Attenuation of broad-band (50-1500 Hz) seismic waves in granitic rocks near the Earth’ surface

1996 ◽  
Vol 23 (15) ◽  
pp. 1981-1984 ◽  
Author(s):  
K. Holliger ◽  
J. Bühnemann
Keyword(s):  
Seismic Waves ◽  
Broad Band ◽  
Granitic Rocks ◽  
Earth Surface ◽  
The Earth

SEISMIC WAVES FROM A HORIZONTAL FORCE

Geophysics ◽  
1956 ◽  
Vol 21 (3) ◽  
pp. 715-723 ◽  
Author(s):  
J. E. White ◽  
S. N. Heaps ◽  
P. L. Lawrence
Keyword(s):  
Surface Waves ◽  
Shear Wave ◽  
Qualitative Agreement ◽  
Seismic Waves ◽  
Shear Waves ◽  
Earth Surface ◽  
Horizontal Force ◽  
The Earth ◽  
Fundamental Research ◽  
The Waves

As part of a program of fundamental research on seismic waves, a generator was built for applying a transient horizontal force at the surface of the ground and the resulting seismic waves were observed in some detail. The force is applied when a mass swinging through an arc strikes a target anchored to the earth. Surface geophones along a line in the direction of the force register vertically polarized shear waves refracted back up to the surface, whereas geophones on a line perpendicular to the force register horizontally polarized shear waves. The speeds of the two types of shear waves are often different, indicating anisotropy. Geophones buried below the target show a down‐going shear wave. Variation of amplitude with angle, and other features, are in qualitative agreement with the results given by Rayleigh and others for the waves due to a force at a point in an infinite solid. Love waves and other surface waves were observed, which of course would not be expected from an nterior force.

Basis for the technique of the external control of the optical equipment for the remote sensing of the Earth surface

1997 ◽  
Vol 3 (3-4) ◽  
pp. 50-53
Author(s):  
O.D. Fedorovskyi ◽  
◽  
V.I. Kononov ◽  
K.Yu. Sukhanov ◽  
◽  
...  
Keyword(s):  
Remote Sensing ◽  
External Control ◽  
Earth Surface ◽  
The Earth

ESTIMATION OF THE EARTH SURFACE TEMPERATURE BY HIMAWARI-8/AHI

2016 ◽  
Vol 72 (2) ◽  
pp. II_1-II_6 ◽  
Author(s):  
Yuuki UCHIDA ◽  
Tomohito ASAKA ◽  
Takashi NONAKA ◽  
Keishi IWASHITA ◽  
Toshiro SUGIMURA
Keyword(s):  
Surface Temperature ◽  
Earth Surface ◽  
The Earth

scholarly journals Twin enigmatic microseismic sources in the Gulf of Guinea observed on intercontinental seismic stations

2013 ◽  
Vol 194 (1) ◽  
pp. 362-366 ◽  
Author(s):  
Yingjie Xia ◽  
Sidao Ni ◽  
Xiangfang Zeng
Keyword(s):  
North America ◽  
Temporal Variation ◽  
Crustal Structure ◽  
Source Region ◽  
Broad Band ◽  
Active Volcano ◽  
Gulf Of Guinea ◽  
Waveform Data ◽  
Seismic Stations ◽  
The Earth

Abstract Based on studies of continuous waveform data recorded on broad-band seismograph stations in Africa, Europe and North America, we report evidences for two temporally persistent and spatially localized monochromatic vibrating sources (around 0.036 and 0.038 Hz, respectively) in the Gulf of Guinea, instead of just one source (0.038 Hz or 26 s) found 50 yr ago. The location of the 0.036 Hz source is close to the Sao Tome Volcano, therefore it may be related to volcano processes. However, the 0.038 Hz source cannot be explained with known mechanisms, such as tectonic or oceanic processes. The most likely mechanism is volcano processes, but there is no reported active volcano in source region. Such repetitive vibration sources may provide valuable tools for detecting temporal variation of crustal structure of the Earth.

Technical photography of surface motion

1962 ◽  
Vol 52 (5) ◽  
pp. 1007-1016
Author(s):  
B. Carder ◽  
J. Hefferman ◽  
D. Barnes
Keyword(s):  
New Mexico ◽  
Long Range ◽  
Short Range ◽  
Surface Displacement ◽  
Earth Surface ◽  
Peak Displacement ◽  
Surface Motion ◽  
Target Weight ◽  
The Earth ◽  
Analysis Of Results

abstract Photographic measurements of the earth-surface displacement were made on the gnome event, an underground nuclear detonation near Carlsbad, New Mexico, November 1961. One long range and three short range photo stations were used to provide complementary coverage. Motionless inertia weights were measured against graduated targets rigidly anchored to the surface. The experiment is described in detail including target/weight arrangement, camera specifications, and photo station locations in relation to Surface Zero. Analysis of results from 6 films from close-in stations and one film from the long range station are reported. The peak displacement measured was slightly greater than six feet at a location 106 feet from surface zero.

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