Lassen Peak ( ), commonly referred to as Mount Lassen, is a
lava dome
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on ...
volcano and the southernmost
active volcano
An active volcano is a volcano which is either erupting or is likely to erupt in the future. An active volcano which is not currently erupting is known as a dormant volcano.
Overview
Tlocene Epoch. Most volcanoes are situated on the Pacific Ri ...
in the
Cascade Range
The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...
of the
Western United States
The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the Wes ...
. Located in the
Shasta Cascade
The Shasta Cascade region of California is located in the northeastern and north-central sections of the state bordering Oregon and Nevada, including far northern parts of the Central Valley and the Sierra Nevada mountain range.
History Ind ...
region of
Northern California
Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...
, it is part of the
Cascade Volcanic Arc
The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern Califo ...
, which stretches from southwestern British Columbia to northern California. Lassen Peak reaches an elevation of , standing above the northern
Sacramento Valley
, photo =Sacramento Riverfront.jpg
, photo_caption= Sacramento
, map_image=Map california central valley.jpg
, map_caption= The Central Valley of California
, location = California, United States
, coordinates =
, boundaries = Sierra Nevada (ea ...
. It supports many flora and fauna among its diverse habitats, which are subject to frequent snowfall and reach high elevations.
Lassen Peak has a volume of , making it one of the largest lava domes on Earth. The volcano arose from the former northern flank of now-eroded
Mount Tehama
Mount Tehama (also called Brokeoff Volcano or Brokeoff Mountain) is an eroded andesitic stratovolcano in the Cascade Volcanic Arc and the Cascade Range in Northern California. Part of the Lassen volcanic area, its tallest remnant, Brokeoff Moun ...
about 27,000 years ago, from a series of eruptions over the course of a few years. The mountain has been significantly eroded by glaciers over the last 25,000 years, and is now covered in
talus deposits.
On May 22, 1915, a powerful
explosive eruption
In volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such ...
at Lassen Peak devastated nearby areas, and spread
volcanic ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...
as far as to the east. This explosion was the most powerful in a series of eruptions from 1914 through 1917. Lassen Peak and
Mount St. Helens
Mount St. Helens (known as Lawetlat'la to the indigenous Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United St ...
in
Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered on ...
were the only two volcanoes in the
contiguous United States
The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...
to erupt during the 20th century.
Lassen Volcanic National Park
Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest lava dome, plug dome volcano in the world and the southernmost volcano in the Cascade Range. L ...
, which encompasses an area of , was created to preserve the areas affected by the eruption, for future observation and study, to protect the nearby volcanic features, and to keep anyone from settling too close to the volcano. The park, along with the nearby
Lassen National Forest
Lassen National Forest is a United States national forest of 1,700 square miles (4,300 km2) in northeastern California. It is named after pioneer Peter Lassen, who mined, ranched and promoted the area to emigrant parties in the 1850s.
Wildli ...
and Lassen Peak, have become popular destinations for recreational activities, including climbing, hiking,
backpacking
Backpacking may refer to:
* Backpacking (travel), low-cost, independent, international travel
* Backpacking (hiking), trekking and camping overnight in the wilderness
* Ultralight backpacking, a style of wilderness backpacking with an emphasis on ...
,
snowshoeing
Snowshoes are specialized outdoor gear for walking over snow. Their large footprint spreads the user's weight out and allows them to travel largely on top of rather than through snow. Adjustable bindings attach them to appropriate winter footwe ...
,
kayaking
Kayaking is the use of a kayak for moving over water. It is distinguished from canoeing by the sitting position of the paddler and the number of blades on the paddle. A kayak is a low-to-the-water, canoe-like boat in which the paddler sits fac ...
, and
backcountry skiing
Backcountry skiing ( US), also called off-piste (Europe), alpine touring, or out-of-area, is skiing in the backcountry on unmarked or unpatrolled areas either inside or outside a ski resort's boundaries. This contrasts with alpine skiing, which i ...
. 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 flow
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or und ...
s,
pyroclastic flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of bu ...
s,
lahar
A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley.
Lahars are extreme ...
s (volcanically induced
mudslide
A mudflow or mud flow is a form of mass wasting involving fast-moving flow of debris that has become liquified by the addition of water. Such flows can move at speeds ranging from 3 meters/minute to 5 meters/second. Mudflows contain a significa ...
s,
landslide
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...
s, and
debris flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally ...
s), ash,
avalanche
An avalanche is a rapid flow of snow down a slope, such as a hill or mountain.
Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and earth ...
s, and floods. To monitor this threat, Lassen Peak and the surrounding vicinity are closely observed with sensors by the
California Volcano Observatory
The California Volcano Observatory (CalVO) is the volcano observatory that monitors the volcanic and geologic activity of California and Nevada. It is a part of the Volcano Hazards Program of the United States Geological Survey, a scientific agency ...
.
Geography
![Mount Lassen aerial](https://upload.wikimedia.org/wikipedia/commons/7/71/Mount_Lassen_aerial.jpg)
Located in
Lassen Volcanic National Park
Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest lava dome, plug dome volcano in the world and the southernmost volcano in the Cascade Range. L ...
, Lassen Peak lies in
Shasta County
Shasta County (), officially the County of Shasta, is a county in the northern portion of the U.S. state of California. Its population is 182,155 as of the 2020 census, up from 177,223 from the 2010 census. The county seat is Redding.
Shasta ...
, east of the city of
Redding, in the U.S. state of
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
.
[ Lassen Peak and the rest of the National Park area are surrounded by the ]Lassen National Forest
Lassen National Forest is a United States national forest of 1,700 square miles (4,300 km2) in northeastern California. It is named after pioneer Peter Lassen, who mined, ranched and promoted the area to emigrant parties in the 1850s.
Wildli ...
, which has an area of . Nearby towns include Mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...
in Tehama County
Tehama County ( ; Wintun for "high water") is a county located in the northern part of the U.S. state of California. As of the 2020 census, the population was 65,829. The county seat and largest city is Red Bluff.
Tehama County comprises th ...
and Viola
The viola ( , also , ) is a string instrument that is bow (music), bowed, plucked, or played with varying techniques. Slightly larger than a violin, it has a lower and deeper sound. Since the 18th century, it has been the middle or alto voice of ...
in Shasta County.
Lassen Peak reaches an elevation of , according to 1992 data from the U.S. National Geodetic Survey
The National Geodetic Survey (NGS) is a United States federal agency that defines and manages a national coordinate system, providing the foundation for transportation and communication; mapping and charting; and a large number of applications ...
; 1981 data from the Geographic Names Information System
The Geographic Names Information System (GNIS) is a database of name and locative information about more than two million physical and cultural features throughout the United States and its territories, Antarctica, and the associated states of ...
lists the mountain's elevation at . Lassen Peak marks the southernmost major volcano in the Cascade Range
The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...
, rising above the northern Sacramento Valley
, photo =Sacramento Riverfront.jpg
, photo_caption= Sacramento
, map_image=Map california central valley.jpg
, map_caption= The Central Valley of California
, location = California, United States
, coordinates =
, boundaries = Sierra Nevada (ea ...
. Bounded by the Sacramento Valley and the Klamath Mountains
The Klamath Mountains are a rugged and lightly populated mountain range in northwestern California and southwestern Oregon in the western United States. As a mountain system within both the greater Pacific Coast Ranges and the California Coast R ...
to the west and the Sierra Nevada mountain range to the south, it is the second tallest peak in the California segment of the Cascades, behind Mount Shasta
Mount Shasta ( Shasta: ''Waka-nunee-Tuki-wuki''; Karuk: ''Úytaahkoo'') is a potentially active volcano at the southern end of the Cascade Range in Siskiyou County, California. At an elevation of , it is the second-highest peak in the Cascades ...
, which lies to the north. Due to its proximity to nearby volcanoes Mount Tehama
Mount Tehama (also called Brokeoff Volcano or Brokeoff Mountain) is an eroded andesitic stratovolcano in the Cascade Volcanic Arc and the Cascade Range in Northern California. Part of the Lassen volcanic area, its tallest remnant, Brokeoff Moun ...
and Mount Diller, it is not easy to distinguish from its neighboring peaks.
Physical geography
Lassen Peak has the highest known winter snowfall
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water throughout ...
amounts in California. There is an average annual snowfall of , and in some years, more than of snow falls at its base elevation of at Lake Helen. The Lassen Peak area receives more precipitation (rain
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...
, sleet, hail
Hail is a form of solid precipitation. It is distinct from ice pellets (American English "sleet"), though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone. Ice pellets generally fal ...
, snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water throughout ...
, etc.) than anywhere in the Cascade Range south of the Three Sisters volcanoes in Oregon.
Though the volcano lies too far to the south to support a permanent snow cover over the entire mountain, the heavy annual snowfall on Lassen Peak creates fourteen permanent patches of snow on and around the mountain top, despite Lassen's rather modest elevation, but no glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...
s.
Lightning
Lightning is a naturally occurring electrostatic discharge during which two electric charge, electrically charged regions, both in the atmosphere or with one on the land, ground, temporarily neutralize themselves, causing the instantaneous ...
has been known to strike the area frequently during summer thunderstorms. These can initiate fires. On July 23, 2012, a lightning strike started the Reading Fire to the northeast of the Paradise Meadow region, which was contained after it reached an area of . During the summer and fall of 2016, the National Park Service
The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational propertie ...
carried out prescribed fires to help reduce the amount of fuel available for fires in the Mineral Headquarters area and the Manzanita and Juniper Lake areas, respectively.
Ecology
Lassen Peak supports a variety of flora that include mountain hemlock
''Tsuga mertensiana'', known as mountain hemlock, is a species of hemlock native to the west coast of North America, found between Southcentral Alaska and south-central California.
Description
''Tsuga mertensiana'' is a large evergreen conifer ...
, whitebark pine
''Pinus albicaulis'', known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, is a conifer tree native to the mountains of the western United States and Canada, specifically subalpine ...
, and alpine wildflower
A wildflower (or wild flower) is a flower that grows in the wild, meaning it was not intentionally seeded or planted. The term implies that the plant probably is neither a hybrid nor a selected cultivar that is in any way different from the w ...
s. Mountain hemlocks generally only reach an elevation of , while whitebark pines reach up to . Throughout the national park, forests can be found featuring red fir
''Abies magnifica'', the red fir or silvertip fir, is a western North American fir, native to the mountains of southwest Oregon and California in the United States. It is a high-elevation tree, typically occurring at elevation, though only rare ...
, mountain alder, western white pine
Western white pine (''Pinus monticola''), also called silver pine and California mountain pine, is a species of pine in the family Pinaceae. It occurs in mountain ranges of northwestern North America. It is the state tree of Idaho.
Description ...
, white fir
''Abies concolor'', the white fir, is a coniferous tree in the pine family Pinaceae. This tree is native to the mountains of western North America, including the Cascade Range and southern Rocky Mountains, and into the isolated mountain range ...
, lodgepole pine
''Pinus contorta'', with the common names lodgepole pine and shore pine, and also known as twisted pine, and contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine, ...
, Jeffrey pine
''Pinus jeffreyi'', also known as Jeffrey pine, Jeffrey's pine, yellow pine and black pine, is a North American pine tree. It is mainly found in California, but also in the westernmost part of Nevada, southwestern Oregon, and northern Baja Califo ...
, ponderosa pine
''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...
, incense cedar
''Calocedrus'', the incense cedar (alternatively spelled incense-cedar), is a genus of coniferous trees in the cypress family Cupressaceae first described as a genus in 1873. It is native to eastern Asia and western North America.
The generi ...
, juniper
Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...
, and live oak
Live oak or evergreen oak is any of a number of oaks in several different sections of the genus ''Quercus'' that share the characteristic of evergreen foliage. These oaks are not more closely related to each other than they are to other oaks.
...
. Other plants found in the Lassen Peak area consist of coyote mint, lupines, mule's ears, fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...
s, corn lilies, red mountain heathers, pinemat manzanitas,
greenleaf manzanitas, bush chinquapins, catchflies, Fremont's butterweed,
buckwheat
Buckwheat (''Fagopyrum esculentum''), or common buckwheat, is a flowering plant in the knotweed family Polygonaceae cultivated for its grain-like seeds and as a cover crop. The name "buckwheat" is used for several other species, such as '' Fago ...
, granite gilia
''Gilia'' is a genus of between 25 and 50 species of flowering plants in the Polemoniaceae family and is related to phlox. These Western native plants are best sown in sunny, well-draining soil in the temperate and tropical regions of the Ameri ...
, mountain pride, mariposa tulips, creambush
''Holodiscus discolor'', commonly known as ocean spray or oceanspray, creambush, or ironwood, is a shrub of western North America.
Description
''Holodiscus discolor'' is a fast-growing deciduous shrub usually from to in height, and up to ta ...
, and a variety of chaparral
Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...
shrubs.
The various habitats in the Lassen Volcanic National Park support about 300 vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
species like mammals, reptile
Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...
s, amphibian
Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...
s, fish, and birds, including bald eagle
The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies the same niche as ...
s, which are listed as "Threatened" under the Endangered Species Act of 1973
The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...
, and peregrine falcon
The peregrine falcon (''Falco peregrinus''), also known as the peregrine, and historically as the duck hawk in North America, is a Cosmopolitan distribution, cosmopolitan bird of prey (Bird of prey, raptor) in the family (biology), family Falco ...
s, which were removed from the endangered species list in 1999.[ In forested areas below , animals include ]American black bear
The American black bear (''Ursus americanus''), also called simply a black bear or sometimes a baribal, is a medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. American black bear ...
s, mule deer
The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer.
Unlike the related whit ...
, marten
A marten is a weasel-like mammal in the genus ''Martes'' within the subfamily Guloninae, in the family Mustelidae. They have bushy tails and large paws with partially retractile claws. The fur varies from yellowish to dark brown, depending on t ...
s, brown creeper
The brown creeper (''Certhia americana''), also known as the American treecreeper, is a small songbird, the only North American member of the treecreeper family Certhiidae.
Description
Adults are brown on the upper parts with light spotting, re ...
s, mountain chickadee
The mountain chickadee (''Poecile gambeli'') is a small songbird, a passerine bird in the tit family Paridae.
Taxonomy
The specific name honors naturalist William Gambel. The mountain chickadee was formerly placed in the genus ''Parus'' with ...
s, white-headed woodpecker
The white-headed woodpecker (''Leuconotopicus albolarvatus'') is a non-migratory woodpecker that resides in pine forests of the mountains of western North America. Description
It has a black body (approximately long) and white head. It has whit ...
s, long-toed salamander
The long-toed salamander (''Ambystoma macrodactylum'') is a mole salamander in the family Ambystomatidae. This species, typically long when mature, is characterized by its mottled black, brown, and yellow pigmentation, and its long outer fourth ...
s, and several bat
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...
species. At higher elevations, Clark's nutcracker
Clark's nutcracker (''Nucifraga columbiana''), sometimes referred to as Clark's crow or woodpecker crow, is a passerine bird in the family Corvidae, native to the mountains of western North America. The nutcracker is an omnivore, but subsists mai ...
s, deer mice
Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...
, and chipmunk
Chipmunks are small, striped rodents of the family Sciuridae. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia.
Taxonomy and systematics
Chipmunks may be classified either as ...
s can be found among mountain hemlock stands, and subalpine zones with sparse vegetation host populations of gray-crowned rosy finch
The gray-crowned rosy finch or gray-crowned rosy-finch (''Leucosticte tephrocotis'') is a species of passerine bird in the family Fringillidae native to Alaska, western Canada, and the north-western United States. Due to its remote and rocky alp ...
es, pika
A pika ( or ; archaically spelled pica) is a small, mountain-dwelling mammal found in Asia and North America. With short limbs, very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but wi ...
s, and golden-mantled ground squirrel
The golden-mantled ground squirrel (''Callospermophilus lateralis'') is a ground squirrel native to western North America. It is distributed in the Rocky Mountains of British Columbia and Alberta, and through much of the western United States.
...
s. Among scattered stands of pinemat manzanita, red fir, and lodgepole pine, animals include dark-eyed junco
The dark-eyed junco (''Junco hyemalis'') is a species of junco, a group of small, grayish New World sparrows. This bird is common across much of temperate North America and in summer ranges far into the Arctic. It is a very variable species, much ...
s, montane vole
The montane vole (''Microtus montanus'') is a species of vole native to the western United States and Canada.
Description
Montane voles are medium-sized voles, with a total length of , including the tail. Adults typically weigh anything from , ...
s, and sagebrush lizard
The sagebrush lizard or sagebrush swift (''Sceloporus graciosus'') is a common species of phrynosomatid lizard found at mid to high altitudes in the western United States of America. It belongs to the genus ''Sceloporus'' (spiny lizards) in ...
s. Meadows at the bottoms of valleys along streams and lakes support Pacific tree frog
The Pacific tree frog (''Pseudacris regilla''), also known as the Pacific chorus frog, has a range spanning the Pacific Northwest, from Northern California, Oregon, and Washington to British Columbia in Canada and extreme southern Alaska. They l ...
s, Western terrestrial garter snake
The western terrestrial garter snake (''Thamnophis elegans'') is a western North American species of colubrid snake. At least five subspecies are currently recognized.
Description
Most western terrestrial garter snakes have a yellow, light orang ...
s, common snipe
The common snipe (''Gallinago gallinago'') is a small, stocky wader native to the Old World.
The breeding habitats are marshes, bogs, tundra and wet meadows throughout the Palearctic. In the north, the distribution limit extends from Iceland ...
s, and mountain pocket gopher
The mountain pocket gopher (''Thomomys monticola'') is a species of rodent in the family Geomyidae. It is endemic to California and Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the ...
s. Other animals found within the national park area include snakes like rubber boa
The rubber boa (''Charina bottae'') is a species of snake in the family Boidae and is native to North America. It is sometimes known as the coastal rubber boa or the northern rubber boa and is not to be confused with the southern rubber boa (''C ...
s, common garter snake
The common garter snake (''Thamnophis sirtalis'') is a species of thamnophis snake, in the natricine subfamily, which is indigenous to North America and found widely across the continent. Most common garter snakes have a pattern of yellow strip ...
s, and striped whipsnake
The striped whipsnake (''Masticophis taeniatus'') is a species of nonvenomous snake in the family Colubridae. It is closely related to the California whipsnake ('' Masticophis lateralis''). The striped whipsnake is native to the western United St ...
s; cougar
The cougar (''Puma concolor'') is a large Felidae, cat native to the Americas. Its Species distribution, range spans from the Canadian Yukon to the southern Andes in South America and is the most widespread of any large wild terrestrial mamm ...
s; amphibians like newt
A newt is a salamander in the subfamily Pleurodelinae. The terrestrial juvenile phase is called an eft. Unlike other members of the family Salamandridae, newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aqua ...
s, salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...
s, rough-skinned newt
The rough-skinned newt or roughskin newt (''Taricha granulosa'') is a North American newt known for the strong toxin exuded from its skin.
Appearance
A stocky newt with rounded snout, it ranges from light brown to olive or brownish-black on t ...
s, and Cascades frog
The Cascades frog (''Rana cascadae'') is a species of frog in the family Ranidae found in the Pacific Northwest, mainly in the Cascade Range and Olympic Mountains.
Description
Appearance
The Cascades frog has a green to brown color on its b ...
s; 216 species of birds including MacGillivray's warbler
MacGillivray's warbler (''Geothlypis tolmiei'') is a species of New World warbler. These birds are sluggish and heavy warblers, preferring to spend most of their time on, or near the ground, except when singing.
left, A MacGillivray's warbler p ...
s, Wilson's warbler
Wilson's warbler (''Cardellina pusilla'') is a small New World warbler. It is greenish above and yellow below, with rounded wings and a long, slim tail. The male has a black crown patch; depending on the subspecies, that mark is reduced or absent ...
s, song sparrow
The song sparrow (''Melospiza melodia'') is a medium-sized New World sparrow. Among the native sparrows in North America, it is easily one of the most abundant, variable and adaptable species.
Description
Adult song sparrows have brown upperp ...
s, spotted owl
The spotted owl (''Strix occidentalis'') is a species of true owl. It is a resident species of old-growth forests in western North America, where it nests in tree hollows, old bird of prey nests, or rock crevices. Nests can be between high and u ...
s, northern goshawk
The northern goshawk (; ''Accipiter gentilis'') is a species of medium-large bird of prey, raptor in the Family (biology), family Accipitridae, a family which also includes other extant diurnal raptors, such as eagles, buzzards and harrier (bird) ...
s, and bufflehead
The bufflehead (''Bucephala albeola'') is a small sea duck of the genus ''Bucephala'', the goldeneyes. This species was first described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae'' as ''Anas albeola''.
The genus na ...
ducks; five species of native fish that include rainbow trout
The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coasta ...
, tui chub
The tui chub (''Siphateles bicolor'') is a cyprinid fish native to western North America. Widespread in many areas, it is an important food source for other fish, including the cutthroat trout.
Range
The tui chub's range includes the Lahonta ...
s, speckled dace
The speckled dace (''Rhinichthys osculus''), also known as the spotted dace and the carpita pinta, is a member of the minnow family. It is found in temperate freshwater in North America, from Sonora, Mexico to British Columbia, Canada.
Canada is ...
s, Lahontan redside
The Lahontan redside (''Richardsonius egregius'') is a cyprinid fish of the Great Basin in eastern California and western Nevada.
Lahontan redsides are noted for their breeding colors, consisting of a bright red stripe with a yellow border on ea ...
s, and Tahoe sucker
The Tahoe sucker (''Catostomus tahoensis'') is a freshwater Cypriniform fish inhabiting the Great Basin region of the Western United States.
Description
The Tahoe sucker is a large, long fish with a tapering head. It can grow up to 24 inches in ...
s; and four invasive fish species including brook trout
The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere ...
, brown trout
The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morph ...
, golden shiner
The golden shiner (''Notemigonus crysoleucas'') is a cyprinid fish native to eastern North America. It is the sole member of its genus. Much used as a bait fish, it is probably the most widely pond-cultured fish in the United States. It can be fo ...
s, and fathead minnow
Fathead minnow (''Pimephales promelas''), also known as fathead or tuffy, is a species of temperate freshwater fish belonging to the genus ''Pimephales'' of the cyprinid family. The natural geographic range extends throughout much of North Ameri ...
s. Prominent invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
species include California tortoiseshell
The California tortoiseshell (''Nymphalis californica'') is a butterfly of the family Nymphalidae.
The wings of the California tortoiseshell have ragged edges. The upper sides of the wings are orange with black spots and a wide black margin. The ...
butterflies.[
]
Geology
Lassen Peak lies near the southern end of the Cascade Volcanic Arc
The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern Califo ...
, at the western edge of the Basin and Range Province
The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating ...
. Like other Cascade volcanoes, it was fed by magma chambers produced by the subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...
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 subduction zone
The Cascadia subduction zone is a convergent plate boundary that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and ...
, which dips eastward beneath the western coast of North America in the Pacific Northwest
The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...
, as well as horizontal stretching to the east of crustal rock in the Basin and Range Province. About 3 million years ago, the southern limit of active volcanoes in the Cascades corresponded to the Yana Volcanic Center to the south of Lassen Peak, but currently the southern edge of the Lassen Volcanic National Park now marks the same border, indicating that the Cascade Arc's southern end migrates at a rate of annually.[
In the southern segment of the Cascades, volcanoes exhibit widespread and long-lived activity produced by magma that ranges from low-]silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...
to siliceous (silica-rich) rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
. The Lassen volcanic center is fed by two magma chambers, one calc-alkaline
The calc-alkaline magma series is one of two main subdivisions of the subalkaline magma series, the other subalkaline magma series being the tholeiitic series. A magma series is a series of compositions that describes the evolution of a mafic mag ...
reservoir common to the rest of the Cascade Volcanoes, and the other a smaller volume of low-potassium olivine tholeiitic basalt associated with the Basin and Range province.[ Within the region, most if not all of the volcanic rock has erupted in the past 3 million years.][ During this period, at least five large ]andesitic
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomina ...
stratovolcanoes (such as Mount Maidu) formed in the vicinity of Lassen Volcanic National Park, building volcanic cone
Volcanic cones are among the simplest volcanic landforms. They are built by ejecta from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and ...
s before going extinct and undergoing erosion. For most volcanic centers in the Southern Cascades, one volcano becomes active and normally becomes extinct as another begins to erupt, but at the Lassen locus, the Maidu and Dittmar volcanic centers overlapped during the late Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58[Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...](_blank)
.[ Volcanism within the Lassen vicinity follows a trend of intermittent, episodic eruptions punctuating long periods of dormancy, a pattern which persisted through the late Pleistocene and ]Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...
. During the past 825,000 years, the area has produced hundreds of explosive eruption
In volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such ...
s over an area of ,[ and the past 50,000 years have seen seven major ]silicic
Silicic is an adjective to describe magma or igneous rock rich in silica. The amount of silica that constitutes a silicic rock is usually defined as at least 63 percent. Granite and rhyolite are the most common silicic rocks.
Silicic is the group ...
eruptive episodes that produced dacitic
Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite ...
lava dome
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on ...
s, tephra
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism.
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they rem ...
, and pyroclastic flows
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...
, along with five periods of basaltic and andesitic lava flow
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or und ...
s.
Local activity began 600,000 years ago with the formation of Brokeoff Volcano (alternatively known as Mount Tehama).[ Around the same time, about 614,000 years ago, an explosive eruption southwest of Lassen Peak produced of ]pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular vol ...
and ash, covering the area between the vent and what is now the city of Ventura, California
Ventura, officially named San Buenaventura (Spanish for "Saint Bonaventure"), is a city on the Southern Coast of California and the county seat of Ventura County. The population was 110,763 at the 2020 census. Ventura is a popular tourist des ...
. This deposit, referred to as the Rockland tephra, reaches up to several inches in thickness within the San Francisco Bay area, and can be found as far as northern Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
and southern Idaho
Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...
. The same eruption also formed one of three known calderas within the Cascade, the others being Crater Lake
Crater Lake (Klamath language, Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The ...
and the Kulshan Caldera at Mount Baker
Mount Baker (Lummi: '; nok, Kw’eq Smaenit or '), also known as Koma Kulshan or simply Kulshan, is a active glacier-covered andesitic stratovolcano in the Cascade Volcanic Arc and the North Cascades of Washington in the United States. Mount ...
. 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). Following the end of volcanism at Brokeoff Volcano hydrothermal fluids began chemically weathering minerals in the andesite flows, altering the once strong rocks into easily eroded materials. Glaciers and streams were able to rapidly erode deep channels into these altered volcanic rocks, reducing the once lofty peak of Brokeoff Volcano into the landscape we see today. Following the erosion of Brokeoff Volcano, volcanism migrated to the Lassen Domefield to the northeast.
Lassen Peak's lava dome formed about 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. The bowl-shaped depression on the volcano's northeastern flank, called a cirque
A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform ...
, was eroded by a glacier that extended out from the dome. By 18,000 years ago, Lassen Peak started to form a mound-shaped dacite lava dome, pushing its way through Tehama's former northern flank. As the lava dome grew it shattered overlaying rock, which formed a blanket of angular talus around the emerging steep-sided volcano. Likely resembling the nearby 1,100-year-old Chaos Crags
Chaos Crags is the youngest group of lava domes in Lassen Volcanic National Park, California. They formed as six dacite domes 1,100-1,000 years ago, one dome collapsing during an explosive eruption about 70 years later. The eruptions at the Ch ...
, Lassen Peak reached its present height in a relatively short time, probably in just a few years. Within the past 1,000 years or so, activity at Lassen Peak has produced six dacite lava domes, erupted tephra and pyroclastic flows, and built Cinder Cone and the Fantastic Lava Beds
Cinder Cone is a cinder cone volcano in Lassen Volcanic National Park within the United States. It is located about northeast of Lassen Peak and provides an excellent view of Brokeoff Mountain, Lassen Peak, and Chaos Crags.
The cone was bui ...
. It also created the rockfalls at Chaos Jumbles.
The only Cascade volcano with an elevation above that is not a stratovolcano, Lassen Peak is a rhyodacitic
Rhyodacite is a volcanic rock intermediate in composition between dacite and rhyolite. It is the extrusive equivalent of those plutonic rocks that are intermediate in composition between monzogranite and granodiorite. Rhyodacites form from rapid ...
lava dome. It represents one of the largest lava domes on Earth, with a height of above its surroundings, and an approximate volume of . Unlike more conventional, conical stratovolcanoes like Mount Shasta or Mount Rainier, Lassen Peak is part of a volcanic center that erupts from different vents, which each remain active for a number of years or decades but often do not erupt from the same vent twice, also known as a monogenetic volcanic field
A monogenetic volcanic field is a type of volcanic field consisting of a group of small monogenetic volcanoes, each of which erupts only once, as opposed to polygenetic volcanoes, which erupt repeatedly over a period of time. The small monogenetic ...
. 2000 years after Lassen's formation, it was surrounded by glaciers which ate away at its spiny protrusions of dacite. Due to glacial erosion from the last local glacial advance, which ceased roughly 15,000 years ago, Lassen's lava dome is now covered in broken rock fragments at the base of crags called talus deposits. Only its crag formations on its southern flank, near the summit trailhead, have not been significantly altered by glacial erosion.
Subfeatures
The Lassen volcanic center includes Brokeoff Volcano, Lassen's dacitic lava dome, and a number of small andesitic shield volcano
A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more v ...
es found northeast of Lassen Peak.[ The Lassen dome field includes 30 dacitic lava domes such as Bumpass Mountain, Mount Helen, Ski Heil Peak, and Reading Peak;][ other major lava domes include Chaos Crags, Eagle Peak, Sunflower Flat, and Vulcans Castle.] Nearby shield volcanoes include Prospect Peak and West Prospect Peak, and there are three cones close to Lassen Peak: Cinder Cone, Hat Mountain, and Raker Peak.[ The hydrothermal area inside the Lassen Peak volcanic center, with features located southeast and southwest of Lassen Peak, represents the largest geothermal area in the United States besides the one present at Yellowstone National Park.
The Chaos Crags, a series of five small lava domes, represent the youngest part of Lassen volcanic center's dome field, reaching an elevation of about above their surroundings. They were produced by vigorous explosive eruptions of pumice and ash followed by ]effusive
In physics and chemistry, effusion is the process in which a gas escapes from a container through a hole of diameter considerably smaller than the mean free path of the molecules. Such a hole is often described as a ''pinhole'' and the escape ...
activity, which created unstable edifices that partially collapsed and formed pyroclastic flows made of incandescent lava blocks and lithic ash. Six domes were originally formed, though one was destroyed by a pyroclastic flow. Roughly 350 years ago, one of the domes collapsed to produce the Chaos Jumbles, an area where three enormous rockfalls transformed the local area and traveled as far as down the dome's slopes.
Cinder Cone, which reaches an elevation of above its surrounding area in the northeastern region of the Lassen Volcanic National Park, forms a symmetrical pyroclastic cone. The youngest mafic volcano in the Lassen volcanic center, it is surrounded by unvegetated block lava and has concentric craters at its summit. Cinder Cone is comprised by five basaltic andesite
Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central Ameri ...
and andesite lava flows, and it also has two cinder cone
A cinder cone (or scoria cone) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions o ...
volcanoes, with two scoria
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''G ...
cones, the first of which was mostly destroyed by lava flows from its base.[ In 1850 and 1851, a number of observers reported an eruption at Cinder Cone visible from more than away, with one observer near the mountain claiming to have observed a lava flow "running down the sides of the volcano." However, despite these testimonies and accounts in newspaper articles and several scientific journals, the veracity of these eruptions has been questioned by scientists from the ]United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
. In addition to the fact that cinder cones usually erupt lava from base vents, there is a lack of physical evidence suggesting activity at the volcano since its formation in 1650. In addition, an old willow
Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
bush growing near the summit crater that was documented during the 1850s was still present in the 1880s after the alleged eruptions, suggesting that no eruptions took place during the 1850s.
Human history
The areas surrounding Lassen Peak, especially to its east, south, and southeast, represented a meeting ground for Maidu
The Maidu are a Native American people of northern California. They reside in the central Sierra Nevada, in the watershed area of the Feather and American rivers. They also reside in Humbug Valley. In Maiduan languages, ''Maidu'' means "man."
...
, Yana
Yana may refer to:
Locations
*Yana, Burma, a village in Hkamti Township in Hkamti District in the Sagaing Region of northwestern Burma
*Yana, India, a village in the Uttara Kannada district of Karnataka, India
* Yana, Nigeria, an administrative ca ...
, Yahi
The Yana were a group of Native Americans indigenous to Northern California in the central Sierra Nevada, on the western side of the range. Their lands, prior to encroachment by white settlers, bordered the Pit and Feather rivers. They were ...
, and Atsugewi
The Atsugewi are Native Americans residing in northeastern California, United States. Their traditional lands are near Mount Shasta, specifically the Pit River drainage on Burney, Hat, and Dixie Valley or Horse Creeks. They are closely related ...
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
The Maidu are a Native American people of northern California. They reside in the central Sierra Nevada, in the watershed area of the Feather and American rivers. They also reside in Humbug Valley. In Maiduan languages, ''Maidu'' means "man."
...
. Because the area was not suitable for permanent habitation, there is relatively scarce archaeological evidence of a native presence in the Lassen area.
The first white man to reach Lassen Peak was Jedediah Smith
Jedediah Strong Smith (January 6, 1799 – May 27, 1831) was an American clerk, transcontinental pioneer, frontiersman, hunter, trapper, author, cartographer, mountain man and explorer of the Rocky Mountains, the Western United States, and ...
, who passed through the area in 1821 as he made his way for the western coast of the United States. After the California Gold Rush
The California Gold Rush (1848–1855) was a gold rush that began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The news of gold brought approximately 300,000 people to California fro ...
brought increased numbers of settlers into the area, Lassen Peak was named in honor of a Danish blacksmith, Peter Lassen
Peter Lassen (October 31, 1800 – April 26, 1859), later known in Spanish as Don Pedro Lassen, was a Danish-born Californian ranchero and gold prospector. Born in Denmark, Lassen immigrated at age 30 to Massachusetts, before eventually final ...
, who guided immigrants past the peak to the Sacramento Valley
, photo =Sacramento Riverfront.jpg
, photo_caption= Sacramento
, map_image=Map california central valley.jpg
, map_caption= The Central Valley of California
, location = California, United States
, coordinates =
, boundaries = Sierra Nevada (ea ...
during the 1830s. This trail was replaced by the Nobles Emigrant Trail
The Nobles Emigrant Trail, also known as the Fort Kearney, South Pass and Honey Lake Wagon Road, is a trail in California that was used by emigrant parties from the east as a shortened route to northern California. It was pioneered in 1851 by Willi ...
, named for the guide William Nobles, who pioneered the trail in 1851.
Lassen Peak's first recorded ascent took place in 1851, led by Grover K. Godfrey. In 1864, painter Helen Tanner Brodt
Helen Alice Tanner Brodt (April 21, – ) was an American landscape and portrait painter.
Helen Tanner was born on April 21, in Elmira, New York. She studied art at the National Academy of Design. She married Aurelius W. Brodt, a school ...
became the first woman to reach the summit of Lassen Peak, wanting to sketch the surrounding landscape. A tarn lake on Lassen Peak is named "Lake Helen" in her honor. The Bumpass Hell, a hydrothermal vent area near Lassen Peak, was named after a pioneer who suffered burns there and lost his leg shortly after. Other historic names for Lassen Peak include Mount Joseph (from 1827), Snow Butte, Sister Buttes, and Mount Lassen.
Lassen Volcanic National Park
United States President Theodore Roosevelt
Theodore Roosevelt Jr. ( ; October 27, 1858 – January 6, 1919), often referred to as Teddy or by his initials, T. R., was an American politician, statesman, soldier, conservationist, naturalist, historian, and writer who served as the 26t ...
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
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
, 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
Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest lava dome, plug dome volcano in the world and the southernmost volcano in the Cascade Range. L ...
on August 9, 1916. The park, in area, can be reached from the California State Route 89
State Route 89 (SR 89) is a state highway in the U.S. state of California that travels in the north–south direction, serving as a major thoroughfare for many mountain communities in the Sierra Nevada and the Cascade Range. It starts from ...
highway.
Eruptive history
Ancient activity
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
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inter ...
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. No volcanic activity took place 190,000 years ago to roughly 90,000 years ago,[ but during the last 100,000 years, there have been at least 12 periods of eruptive activity in the Lassen volcanic center,] and since 90,000 years ago, the Twin Lakes sequence has been producing mixed lavas with variable appearances and compositions, including andesite and basaltic andesite lava flows and agglutinated volcanic cones (made of fused pyroclastic rocks) located by the Lassen dome field. The Twin Lakes sequence includes the construction of the Chaos Crag dome complex between 1100 and 1000 years ago and eruptions at Lassen Peak beginning in 1914.[
Prior to 1914, Lassen Peak likely underwent at least one explosive eruption, which created a summit crater deep with a diameter of . Deposits from older mudflows that can be traced specifically to the Lassen dome have also been found in Hat Creek, Lost Creek, and in a region to the east of the Devastated Area.
]
1914–1921
On May 30, 1914, despite an apparent lack of precursor earthquakes, Lassen became volcanically active again after 27,000 years of dormancy
Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps an organism to conserve energy. Dormancy tends to be clo ...
, when it produced a steam explosion
A steam explosion is an explosion caused by violent boiling or flashing of water or ice into steam, occurring when water or ice is either superheated, rapidly heated by fine hot debris produced within it, or heated by the interaction of molten m ...
that carved out a small crater with a fairly deep lake on the volcano's summit. 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 . On May 14, 1915, Lassen Peak erupted lava blocks, which extended as far as Manton, west of the mountain. By the next day, the volcano had produced a dacitic lava dome, between 63 and 68 percent silica, which occupied its summit crater. On May 19, a large eruption destroyed this dome, and a new crater formed at the summit. No lava erupted, but parts of the dome fell on the upper flanks of the mountain, which were covered in more than of snow. The lava mixed with snow and rock to form a lahar
A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley.
Lahars are extreme ...
(volcanically induced mudslide
A mudflow or mud flow is a form of mass wasting involving fast-moving flow of debris that has become liquified by the addition of water. Such flows can move at speeds ranging from 3 meters/minute to 5 meters/second. Mudflows contain a significa ...
, landslide
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...
, and debris flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally ...
), in width, which coursed down the side of the volcano, traveling and reaching Hat Creek. After being deflected to the northwest at Emigrant Pass, the lahar extended an additional down Lost Creek. On May 20, the lower Hat Creek valley flooded with muddy water, which damaged ranch houses in the Old Station area and caused minor injuries among a few people, all of whom escaped. Removing homes from their foundation, the lahar also uprooted trees more than tall. The flood continued for another , killing fish in the Pit River
The Pit River is a major river draining from northeastern California into the state's Central Valley. The Pit, the Klamath and the Columbia are the only three rivers in the U.S. that cross the Cascade Range.
The longest tributary of the Sacr ...
. Simultaneously, dacite lava with lower viscosity than dacite from the previous eruption filled the summit crater, overflowing and extending in two streams for down the mountain's western and northeastern sides.
On May 22, 1915, at about 4:00 p.m., Lassen Peak produced a violent explosive eruption that ejected rock and pumice and formed a larger and deeper crater at its summit. Within 30 minutes, volcanic ash and gas formed a column that reached altitudes of more than and could be seen from the city of Eureka
Eureka (often abbreviated as E!, or Σ!) is an intergovernmental organisation for research and development funding and coordination. Eureka is an open platform for international cooperation in innovation. Organisations and companies applying th ...
, to the west. This column underwent a partial collapse, generating a pyroclastic flow composed of hot ash, pumice, rock, and gas that destroyed of land and spawned a lahar extending from the volcano and again reaching Hat Creek Valley. Smaller mudflows also formed on every side of the volcano, as well a layer of pumice and volcanic ash that reached as far as northeast; volcanic ash was detected up to east at the city of Elko, Nevada
Elko (Shoshoni: Natakkoa, "Rocks Piled on One Another") is the largest city in and county seat of Elko County, Nevada, United States. With a 2020 population of 20,564, Elko is currently growing at a rate of 0.31% annually and its population has i ...
. Additionally, the lava flow on the volcano's northeastern flank was removed by this eruption, but not the similar deposit on the western flank.
The eruptive output volume totaled , dwarfed by the 1980 eruption of Mount St. Helens
On March 27, 1980, a series of volcanic explosions and pyroclastic flows began at Mount St. Helens in Skamania County, Washington, United States. A series of phreatic blasts occurred from the summit and escalated until a major explosive eru ...
, which had a volume of . The region on the volcano's northeastern flank destroyed by the eruptions, in area, is now known as the Devastated Area, and it along with other deposits from the volcano has been altered by erosion and regrowth of vegetation, though the vegetation in Devastated Area is sparse due to its siliceous (rich in silica), nutrient-deprived soil, which cannot sustain normal tree growth due to its lack of water retention. Due to their small size and thin deposits, the 1915 eruptions will likely not be well-preserved geologically.
After 1915, steam explosions continued for several years, indicating extremely hot rock beneath Lassen Peak's surface. In May 1917, an especially strong steam explosion formed the northern crater on Lassen Peak's summit, with eruptions lasting two days and producing an ash cloud that extended into the sky. June saw 21 additional explosions reported, further transforming the crater and creating a new vent on Lassen Peak's northwestern summit. In June 1919, steam eruptions occurred, and similar activity was observed on April 8 and 9 in 1920, followed by steam eruptions lasting 10–12 hours in October of the same year. During February 1921, white steam erupted from eastern fissures on the volcano. In total, about 400 eruptions were observed between 1914 and 1921, which were the last eruptions in the Cascades before the 1980 eruption of Mount St. Helens, which was the only other volcanic eruption in the contiguous United States
The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...
during the 20th century.
Documentation of 20th century eruptions through pictures and film
During its eruptions in the early 20th century, Lassen Peak attracted widespread media attention as the first volcano to erupt in the United States during the 20th century. Unlike eruptions at Mount Baker, Mount Rainier
Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a s ...
, Mount St. Helens, or Mount Hood
Mount Hood is a potentially active stratovolcano in the Cascade Volcanic Arc. It was formed by a subduction zone on the Pacific coast and rests in the Pacific Northwest region of the United States. It is located about east-southeast of Portlan ...
during the 19th century, Lassen Peak's eruptions
were very well documented by newspapers and extensively photographed. Though there is a large supply of images documenting these eruptions at Lassen Peak, the best and most complete images were taken by the local businessman Benjamin Franklin Loomis. Using an 8x10-inch camera with glass-plate negatives, Loomis made his own film and set up a darkroom in a tent. He wrote of the eruption he witnessed on June 14, 1914, "The sight was fearfully grand." Loomis's pictures were published in his book ''Pictorial History of the Lassen Volcano'' (1926); a number of his original plates remain in the archives of the National Park Service. His photographs have been used to help understand the timeline and geology of the 1915 eruptions of Lassen Peak.
One of Lassen Peak's 1917 eruptions was captured on film by Justin Hammer from the nearby Catfish Lake. Originally silent, the film features sound effects added by his grandson, Craig Martin. The film was rediscovered and published in 2015 by the Shasta Historical Society.
Recent activity and current threats
Lassen Peak remains an active volcano
An active volcano is a volcano which is either erupting or is likely to erupt in the future. An active volcano which is not currently erupting is known as a dormant volcano.
Overview
Tlocene Epoch. Most volcanoes are situated on the Pacific Ri ...
, as volcanic activity including fumarole
A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...
s (steam vents), hot spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...
s, and mudpot
A mudpot, or mud pool, is a sort of acidic hot spring, or fumarole, with limited water. It usually takes the form of a pool of bubbling mud. The acid and microorganisms decompose surrounding rock into clay and mud.
Description
The mud of a mudp ...
s can be found throughout Lassen Volcanic National Park. Their activity varies based on the season; during the spring, when meltwater is more abundant, fumaroles and pools of water have lower temperatures, while mudpots have more fluid mud supplies. During summer and droughts, they become drier and hotter, since they cannot be cooled by ground water. Geothermal activity can be observed at Bumpass Hell, Little Hot Springs Valley, Pilot Pinnacle, Sulphur Works, Devils Kitchen, Boiling Springs Lake, and Terminal Geyser, as well as the Morgan and Growler Hot Springs south of the national park in Mill Canyon. These are produced by the boiling of underground bodies of water, which generates steam. At Bumpass Hell, these features are at their most vigorous, with temperatures reaching at Big Boiler, the park's biggest fumarole and one of the hottest hydrothermal fumaroles in the world. Because of their acidic conditions and heat, none of these hydrothermal bodies are safe for bathing except for at Drakesbad Guest Ranch. Fumaroles near Lassen Peak in particular remained active through the 1950s, but have grown weaker over time; they can still be found among the volcano's summit craters. These hydrothermal features are monitored continuously for their physical and chemical conditions by the United States Geological Survey.[
Climbers reported steam eruptions in the summit craters for decades after activity apparently ceased in 1921, and the naturalist Paul Schulz documented 30 steam vents at the summit in the 1950s. A report from the United States Geological Survey declared that "No one can say when, but it is almost certain that the Lassen area will experience volcanic eruptions again." Similarly, the California Volcano Observatory lists its threat level as "Very High."][ At the time of the early 20th century eruptions, the area surrounding the volcano was only sparsely populated, but a similar eruption today would threaten many lives and the northern Californian economy. Volcanic eruptions occur with similar frequency to major earthquakes from the ]San Andreas Fault
The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonics, tectonic boundary between the Pacific Plate and the North American Plate, and its motion is Fault (geology)#Strike-slip fau ...
, and at least 10 eruptions have taken place within the state during the past 1,000 years, the most recent at Lassen Peak. Under 1 percent of the state's population lives within hazard zones that could be affected by an eruption, but collectively hazard zones are visited by more than 20 million people each year. Moreover, a number of the potentially active Californian volcanoes reside less than from highly populated areas, and explosive eruptions could produce ash that travels for several hundred miles. In the case of signs that suggest impending volcanic activity, the United States Geological Survey has a plan in place to utilize portable monitoring instruments, deploy scientists to the area,[ and implement an emergency response plan developed by the National Park Service if an eruption were imminent.
Although basaltic lava flows are the most common eruptive activity in the Lassen volcanic center, they could also produce more violent and thus more hazardous silicic lava flows, in addition to building additional, unstable lava domes that could collapse and spawn pyroclastic flows that could extend for several miles. Because Lassen Peak has a significant amount of snow and ice, these pyroclastic flows (or hot volcanic ash) might mix with water to form lahars (volcanically induced mudslides, landslides, and debris flows) that could destroy nearby communities. Dacitic eruptions could produce volcanic columns of gas and ash that could threaten aircraft in the area. Moreover, the Lassen volcanic center poses threats to visitors from sudden avalanches that could be entirely unrelated to eruptive activity. Due to the threat of an ]avalanche
An avalanche is a rapid flow of snow down a slope, such as a hill or mountain.
Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and earth ...
from nearby Chaos Crag if volcanic activity renewed in the area or an earthquake occurred, the Visitor Center for Lassen Peak located at Manzanita Lake closed in 1974. In 1993, a rockfall with a volume of fell down Lassen Peak's northeastern flank, but no visitors were harmed. Despite the volcano's current quiet state, rockfalls still pose significant hazards due to the peak's inherent instability.
The volcano is monitored by the California Volcano Observatory, which has a sensor network that can measure increased seismicity, ground deformation, or gas emissions suggesting movement of magma towards the surface near the volcano. The United States Geological Survey, in cooperation with the National Park Service, has been monitoring Lassen Peak and other volcanic areas in the park with tiltmeter
A tiltmeter is a sensitive inclinometer designed to measure very small changes from the vertical level, either on the ground or in structures. Tiltmeters are used extensively for monitoring volcanoes, the response of dams to filling, the small m ...
s, seismometer
A seismometer is an instrument that responds to ground noises and shaking such as caused by earthquakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The outpu ...
s, and inclinometer
An inclinometer or clinometer is an measuring instrument, instrument used for measuring angles of slope, elevation, or depression (geology), depression of an object with respect to gravity's direction. It is also known as a ''tilt indicator'', ' ...
s. Prior to 1996, geodetic
Geodesy ( ) is the Earth science of accurately measuring and understanding Earth's figure (geometric shape and size), orientation in space, and gravity. The field also incorporates studies of how these properties change over time and equivale ...
surveys at Lassen Peak did not detect ground deformation, but Interferometric synthetic-aperture radar Interferometric synthetic aperture radar, abbreviated InSAR (or deprecated IfSAR), is a radar technique used in geodesy and remote sensing. This geodetic method uses two or more synthetic aperture radar (SAR) images to generate maps of surface defor ...
(InSAR) surveys between 1996 and 2000 suggested that downward subsidence
Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope move ...
was occurring at a rate of each year within a circular area with a diameter of centered just of the volcano. As a result, additional surveys using the Global Positioning System
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
took place in 2004, and further InSAR surveys showed that subsidence continued through 2010. Lassen Peak is one of four Cascade volcanoes that has undergone subsidence since 1990, with Medicine Lake Volcano
Medicine Lake Volcano is a large shield volcano in northeastern California about northeast of Mount Shasta. The volcano is located in a zone of east-west crustal extension east of the main axis of the Cascade Volcanoes, Cascade Volcanic Arc ...
, Mount Baker, and Mount St. Helens. Though not conclusively linked to a possible eruption, this subsidence may offer insight into how magma is stored within the region, tectonic setting, and how hydrothermal systems evolve over long periods of time. GPS receivers have been in place to monitor deformation
Deformation can refer to:
* Deformation (engineering), changes in an object's shape or form due to the application of a force or forces.
** Deformation (physics), such changes considered and analyzed as displacements of continuum bodies.
* Defo ...
within the Lassen volcanic center since 2008, and 13 seismometers in the vicinity, first installed in 1976 and since updated each decade, continually survey earthquakes within the locale.
Recreation
The Lassen Volcanic National Park is visited by more than 350,000 people every year.[ Incorporating more than of hiking trails, it is visited by people looking to hike or ]backpack
A backpack—also called knapsack, schoolbag, rucksack, rucksac, pack, sackpack, booksack, bookbag or backsack—is, in its simplest frameless form, a fabric sack carried on one's back and secured with two straps that go over the shoulders ...
during the summers. Popular winter activities include snowshoeing
Snowshoes are specialized outdoor gear for walking over snow. Their large footprint spreads the user's weight out and allows them to travel largely on top of rather than through snow. Adjustable bindings attach them to appropriate winter footwe ...
and backcountry skiing
Backcountry skiing ( US), also called off-piste (Europe), alpine touring, or out-of-area, is skiing in the backcountry on unmarked or unpatrolled areas either inside or outside a ski resort's boundaries. This contrasts with alpine skiing, which i ...
. As the second-tallest volcano in Northern California, trailing only Mount Shasta, Lassen Peak is frequently visited by climbers and hikers from around the world.[ The summit opens for use most years near the end of June, remaining in use until heavy snow falls in October or November. After a 9-year-old boy died from a collapsed ]retaining wall
Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides.
Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to ...
along the summit trail on July 29, 2009, the path closed for six years for construction, reopening in 2015.
The mountain's summit trail can be accessed from a parking lot on the northern side of the California State Route 89. The Lassen Peak Trail, which starts from this parking area, runs for with switchback turns, a round-trip hike in length that ascends approximately from the trailhead at to the summit at . From the northeast summit, Lassen's 1915 mudflow and Prospect Peak are visible; the northwestern summit offers views of Lassen's two bowl-shaped craters and Mount Shasta, to the north.
The southern entrance to the park area has a winter sports area where visitors can ski
A ski is a narrow strip of semi-rigid material worn underfoot to glide over snow. Substantially longer than wide and characteristically employed in pairs, skis are attached to ski boots with ski bindings, with either a free, lockable, or partial ...
, snowshoe
Snowshoes are specialized outdoor gear for walking over snow. Their large footprint spreads the user's weight out and allows them to travel largely on top of rather than through snow. Adjustable bindings attach them to appropriate winter footwe ...
, and within the Lassen National Forest, visitors can also bicycle, go boating
Boating is the leisurely activity of travelling by boat, or the recreational use of a boat whether Motorboat, powerboats, Sailing, sailboats, or man-powered vessels (such as rowing and paddle boats), focused on the travel itself, as well as sp ...
, or use snowmobile
A snowmobile, also known as a Ski-Doo, snowmachine, sled, motor sled, motor sledge, skimobile, or snow scooter, is a motorized vehicle designed for winter travel and recreation on snow. It is designed to be operated on snow and ice and does not ...
s.[
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See also
*List of highest points in California by county
This is a list of highest points in California, in alphabetical order by county.
All elevations use the North American Vertical Datum of 1988 (NAVD88), the currently accepted vertical control datum for United States, Canada and Mexico. Elevations ...
*List of Ultras of the United States
The following sortable table comprises the 200 most topographically prominent mountain peaks of the United States of America.
The summit of a mountain or hill may be measured in three principal ways:
#The topographic elevation of a summit me ...
*List of volcanoes in the United States
A list of volcanoes in the United States and its territories.
Alaska
American Samoa
Arizona
California
Colorado
Hawaii
/[./[Https://www.sci.news/geology/puhahonu-shield-volcano-08435.html Puhahonu ...
References
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External links
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{{Authority control
Cascade Range
Volcanoes of Shasta County, California
Highest points of United States national parks
Lassen Volcanic National Park
Subduction volcanoes
Pleistocene lava domes
Cascade Volcanoes
Cirques
20th-century volcanic events
Volcanoes of California
North American 3000 m summits
Holocene lava domes