Studies by a horde of seismologists, geologists and other earth scientists who swarmed into the Firehole Basin in the months after the quake show that during the night of August 17 the hot spring activity in this area changed more than during the 87 years since a park was created out of the mysterious, steaming country which had been known as “Coulter’s Hell.” The scientists termed these changes as “profound and far reaching.” These changes in thermal features are, and will be, in years to come, tremendously interesting. The majority of these changes came with, or just after, the initial quakes. The earthquake acted as a trigger to start eruption in hundreds of springs, nearly half of them erupting for the first time in their known histories. The whole place blew, then subsided. There was considerable juggling of the intervals and playing times of some of the better-known geysers. Great Fountain, Riverside, Daisy, Castle, and Oblong shortened the length of their eruption intervals, but they play nearly twice as frequently as they did prior to the quake. Sapphire, a minor geyser, became a major geyser, but has subsided to a status somewhere in between. Clepsydra Geyser went frantically wild, and has erupted continuously since the quake. [Illustration: The quake gave Yellowstone Park’s famous Morning Geyser in lower Geyser Basin a shot in the arm. Normally erupting once a day, after the quake it blasted off every four hours. (National Park Service)] Steady Geyser just up and quit. So did Grand Geyser. Giantess Geyser, located just across the river from Old Faithful, habitually shook the ground in the vicinity every time it erupted. Right after the quake it blasted off and kept blowing for a continuous 100 hours, instead of its usual 30-hour run. The Fountain Paint Pots became so active, and spread so, that they took over what used to be an asphalt-paved parking area. In the midst of these changing patterns, Old Faithful goes on in much the same way, except for perhaps a slight increased interval between blasts. Studies of 14,317 eruptions were clocked, with an average interval of 63.8 minutes. The shortest interval was 33 minutes, in 1948-51, the longest is 93 minutes, measured in ’55. But none of these changes are static. Just when Grand Geyser, having been dormant for five months, was considered dead, it moved into a sporadic blasting phase. These quake-caused fluctuations in thermal features, plus strong curiosity as to the earthquake’s effects in the surrounding area, Sup’t. Lon Garrison feels, will make Yellowstone’s post-quake years bigger than ever. [Illustration: _MADISON CANYON EARTHQUAKE AREA_]