Mount Bachelor, formerly named Bachelor Butte, is a dormant stratovolcano atop a shield volcano in the Cascade Volcanic Arc and the Cascade Range of central Oregon. Named Mount Bachelor because it stands apart from the nearby Three Sisters, it lies in the eastern segment of the central portion of the High Cascades, the eastern segment of the Cascade Range. The volcano lies at the northern end of the 15-mile (24 km) long Mount Bachelor Volcanic Chain, which underwent four major eruptive episodes during the Pleistocene and the Holocene. The United States Geological Survey considers Mount Bachelor a moderate threat, but Bachelor poses little threat of becoming an active volcano in the near future. It remains unclear whether the volcano is extinct or just inactive.
The Lassen volcanic area presents a geological record of sedimentation and volcanic activity in and around Lassen Volcanic National Park in Northern California, U.S. The park is located in the southernmost part of the Cascade Mountain Range in the Pacific Northwest region of the United States. Pacific Oceanic tectonic plates have plunged below the North American Plate in this part of North America for hundreds of millions of years. Heat and molten rock from these subducting plates has fed scores of volcanoes in California, Oregon, Washington and British Columbia over at least the past 30 million years, including these in the Lassen volcanic areas.
Lassen Peak, commonly referred to as Mount Lassen, is a lava dome volcano and the southernmost active volcano in the Cascade Range of the Western United States. Located in the Shasta Cascade region of Northern California, it is part of the Cascade Volcanic Arc, which stretches from southwestern British Columbia to northern California. Lassen Peak reaches an elevation of 10,457 ft (3,187 m), standing above the northern Sacramento Valley. It supports many flora and fauna among its diverse habitats, which are subject to frequent snowfall and reach high elevations.
Novarupta is a volcano that was formed in 1912, located on the Alaska Peninsula on a slope of Trident Volcano in Katmai National Park and Preserve, about 290 miles (470 km) southwest of Anchorage. Formed during the largest volcanic eruption of the 20th century, Novarupta released 30 times the volume of magma of the 1980 eruption of Mount St. Helens.
The Valley of Ten Thousand Smokes is a valley within Katmai National Park and Preserve in Alaska which is filled with ash flow from the eruption of Novarupta on June 6–8, 1912. Following the eruption, thousands of fumaroles vented steam from the ash. Robert F. Griggs, who explored the volcano's aftermath for the National Geographic Society in 1916, gave the valley its name, saying that "the whole valley as far as the eye could reach was full of hundreds, no thousands—literally, tens of thousands—of smokes curling up from its fissured floor."
Katmai National Park and Preserve is an American national park and preserve in southwest Alaska, notable for the Valley of Ten Thousand Smokes and for its brown bears. The park and preserve encompass 4,093,077 acres, which is between the sizes of Connecticut and New Jersey. Most of the national park is a designated wilderness area. The park is named after Mount Katmai, its centerpiece stratovolcano. The park is located on the Alaska Peninsula, across from Kodiak Island, with headquarters in nearby King Salmon, about 290 miles (470 km) southwest of Anchorage. The area was first designated a national monument in 1918 to protect the area around the major 1912 volcanic eruption of Novarupta, which formed the Valley of Ten Thousand Smokes, a 40-square-mile (100 km2), 100-to-700-foot-deep pyroclastic flow. The park includes as many as 18 individual volcanoes, seven of which have been active since 1900.
Mount Katmai is a large stratovolcano on the Alaska Peninsula in southern Alaska, located within Katmai National Park and Preserve. It is about 6.3 miles (10 km) in diameter with a central lake-filled caldera about two by three miles in size, formed during the Novarupta eruption of 1912. The caldera rim reaches a maximum elevation of 6,716 feet (2,047 m). In 1975 the surface of the crater lake was at an elevation of about 4,220 feet (1,286 m), and the estimated elevation of the caldera floor is about 3,400 ft (1,040 m). The mountain is located in Kodiak Island Borough, very close to its border with Lake and Peninsula Borough.
Trident Volcano is an eroded volcanic complex on the Alaska Peninsula in Katmai National Park, Alaska. Up to 23 domes comprise the complex stratovolcano, with the greatest elevation of 6,115 feet (1,864 m). The most recent major activity produced a 3,599-foot (1,097 m) dome in an amphitheater on the southwest flank of the southwest peak. Volcano Novarupta formed on its slopes in the largest volcanic eruption of the 20th century.
Medicine Lake Volcano is a large shield volcano in northeastern California about 30 mi (50 km) northeast of Mount Shasta. The volcano is located in a zone of east-west crustal extension east of the main axis of the Cascade Volcanic Arc and the Cascade Range. The 0.6 mi (1 km) thick shield is 22 mi (35 km) from east to west and 28 to 31 mi from north to south, and covers more than 770 sq mi (2,000 km2). The underlying rock has downwarped by 0.3 mi (0.5 km) under the center of the volcano. The volcano is primarily composed of basalt and basaltic andesite lava flows, and has a 4.3 by 7.5 mi caldera at the center.
Mount Sanford is a shield volcano in the Wrangell Volcanic Field, in eastern Alaska near the Copper River. It is the sixth highest mountain in the United States and the third highest volcano behind Mount Bona and Mount Blackburn. The south face of the volcano, at the head of the Sanford Glacier, rises 8,000 feet (2,400 m) in 1 mile (1,600 m) resulting in one of the steepest gradients in North America.
Mount Kaguyak is a stratovolcano located in the northeastern part of the Katmai National Park and Preserve in the U.S. state of Alaska. The 2.5 km wide caldera is filled by a more than 180 m deep crater lake. The surface of the crater lake lies about 550 m below the rim of the caldera. Postcaldera lava domes form a prominent peninsula in the center of the lake. The volcano is 901 metres (2,956 ft) high and is topographically prominent because it rises from lowland areas near sea level in the south of the Big River. Based on radiocarbon dating the caldera-forming eruption occurred about 5800 years before present. During this eruption at least 120 km2 (46 sq mi) were covered in a dacitic ignimbrite.
Mount Griggs, formerly known as Knife Peak Volcano, is a stratovolcano, which lies 10 km behind the volcanic arc defined by other Katmai group volcanoes. Although no historic eruptions have been reported from Mount Griggs, vigorously active fumaroles persist in a summit crater and along the upper southwest flank. The fumaroles on the southwest flank are the hottest, and some of the flank fumaroles can roar so loudly that they can be heard from the valley floor. The slopes of Mount Griggs are heavily mantled by fallout from the 1912 eruption of Novarupta volcano. The summit consists of three concentric craters, the lowest and largest of which contains a recent summit cone topped by two craters. The volume of the volcanic edifice is estimated at about 25 cubic kilometers (6.0 cu mi). Isotopic analysis indicates that the source of Griggs' magma is distinct from the other Katmai volcanoes.
Mount Martin is a stratovolcano, located on the Alaska Peninsula, United States, in Katmai National Park and Preserve. It is one of the volcanoes in the vicinity of the Valley of Ten Thousand Smokes. Mount Martin's cone stands only about 500 metres (1,600 ft) higher than the surrounding ridge. Although an eruption in 1953 is now considered questionable and no other confirmed eruptive activity has taken place at Mount Martin, there is intense fumarolic activity within its summit crater. The summit crater is also breached to the southeast. The 300 m (984 ft)-wide summit crater is often ice-free due to the geothermal heat and contains an intermittent acidic crater lake. The fumaroles in the summit crater produce extensive sulfur deposits.
Mount Wrangell, in Ahtna K’ełt’aeni or K’ełedi when erupting, is a massive shield volcano located in Wrangell-St. Elias National Park and Preserve in southeastern Alaska, United States. The shield rises over 12,000 feet (3,700 m) above the Copper River to its southwest. Its volume is over 220 cubic miles (920 km3), making it more than twice as massive as Mount Shasta in California, the largest stratovolcano by volume in the Cascades. It is part of the Wrangell Volcanic Field, which extends for more than 250 kilometers (160 mi) across Southcentral Alaska into the Yukon Territory in Canada, and has an eruptive history spanning the time from Pleistocene to Holocene.
The Three Sisters are closely spaced volcanic peaks in the U.S. state of Oregon. They are part of the Cascade Volcanic Arc, a segment of the Cascade Range in western North America extending from southern British Columbia through Washington and Oregon to Northern California. Each more than 10,000 feet (3,000 m) in elevation, they are the third-, fourth- and fifth-highest peaks in Oregon. Located in the Three Sisters Wilderness at the boundary of Lane and Deschutes counties and the Willamette and Deschutes national forests, they are about 10 miles (16 km) south of the nearest town, Sisters. Diverse species of flora and fauna inhabit the area, which is subject to frequent snowfall, occasional rain, and extreme temperature variation between seasons. The mountains, particularly South Sister, are popular destinations for climbing and scrambling.
Mount Price is a small stratovolcano in the Garibaldi Ranges of the Pacific Ranges in southwestern British Columbia, Canada. It has an elevation of 2,049 metres and rises above the surrounding landscape on the western side of Garibaldi Lake in New Westminster Land District. The mountain contains a number of subfeatures, including Clinker Peak on its western flank, which was the source of two thick lava flows between 15,000 and 8,000 years ago that ponded against glacial ice. These lava flows are structurally unstable, having produced large landslides as recently as the 1850s. A large provincial park surrounds Mount Price and other volcanoes in its vicinity. It lies within an ecological region that surrounds much of the Pacific Ranges.
The Alaska Volcano Observatory (AVO) is a joint program of the United States Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO was formed in 1988, and uses federal, state, and university resources to monitor and study Alaska's volcanology, hazardous volcanoes, to predict and record eruptive activity, and to mitigate volcanic hazards to life and property. The Observatory website allows users to monitor active volcanoes, with seismographs and webcameras that update regularly. AVO now monitors more than 20 volcanoes in Cook Inlet, which is close to Alaskan population centers, and the Aleutian Arc due to the hazard that plumes of ash pose to aviation.
Devils Desk is a stratovolcano in Alaska's Katmai National Park, split between the Kodiak Island and Lake and Peninsula boroughs of that U.S. state. Its peak, which is located in Kodiak Island Borough, lies 5,879 feet (1,792 m) above sea level. It has an elevation of 6,411 ft (1,954 m). The age of the volcano is not certain, but a sample from the southwest face of the volcano was dated at 245,000 years old. The edifice represents the neck of a formerly larger stratovolcano, whose flanks have been removed by glacial erosion. The summit is almost encircled by Hook Glacier.
Mount Labo, is a potentially active stratovolcano in the province of Camarines Norte, in the Bicol Region (Region V), on Luzon Island, in the Philippines. It is located at the northwest end of the Bicol Peninsula.
Kejulik Volcano, also known as Mount Kejulik or the Kejulik Pinnacles, are highly eroded remnants of an andesitic stratovolcano located in the southwestern Kejulik Mountains within the Aleutian Range near Becharof Lake. The volcano lies on the border of Katmai National Park and Preserve and the Becharof National Wildlife Refuge, about 30 miles southwest of Mount Katmai. Little information is available regarding Kejulik, according to the Alaska Volcano Observatory, and any possible volcanic activity is currently unknown.
