Analysis of Observed and Predicted Tsunami Travel Times for the Pacific and Indian Oceans

2009 ◽  
pp. 301-324
Author(s):  
Paul Wessel
Keyword(s):  
Travel Times ◽  
The Pacific

Seismic wave travel times from nuclear explosions

1958 ◽  
Vol 48 (4) ◽  
pp. 377-398
Author(s):  
Dean S. Carder ◽  
Leslie F. Bailey
Keyword(s):  
Travel Time ◽  
Travel Times ◽  
Strong Variation ◽  
Time Data ◽  
Owens Valley ◽  
Central California ◽  
Nuclear Explosions ◽  
Travel Time Data ◽  
The Pacific ◽  
Wave Travel

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.

Hawaiian travel times*

1935 ◽  
Vol 25 (1) ◽  
pp. 33-61
Author(s):  
Austin E. Jones
Keyword(s):  
Seismic Waves ◽  
Complex Structure ◽  
Hawaiian Islands ◽  
Compressional Wave ◽  
Distance Graph ◽  
Time Interval ◽  
Research Association ◽  
Travel Times ◽  
Linear Relations ◽  
The Pacific

Summary In Part I a special study has been made on seismogram phases, showing how to locate Hawaiian local earthquakes without the necessity of accurate time checks on all of the master clocks of the several seismograph stations on Hawaii. This was done by searching old records of the Hawaiian Volcano Research Association network for dates and times when an earthquake occurred very close to one station and was well recorded on the seismographs 37, 70, or 89 kilometers away. Records gave fourteen earthquakes of this kind, of which ten were used. These records were studied and the interval in seconds between the arrivals of the distortional (S) and compressional (P) waves was plotted for the distance of the station away from the origin of the disturbance. On each record there appeared more than one compressional wave and more than one distortional wave, giving rise to various differences, as Sn — Pn, S* — P*, and Sg — Pg. Simple linear relations were found between time-interval and distance for special earthquakes. These linear relations were to be used in locating other earthquakes away from all stations by the geometric method of Isikawa. In Part II a study has been made on travel times; that is, the speeds with which different seismic waves travel through rock constituting the Hawaiian Islands, between the islands of Hawaii and Oahu. This study is based on Part I, for practically no earthquakes have been recorded near any one seismograph station on Hawaii that were large enough to record clearly on Oahu. Oahu is about 300 kilometers away from the seismic origins considered. This study came within five per cent of verifying the speeds of seismic waves through the floor of the Pacific Ocean as found by others. These velocities may prove useful in determining the physical constants of the rocks and indicate what makes up the basement of the Hawaiian Islands. Other waves were found which may indicate a complex structure of four to seven discontinuities in the Hawaiian ridge, it being distinct from the floor of the Pacific and analogous to the structure of continental areas. A travel-time, distance graph has been included which should aid in locating earthquakes in the Hawaiian Islands. These wave velocities, for further corroboration, should lead to geophysical experiments.

scholarly journals On supposed regional variations in travel times*

1937 ◽  
Vol 27 (4) ◽  
pp. 337-347
Author(s):  
B. Gutenberg
Keyword(s):  
Pacific Ocean ◽  
Travel Time ◽  
Travel Times ◽  
Regional Variations ◽  
Local Structures ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Observational Errors ◽  
Limits Of Error

Summary An investigation of the Tango earthquake of March 7, 1927, shows that travel times for P observed in that shock agree within the limits of error of one or two seconds with the travel times found for other earthquakes and that thus far there is no indication of differences beyond the limits of observational errors between the travel-time curves of earthquakes in different regions. This statement, however, does not include the travel times to short epicentral distances of a few degrees found in various regions which are influenced by the local structures in those regions, and especially not to the travel times found from waves which have traversed only the uppermost parts under the Pacific Ocean.

The Philological Association of The Pacific Coast

PMLA ◽  
1935 ◽  
Vol 50 (4) ◽  
pp. 1373-1374
Keyword(s):  
Annual Meeting ◽  
Pacific Coast ◽  
Stanford University ◽  
The Pacific

The thirty-seventh annual meeting of the Philological Association of the Pacific Coast was held at Stanford University, California, on November 29 and 30, 1935.

A scanning electron microscopic study of the veliger larvae of the scallop argopecten purpuratus

1988 ◽  
Vol 46 ◽  
pp. 284-285
Author(s):  
G.C. Bellolio ◽  
K.S. Lohrmann ◽  
E.M. Dupré
Keyword(s):  
Morphological Description ◽  
Electron Microscopic ◽  
Larval Stages ◽  
Scanning Electron Microscopic Study ◽  
The Pacific ◽  
Argopecten Purpuratus ◽  
Veliger Larvae ◽  
20 Nm ◽  
Ethanol Series ◽  
Scanning Electron

Argopecten purpuratus is a scallop distributed in the Pacific coast of Chile and Peru. Although this species is mass cultured in both countries there is no morphological description available of the development of this bivalve except for few characterizations of some larval stages described for culture purposes. In this work veliger larvae (app. 140 pm length) were examined by the scanning electron microscope (SEM) in order to study some aspects of the organogenesis of this species.Veliger larvae were obtained from hatchery cultures, relaxed with a solution of MgCl2 and killed by slow addition of 21 glutaraldehyde (GA) in seawater (SW). They were fixed in 2% GA in calcium free artificial SW (pH 8.3), rinsed 3 times in calcium free SW, and dehydrated in a graded ethanol series. The larvae were critical point dried and mounted on double scotch tape (DST). To permit internal view, some valves were removed by slightly pressing and lifting the tip of a cactus spine wrapped with DST, The samples were coated with 20 nm gold and examined with a JEOL JSM T-300 operated at 15 KV.

Decolonisation and the Pacific

2016 ◽  
Author(s):  
Tracey Banivanua Mar
Keyword(s):  
The Pacific

Letter Across the Pacific

Crisis ◽  
2000 ◽  
Vol 21 (3) ◽  
pp. 107-109
Author(s):  
Chris Cantor
Keyword(s):  
The Pacific

Letter Across the Pacific

Crisis ◽  
2000 ◽  
Vol 21 (4) ◽  
pp. 154-155
Author(s):  
John T. Maltberger
Keyword(s):  
The Pacific
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