Trail and timberline . rseveral months was the developmentof new hot ground. These new hotspots were made evident by groups ofdead or dying lodgepole pines. In themajority of these dead-tree groupsthere is no evidence of surface fractur-ing. Many breaks permitting the evo-lution of gases apparently did notreach the surface. In a few of the newhot spots, there is evidence of continu-ous development, suggestive that newthermal units will yet evolve. Tempera-tures taken in late 1960 a foot belowthe surface, at the roots of many deadtrees, show a temperature range of 64to 204 degrees Fahrenheit. C
Trail and timberline . rseveral months was the developmentof new hot ground. These new hotspots were made evident by groups ofdead or dying lodgepole pines. In themajority of these dead-tree groupsthere is no evidence of surface fractur-ing. Many breaks permitting the evo-lution of gases apparently did notreach the surface. In a few of the newhot spots, there is evidence of continu-ous development, suggestive that newthermal units will yet evolve. Tempera-tures taken in late 1960 a foot belowthe surface, at the roots of many deadtrees, show a temperature range of 64to 204 degrees Fahrenheit. Changes Persisting One of the interesting aspects re-lating to the changes induced by theearthquake is that most of thesechanges are persisting. It is now overa year since the August 1959 incident,but in the majority of cases the springshave not returned to pre-quake only as a result of new surfacefracturing, permitting new avenues ofescape of the thermal energy, but deep-seated fracturing has also so altered. Photo by the National Park Park, WyomingThe Hebgen Lake earthquake jarredinto eruption this geyser in the LowerGeyser Basin, Earthquake Geyser. NO. 504, DECEMBER, 1960 183 the former avenues of steam egressthat there is little or no likelihood thatconditions in the geyser basins willever be the same as before the bigtremor. It can safely be said that agreater amount of change took placein the Firehole Geyser Basins duringthe night of August 17, 1959, than dur-ing all of the 90 years since their in the Future The Hebgen Lake earthquake is notan isolated incident. Since Yellowstonebecame a National Park in 1872, a num-ber of earthquakes have been of these quakes have had theirepicenters in the rhyolite mass formingthe central plateau. Seismic recordsindicate that on an average of aboutonce in every 10 years a strong earth-quake is registered in the states ad-joining Yellowstone. The last majorearthquake alon
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmountaineering, booky
