Lunar rock Q in 3000-5000 range achieved in laboratory

Q measurements carried out by the vibrating bar technique on lunar sample 70215,85 have yielded Q values as high as 4800 at room temperature. The strong outgassing procedures necessary to raise the Q to these high values from Q =- 60 (when received) and studies of the effect on Q by a variety of different gases shows that the removal of thin layers of adsorbed H2O are responsible for the dramatic increase in Q. Experiments carried out with a low frequency apparatus on a terrestrial analogue at 50 Hz suggest similar increases in Q with outgassing, thus providing evidence that dramatic effects on Q can be expected to occur down to seismic frequencies. These results, in part, explain the contrast between seismic data in the lunar and terrestrial crust in terms of the absence and presence respectively of adsorbed H2O.