BILLINGS, Mont - A new study by scientists from the U.S. Geological Survey says that a recently discovered surface bulge in Yellowstone National Park could be indicative of some mysterious geothermal activity underneath the surface in recent years.
The bulge, which covers an area of about 25 miles, has risen by 5 inches in six years from 1997 to 2003. Scientists speculate that this might be responsible for the unusually high temperatures in the Norris Geyser Basin.
The bulge could also have awakened the Steamboat geyser besides forming new steam vents. Charles Wicks, a USGS scientist who worked on the study that appears in Thursday's edition of the journal Nature, admitted that the undersurface activities in Yellowstone Park remain a mystery, but that scientists had been able to understand a great deal about the Yellowstone caldera.
The caldera is the collapsed volcano that is located in the center of the park. The volcano last erupted 640,000 years ago. The northern rim of the caldera was discovered pretty recently and Wicks and his team used satellite images to monitor the swelling up of this area labeled as the North Rim Uplift Anomaly.
It was also noted that the caldera's floor moved down as the molten rock swelled. USGS findings prove that the unusual occurrences like the rise in temperatures began at around the same time. In 2003, the temperatures reached such a high level that officials closed some boardwalks for the fear that some people could burn themselves.
Additionally the Nymph Lake near Norris began showing new steam vents that spouted white clouds of gas. The Steamboat geyser burst open in May 2000 after staying silent for nine years. Subsequently there were five more eruptions between 2002 and 2003.
Yellowstone's lead geologist Henry Heasler said that they were aware of the heaving caldera for quite sometime, "We've known that the caldera breathes," he said. "Now we're starting to get a much better idea of those respirations." Heasler added that this research assumes significance in that volcanic activity can be predicted thus taking care of public safety.
