Azimuthal Anisotropy of the Megaregolith at the Apollo 14 Landing Site

The characterization of the megaregolith on the Moon has been investigated in various ways including analysis of lunar meteorites, remote sensing of mineralogy and gravity, and deriving a seismic velocity profile. In this study, we propose a method for analyzing azimuthal anisotropy of the megaregolith. We call this method deep-moonquake...

Tectonic tremor characterized by principal-component analysis in the vicinity of central Chile and Argentina

No conclusive evidence has been presented to date for tectonic tremor (TT) in the vicinity of central Chile, where the Nazca Plate is subducting beneath the South American Plate. Subduction in our experimental location (roughly 35.5° S, 70.5° W) is steep and fairly unobstructed compared to the flattened and more seismogenic behavior to the north...

Automatic 3D illumination-diagnosis method for large-N arrays: robust data scanner and machine-learning feature provider

The main issues related to passive-source reflection imaging with seismic interferometry (SI) are inadequate acquisition parameters for sufficient spatial wavefield sampling and vulnerability of surface arrays to the dominant influence of the omnipresent surface-wave sources. Additionally, long recordings provide large data volumes that...

Crustal-scale reflection imaging and interpretation by passive seismic interferometry using local earthquakes

We have developed an application of passive seismic interferometry (SI) using P-wave coda of local earthquakes for the purpose of crustal-scale reflection imaging. We processed the reflection gathers retrieved from SI following a standard seismic processing in exploration seismology. We applied SI to the P-wave coda using crosscorrelation,...

Reflection imaging of aseismic zones of the Nazca slab by global-phase seismic interferometry

Obtaining detailed images of aseismic parts of subducting slabs remains a large challenge for understanding slab dynamics. Hypocenter mapping cannot be used for the purpose due to the absence of seismicity, whereas the use of receiver functions might be compromised by the presence of melt. Global tomography can be used to identify the presence...

Reflection imaging of the Moon's interior using deep-moonquake seismic interferometry

The internal structure of the Moon has been investigated over many years using a variety of seismic methods, such as travel time analysis, receiver functions, and tomography. Here we propose to apply body-wave seismic interferometry to deep moonquakes in order to retrieve zero-offset reflection responses (and thus images) beneath the Apollo...

Reflection imaging of the Moho and the aseismic Nazca slab in the Malargüe region with global-phase seismic interferometry; abstract

Mapping a part of Neuquen Basin in Argentina by global-phase H/V spectral ratio

We investigated the applicability of global phases (epicentral distances of ? 120° and ? 150°) for the H/V spectral ratio to identify the fundamental resonance frequency. We applied the method to delineate a part of Neuquén basin in Argentina without the need for active seismic sources. We obtained fairly identifiable fundamental resonance...

The potential of imaging subsurface heterogeneities by local, natural earthquakes

We have developed a new imaging technique of subsurface heterogeneities that uses Sp-waves from natural earthquakes. This technique can be used as a first screening tool in frontier exploration areas before conventional active exploration. Analyzing Sp-waves from 28 earthquakes (Mj 2.0 to 4.2) recorded by two permanent seismic stations, we built...

Global-phase H/V spectral ratio for delineating the basin in the Malargüe Region, Argentina

Structural estimation of unconsolidated sediments and basins is of fundamental importance for resources exploration, geohazard assessments, and other geophysical aspects. The estimation contributes not only to the understanding of the tectonic settings, but also to the choice of parameters for possible further seismic processing, for example,...