There's new activity in Yellowstone National Park's Norris Geyser Basin and – besides steam -- nobody's sure what's up. The basin floor is bulging and experts don't know if there's molten material involved or hot water is pushing in from other areas of the park.
Then there's Steamboat -- an unpredictable geyser that's gone as long as 50 years without spewing. This year it's erupted twice and also twice last year and in 2000.
Monitoring devices have been installed around the basin to record water temperature and flow levels. Jacob Lowenstern of the U-S Geological Survey says there's no sign of any threat. Researchers are hoping the geyser activity gives hints about what will happen later.