In Yellowstone National Park, scientists have been busy monitoring earthquake swarms in and around the Yellowstone Caldera.
University of Utah geophysics professor Bob Smith says they have come across three simultaneous earthquake swarms, which he says are "remarkable."
Smith says the swarms have left many questions for scientists to ponder, because concurrent swarms have never been detected in the past. Temblors from the three quake swarms mostly hit in three areas: Lewis Lake, the Lower Geyser Basin and the northwest part of Norris Geyser Basin. A total of 130 earthquakes ranging from magnitude 0.6 to 3.6 were observed.
Yellowstone's recent earthquake swarms ran for six days, starting on September 10 and shaking until about 11:30 in the morning of September 16.