Since 1980, 45
eruptions and 15 cases of notable volcanic unrest have occurred at 33 U.S.
volcanoes. Lava flows, debris avalanches, and explosive blasts have invaded
communities, swept people to their deaths, choked major riverways, destroyed
bridges, and devastated huge tracts of forest. Noxious volcanic gas emissions
have caused widespread lung problems. Airborne ash clouds have disrupted the
health, lives, and businesses of hundreds of thousands of people; caused
millions of dollars of aircraft damage; and nearly brought down passenger
flights.
About 11
percent of the world’s active volcanoes are located in the United
States. Many of them lie below active air traffic routes.
From 1973
through 2003, about 100 encounters of aircraft with airborne volcanic
ash have been documented. About 20 percent of the reported encounters
involved significant damage to engines and airframes. In eight
encounters, damage was so severe that in-flight engine failures
occurred.
Mount
Rainier volcano in Washington State is one of the Nation’s most
dangerous volcanoes. More than 100,000 people live in areas near
Rainier that have been buried by volcanic debris flows during the past
few thousand years
Alaska
contains over 130 volcanoes and volcanic fields which have been active
within the last two million years.
Of these volcanoes, about 90 have been active within the last 10,000 years
(and might be expected to erupt again), and more than 50 have been active
within historical time (since about 1760, for Alaska).
Volcanoes in Alaska make up
well over three-quarters of U.S. volcanoes that have erupted in the last
two hundred years.
Alaska's volcanoes are potentially hazardous to passenger and freight
aircraft as jet engines sometimes fail after ingesting volcanic ash.
Volcanic History Overview:
Mount Rainier, the highest peak in the Cascade Range at 4,392m (14,410
ft.), forms a dramatic backdrop to the Puget Sound region. During an
eruption 5,600 years ago the once-higher edifice collapsed. Ensuing
eruptions rebuilt the summit, filling the large collapse crater. Large
mudflows from eruptions and from collapses of this massive, heavily
glaciated andesitic volcano have reached as far as the Puget Sound
lowlands. On more than a dozen occasions since the last ice age, explosive
eruptions spread tephra (ash, pumice) across parts of Washington. The last
magmatic eruption was about 1,000 years ago. Extensive hydrothermal
alteration of the upper portion of the volcano has contributed to its
structural weakness promoting collapse. There is also a labyrinth of steam
caves beneath the summit icecap produced by an active thermal system
driven by magma deep beneath the volcano.
Volcanic History Overview:
The Yellowstone Plateau volcanic field developed through three volcanic
cycles spanning two million years that included some of the world's
largest known eruptions. Eruption of the >2450 cu km Huckleberry Ridge
Tuff about 2.1 million years ago created the more than 75-km-long Island
Park caldera. The second cycle concluded with the eruption of the Mesa
Falls Tuff around 1.3 million years ago, forming the 16-km-wide Henrys
Fork caldera at the western end of the first caldera. Activity
subsequently shifted to the present Yellowstone Plateau and culminated
640,000 years ago with the eruption of the >1000 cu km Lava Creek Tuff and
the formation of the present 45 x 85 km caldera. Resurgent doming
subsequently occurred at both the NE and SW sides of the caldera and
voluminous (1000 cu km) intracaldera rhyolitic lava flows were erupted
between 150,000 and 70,000 years ago. No magmatic eruptions have occurred
since the late Pleistocene, but large phreatic eruptions took place near
Yellowstone Lake during the Holocene. Yellowstone is presently the site of
one of the world's largest hydrothermal systems including Earth's largest
concentration of geysers.
Volcanic History Overview:
Prior to 1980, Mount St. Helens formed a conical, youthful volcano
sometimes known as the Fuji-san of America. During the 1980 eruption the
upper 400 m of the summit was removed by slope failure, leaving a 2 x 3.5
km horseshoe-shaped crater now partially filled by a lava dome. Mount St.
Helens was formed during nine eruptive periods beginning about 40-50,000
years ago and has been the most active volcano in the Cascade Range during
the Holocene. Prior to 2200 years ago, tephra, lava domes, and pyroclastic
flows were erupted, forming the older St. Helens edifice, but few lava
flows extended beyond the base of the volcano. The modern edifice was
constructed during the last 2200 years, when the volcano produced basaltic
as well as andesitic and dacitic products from summit and flank vents.
Historical eruptions in the 19th century originated from the Goat Rocks
area on the north flank, and were witnessed by early settlers.
Alphabetical
partial list of U.S. Volcanoes
•Agrigan - Mariana
Islands, Mariana Islands
•Ahyi - Mariana Islands, Mariana Islands
•Akutan - Alaska, Aleutians
•Alamagan - Mariana Islands, Mariana Islands
•Amak - Alaska, Alaska Peninsula
•Amboy - Western US, CA
•Amchixtam Chaxsxii - Alaska, Aleutians
•Amukta - Alaska, Aleutians
•Anatahan - Mariana Islands, Mariana Islands
•Aniakchak - Alaska, Alaska Peninsula
•Asuncion - Mariana Islands, Mariana Islands
•Atka - Alaska, Aleutians
•Augustine - Alaska, Cook Inlet-South Central
•Bald Knoll volcanic field - Western US, UT
•Belknap Shield Volcano - Western US, OR
•Big Cave - Western US, CA
•Black Peak - Alaska, Alaska Peninsula
•Black Rock Desert volcanic field - Western US, UT
•Blue Lake Crater - Western US, OR
•Bobrof - Alaska, Aleutians
•Bogoslof - Alaska, Aleutians
•Brushy Butte - Western US, CA
•Buldir - Alaska, Aleutians
•Buzzard Creek - Alaska, Interior Alaska
•Carlisle - Alaska, Aleutians
•Carrizozo - Western US, NM
•Cerberus, Mt - Alaska, Alaska Peninsula
•Chagulak - Alaska, Aleutians
•Chiginagak - Alaska, Alaska Peninsula
•Cinnamon Butte - Western US, OR
•Clear Lake - Western US, CA
•Cleveland - Alaska, Aleutians
•Coso Volcanic Field - Western US, CA
•Crater Lake - Western US, OR
•Craters of the Moon volcanic field - Western US, ID
•Dana - Alaska, Alaska Peninsula
•Davidof - Alaska, Aleutians
•Davis Lake - Western US, OR
•Denison - Alaska, Alaska Peninsula
•Devils Garden - Western US, OR
•Diamond Craters - Western US, OR
•Dotsero - Western US, CO
•Douglas - Alaska, Alaska Peninsula
•Duncan Canal - Alaska, Southeast Alaska
•Dutton - Alaska, Alaska Peninsula
•Eagle Lake Field - Western US, CA
•East Cape volcano - Alaska, Aleutians
•Edgecumbe - Alaska, Southeast Alaska
•Emmons Lake Volcanic Center - Alaska, Alaska Peninsula
•Esmeralda Bank - Mariana Islands, Mariana Islands
•Falling Mtn - Alaska, Alaska Peninsula
•Farallon de Pajaros - Mariana Islands, Mariana Islands
•Fisher - Alaska, Aleutians
•Four Craters Lava Field - Western US, OR
•Fourpeaked - Alaska, Alaska Peninsula
•Frosty - Alaska, Alaska Peninsula
•Gareloi - Alaska, Aleutians
•Gilbert - Alaska, Aleutians
•Glacier Peak - Western US, WA
•Golden Trout Creek - Western US, CA
•Gordon - Alaska, Wrangell Volcanic Field
•Great Sitkin - Alaska, Aleutians
•Griggs - Alaska, Alaska Peninsula
•Guguan - Mariana Islands, Mariana Islands
•Haleakala - Hawaii and Pacific Ocean, HI
•Hayes - Alaska, Cook Inlet-South Central
•Hells Half Acre volcanic field - Western US, ID
•Herbert - Alaska, Aleutians
•Hualalai - Hawaii and Pacific Ocean, HI
•Iliamna - Alaska, Cook Inlet-South Central
•Indian Heaven - Western US, WA
•Ingakslugwat Hills - Alaska, Southwest Alaska
•Inyo Craters - Western US, CA
•Iskut-Unuk River cones - Alaska, Southeast Alaska
•Jackies Butte - Western US, OR
•Jordan Craters - Western US, OR
•Kagamil - Alaska, Aleutians
•Kaguyak - Alaska, Alaska Peninsula
•Kanaga - Alaska, Aleutians
•Kasatochi - Alaska, Aleutians
•Katmai - Alaska, Alaska Peninsula
•Khvostof - Alaska, Aleutians
•Kialagvik - Alaska, Alaska Peninsula
•Kilauea - Hawaii and Pacific Ocean, HI
•Kiska - Alaska, Aleutians
•Klawasi Group - Alaska, Wrangell Volcanic Field
•Kookooligit Mountains - Alaska, Bering Sea
•Korovin - Alaska, Aleutians
•Kukak - Alaska, Alaska Peninsula
•Kupreanof - Alaska, Alaska Peninsula
•Lassen Volcanic Center - Western US, CA
•Lava Mountain - Western US, OR
•Lavic Lake - Western US, CA
•Little Sitkin - Alaska, Aleutians
•Long Valley Volcanic Center - Western US, CA
•Lo`ihi - Hawaii and Pacific Ocean, HI
•Mageik - Alaska, Alaska Peninsula
•Makushin - Alaska, Aleutians
•Mammoth Mountain - Western US, CA
•Markagunt Plateau volcanic field - Western US, UT
•Martin - Alaska, Alaska Peninsula
•Maug Islands - Mariana Islands, Mariana Islands
•Mauna Kea - Hawaii and Pacific Ocean, HI
•Mauna Loa - Hawaii and Pacific Ocean, HI
•Medicine Lake Volcano - Western US, CA
•Moffett - Alaska, Aleutians
•Mono Lake Volcanic Field - Western US, CA
•Mount Adams - Western US, WA
•Mount Bachelor - Western US, OR
•Mount Baker - Western US, WA
•Mount Hood - Western US, OR
•Mount Jefferson - Western US, OR
•Mount Rainier - Western US, WA
•Mount Shasta - Western US, CA
•Mount St. Helens - Western US, WA
•Mount Washington - Western US, OR
•Newberry Volcano - Western US, OR
•North Sister Field - Western US, OR
•Novarupta - Alaska, Alaska Peninsula
•Nunivak Island - Alaska, Southwest Alaska
•Okmok - Alaska, Aleutians
•Pagan - Mariana Islands, Mariana Islands
•Pavlof - Alaska, Alaska Peninsula
•Pavlof Sister - Alaska, Alaska Peninsula
•Recheshnoi - Alaska, Aleutians
•Redoubt - Alaska, Cook Inlet-South Central
•Roundtop - Alaska, Aleutians
•Ruby - Mariana Islands, Mariana Islands
•Salton Buttes - Western US, CA
•San Francisco Peaks volcanic field - Western US, AZ
•Sand Mountain Field - Western US, OR
•Sanford - Alaska, Wrangell Volcanic Field
•Santa Clara volcanic field - Western US, UT
•Sarigan - Mariana Islands, Mariana Islands
•Seguam - Alaska, Aleutians
•Segula - Alaska, Aleutians
•Semisopochnoi - Alaska, Aleutians
•Shishaldin - Alaska, Aleutians
•Shoshone Lava Field - Western US, ID
•Silver Lake - Western US, CA
•Snowy - Alaska, Alaska Peninsula
•Soda Lakes - Western US, NV
•South Sister - Western US, OR
•Spurr - Alaska, Cook Inlet-South Central
•St. Michael - Alaska, Southwest Alaska
•St. Paul Island - Alaska, Bering Sea
•Steamboat Springs - Western US, NV
•Steller - Alaska, Alaska Peninsula
•Stepovak Bay 2 - Alaska, Alaska Peninsula
•Stepovak Bay 3 - Alaska, Alaska Peninsula
•Stepovak Bay 4 - Alaska, Alaska Peninsula
•Submarine 002 - Alaska, Aleutians
•Submarine 005 - Alaska, Aleutians
•Supply Reef - Mariana Islands, Mariana Islands
•Table Top Mtn - Alaska, Aleutians
•Takawangha - Alaska, Aleutians
•Tana - Alaska, Aleutians
•Tanaga - Alaska, Aleutians
•Tlevak Strait-Suemez Island - Alaska, Southeast Alaska
•Trident - Alaska, Alaska Peninsula
•Tumble Buttes - Western US, CA
•Twin Buttes - Western US, CA
•Ubehebe Craters - Western US, CA
•Ugashik-Peulik - Alaska, Alaska Peninsula
•Uinkaret volcanic field - Western US, AZ
•Ukinrek Maars - Alaska, Alaska Peninsula
•Uliaga - Alaska, Aleutians
•Unnamed (near Ukinrek Maars) - Alaska, Alaska Peninsula
•Valles Caldera - Western US, NM
•Veniaminof - Alaska, Alaska Peninsula
•Vsevidof - Alaska, Aleutians
•Wapi Lava Field - Western US, ID
•West Crater - Western US, WA
•Westdahl - Alaska, Aleutians
•Wide Bay cone - Alaska, Aleutians
•Wrangell - Alaska, Wrangell Volcanic Field
•Yantarni - Alaska, Alaska Peninsula
•Yellowstone - Western US, WY
•Yunaska - Alaska, Aleutians
•Zuni-Bandera volcanic field - Western US, NM
