

2013 ◽  
Vol 12 (3) ◽  
pp. 405-414 ◽  
Author(s):  
Robert J. Whiteley ◽  
Peter Caffi
Keyword(s):  
Surface Waves ◽  
Low Frequency ◽  
Seismic Surface Waves ◽  
Geotechnical Testing ◽  
Brownfield Site

Low-Frequency Seismic Surface Waves in the Upper Mississippi Embayment

1994 ◽  
Vol 65 (2) ◽  
pp. 137-148 ◽  
Author(s):  
James Dorman ◽  
Robert Smalley
Keyword(s):  
Surface Waves ◽  
Broad Band ◽  
Low Frequency ◽  
Shear Velocity ◽  
Low Velocity ◽  
Surface Wave Dispersion ◽  
Mississippi Embayment ◽  
Basin Surface ◽  
Upper Mississippi Embayment ◽  
Seismic Surface Waves

Abstract Low-frequency seismic surface waves lasting about 6 minutes were recorded at Memphis following the magnitude 4.6 Risco, Missouri earthquake of May 4, 1991. The motion following S included a very long, sinusoidal train of Love waves with periods of 3 to 5 seconds and weaker groups of Rayleigh waves of periods between 2 and 7 seconds arriving early and late. The unusual Risco surface waves travel a source-receiver path internal to the upper Mississippi embayment, a shallow basin containing soft, young sediments overlying rigid carbonate rocks. In contrast to the strong Risco surface waves, the magnitude 4.8 Cape Girardeau, Missouri earthquake of September 26, 1990, which occurred near the edge of the basin, produced relatively weak surface waves at Memphis. The Risco and Cape Girardeau earthquakes are the largest regional earthquakes ever recorded on long-period and broad-band seismographs within the embayment. They show that (1) the sedimentary basin has a profound effect on low-frequency seismic surface waves; (2) the velocity dispersion of a Love wave mode and two Rayleigh wave modes between periods of 2 and 7 sec is well explained by the layering of low-velocity embayment sediments overlying the high-velocity Knox dolomite; (3) because of their strong dispersion, the characteristic basin surface waves can shake the entire embayment for several minutes following any large intra-basin earthquake; (4) excitation of this characteristic basin disturbance seems to be inefficient for strong earthquakes marginal or external to the basin. Lacking direct measurements of shear velocity in the young embayment clastic section, we find that a simple non-linear relationship between shear velocity and logged compressional velocity makes the sediment physical properties compatible with the observed surface wave dispersion.

What Is Tsunami Earthquake?

2021 ◽  
Author(s):  
Toshikazu Ebisuzaki
Keyword(s):  
Surface Waves ◽  
Seismic Waves ◽  
Submarine Landslides ◽  
Lower Efficiency ◽  
Tsunami Waves ◽  
Tsunami Earthquakes ◽  
Seismic Surface Waves ◽  
Tsunami Earthquake ◽  
Volcanic Islands ◽  
2004 Tsunami

Abstract A tsunami earthquake is defined as an earthquake which induces abnormally strong tsunami waves compared with its seismic magnitude (Kanamori 1972; Kanamori and Anderson 1975; Tanioka and Seno 2001). We investigate the possibility that the surface waves (Rayleigh, Love, and tsunami waves) in tsunami earthquakes are amplified by secondly submarine landslides, induced by the liquefaction of the sea floor due to the strong vibrations of the earthquakes. As pointed by Kanamori (2004), tsunami earthquakes are significantly stronger in longer waves than 100 s and low in radiation efficiencies of seismic waves by one or two order of magnitudes. These natures are in favor of a significant contribution of landslides. The landslides can generate seismic waves with longer period with lower efficiency than the tectonic fault motions (Kanamori et al 1980; Eissler and Kanamori 1987; Hasegawa and Kanamori 1987). We further investigate the distribution of the tsunami earthquakes and found that most of their epicenters are located at the steep slopes in the landward side of the trenches or around volcanic islands, where the soft sediments layers from the landmass are nearly critical against slope failures. This distribution suggests that the secondly landslides may contribute to the tsunami earthquakes. In the present paper, we will investigate the rapture processes determined by the inversion analysis of seismic surface waves of tsunami earthquakes can be explained by massive landslides, simultaneously triggered by earthquakes in the tsunami earthquakes which took place near the trenches.

Evidence of metamaterial physics at the geophysics scale: the METAFORET experiment

2019 ◽  
Author(s):  
Martin Lott ◽  
Philippe Roux ◽  
Stéphane Garambois ◽  
Philippe Guéguen ◽  
Andrea Colombi
Keyword(s):  
Surface Waves ◽  
Attenuation Length ◽  
Dense Forest ◽  
Complex Wave ◽  
Seismic Surface Waves ◽  
Source Excitation ◽  
Ground Penetrating ◽  
Dense Seismic Array ◽  
Seismic Wavefield ◽  
Large Frequency

Abstract The METAFORET experiment was designed to demonstrate that complex wave physics phenomena classically observed at the meso- and micro-scales in acoustics and in optics also apply at the geophysics scale. In particular, the experiment shows that a dense forest of trees can behave as a locally resonant metamaterial for seismic surface waves. The dense arrangement of trees anchored into the ground creates anomalous dispersion curves for surface waves, which highlight a large frequency band-gap around one resonant frequency of the trees, at ∼45 Hz. This demonstration is carried out through the deployment of a dense seismic array of ∼1000 autonomous geophones providing seismic recordings under vibrating source excitation at the transition between an open field and a forest. Additional geophysical equipment was deployed (e.g. ground-penetrating radar, velocimeters on trees) to provide essential complementary measurements. Insights and interpretations on the observed seismic wavefield, including the attenuation length, the intensity ratio between the field and the forest and the surface wave polarization, are validated with 2D numerical simulations of trees over a layered halfspace.

Fundamental properties of surface waves in lossless stratified structures

2010 ◽  
Vol 466 (2120) ◽  
pp. 2447-2469 ◽  
Author(s):  
Guido Valerio ◽  
David R. Jackson ◽  
Alessandro Galli
Keyword(s):  
Surface Waves ◽  
Dispersion Equation ◽  
High Frequency ◽  
Low Frequency ◽  
Layered Structures ◽  
Graphical Solution ◽  
Fundamental Properties ◽  
The Past ◽  
Permittivity And Permeability ◽  
Constitutive Parameters

This paper is focused on dispersive properties of lossless planar layered structures with media having positive constitutive parameters (permittivity and permeability), possibly uniaxially anisotropic. Some of these properties have been derived in the past with reference to specific simple layered structures, and are here established with more general proofs, valid for arbitrary layered structures with positive parameters. As a first step, a simple application of the Smith chart to the relevant dispersion equation is used to prove that evanescent (or plasmonic-type) waves cannot be supported by layers with positive parameters. The main part of the paper is then focused on a generalization of a common graphical solution of the dispersion equation, in order to derive some general properties about the behaviour of the wavenumbers of surface waves as a function of frequency. The wavenumbers normalized with respect to frequency are shown to be always increasing with frequency, and at high frequency they tend to the highest refractive index in the layers. Moreover, two surface waves with the same polarization cannot have the same wavenumber at a given frequency. The low-frequency behaviours are also briefly addressed. The results are derived by means of a suitable application of Foster’s theorem.

Shear-coupled higher mode seismic surface waves

1967 ◽  
Vol 57 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Stuart Crampin
Keyword(s):  
Surface Waves ◽  
Wave Motion ◽  
S Wave ◽  
Higher Modes ◽  
Mode Wave ◽  
Mode Dispersion ◽  
Seismic Surface Waves ◽  
Wave Trains ◽  
Group Velocities

abstract Some higher mode wave trains with irregular dispersion, and some anomalies in the S-wave motion at epicentral distances less than 30°, are shown to be shear-coupled higher modes. The group velocities along the higher mode portions of the paths agree well with observations of direct higher mode dispersion in Scandinavia.

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