Induced ground waves

Induced Ground Waves. See Vol 3, p D4-L under Damage Potential of Air and Ground Blast Waves... 

Cook (Ref) reported that only the S-wave and the induced ground wave were apparent in seismic disturbances from surface explns at Tooele, Utah and for unconfined or dirt-covered shots the induced ground wave had an index 5-30 times greater than the S-wave. Synchronous ground-wave induction apparently requires simply matching of the frequency of the air blast with the natural frequency of the ground in the region of the blast. 

Obviously no induced wave can be more intense than its source. Air blast waves, therefore,are always more likely to cause damage than ground disturbances. Even air blast or induced ground waves beyond the range of damage serve merely as sources of annoyances rather than sources of actual damage Ref Cook (1958), pp 353-75... 

There is evidence that seismic surface ground waves can generate seiches in both closed and semi-closed basins. In particular, the Great 1755 Lisbon earthquake triggered remarkable seiches in a number of Scottish lochs, and in rivers and ponds throughout England, western Europe and Scandinavia. Similarly, the Alaska earthquake of 27 March 1964 = 9.2) induced seismic surface waves that took... 

The energy released as heat in the course of the nonradiative decay of P to the ground state and detected as a pressure wave by laser-induced optoacoustic spectroscopy (LIOAS) exhibits positive deviations (i.e., a> 1 cf. Eq. (1)) from the values which were calculated on the basis of the absorption spectrum of Pr alone (Figure 15) [90,115]. This indicates that already within the 15-ns duration of the excitation flash, one or several intermediates must have been formed. These in turn, within the same interval, may again absorb light from an intense laser flash and (at least in part) dissipate heat upon their return to the ground state of the same species (internal conversion) and/or to Pr (photochemical back reaction). The formation of primary photoproducts within the nanosecond flash duration was of course to be expected in view of the much shorter lifetimes of the photochromic fluorescence decay compo-... 

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