Effect of Seismic Wave Form on the Behavior of River Embankment on the Soft Soil Deposit

Abstract Seismic monitoring on three Cascade volcanoes in Washington State, U.S.A., has shown that small seismic events are generated by the active glaciers found on each mountain. Detailed seismic experiments have been conducted to investigate the sources for these icequakes. Considerable evidence indicates that the events are the result of a stick–slip type of motion taking place at the bed of the glaciers. The few events we have been able to locate had depths comparable with the glaciers’ thickness. The similarity of wave form from an explosion at the bottom of a glacier and natural icequakes suggests that the complexity of the seismic wave form is due to the path and not the source. The events exhibit an annual trend with more events being recorded in the summer than during the winter. A ten-fold increase in the number of events preceded a large ice avalanche that involved the entire glacier thickness, suggesting that seismic monitoring may be useful in predicting catastrophic ice movements.

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Seismic Evidence for Discrete Glacier Motion at the Rock–Ice Interface

Journal of Glaciology ◽

10.3189/s0022143000029816 ◽

1979 ◽

Vol 23 (89) ◽

pp. 171-184 ◽

Cited By ~ 9

Author(s):

Craig S. Weaver ◽

Stephen D. Malone

Keyword(s):

Seismic Wave ◽

Fold Increase ◽

Seismic Monitoring ◽

Washington State ◽

Wave Form ◽

Seismic Events ◽

Stick Slip ◽

Considerable Evidence ◽

Glacier Motion ◽

Ice Avalanche

AbstractSeismic monitoring on three Cascade volcanoes in Washington State, U.S.A., has shown that small seismic events are generated by the active glaciers found on each mountain. Detailed seismic experiments have been conducted to investigate the sources for these icequakes. Considerable evidence indicates that the events are the result of a stick–slip type of motion taking place at the bed of the glaciers. The few events we have been able to locate had depths comparable with the glaciers’ thickness. The similarity of wave form from an explosion at the bottom of a glacier and natural icequakes suggests that the complexity of the seismic wave form is due to the path and not the source. The events exhibit an annual trend with more events being recorded in the summer than during the winter. A ten-fold increase in the number of events preceded a large ice avalanche that involved the entire glacier thickness, suggesting that seismic monitoring may be useful in predicting catastrophic ice movements.

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Visual-Neural Correlate of Speechreading Ability in Normal-Hearing Adults

Journal of Speech Language and Hearing Research ◽

10.1044/jshr.2504.521 ◽

1982 ◽

Vol 25 (4) ◽

pp. 521-527 ◽

Cited By ~ 7

Author(s):

David C. Shepherd

Keyword(s):

Normal Hearing ◽

Wave Form ◽

Firing Time ◽

Neural Firing ◽

Neural Correlate ◽

Retest Reliability ◽

Repeated Word ◽

Negative Peak ◽

The Stability ◽

Test Retest Reliability

In 1977, Shepherd and colleagues reported significant correlations (–.90, –.91) between speechreading scores and the latency of a selected negative peak (VN 130 measure) on the averaged visual electroencephalic wave form. The primary purpose of this current study was to examine the stability, or repeatability, of this relation between these cognitive and neurophysiologic measures over a period of several months and thus support its test-retest reliability. Repeated speechreading word and sentence scores were gathered during three test-retest sessions from each of 20 normal-hearing adults. An average of 56 days occurred from the end of one to the beginning of another speechreading sessions. During each of four other test-retest sessions, averaged visual electroencephalic responses (AVER s ) were evoked from each subject. An average of 49 clays intervened between AVER sessions. Product-moment correlations computed among repeated word scores and VN l30 measures ranged from –.61 to –.89. Based on these findings, it was concluded that the VN l30 measure of visual neural firing time is a reliable correlate of speech-reading in normal-hearing adults.

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