Page 213 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists
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195 Wave and
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Earthquakes thinner water layer. Uplifted Above Level Sea a) Configuration of sea bottom some areas out of the sea Plate suddenly unflexed
of causes water wave. Wave is low level. d)
Characteristics inundating coastal areas. After Earthquake Below eet Ree After Earthquake Downdropped as Stress Released i hquake. earth: lift may above sea region
of seafloor during earthquake with sea bottom in shallow area channels energy into violently) b) Dro, d) i i Rebound during earthquake uplifts coastal flooding region.
Wave Earthquake Focus offset Effects of tilting due to elastic rebound during earthquake. b) plate flexed in
Generates “Sy Interaction Earthquake Earthquake iltii before Bulge during earthquake. downdropping and
Small Amplitude Ocean 7.8 cm) in deep ocean. b) Before a) Before c) Stress FIGURE and
‘ Tsunami.a) Abrupt amplitude grows considerably. rapidly (and often Uplifted as Builds 7.9 land surface submerge others. c)
a) in Deep FIGURE
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Effects of ground motion a) Wavefronts of waves. Higher seismic station. b) S and surface waves, arriving P-waves, are commonly wave energy is prolonging the earthquakes. life of loss and cause can lines install to is and electricity gas or uplifts down- generating water a These ocean. the few (a amplitudes water shallow uplifting. down- or shallow and lowlands sub- during flexed r
7.7 from earthquake waves radiating from surface initial violent. Surface 3.17), (Fig. shaking during large damage electrical solution the faulting 7.8a), cross to low in m several tilting, marshes turn flooding of coastal is that the in flexure, raising each are north-south,
FIGURE P,S. and focus toward amplitude after the more dispersed violent more and of gas effective down shut earthquake (Fig. hours have to cause can and plate plate the relaxes the seismometers, directions
Seismic Station fi P often breaking low-cost automatically Sometimes very taking “tidal earthquake bottom. causes earthquake three 7.10). to
non Focus cause and abruptly several waves”) grow can can Uplift sinking lithospheric of bulging The vertical,
Seismology z Z f Earthquake Surface Waves (Dispersed) earthquakes from the A burn. that shake. seafloor km/hr, called amplitudes but 7.8b). an sea or involves a causes strain an during have least at motion (Fig. responding
Earthquake As i e a et Seon 1 + 1 ' 1 ‘ 1 ‘ i ' ' ' ! ( of effects Fires itself. cities to valves cut-off to starts the of 1000 about mistakenly water, (Fig. during rebound surface land ground: downdropping case special Elastic of strain 7.9d). (Fig. typically ground (orthogonal).
* ‘ * ae shaking of sections at (sometimes ocean beaches the A 7.9c). regions Seismograms of
a i . 5 Secondary portions and building traveling deep of dry a,b). (Fig. rebound stations direction
Chapter? the switches a large tsunamis in approaching Elastic dropping into 7.9 coastal another
buryeys punos than large when warps wave cm) bays (Fig. duction sudden ing Earthquake Seismic ferent one motions.
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