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Lassen Peak | |
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Elevation | 10,457 ft (3,187 m) NAVD 88 |
Prominence | 5,229 ft (1,594 m) |
How long did it take for Lassen Peak to erupt?
The crater grew as it was carved by more than 180 similar phreatic explosions over the span of more than 11 months, reaching a length of 1,000 ft (300 m). On May 14, 1915, Lassen Peak erupted lava blocks, which extended as far as Manton, 20 mi (32 km) west of the mountain.
How old are the volcanoes in the Lassen area?
In periods of about 50,000 - 200,000 years, concentrated volcanism occurred in localized areas. These "volcanic centers" are defined as large, long-lived edifices erupting the full range of lava compositions from basalt to rhyolite. The oldest volcanic rocks in the Lassen vicinity comprise the Latour and Yana volcanic centers.
How did Lassen Peak get its lava dome?
These lava domes formed as a result of rising lava that was pushed up but was too viscous to escape its source, creating steep edifices. Lassen Peak's lava dome formed 27,000 years ago from a series of eruptions over a few years, undergoing significant glacial erosion between 25,000 and 18,000 years ago.
How dangerous is the Lassen Peak volcano?
Lassen Peak is dormant, meaning the volcano is merely inactive, and it has a functioning magma chamber under the ground still capable of eruptions. Thus it poses a threat to the nearby area through lava flows, pyroclastic flows, lahars (volcanically induced mudslides, landslides, and debris flows ), ash, avalanches, and floods.
How big was Mt Lassen before it erupted?
Eruptions about 27,000 years ago formed Lassen Peak, probably in only a few years. With a height of 2,000 feet and a volume of half a cubic mile, it is one of the largest lava domes on Earth.
How tall is Mount Lassen?
10,457′Lassen Peak / ElevationThe peak stands at the southern end of the Cascade Range, some 50 miles (80 km) east of Redding, and rises above the surrounding area to an elevation of 10,457 feet (3,187 metres).
What was the tallest volcanic eruption?
of Mount TamboraThe explosion of Mount Tambora is the largest ever recorded by humans, ranking a 7 (or "super-colossal") on the Volcanic Explosivity Index, the second-highest rating in the index.
What would happen if Mt Lassen erupted?
Areas affected or could be affected by an eruption have considerably more people today, Clynne said. Infrastructure would be impacted, he said. Roads and highways would be covered with lava and other debris making travel difficult. Air travel would also be changed.
How tall is Mount Shasta California?
14,180′Mount Shasta / ElevationShasta stands above the clouds. Beyond the mountain lies the northeasternmost extent of California, where the Great Basin Desert meets the Cascade Range. At a height of 4,322 meters (14,180 feet) above sea level, Mt. Shasta is typically snowcapped year-round.
When did Lassen Peak last erupt?
1921Lassen Peak / Last eruption
What was the worst volcano ever?
The world's largest volcanic eruption to happen in the past 100 years was the June 15, 1991, eruption of Mount Pinatubo in the Philippines.
What was the biggest volcanic eruption in the last 50 years?
1. Mount Pinatubo. Mount Pinatubo is on the island of Luzon in the Philippines. It erupted in 1991 and registered a 6 on the volcanic eruption index, making it the biggest volcano eruption since the Krakatoa eruption in 1883.
What is the largest supervolcano on Earth?
1 – La Garita Caldera.2 – Lake Toba.3 – Cerro Guacha.4 – Yellowstone Caldera.5 – Lake Taupo.6 – Cerro Galán.7 – Island Park Caldera.8 – Vilama.More items...•
What are the 7 volcanoes in California?
At least seven California volcanoes—Medicine Lake Volcano, Mount Shasta, Lassen Volcanic Center, Clear Lake Volcanic Field, Long Valley Volcanic Region, Coso Volcanic Field, and Salton Buttes - have partially molten rock (magma) deep within their roots, and research on past eruptions indicates they will erupt again in ...
Is Mount Lassen considered an active volcano?
However, Lassen Peak is considered active because it last erupted about 100 years ago (read more). Geologically recent volcanic activity in an area is the best guide to forecasting future eruptions.
Is Mount Lassen still an active volcano?
The Lassen area remains volcanically active, and the volcano hazards demonstrated in 1915 still can threaten not only nearby areas but also more distant communities.
How tall is Lassen Peak?
It represents one of the largest lava domes on Earth, with a height of 2,000 ft (610 m) above its surroundings , and an approximate volume of 0.60 cu mi (2.5 km 3 ).
What is the elevation of Lassen Peak?
Mountain hemlocks generally only reach an elevation of 9,200 ft (2,800 m), while whitebark pines reach up to 10,000 ft (3,000 m).
How did Lassen Peak form?
These lava domes formed as a result of rising lava that was pushed up but was too viscous to escape its source, creating steep edifices. Lassen Peak's lava dome formed 27,000 years ago from a series of eruptions over a few years, undergoing significant glacial erosion between 25,000 and 18,000 years ago.
What type of volcanoes formed in the Lassen area?
Shortly after, the Lassen volcanic center, a cluster of closely spaced volcanoes, formed in the area, covering the nearby caldera. During the late Pleistocene it produced andesite lava flows that built the Brokeoff composite volcano (stratovolcano).
How long did it take for Lassen Peak to explode?
The crater grew as it was carved by more than 180 similar phreatic explosions over the span of more than 11 months, reaching a length of 1,000 ft (300 m). On May 14, 1915, Lassen Peak erupted lava blocks, which extended as far as Manton, 20 mi (32 km) west of the mountain.
How long is the Lassen Peak Trail?
The Lassen Peak Trail, which starts from this parking area, runs for 2.5 mi (4.0 km) with switchback turns, a round-trip hike 5 mi (8.0 km) in length that ascends approximately 2,000 ft (610 m) from the trailhead at 8,500 ft (2,600 m) to the summit at 10,457 ft (3,187 m).
When was Lassen Peak National Monument built?
United States President Theodore Roosevelt established the Lassen Peak National Monument in 1907. Despite Native population claims that Lassen Peak was "full of fire and water" and would erupt again, this motion was based on the general belief that Lassen Peak was now extinct, and that its vicinity contained intriguing volcanic phenomena, which could be studied and observed. Once the volcano became active again in 1914, the monument was expanded to establish the Lassen Volcanic National Park on August 9, 1916. The park, 106,372 acres (430.47 km 2) in area, can be reached from the California State Route 89 highway.
How tall was Mount Lassen before eruption?
Eruptions about 27,000 years ago formed Lassen Peak, probably in only a few years. With a height of 2,000 feet and a volume of half a cubic mile, it is one of the largest lava domes on Earth.
Is Mt Shasta taller than Mt Lassen?
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. Lassen Peak Easiest route Hike.
How dangerous is Mount Lassen?
Avalanches, mudflows, and flows of hot ash and gas devastated nearby areas, and volcanic ash fell as far away as 200 miles to the east. The Lassen area remains volcanically active, and the volcano hazards demonstrated in 1915 still can threaten not only nearby areas but also more distant communities.
Is Mt Vesuvius a supervolcano?
A volcano which erupts and throws magma and rocky particles over an area greater than 240 cubic miles (1000 cubic kilometers) is considered a supervolcano. If Mount Vesuvius had been a supervolcano, it would have produced 100 million cubic yards of magma per second. Yellowstone National Park is a famous supervolcano.
Would we all die if Yellowstone erupts?
Scientists have talked about what could happen if Yellowstone’s supervolcano were to erupt in a modern-day setting throughout the United States. One scientist spoke to medically daily and reported that scientists predict that 5 billion people in total would die as a result of an eruption.
What town is closest to Mt Rainier?
Closest Large Cities Adjacent Olympia is approximately 17 miles from Rainier. Tacoma is approximately 40 miles from Rainier. Seattle is approximately 70 miles from Rainier.
Does California have a supervolcano?
Scientists have discovered 240 cubic miles of semi-molten magma below the Long Valley Caldera, a supervolcano in eastern California near Mammoth Mountain. The supervolcano erupted 760,000 years ago and blanketed land within a 30-mile radius in hot ash.
When did Lassen Peak erupt?
Eruptions of Lassen Peak, California, 1914 to 1917. On May 22, 1915, an explosive eruption at Lassen Peak, California, the southernmost active volcano in the Cascade Range, devastated nearby areas and rained volcanic ash as far away as 200 miles to the east. This explosion was the most powerful in a 1914–17 series of eruptions ...
When did the Lassen eruption happen?
Then the character of the eruption changed dramatically. On the evening of May 14, 1915, incandescent blocks of lava could be seen bouncing down the flanks of Lassen from as far away as the town of Manton, 20 miles to the west.
What volcano erupted in 1915?
For example, the bowl-shaped depression on the volcano’s northeastern flank, called a cirque, was eroded by a glacier that extended out 7 miles from the dome. The May 22, 1915, explosive eruption of Lassen Peak, California, blasted rock fragments and pumice high into the air and rained fine volcanic ash as far away as Winnemucca, Nevada, ...
How long ago did Lassen Peak form?
Eruptions about 27,000 years ago formed Lassen Peak, probably in only a few years. With a height of 2,000 feet and a volume of half a cubic mile, it is one of the largest lava domes on Earth. When Lassen Peak formed, it looked much like the nearby 1,100-year-old Chaos CragsDomes, with steep sides covered with angular rock talus.
What was the forest on Lassen Peak covered with?
As shown in the left photograph, the northeastern flank of Lassen Peak was covered by mature conifer forest before 1914. The photograph on the right, taken by Loomis in June 1915 from nearly the same location shows the devastation caused by the two most powerful eruptions in the series, those of May 19 and 22 of that year.
How many steam explosions were there in 1915?
The hot water rises under pressure through cracks and, on nearing the surface, vaporizes and vents explosively. By mid-May 1915, more than 180 steam explosions had blasted out a 1,000-foot-wide crater near the summit of Lassen Peak. Then the character of the eruption changed dramatically. On the evening of May 14, 1915, ...
Where is Lassen Peak?
Lassen Peak is the largest of a group of more than 30 volcanic domes erupted over the past 300,000 years in Lassen Volcanic National Park in northern California. These mound-shaped accumulations of volcanic rock, called lava domes, were created by eruptions of lava too viscous to flow readily away from its source.
How many ka are there in Lassen Volcanic National Park?
These include the most prominent young volcanic features in in Lassen Volcanic National Park: Lassen Peak (27 ka) and Chaos Crags (1.1 ka), as well as the products of 5 older eruptions.
What are the oldest volcanic rocks in Lassen?
The oldest volcanic rocks in the Lassen vicinity comprise the Latour and Yana volcanic centers. Rocks of the Latour Volcanic Center (>3 Ma) are present northwest of Lassen Volcanic National Park, whereas rocks of the Yana Volcanic Center (~3.4–2.4 Ma) dominate the area southwest of Lake Almanor. These two volcanic centers are important as the primary sources of the Tuscan Formation (~3.5 to 2.5 My old), a broad volcanic and volcaniclastic wedge of fragmental material emplaced on west slope of the southernmost Cascade Range. The Tuscan Formation consists primarily of volcanic debris flows (lahars), conglomerate, sandstone, and siltstone, with minor silicic ash -flow and airfall tuffs and several basaltic to andesitic lava flows.
What is the name of the volcano that erupted in the Rockland Tephra eruption?
Brokeoff Volcano, also designated “Mount Tehama” by the National Park Service, consists of a large, 80-km 3 (19.2 mi 3) composite volcano. Almost immediately after eruption of the Rockland tephra, its caldera began to fill as renewed activity formed Brokeoff Volcano. The stratigraphy of Brokeoff Volcano is described by Clynne and Muffler (USGS Scientific Investigations Map 2899) as two sequences of deposits: the Mill Canyon sequence and the Diller sequence. The Mill Canyon sequence consists of dozens of small-volume basaltic andesite to dacite lavaflows and interlaid layers of explosive deposits erupted from a central vent between about 590 and 470 ka. The Diller sequence consists primarily of 6 thick, large-volume, lithologically similar, lava flows that erupted from flank vents between 470 and 385 ka.
What are the two sequences of the Brokeoff Volcano?
The stratigraphy of Brokeoff Volcano is described by Clynne and Muffler (USGS Scientific Investigations Map 2899) as two sequences of deposits: the Mill Canyon sequence and the Diller sequence.
What is the Tuscan Formation?
The Tuscan Formation consists primarily of volcanic debris flows (lahars), conglomerate, sandstone, and siltstone, with minor silicic ash -flow and airfall tuffs and several basaltic to andesitic lava flows .
Where is the Dittmar Volcanic Center?
The Dittmar Volcanic Center (2.4–1.4 Ma) lies at the NW end of the Lake Almanor Graben. Deposits of the Dittmar Volcanic Center are grouped into 3 stratigraphic stages: Stage 1, early growth of the composite cone (1.6 to 2.3 Ma) with thin lava flows and intermixed layers (interbedded) of air-fall and volcanoclastic deposits; Stage 2, later growth of the composite cone (1.4 Ma) with thick lava flows and some intermixed explosive or sedimented deposits; and Stage 3, late silicic volcanism (1.3 Ma) with a few lava flows and domes of rhyodacite and rhyolite.
What is the age range of the Rockland caldera?
The Rockland caldera complex consists of the Rockland tephra and a group of dacite to rhyolite domes and flows ranging in age from ~825 to 609 ka. Effusive eruption (extrusion) of these domes and flows culminated in explosive eruption of the Rockland tephra about 610 ka.
When did Lassen Peak erupted?
2. When Lassen Peak Erupted in 1914, there were no advanced photographical instruments. There were no DSLR’s or drones or GoPro’s, making the visual documentation of the eruption both difficult and astounding. From many places in NorCal, you can see the peaks of two large and active volcanoes, leaving one to daydream about what an eruption ...
What happened to Hat Creek Valley?
Hat Creek Valley was flooded with muddy water on May 20th, which damaged several ranches in the Old Station area. Floodwaters headed down Hat Creek to the Pit River, over 30 miles, and witnesses claimed the muddy waters killed many fish. Of course, there were salmon and steelhead in all these waters back then.
Is Lassen Peak a composite volcano?
All four types of volcanoes found in the entire world are represented in Lassen Volcanic National Park— shield (Prospect Peak), plug dome (Lassen Peak), Cinder Cone (Cinder Cone), and Composite (Brokeoff Volcano) volcanoes. In August of 1916, Lassen Volcanic National Park was established.
Is Mount Lassen a dormant volcano?
In May 1915, Lassen Peak, California, the southernmost active volcano in the Cascade Range, erupted explosively. The Lassen area remains volcanically active, and the volcano hazards demonstrated in 1915 still can threaten not only nearby areas but also more distant communities.
Can you swim in Lassen Volcanic National Park?
From the Loomis Museum, drive east on Highway 89 {Lassen Volcanic National Park Highway} for 300 feet and take the next right. Follow the road for 0.7 miles to reach the campground, but if you’re just here to swim, there is a day-use parking area just before reaching the Camper Store.
What is the most dangerous volcano in the US?
1: Kilauea volcano, Hawaii. Threat Score: 263. Aviation Threat: 48. This active volcano is continuously erupting and was given the highest threat score by the US Geological Survey.
When was the last volcanic eruption California?
The last series of eruptions in California occurred from 1914 to 1917 within the Lassen Volcanic Center, with an explosive eruption of Lassen Peak on May 22, 1915.
How many people died when Lassen Peak erupted?
A ring of fire. Volcanoes in the Lassen, Shasta and Long Valley areas are capable of producing pyroclastic flows or surges when they do erupt — fast-moving flows of hot ash, rock and gas sweeping down the sides of mountains, of the type that killed 57 people when Mt.
Is Lassen Peak dangerous?
This is extremely dangerous for children who often put their hands on the rocks and heads down when climbing over bigger rocks. Jul 23, 2016
When was Lassen Peak crater?
The most recent period of activity at Lassen Peak took place between 1914 and 1921. After 27,000 years of dormancy, Lassen Peak was shaken by a steam explosion on May 30 th, 1914. By mid-May 1915, more than 180 steam explosions had gouged out a 300 metre-wide (1,000 ft) crater near the summit.
How did Lassen Peak form?
About 27,000 years ago, Lassen Peak started to form as a mound-shaped dacite lava dome pushed its way through the shattered north-eastern flank of Mount Tehama. As the lava dome grew, it shattered overlaying rock, which formed a collar of angular talus around the steep-sided volcanic dome.
What type of lava flows did Mount Tehama have?
As for the central volcano itself, there was a final, large lava flow on the north-eastern flank consisting of glassy dacite and further dacite flows formed smaller cones such as Mount Conard and Diamond Peak on the flanks of Mount Tehama. Diamond Peak, a dacitic satellite cone of Mount Tehama. (vibadirect.com)
What is the name of the volcano that was built by more than thirty other volcanoes?
Further activity built more than thirty other cones which are sometimes referred to as the Lassen Domes . As we have already seen, Mount Tehama began life as a rather typical andesitic stratovolcano, but subsequent activity became more and more silicic.
What are the major features of Lassen Volcanic Complex?
The major features of the Lassen Volcanic Complex. The most important ones are Brokeoff Mountain, the major remnant of ancestral Mount Tehama, Lassen Peak itself and the Chaos Crags. Please note the extent of volcanic features within the Park. (USGS) Volcanic activity in the area goes back at least three million years.
What is the name of the volcano that was once the largest of the Cascade volcanoes?
Brokeoff Mountain, a sad remnant of what was once the largest of the Cascade volcanoes. (Sing H. Lin, shltrip.com) Activity at Mount Tehama continued for about 200,000 years and consisted mostly of pyroclastics and andesitic lava flows containing olivine. During the same period of time, other volcanic vents began to appear such as ...
What volcano is the only visible remnant of the eruption of Mount Tehama?
(vibadirect.com) Subsequent glaciation combined with extensive hydrothermal activity led to major erosion and to a subsequent collapse of Mount Tehama of which today the only visible, large remnant is Brokeoff Volcano, also known as Brokeoff Mountain.

Overview
Eruptive history
Between 385,000 and 315,000 years ago, volcanism at the Lassen center shifted from andesitic stratovolcano construction to production of dacite domes. Over the past 300,000 years, the Lassen Peak area has produced more than 30 lava domes, Lassen Peak being the largest. These lava domes formed as a result of rising lava that was pushed up but was too viscous to escape its source, creati…
Geography
Located in Lassen Volcanic National Park, Lassen Peak lies in Shasta County, 55 mi (89 km) east of the city of Redding, in the U.S. state of California. Lassen Peak and the rest of the National Park area are surrounded by the Lassen National Forest, which has an area of 1,200,000 acres (4,900 km ). Nearby towns include Mineral in Tehama County and Viola in Shasta County.
Ecology
Lassen Peak supports a variety of flora that include mountain hemlock, whitebark pine, and alpine wildflowers. Mountain hemlocks generally only reach an elevation of 9,200 ft (2,800 m), while whitebark pines reach up to 10,000 ft (3,000 m). Throughout the national park, forests can be found featuring red fir, mountain alder, western white pine, white fir, lodgepole pine, Jeffrey pine, ponderosa pine, incense cedar, juniper, and live oak. Other plants found in the Lassen Peak area c…
Geology
Lassen Peak lies near the southern end of the Cascade Volcanic Arc, at the western edge of the Basin and Range Province. Like other Cascade volcanoes, it was fed by magma chambers produced by the subduction of the oceanic Juan de Fuca tectonic plate under the western edge of the continental North American tectonic plate. The region is also affected geologically by the Cascadia subduc…
Human history
The areas surrounding Lassen Peak, especially to its east, south, and southeast, represented a meeting ground for Maidu, Yana, Yahi, and Atsugewi Native Americans. The volcano is known among some native populations as Amblu Kai, which means "Mountain Ripped Apart" or "Fire Mountain," and as Kom Yamani, which means "Snow Mountain," among the Mountain Maidu. Because …
Recreation
The Lassen Volcanic National Park is visited by more than 350,000 people every year. Incorporating more than 150 mi (240 km) of hiking trails, it is visited by people looking to hike or backpack during the summers. Popular winter activities include snowshoeing and backcountry skiing. As the second-tallest volcano in Northern California, trailing only Mount Shasta, Lassen Peak is frequently visit…
See also
• List of highest points in California by county
• List of Ultras of the United States
• List of volcanoes in the United States
Initial Rumblings
Events of May 19–20, 1915
- Late on the evening of May 19, a large steam explosion fragmented the dacite dome, creating a new crater at the summit of Lassen Peak. No new magma was ejected in this explosion, but glowing blocks of hot lava from the dome fell on the summit and snow-covered upper flanks of Lassen Peak. These falling blocks launched a half-mile-wide avalanche of snow and volcanic ro…
Climactic Eruption of May 22, 1915.
- Late on the afternoon of May 22, after two quiet days, Lassen Peak exploded in a powerful eruption that blasted rock fragments and pumice high into the air, creating the larger and deeper of the two craters seen near the summit of the volcano today. A huge column of volcanic ash and gas rose more than 30,000 feet into the air and was visible from a...
Continuing Volcanic Activity and Future Eruptions
- For several years after the May 22, 1915, eruption, spring snowmelt percolating down into Lassen Peak triggered steam explosions, indicating that rocks beneath the volcano’s surface remained hot. Particularly vigorous steam explosions in May 1917 blasted out the second of the two craters now seen near the volcano’s summit. Steam vents could be found in the area of these craters int…
Yana and Latour Volcanic Centers and The Tuscan Formation
- The oldest volcanic rocks in the Lassen vicinity comprise the Latour and Yana volcanic centers. Rocks of the Latour Volcanic Center (>3 Ma) are present northwest of Lassen Volcanic National Park, whereas rocks of the Yana Volcanic Center (~3.4–2.4 Ma) dominate the area southwest of Lake Almanor. These two volcanic centers are important as the primary sources of the Tuscan F…
Dittmar Volcanic Center
- The Dittmar Volcanic Center (2.4–1.4 Ma) lies at the NW end of the Lake Almanor Graben. Deposits of the Dittmar Volcanic Center are grouped into 3 stratigraphic stages: Stage 1, early growth of the composite cone (1.6 to 2.3 Ma) with thin lava flows and intermixed layers (interbedded) of air-fall and volcanoclastic deposits; Stage 2, later growth o...
Maidu Volcanic Center
- The Maidu Volcanic Center (2.4–1.2 Ma) formed at a similar time as the Dittmar Volcanic Center and is located southwest of Lassen Volcanic National Park where it overlies the Tuscan Formation and rocks of the Yana Volcanic Center. Like the Dittmar, it consists of three stratigraphic stages: Stage 1, early composite cone growth with thin lava flows and fragm…
Lassen Volcanic Center
- The major stratigraphic divisions of the Lassen Volcanic Center are designated as the Rockland caldera complex, Brokeoff Volcano, and the Lassen domefield. These eruptive stages are connected periods volcanism distinctly different from one another but linked by a common magmatic system. Rockland caldera complex The Rockland caldera complex consists of the Ro…