Results 221 to 230 of about 95,337 (259)

Three-dimensional determination of structure and velocity by seismic tomography

Geophysics, 1986
Abstract A computerized seismic tomographic method was developed to obtain body-wave velocities and three-dimensional (3-D) structure of interfaces from reflection data simultaneously. The medium consists of layers with continuous arbitrary 3-D curved interfaces separating homogeneous material with different acoustic properties.
S. K. L. Chiu, E. R. Kanasewich, S. Phadke   +2 more
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Three-dimensional green water velocity on a model structure

Experiments in Fluids, 2011
Flow kinematics of green water due to plunging breaking waves impinging on a simplified, 3D model structure was investigated in the laboratory. Two breaking wave conditions were tested: one with waves impinging on the vertical wall of the model at still water level, and the other with waves impinging on the horizontal deck surface.
Kuang-An Chang, Kusalika Ariyarathne, Richard Mercier   +2 more
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Three-Dimensional Velocity Structure of the Earth’s Upper Mantle

1997
Global seismic tomography now has a history of more than 20 years, and it is possible to identify several trends in research and the continuing evolution towards more accurate and refined models of the Earth’s interior: (1) The incorporation of a variety of seismological observations.
Göran Ekström, Adam M. Dziewonski
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Tomographic inversion for the three-dimensional seismic velocity structure of the Aswan region, Egypt

pure and applied geophysics, 1995
The Thurber iterative simultaneous inversion program is used to determine the three-dimensional P-wave velocity structure in the Aswan seismic region of Egypt. The tomographic inversion presented in this study is based on 1131 P-phase observations at 13 stations from 89 local earthquakes, all of which occurred within the Kalabsha fault zone.
Mohamed Awad, Megume Mizoue
openaire   +1 more source

Three-dimensional P- and S-wave velocity structures beneath Japan

Physics of the Earth and Planetary Interiors, 2008
Abstract We determined the three-dimensional Vp and Vs structures beneath Japan by applying seismic tomography to a large number of arrival times recorded at temporary stations in the Japan Sea and the Pacific Ocean, as well as those at permanent stations on the Japan Islands. As a result, we obtained more precise seismic images than previous studies.
Masaki Nakamura, Yasuhiro Yoshida, Dapeng Zhao, Hiroyuki Takayama, Koichiro Obana, Hiroshi Katao, Junzo Kasahara, Toshihiko Kanazawa, Shuichi Kodaira, Toshinori Sato, Hajime Shiobara, Masanao Shinohara, Hideki Shimamura, Narumi Takahashi, Ayako Nakanishi, Ryota Hino, Yoshio Murai, Kimihiro Mochizuki   +17 more
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Three-dimensional P-wave velocity structure of Tungurahua Volcano, Ecuador

Journal of Volcanology and Geothermal Research, 2005
Abstract Tungurahua Volcano in the Ecuadorian Andes is a large andesitic stratovolcano (5023 m) that has been erupting mildly since 1999. We studied the three-dimensional (3-D) P-wave velocity (Vp) structure beneath the volcano down to 5 km below the summit.
Indira Molina, Hiroyuki Kumagai, Jean-Luc Le Pennec, Minard Hall   +3 more
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Three-dimensional seismic velocity structure and earthquake relocations at Katmai, Alaska

Journal of Volcanology and Geothermal Research, 2014
Abstract We invert arrival time data from local earthquakes occurring between September 2004 and May 2009 to determine the three-dimensional (3D) upper crustal seismic structure in the Katmai volcanic region. Waveforms for the study come from the Alaska Volcano Observatory's permanent network of 20 seismic stations in the area (predominantly single ...
Rachel Murphy, Clifford Thurber, Stephanie Prejean, Ninfa Bennington   +3 more
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Three-Dimensional Structure and Evolution of the Vertical Velocity and Divergence Fields in the MJO

Journal of the Atmospheric Sciences, 2014
Abstract The features in the planetary-scale wind field that shape the MJO-related vertical velocity field are examined using the linear analysis protocol based on the daily global velocity potential field described in a companion paper, augmented by a compositing procedure that yields a more robust and concise description of the ...
John M. Wallace, Ángel F. Adames
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Three-Dimensional Magnetic and Velocity Structures of Active Region 12673

2020
<p>We study the Solar Active Region (AR) 12673 in September 2017, which is the most flare productive AR in the solar cycle 24.  Observations from Goode Solar Telescope (GST) show the strong photospheric magnetic fields (nearly 6000 G) in polarity  inversion line (PIL) and apparent photospheric twist on ...
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Travel-time residuals and three-dimensional velocity structure of Italy

pure and applied geophysics, 1982
Jeffreys-Bullen P and PKP travel-time residuals observed at more than 50 seismic stations distributed along Italy and surrounding areas in the time interval 1962–1979, indicate the complex velocity pattern of this region. Strong lateral velocity inhomogeneities and low velocity zones are required to explain the observed pattern of residuals.
openaire   +1 more source