HR: 1340h
AN: S23B-0240    [Abstracts]
TI: Preliminary Report on Seismic Activity on the Mogollon Plateau, Arizona (2005)
AU: * Brumbaugh, D S
EM: david.brumbaugh@nau.edu
AB: The Blue Ridge area of the Mogollon Plateau has been the site of continuous earthquake activity beginning in late January 2005. The largest events have been a M3.9 on January 28,a second M3.9 on January 30, and the largest so far a M4.6 on March 2 that was felt over much of central and northern Arizona. These larger tremors have been accompanied and followed by numerous smaller earthquakes in the area that have continued up to the present The tremors are too small to have created ground breakage and fault slip at the surface although a number of prominent faults do occupy the Blue Ridge area, including the Quayle Hill fault that crosses State Route 87. The presently occurring activity mirrors that which occurred in the same area in 1989. At present 180 events have been recorded by regional stations and by a field array of portable units. Processing the data so far has resulted in 75 locations. The epicenters cluster in two groups, the southernmost one of which is located in the midst of surface fault traces of the Leonard Point fault, and another unnamed adjacent fault. The northernmost cluster contains most of the events and stretches from the Quayle Hill-Red Hill faults to the northeast over a distance of about 20 kilometers. Depths range from 1.5 to 9 kilometers. The only fault plane solution so far indicates normal faulting on WNW trending surfaces.
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: Fall Meeting 2005