History of earthquakes in Arizona (from the US
Geological Survey)
The largest earthquake centered
entirely within Arizona was July 21, 1959. This earthquake registered 5.6 on the
Richter scale, and was located approximately 13 miles southeast of Fredonia, AZ,
or 14 miles south of the Utah border.
The only earthquake to cause considerable damage in Arizona was the Sonora Earthquake on May 3, 1887.
The earthquake had a magnitude of 7.6, and was actually centered in Sonora, Mexico,
about 30 miles southeast of Douglas, AZ. People reported hearing rumbling sounds in
Tucson and Phoenix, and it damaged buildings as far away as Phoenix. In spite of significant
damage documented in Arizona, there do not appear to have been any deaths from the quake in
Arizona (there were approximately 60 deaths in Mexico).
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.