RHH's photos with the keyword: thermal activity

Photographed in the Norris Geyser Basin, this hot spring appears to be rather new with trees still standing in and around it and only a small area affected by the heat and acidity of the water. It is also very hot as the bluish color shows. Another indication that is new is the lack of a name. Most of the geysers, hot pools, hot springs, terraces and other features in the tourist areas have names, but this did not. Thermal activity can spring up nearly anywhere, especially in an very active area like Norris and can also just as quickly disappear. Seismic activity in and outside of the park, annual rainfall or lack thereof, and other factors all affect the thermal activity.

Mammoth Hot Springs is at the north end of Yellowstone National Park and is one of the more active thermal areas, though for years now the activity has slowed. The white mounds in the picture are part of the terraces, but a part that is mostly inactive. I have pictures, however, from the 1970's that show at a great deal of activity in this area. In this area it is possible to walk through the terraces on boardwalks, just visible at the lower end of the picture and of the terraces, but otherwise the ground in these thermal areas is very unstable and very dangerous.

This geyser was just finishing erupting as we drove up. It would have been nice if someone could have stood nearby to give a sense of scale, but that is forbidden and dangerous. The sinter cone of this geyser is 15-20 feet high and is built of the same dissolved limestone as the mound in the previous picture, only here is is deposited by hot water and steam erupting up through the ground.

This geyser,near Old Faithful is quite regular and predictable in its eruptions. It is unique, however, in that it is almost in the Firehole River. The white plume is steam and hot water erupting from the geyser to a height of about 75 feet. These eruptions take place every five to seven hours.

In this area thermal activity has built up huge terraces of sinter deposits. The actual activity changes from year to year and areas that are active at one time may be inactive at others. These springs are on the southern end of the terraces but years ago when we visited Yellowstone this area was inactive and the main area, now dead, was very active.