Observations Why Does Ice Float

Relaxation of the Chemical Bond, Springer Series in Chemical Physics 108, DOI 10.1007/978-981-4585-21-7 36, Springer Science+Business Media Singapore 2014 

36 Thermally Driven Density and Phonon-Stiffness Oscillation 

At T 80 K, both the coh and the co conserve [43,44]. Using IR spectroscopy, Medcraft et al. [44] measured the size and temperature dependence of the low-frequency 0 H (col 200 cm ) phonons in the temperature range of 4—190 K and observed that heating softens the co at T 80 K, but the (o changes insignificantly at r 80 K see Fig. 36.3. Earlier Raman spectroscopy [46] of bulk ice revealed that the co drops monotonicaUy within the temperature range of 25 and 272 K in addition to the resolvable fluctuations in frequency at temperatures close to 272 K [47]. 

Theoretical studies on density anomalies of water ice have mainly focused on the density change of the freezing temperatures with supercooling water to mimic the freezing process. This process was discussed in the following mechanisms  

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