Editing Old Faithful (section)

==Measurement==
Between 1983 and 1994, four probes containing temperature and pressure measurement devices and video equipment were lowered into Old Faithful. The probes were lowered as deep as {{convert|72|ft}}. Temperature measurements of the water at this depth were  {{convert|244|F|C}}, the same as was measured in 1942. The video probes were lowered to a maximum depth of {{convert|42|ft}} to observe the conduit formation and the processes that took place in the conduit. Some of the processes observed include fog formation from the interaction of cool air from above mixing with heated air from below, the recharge processes of water entering into the conduit and expanding from below, and entry of superheated steam measuring as high as {{convert|265|F|C}} into the conduit.<ref>{{cite journal |vauthors=Hutchinson RA, Westphal JA, Kieffer SW | author3-link=Susan Kieffer | title=In situ observations of Old Faithful Geyser | journal=Geology | volume=25 | issue=10 | year=1997 | pages=875–878 | url=http://geology.geoscienceworld.org/cgi/content/abstract/25/10/875 | doi=10.1130/0091-7613(1997)025<0875:ISOOOF>2.3.CO;2|bibcode = 1997Geo....25..875H | url-access=subscription }}</ref>