scholarly journals ASP: An Automated Seismic Processor for microearthquake networks

1982 ◽  
Vol 72 (1) ◽  
pp. 303-325
Author(s):  
T. V. McEvilly ◽  
E. L. Majer

abstract ASP, a low-power, in-field Automated Seismic Processor of microearthquake network data has been designed, fabricated, and deployed for initial operation in four different field areas to monitor seismicity associated with two geothermal areas (The Geysers, California, and Cerro Prieto, Mexico), a nuclear explosion with its related collapse and aftershock sequence, and late (>1 year) activity in a major aftershock series (Livermore, California). A second ASP system, with a high-speed front-end, is used in acoustic emission (1 to 20 kHz) analysis for fracture monitoring. Each of the 15 channels of ASP (configured for up to 128 channels) automatically detects, measures times and amplitudes, and computes and fits FFT's for both the P and S waves on data sampled at 100 samples/sec. These data from each channel are then processed with a central microprocessor for hypocenter location, running b values, source parameters, event count, and P-wave polarities. The system is capable of processing a 15-station detection in approximately 40 sec, excluding printout. The initial trials have demonstrated that in-field real-time analysis of data maximizes the efficiency of microearthquake surveys allowing flexibility in experimental procedures, with a minimum of the traditional labor-intensive postprocessing. Current efforts are directed toward improving efficiency of computation and data output and in expanding software capabilities.

2001 ◽  
Vol 23 ◽  
Author(s):  
K. N. Khanal

The earthquake of 19 November 1980, which occurred in the Sikkim Himalaya was investigated by waveform modelling technique. The synthetic seismograms for both the P- and S-waves were generated using wave number integration method. The P- wave seismograms were generated using different velocity models for the source and receiver crusts. The S-wave seismograms were produced using only the half-space model for both the source and receiver crusts. Comparing the seismograms of these waves with the respective seismograms digitally recorded by the Global Digital Seismograph Network the source parameters have been estimated. The orientation parameters determined in this way are strike = 119 °, dip = 74° and dip direction = S29W for one modal plane and strike = 218 °, dip= 64° and dip direction = N52W for the other modal plane. The modal plane striking in NW direction has been preferred as representing the fault plane. The depth of the earthquake has been estimated to be 22 km. The total duration of the rupture process has been estimated to be 7 s.


Author(s):  
R.P. Goehner ◽  
W.T. Hatfield ◽  
Prakash Rao

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.


2020 ◽  
Vol 67 (4) ◽  
pp. 1197-1205 ◽  
Author(s):  
Yuki Totani ◽  
Susumu Kotani ◽  
Kei Odai ◽  
Etsuro Ito ◽  
Manabu Sakakibara

2021 ◽  
Vol 2021 (4) ◽  
pp. 7-16
Author(s):  
Sivaraman Eswaran ◽  
Aruna Srinivasan ◽  
Prasad Honnavalli

2021 ◽  
Vol 57 (28) ◽  
pp. 3430-3444
Author(s):  
Vinod Kumar

This article describes our journey and success stories in the development of chemical warfare detection, detailing the range of unique chemical probes and methods explored to achieve the specific detection of individual agents in realistic environments.


2021 ◽  
Vol 77 (2) ◽  
pp. 98-108
Author(s):  
R. M. Churchill ◽  
C. S. Chang ◽  
J. Choi ◽  
J. Wong ◽  
S. Klasky ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document