Listen. I know hot water, mainly because I am always in it. A new study reports the hottest water ever recorded 464 degrees C (867.2 F). That so hot the water is in the vapor-phase supercritical region (say three time out loud), basically somewhere between gas and liquid. But doesn't water boil, i.e. go into the gas phase, at 99.97 degrees C? It does at 1 atm but at 3000 meters the increased pressure allows water to stay a liquid at higher temperatures.
I wondered about this when I first read about it, dunno where, a few days ago. They made it sound like supercritcal water was almost unknown outside the lab. It seems like I heard that Iceland taps supercritical water for power generation, from more than a kilometer down. Maybe it was a test well or something, but I thought they were using it. Waaaay more energy in the stuff than yer plain ol boiling water. By the way, and mostly off topic, did you hear about the 800 degree soil and venting smoke in Ventura County? The LA Times article suggests the shallow oil field is responsible. I am very uninformed about such stuff, but I had never heard of an oilfield cooking off before. Even coal seams won't burn unless they have access to air. What do you think? rb
I had not heard about the 800 degree soil. Do you have a link? You were correct Iceland (http://news.bbc.co.uk/2/hi/science/nature/4846574.stm). Supercritical water while uncommon on Earth is common around hydrothermal vents in the deep.
You didn't check Slashdot. Here's a link: