Choice of a teleseismicP-wave travel-time model and the associated source corrections

1972 ◽  
Vol 101 (1) ◽  
pp. 74-89
Author(s):  
S. K. Arora ◽  
C. A. Krishnan
Keyword(s):  
1990 ◽  
Vol 38 (2) ◽  
pp. 163-177 ◽  
Author(s):  
Ichiro Nakanishi ◽  
Yoshinobu Motoya
Keyword(s):  
P Wave ◽  

1958 ◽  
Vol 48 (4) ◽  
pp. 377-398
Author(s):  
Dean S. Carder ◽  
Leslie F. Bailey

Abstract A large number of seismograph records from nuclear explosions in the Nevada and Pacific Island proving grounds have been collected and analyzed. The Nevada explosions were well recorded to distances of 6°.5 (450 mi.) and weakly recorded as far as 17°.5, and under favorable circumstances as far as 34°. The Pacific explosions had world-wide recording except that regional data were necessarily meager. The Nevada data confirm that the crustal thickness in the area is about 35 km., with associations of 6.1 km/sec. speeds in the crust and 8.0 to 8.2 km/sec. speeds beneath it. They indicate that there is no uniform layering in the crust, and that if higher-speed media do exist, they are not consistent; also, that the crust between the proving grounds and central California shows a thickening probably as high as 70 or 75 km., and that this thickened portion may extend beneath the Owens Valley. The data also point to a discontinuity at postulated depths of 160 to 185 km. Pacific travel times out to 14° are from 4 to 8 sec. earlier than similar continental data partly because of a thinner crust, 17 km. or less, under the atolls and partly because speeds in the top of the mantle are more nearly 8.15 km/sec. than 8.0 km/sec. More distant points, at 17°.5 and 18°.5, indicate slower travel times—about 8.1 km/sec. A fairly sharp discontinuity at 19° in the travel-time data is indicated. Travel times from Pacific sources to North America follow closely Jeffreys-Bullen 1948 and Gutenberg 1953 travel-time curves for surface foci except they are about 2 sec. earlier on the continent, and Arctic and Pacific basin data are about 2 sec. still earlier. The core reflection PcP shows a strong variation in amplitude with slight changes in distance at two points where sufficient data were available.


1977 ◽  
Vol 37 (1-3) ◽  
pp. 83-93 ◽  
Author(s):  
Søren Gregersen
Keyword(s):  
P Wave ◽  

Author(s):  
N.N. Biswas ◽  
M.N. Toksoez ◽  
H.H. Kehrer
Keyword(s):  
P Wave ◽  

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Leng Jun-qiang ◽  
Feng Yu-qin ◽  
Zhai Jing ◽  
Bao Lei ◽  
He Yi

The travel time of left-turning vehicles at signalized intersection was discussed. Under the assumption that the opposing through vehicles headway follows M3 distribution, the travel time model was established on the basis of gap theory and queue theory. Comparison was done with the common model based on the assumption that the opposing through vehicles headway follows negative exponential distribution. The results show that the model in this paper has stronger applicability and its most relative error is less than 15%. In addition, the sensitivity analysis was done. The results show that the opposing through flow rate has significant impact on travel time. The impact of left-turning flow rate and following headway is light when the opposing through flow rate is small, the threshold is about 0.18 veh/s. The model established in this paper can well calculate travel time of left-turning vehicles at intersection, and the methodology may provide reference to other occasions.


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