The University of Utah seismograph stations recorded 308 earthquakes in the Utah region during the second quarter of 1991, up from 168 and 205 tremors respectively, in the previous two quarters.
Susan J. Nava, senior staff seismologist, said only four of the earthquakes were magnitude 3 or greater on the Reichter scale, while about 170 were between magnitudes of 2 and 3. The strongest jolt was a 3.8, registered on April 20 about 12 miles north of Paragonah.The station's new quarterly study reports a 119-earthquake swarm in the Parowan Valley of southwestern Utah, with most quakes coming in late April. Swarms of this kind are not unusual in southwestern Utah.
Other strong quakes last quarter were: a 3.4 tremor on April 8, about 31 miles west of Ivins and northwest of St. George; a 3.1 quake on April 26 about 12 miles north of Paragonah; and a 3.0 jolt on June 25 about 45 miles southwest of Bluff.
The university's seismic network centralizes and records the operation of more than 80 stations.