Carbon dioxide clathrate

[2] There has also been some experimental evidence for the development of a metastable Type II phase at a temperature near the ice melting point.

The first evidence for the existence of CO2 hydrates dates back to the year 1882, when Zygmunt Florenty Wróblewski[9][10][11] reported clathrate formation while studying carbonic acid.

He noted that gas hydrate was a white material resembling snow and could be formed by raising the pressure above a certain limit in his H2O - CO2 system.

[20] Recently, Professor Praveen Linga and his group in collaboration with ExxonMobil have demonstrated the first-ever experimental evidence of the stability of carbon dioxide hydrate in deep-oceanic sediments.

The question of a possible diurnal and annual CO2 hydrate cycle on Mars remains, since the large temperature amplitudes observed there cause exiting and reentering the clathrate stability field on a daily and seasonal basis.

[33] The decomposition of CO2 hydrate is believed to play a significant role in the terraforming processes on Mars, and many of the observed surface features are partly attributed to it.

[37] Milton (1974) suggested the decomposition of CO2 clathrate caused rapid water outflows and formation of chaotic terrains.

[38] Cabrol et al. (1998) proposed that the physical environment and the morphology of the south polar domes on Mars suggest possible cryovolcanism.

[41] Stewart & Nimmo (2002) find it is extremely unlikely that CO2 clathrate is present in the Martian regolith in quantities that would affect surface modification processes.

[42] Baker et al. 1991 suggests that, if not today, at least in the early Martian geologic history the clathrates may have played an important role for the climate changes there.

[43] Since not too much is known about the CO2 hydrates formation and decomposition kinetics, or their physical and structural properties, it becomes clear that all the above-mentioned speculations rest on extremely unstable bases.

The dark gray region (V-I-H) represents the conditions at which CO2 hydrate is stable together with gaseous CO2 and water ice (below 273.15 K).