The earliest documents which describe Arizona earthquakes were those recorded at Fort Yuma, located in the 1800's on the California side of the Colorado River. Shocks which probably centered in the Imperial Valley of California, or in Mexico, have been noted there since late 1852.
No earthquake in recorded history has caused deaths or injuries in Arizona. In the past century or more, 14 tremors of intensity V to VII have centered within its borders, of which 12 were reported after Arizona entered the Union in February 1912. All of these shocks, however, were moderate in intensity, with one intensity VII, one VI-VII, four VI, and eight V.
Probably the most famous earthquake in this region occurred in 1887 near Bavispe, Mexico, about 190 miles southeast of Tucson. The temblor caused great destruction near its epicenter. From Guaymas to Nogales, Mexico, Benson and Tucson, Arizona, and at towns as far distant as Albuquerque, New Mexico, water in tanks spilled over, buildings cracked, chimneys were toppled, and railroad cars were set in motion. An observer at Tombstone, near the Mexican border, reported sounds ``like prolonged artillery fire.''
The first damaging earthquake known to have centered within Arizona's borders occurred on January 25, 1906, the year of the great San Francisco earthquake, and of a damaging series of shocks at Socorro, New Mexico. The shock was violent at Flagstaff, about 115 miles north of Phoenix.
The cumulative terror produced by a series of 52 earthquakes, from September 10 to 23, 1910, caused a construction crew in the Coconino Forest near Flagstaff to break camp and leave the area. Boulders rolled down on their camp from nearby mountains, and the earth maintained a constant quiver. The shocks grew in intensity until September 23, when a very strong shock raged throughout northern Arizona. It was so severe north of the San Francisco Mountains that Indians fled from the region.
A tremor on August 18, 1912, caused a 50-mile-long crack in the earth north of the San Francisco Range. Houses were damaged at Williams, and the shock was strong in Coconino County, north of Flagstaff. Rockslides roared down the mountainsides, and the earth seemed to roll ``like waves on the Colorado River.''
A shock that cracked walls and plaster at Wellton, located a few miles east of Yuma in southwestern Arizona, occurred January 2, 1935. Although few residents of the small town were frightened by the tremor, everyone felt the ground quiver, and homes shake.
Eight days later, a slightly stronger earthquake awakened sleepers at Grand Canyon, 175 miles north of Phoenix. Many were frightened by the distinct subterranean rumble and the movement of their houses. Walls were cracked in some cases, and rockslides occurred in the mountains. Three slight foreshocks were felt by Grand Canyon residents during the first week of January, and one very minor aftershock was noted on January 15.
On January 16, 1950, a strong earthquake in Apache County left several cracks in the ground as it rumbled through the small town of Ganado. The cracks, one-half inch wide and up to 12 feet long, extended in a north-south direction near the Ganado trading post.
Abridged from Earthquake Information Bulletin, Volume 2, Number 3, May-June 1970
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