Not long after the sun dips behind the Talkeetna Mountains to the west and north the air takes a noticeable drop in temperature and clouds begin to form around the mountains. When morning rolls around the mountains seem fully enclosed in clouds and there s a good chill in the air. As a result the workdays starts a bit later in order to take advantage of better temperatures.
Temperatures rise and remain at a very comfortable level into the early evening hours.
This morning a constant but light rain was falling and although everyone was awake and ready to go out for the day, we held back to see if the sun might burn off some clouds and lighten things up a bit. A vent is a location near the terminus of the glacier where there is an upward discharge of water that has been flowing in and under the glacier and is now coming out to create surface runoff. There are a number of these large vents on the Matanuska glacier and each is referred to with a different name for obvious reasons. The water coming out of a vent is under fairly high pressure due to the weight of all the water in the subglacial drainage system above that feeds into it. This results in water coming out that is supercooled and freezes upon reaching normal pressures at the surface.