Vertical Distributions of Cadmium,Copper,Nickel and Zinc in the Western Philippine Sea and a Comparison with Data from Other Parts of the Pacific Ocean

The seismic waveform data recorded by the Taiwan Telemetered SeismographicNetwork(TTSN)were used to deduce the three-dimensionalQ(subscript p)structure beneath Taiwan.The data consist of three-dimensional,digitalseismograms of 98 earthquakes with magnitudes between 2.2 and 5.7.The Q(subscript p)structure was obtained by the damped least-square method fromattenuation time values(t(superscript *))and travel times.Attenuation time values(t(superscript *))were calculated from these events by using a spectral decay technique underthe assumption of that t(superscript *)is independent of frequency.P-wave spectrawere corrected for a source spectrum of ω^(2)model.Least-square fittingwas done in the frequency domain of 4 to 25 Hz.Frequencies above 25 Hzare usually avoided due to the uncertainty of instrument correction.Ourresults show that the distribution pattern of Q(subscript p)values in the Taiwan areacorrelate well with the seismicity.In the upper crust(depths of between 0to 10 km),the lower Q(subscript p)area is consistent with an area of higher seismicity.However,in the lower crust(10 to 25 km)and upper mantle,the area ofhigher seismicity is consistent with higher Q(subscript p)values.

並列關鍵字

Cadmium ； Copper ； Nickel ； Zinc ； Philippine Sea

國際替代計量

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