by noise from underground. On August 29, 1878, an entire
town on Unalaska Island appears to have been destroyed by
a tsunami and earthquake.
Augustine volcano erupted on October 6, 1883; a very
powerful earthquake and a tsunami occurred in connection
with this eruption. An earthquake in the area of Prince Wil-
liam Sound in May 1896 was so violent that people who
were standing had trouble remaining on their feet. The Yaku-
tat Bay earthquakes of September 3 and 10, 1899, were esti-
mated at Mercalli intensity XI and at Richter magnitudes
8.3 and 8.6, respectively. The epicenter was located near
Cape Yakataga. The first of these earthquakes was felt with
tremendous violence at Cape Yakataga, but the second earth-
quake was the one that caused major changes in topography.
A U.S. Geological Survey expedition to the region six years
after the earthquakes found widespread evidence of topo-
graphic changes. Beaches had been raised, and barnacles and
other aquatic organisms were lifted out of the water. On the
west shore of Disenchantment Bay, an uplift of more than
47 feet (14 m) was measured—approximately the height of
a five-story building. Over a wide area, uplift of 17 feet (6
m) or more was observed. In some areas, depressions of sev-
eral feet occurred. A tsunami thought to have been perhaps
35 feet (11 m) high occurred in Yakutat Bay, and tsunamis
were reported at other locations along the coast of Alaska as
well. There were reports of volcanic eruptions associated with
these earthquakes, but the “eruptions” are presumed to have
been merely large clouds of snow released in slides caused
by the earthquakes. Strong aftershocks occurred over sev-
eral months following these earthquakes. No loss of life was
attributed to the earthquakes because the area was not yet
settled; a small number of Native Americans and prospectors,
however, witnessed the earthquakes firsthand.
On September 21, 1911, an earthquake of Richter mag-
nitude 6.9 on the Kenai Peninsula and Prince William Sound
broke cables, caused great rockslides, and killed large num-
bers of fish; water at Wells Bay was reportedly disturbed
greatly. Cables broke also in another earthquake on Janu-
ary 31, 1912, in the vicinity of Prince William Sound; this
earthquake, which was measured at Richter magnitude 7.25,
appears to have been centered west of Valdez and was felt
in Fairbanks. Very strong shocks occurred at Kanatak, Nush-
agak, and Uyak on June 4–5, 1912, and were felt more than
100 miles (161 km) away from Mount Katmai, although the
earthquakes may have been unaffiliated with the June 6 erup-
tion of Mount Katmai. An earthquake of Richter magnitude
6.4 at Cook Inlet on June 6, 1912, coincided with a bright
display of light from Katmai, and the shock was recorded
at many distant locations, including Ottawa, Ontario, and
Irkutsk in Russia. Very strong earthquakes were reported on
the night of June 6 at Kodiak, and on June 7, a strong earth-
quake struck Kanatak, together with rockslides and a pow-
erful rumbling noise.
An earthquake near Seward on January 3, 1933, mea-
sured at Richter magnitude 6.25, was felt very strongly at
Anchorage, and caused alarm at Seward; the ground cracked
in numerous places in the vicinity of Seward, notably for a
distance of 20 miles (33 km) along a road extending north
from the city. On April 26, 1933, an earthquake northwest
of Anchorage severed telegraph lines and broke plate-glass
windows and was felt also in Fairbanks and in the Aleutian
Islands. Houses were displaced from their foundations at
Old Tyonek. The principal shock measured Richter mag-
nitude 7.0. Old Tyonek experienced further damage several
weeks later when an earthquake of magnitude 6.25 occurred
there on June 13, 1933. The May 14, 1934, earthquake on
Kodiak Island measured magnitude 6.5 and was felt strongly
on Whale and Kodiak Islands; plaster was cracked, and roads
were blocked by landslides. An earthquake of magnitude
6.75 in south central Alaska was strong enough to break
plate glass in Anchorage on August 1, 1934.
Tsunami damage was remarkable in the magnitude 7.4
earthquake of April 1, 1946. Centered about 90 miles (145
km) southeast of Scotch Cap Lighthouse, the earthquake pro-
duced a tsunami that demolished the lighthouse and caused
damage at widely separated locations in and around the
Pacific Basin, along the Pacific coasts of North and South
America, in the Aleutian Islands, and in the Hawaiian
Islands, where 173 persons drowned and property damage
was estimated at $25 million.
The earthquake of March 9, 1957, measured Richter
magnitude 8.3 and was one of the greatest natural calamities
in Alaskan history. The earthquake, which involved hundreds
of aftershocks and affected an area approximately 700 miles
(1,127 km) in length along the southern border of the Aleu-
tian Islands between Amchitka Pass and Unimak Island, was
accompanied by a tsunami 40 feet (12 m) high that struck
the shore at Scotch Cap, and a 26-foot (8-m)-high tsunami
that caused extensive damage at Sand Bay. On the islands of
Kauai and Oahu in Hawaii, the waves destroyed two villages
and caused several million dollars in damage. The tsunami
was 10 feet (3 m) high along the coast of Japan, and a wave
six feet (2 m) high was reported in Chile.
The earthquake of July 9, 1958, is famous for the dra-
matic effect it produced at Lituya Bay, on the Gulf of Alaska
in the southeastern part of the state. A tremendous rockslide
at the head of the bay produced a giant wave (seiche)—more
than 1,700 feet (518 m) high—that swept outward through
the mouth of the bay and is thought to have killed two peo-
ple who were caught in the wave. A fishing boat with two
occupants was carried out of the bay by the wave front and
reportedly cleared the spit at the mouth of the bay by at
least 100 feet (30 m). The wave also wiped the rim of the
bay clean of trees. Otherwise, little damage was reported
from this earthquake, except that underwater communication
cables were broken in the vicinity of Skagway, and Yakutat
experienced damage to bridges, a dock, and oil lines. Great
landslides reportedly occurred in the mountains, and fis-
sures and sand blows were reportedly widespread on the
coastal plain near Yakutat.
The Good Friday earthquake of March 27, 1964, is cov-
ered in detail elsewhere in this volume.
Among the volcanoes of Alaska are Katmai, Augustine,
Pavlof, Redoubt, Iliamna, and Shishaldin. Numerous
calderas, indicative of eruptive activity followed by collapse,
are found at locations such as Aniakchak, Emmons Lake,
Fisher, Little Sitkin, Okmok, Semisopochnoi, Veniami-
nof, and the Wrangell Mountains.
6 Alaska