HYPOELLIPSE/MULTICS; a computer program for determining local earthquake hypocentral parameters, magnitude, and first motion pattern

1979 ◽  
Author(s):  
John C. Lahr
Keyword(s):  
Computer Program ◽  
Motion Pattern ◽  
Local Earthquake ◽  
Hypocentral Parameters ◽  
First Motion

Complex seismic activity and local stress perturbation of the Pyeongnam basin, northern Korean Peninsula

2020 ◽  
Author(s):  
Tae-Seob Kang ◽  
Heekyoung Lee
Keyword(s):  
Principal Stress ◽  
Korean Peninsula ◽  
Local Stress ◽  
Velocity Model ◽  
Maximum Principal Stress ◽  
Focal Mechanisms ◽  
Body Waves ◽  
Hypocentral Parameters ◽  
First Motion ◽  
Using Data

<div> <div> <div> <p>The western region of the Pyeongnam Basin has relatively higher e​arthquake activity than the rest of the Korean Peninsula. We analyzed 48 earthquakes in the area, with a magnitude (M<sub>L</sub>) of 2.0 or more, from January 2009 to June 2019. The hypocentral parameters were re-determined using an iterative algorithm that repeats the calculation until the residual error between the observed and calculated arrival time of a seismic phase at each station is minimized. Using the hypocenters and the optimal 1-D velocity model derived from this process, the focal mechanisms were determined using the first-motion polarities of body waves. Many earthquakes are associated with left-lateral strike-slip faults, with a strike in the NW-SE direction and a normal faulting component. A stress inversion was performed using data of the pressure and tensional axes from the focal mechanisms. The maximum principal stress in the study area acts in the NW-SE direction with high angles of plunge and differs from the maximum horizontal principal stress in the rest of the Korean Peninsula. This stress perturbation is caused by the detachment of a small local stress from the regional stress field due to the presence of weak faults with low shear strength that develop in the sedimentation environment of the Pyeongnam Basin.</p> </div> </div> </div>

A general computer program for the extended plate overlap algorithm

1978 ◽  
Vol 48 ◽  
pp. 287-293 ◽  
Author(s):  
Chr. de Vegt ◽  
E. Ebner ◽  
K. von der Heide
Keyword(s):  
Computer Program ◽  
Simultaneous Determination ◽  
General Computer Program ◽  
General Computer

In contrast to the adjustment of single plates a block adjustment is a simultaneous determination of all unknowns associated with many overlapping plates (star positions and plate constants etc. ) by one large adjustment. This plate overlap technique was introduced by Eichhorn and reviewed by Googe et. al. The author now has developed a set of computer programmes which allows the adjustment of any set of contemporaneous overlapping plates. There is in principle no limit for the number of plates, the number of stars, the number of individual plate constants for each plate, and for the overlapping factor.

Structures and crystallization of vacuum-deposited amorphous Se and Sb films

1990 ◽  
Vol 48 (4) ◽  
pp. 140-141
Author(s):  
Makoto Shiojiri ◽  
Toshiyuki Isshiki ◽  
Tetsuya Fudaba ◽  
Yoshihiro Hirota
Keyword(s):  
Monte Carlo ◽  
Electron Microscope ◽  
Monte Carlo Method ◽  
Computer Program ◽  
Radial Distribution ◽  
Film Formation ◽  
Amorphous State ◽  
Two Dimensional ◽  
Amorphous Films ◽  
Binding Condition

In hexagonal Se crystal each atom is covalently bound to two others to form an endless spiral chain, and in Sb crystal each atom to three others to form an extended puckered sheet. Such chains and sheets may be regarded as one- and two- dimensional molecules, respectively. In this paper we investigate the structures in amorphous state of these elements and the crystallization.HRTEM and ED images of vacuum-deposited amorphous Se and Sb films were taken with a JEM-200CX electron microscope (Cs=1.2 mm). The structure models of amorphous films were constructed on a computer by Monte Carlo method. Generated atoms were subsequently deposited on a space of 2 nm×2 nm as they fulfiled the binding condition, to form a film 5 nm thick (Fig. 1a-1c). An improvement on a previous computer program has been made as to realize the actual film formation. Radial distribution fuction (RDF) curves, ED intensities and HRTEM images for the constructed structure models were calculated, and compared with the observed ones.

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