Manzanita Lake Naturalist's Services Historic District
The Manzanita Lake Naturalist's Services Historic District encompasses the historic area devoted to visitor interpretation services at the northwest entrance of Lassen Volcanic National Park in northeastern California. The district's earliest structures were built by Benjamin and Estella Loomis, who were instrumental in the establishment of the park and among the park's first concessioners; the 1927 Loomis Museum and its seismograph hut were built by the Loomises and were donated, together with 40 acres of land to the National Park Service in 1929. The Loomis House known as the Loomis Art House and Manzanita Lake Ranger Station, was built about the same time as the museum and served as their residence, photography studio and shop until the 1950s under the name "B. F. Loomis Photo and Art Store". Park Service structures were developed at Manzanita Lake in the 1930s. Park Service-designed and constructed buildings include the entrance station, the ranger residence and the comfort station; the naturalist's residence shares a similar design to its counterparts at Crater Lake National Park, with their design and construction techniques adapted to the short building seasons prevalent at both parks.
The residence was built using Civilian Conservation Corps labor. The area was abandoned in 1973 after a geological report indicated that a rockfall in the Chaos Crags could reach the Manzanita Lake area in 90 seconds; the Manzanita Lodge and cabins were therefore demolished. In 1987 a reassessment indicated that such a rockfall could not reach Manzanita Lake and the area was reoccupied and renovated; the lodge was never rebuilt. The Manzanita Lake Naturalist's Services Historic District was placed on the National Register of Historic Places on June 23, 2006
The term landslide or, less landslip, refers to several forms of mass wasting that include a wide range of ground movements, such as rockfalls, deep-seated slope failures and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients: from mountain ranges to coastal cliffs or underwater, in which case they are called submarine landslides. Gravity is the primary driving force for a landslide to occur, but there are other factors affecting slope stability which produce specific conditions that make a slope prone to failure. In many cases, the landslide is triggered by a specific event, although this is not always identifiable. Landslides occur when the slope undergoes some processes that change its condition from stable to unstable; this is due to a decrease in the shear strength of the slope material, to an increase in the shear stress borne by the material, or to a combination of the two. A change in the stability of a slope can be caused by a number of factors, acting alone.
Natural causes of landslides include: saturation by rain water infiltration, snow melting, or glaciers melting. Slope material that becomes saturated with water may develop into a debris mud flow; the resulting slurry of rock and mud may pick up trees and cars, thus blocking bridges and tributaries causing flooding along its path. Debris flow is mistaken for flash flood, but they are different processes. Muddy-debris flows in alpine areas cause severe damage to structures and infrastructure and claim human lives. Muddy-debris flows can start as a result of slope-related factors and shallow landslides can dam stream beds, resulting in temporary water blockage; as the impoundments fail, a "domino effect" may be created, with a remarkable growth in the volume of the flowing mass, which takes up the debris in the stream channel. The solid–liquid mixture can reach densities of up to 2,000 kg/m3 and velocities of up to 14 m/s; these processes cause the first severe road interruptions, due not only to deposits accumulated on the road, but in some cases to the complete removal of bridges or roadways or railways crossing the stream channel.
Damage derives from a common underestimation of mud-debris flows: in the alpine valleys, for example, bridges are destroyed by the impact force of the flow because their span is calculated only for a water discharge. For a small basin in the Italian Alps affected by a debris flow, estimated a peak discharge of 750 m3/s for a section located in the middle stretch of the main channel. At the same cross section, the maximum foreseeable water discharge, was 19 m3/s, a value about 40 times lower than that calculated for the debris flow that occurred. An earthflow is the downslope movement of fine-grained material. Earthflows can move at speeds within a wide range, from as low as 1 mm/yr to 20 km/h. Though these are a lot like mudflows, overall they are more slow moving and are covered with solid material carried along by flow from within, they are different from fluid flows. Clay, fine sand and silt, fine-grained, pyroclastic material are all susceptible to earthflows; the velocity of the earthflow is all dependent on how much water content is in the flow itself: the higher the water content in the flow, the higher the velocity will be.
These flows begin when the pore pressures in a fine-grained mass increase until enough of the weight of the material is supported by pore water to decrease the internal shearing strength of the material. This thereby creates a bulging lobe which advances with a rolling motion; as these lobes spread out, drainage of the mass increases and the margins dry out, thereby lowering the overall velocity of the flow. This process causes the flow to thicken; the bulbous variety of earthflows are not that spectacular, but they are much more common than their rapid counterparts. They develop a sag at their heads and are derived from the slumping at the source. Earthflows occur much more during periods of high precipitation, which saturates the ground and adds water to the slope content. Fissures develop during the movement of clay-like material which creates the intrusion of water into the earthflows. Water increases the pore-water pressure a
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 plug dome volcano in the world and the southernmost volcano in the Cascade Range. Lassen Volcanic National Park started as two separate national monuments designated by President Theodore Roosevelt in 1907: Cinder Cone National Monument and Lassen Peak National Monument; the source of heat for the volcanism in the Lassen area is subduction of the Gorda Plate diving below the North American Plate off the Northern California coast. The area surrounding Lassen Peak is still active with boiling mud pots and hot springs. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found—plug dome, cinder cone, stratovolcano; the park is accessible via State Routes 89 and 44. SR 89 passes north-south through the park, beginning at SR 36 to the south and ending at SR 44 to the north. SR 89 passes adjacent to the base of Lassen Peak.
There are five vehicle entrances to the park: the north and south entrances on SR 89. The park can be accessed by trails leading in from the Caribou Wilderness to the east, as well as the Pacific Crest Trail, two smaller trails leading in from Willow Lake and Little Willow Lake to the south; the Lassen Chalet, a large lodge with concession facilities, was located near the southwest entrance, but was demolished in 2005. A new full-service visitor center in the same location opened to the public in 2008; the Lassen Ski Area was located near the lodge. Native Americans have inhabited the area since long; the natives knew that the peak was full of fire and water and thought it would one day blow itself apart. White immigrants in the mid-19th century used Lassen Peak as a landmark on their trek to the fertile Sacramento Valley. One of the guides to these immigrants was a Danish blacksmith named Peter Lassen, who settled in Northern California in the 1830s. Lassen Peak was named after him. Nobles Emigrant Trail was cut through the park area and passed Cinder Cone and the Fantastic Lava Beds.
Inconsistent newspaper accounts reported by witnesses from 1850 to 1851 described seeing "fire thrown to a terrible height" and "burning lava running down the sides" in the area of Cinder Cone. As late as 1859, a witness reported seeing fire in the sky from a distance, attributing it to an eruption. Early geologists and volcanologists who studied the Cinder Cone concluded the last eruption occurred between 1675 and 1700. After the 1980 eruption of Mount St. Helens, the United States Geological Survey began reassessing the potential risk of other active volcanic areas in the Cascade Range. Further study of Cinder Cone estimated the last eruption occurred between 1630 and 1670. Recent tree-ring analysis has placed the date at 1666; the Lassen area was first protected by being designated as the Lassen Peak Forest Preserve. Lassen Peak and Cinder Cone were declared as U. S. National Monuments in May 1907 by President Theodore Roosevelt. Starting in May 1914 and lasting until 1921, a series of minor to major eruptions occurred on Lassen.
These events created a new crater, released lava and a great deal of ash. Because of warnings, no one was killed, but several houses along area creeks were destroyed; because of the eruptive activity, which continued through 1917, the area's stark volcanic beauty, Lassen Peak, Cinder Cone and the area surrounding were declared a National Park on August 9, 1916. The 29-mile Main Park Road was constructed between 1925 and 1931, just 10 years after Lassen Peak erupted. Near Lassen Peak the road reaches 8,512 feet, it is not unusual for 40 ft of snow to accumulate on the road near Lake Helen and for patches of snow to last into July. In October 1972, a portion of the park was designated as Lassen Volcanic Wilderness by the US Congress; the National Park Service seeks to manage the wilderness in keeping with the Wilderness Act of 1964, with minimal developed facilities and trails. The management plan of 2003 adds that, "The wilderness experience offers a moderate to high degree of challenge and adventure."In 1974, the National Park Service took the advice of the USGS and closed the visitor center and accommodations at Manzanita Lake.
The Survey stated that these buildings would be in the way of a rockslide from Chaos Crags if an earthquake or eruption occurred in the area. An aging seismograph station remains. However, a campground and museum dedicated to Benjamin F. Loomis stands near Manzanita Lake, welcoming visitors who enter the park from the northwest entrance. After the Mount St. Helens eruption, the USGS intensified its monitoring of active and active volcanoes in the Cascade Range. Monitoring of the Lassen area includes periodic measurements of ground deformation and volcanic-gas emissions and continuous transmission of data from a local network of nine seismometers to USGS offices in Menlo Park, California. Should indications of a significant increase in volcanic activity be detected, the USGS will deploy scientists and specially designed portable monitoring instruments to evaluate the threat. In addition, the National Park Service has developed an emergency response plan that would be activated to protect the public in the event of an impending eruption.
The NPS tracks visitors by counting vehicles entering the park via in-road inductive loops at all vehicle entrances. Buses and other non-reportable vehicles are subtracted from
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 Chaos Crags mark one of just three instances of Holocene activity within the Lassen volcanic center. The cluster of domes is located north of Lassen Peak and form part of the southernmost segment of the Cascade Range in Northern California; each year, a lake forms at the base of the Crags, dries by the end of the summer season. From the base of the crags and extending toward the northwest corner of the park is Chaos Jumbles, a rock avalanche that undermined Chaos Crags' northwest slope 300 years ago. Riding on a cushion of compressed air, the rock debris traveled at about 100 miles per hour, flattened the forest before it, dammed Manzanita Creek, forming Manzanita Lake. In addition to the possibility of forming additional lava domes, future activity at the Chaos Crags could pose hazards from pumice, pyroclastic flows, or rockfalls.
Geological study of the Chaos Crags, which continues today, began in the late 1920s, when Howel Williams wrote about its pyroclastic rock deposits, rockfall avalanches, eruptions. The area is monitored for rockslide threats; the Crags and the surrounding area's lakes and forests support numerous animal species. The area is not a popular destination for visitors, despite its accessibility; the Chaos Crags and Crags Lake Trail, which lasts about three hours round-trip, runs to the summit, offers views of volcanic phenomena nearby, as well as the Hat Creek valley and the Thousand Lakes Wilderness. The Chaos Crags form part of the southernmost segment of the Cascade Range in Northern California, they lie in the northwest corner in Shasta County. Located 2 miles to the north of Lassen Peak, they have an elevation of about 8,448 feet; the Lassen Volcanic National Park area is surrounded by the Lassen National Forest, which has an area of 1,200,000 acres. Nearby towns include Mineral in Tehama Viola in Shasta County.
At the base of the Crags, a lake forms temporarily each year. Known as the Crags Lake or the Chaos Crater, it forms in a depression that acts as a basin to collect melted snow during the spring season; the lake has cool temperatures near the shores, grows colder near its center. It dries up by the end of August. Between 385,000 and 315,000 years ago, volcanic activity in the Lassen volcanic center shifted from building andesitic stratovolcanoes to producing lava domes made of dacite; these eruptions formed the Lassen dome field, staged as andesite lava flows surrounding two sequences of dacitic lava domes. The first sequence of lava domes, known as the Bumpass domes, formed between 300,000 and 190,000 years ago, while the production of the younger Eagle Peak domes began about 70,000 years ago; the andesite lava flows form the older and younger Twin Lakes sequences, date to between 315,000 and 240,000 years ago and between 90,000 years ago and present, respectively. Beginning 190,000 years ago, eruptions ceased in the Lassen Volcanic center for 100,000 years.
Dacitic magma at the Lassen center formed from mafic magma meeting silicic magma chambers with felsic phenocrysts. Some dacitic crystals were reabsorbed as a result of mixing of hot mafic magma with cool dacitic magma, this along with undercooling of mixed magma led to phenocryst variation within certain domes exceeding variation between the domes. All three sequences — Bumpass, Eagle Peak, Twin Lakes — formed from lava subjected to magma-mixing processes, accounting for their heterogeneous appearance and composition; because of these mixing mechanisms, lavas may have different compositions but similar appearances, or similar compositions with different appearances. The eruption that produced the Chaos Crags consisted of more than 90% mixed magma, resulted from the interaction of felsic and mafic magmas; the Eagle Peak sequence, which includes the Chaos Crags, consists of seven dacite and rhyodacite lava domes and lava flows, along with pyroclastic rock deposits. The Chaos Crags consist of five small lava domes, made of rhyodacite, which line up with the western edge of the Mount Tehama caldera.
The youngest part of the Lassen volcanic center's dome field and the youngest domes in the Eagle Peak sequence, they reach an elevation of about 1,800 feet above their surroundings. They lack a summit crater; the domes began forming about 1,100 years ago, beginning with vent-opening eruptions vigorous explosive eruptions of pumice and ash followed by effusive activity. This created unstable edifices that collapsed and formed pyroclastic flows, similar to the most recent eruptions at the Mono–Inyo Craters. Two of the pyroclastic flows were deposited as one unit, pumice fell to build a tuff cone at the northern edge of the Crags, while lava dome A formed and magma in the eruptive conduit cooled to plug the eruptive vent. Domes B through F followed in that order. Lasting from 1125 years ago to 1060 years ago, this eruptive phase resembled the Lassen Peak eruptions in May 1915, though the Chaos Crag eruption had a magnitude 100 times greater, with an output volume of 0.34 cubic miles. The eruptions created a cone made of tephra material, along with two pyroclastic flows, which had a volume of about 0.036 cubic miles.
Six domes were formed, though after 70 years of quiescence, one was destroyed by a violent eruption that produced a pyroclastic flow and teph
The brown trout is a European species of salmonid fish, introduced into suitable environments globally. It includes both purely freshwater populations, referred to as the riverine ecotype, Salmo trutta morpha fario, a lacustrine ecotype, S. trutta morpha lacustris called the lake trout, as well as anadromous forms known as the sea trout, S. trutta morpha trutta. The latter migrates to the oceans for much of its life and returns to fresh water only to spawn. Sea trout in the Ireland and Britain have many regional names: sewin in Wales, finnock in Scotland, peal in the West Country, mort in North West England, white trout in Ireland; the lacustrine morph of brown trout is most potamodromous, migrating from lakes into rivers or streams to spawn, although evidence indicates stocks spawn on wind-swept shorelines of lakes. S. trutta morpha fario forms stream-resident populations in alpine streams, but sometimes in larger rivers. Anadromous and nonanadromous morphs. What determines whether or not they migrate remains unknown.
The scientific name of the brown trout is Salmo trutta. The specific epithet trutta derives from the Latin trutta, meaning "trout". Behnke relates that the brown trout was the first species of trout described in the 1758 edition of Systema Naturae by Swedish zoologist Carl Linnaeus. Systema Naturae established the system of binomial nomenclature for animals. Salmo trutta was used to describe sea-run forms of brown trout. Linnaeus described two other brown trout species in 1758. Salmo fario was used for riverine forms. Salmo lacustris was used for lake-dwelling forms; the native range of brown trout extends from northern Norway and White Sea tributaries in Russia in the Arctic Ocean to the Atlas Mountains in North Africa. The western limit of their native range is Iceland in the north Atlantic, while the eastern limit is in Aral Sea tributaries in Afghanistan and Pakistan. Brown trout have been introduced into suitable environments around the world, including North and South America, Australasia and South and East Africa.
Introduced brown trout have established self-sustaining, wild populations in many introduced countries. The first introductions were in Australia in 1864 when 300 of 1500 brown trout eggs from the River Itchen survived a four-month voyage from Falmouth, Cornwall, to Melbourne on the sailing ship Norfolk. By 1866, 171 young brown trout were surviving in a Plenty River hatchery in Tasmania. Thirty-eight young trout were released in the river, a tributary of the River Derwent in 1866. By 1868, the Plenty River hosted a self-sustaining population of brown trout which became a brood source for continued introduction of brown trout into Australian and New Zealand rivers. Successful introductions into the Natal and Cape Provinces of South Africa took place in 1890 and 1892, respectively. By 1909, brown trout were established in the mountains of Kenya; the first introductions into the Himalayas in northern India took place in 1868, by 1900, brown trout were established in Kashmir and Madras. The first introductions in Canada occurred in 1883 in Newfoundland and continued up until 1933.
The only Canadian regions without brown trout are Northwest Territories. Introductions into South America began in 1904 in Argentina. Brown trout are now established in Chile and the Falklands. In the 1950s and 1960s, Edgar Albert de la Rue, a French geologist, began the introduction of several species of salmonids on the remote Kerguelen Islands in the southern Indian Ocean. Of the seven species introduced, only brook trout, Salvelinus fontinalis, brown trout survived to establish wild populations. Sea-run forms of brown trout exceeding 20 lb are caught by local anglers on a regular basis; the first introductions into the U. S. started in 1883 when Fred Mather, a New York pisciculturist and angler, under the authority of the U. S. Fish Commissioner, Spencer Baird, obtained brown trout eggs from a Baron Lucius von Behr, president of the German Fishing Society; the von Behr brown trout came from both mountain streams and large lakes in the Black Forest region of Baden-Württemberg. The original shipment of "von Behr" brown trout eggs were handled by three hatcheries, one on Long Island, the Cold Spring Hatchery operated by Mather, one in Caledonia, New York operated by pisciculturalist Seth Green, other hatchery in Northville, Michigan.
Additional shipments of "von Behr" brown trout eggs arrived in 1884. In 1885, brown trout eggs from Loch Leven, arrived in New York; these "Loch Leven" brown trout were distributed to the same hatcheries. Over the next few years, additional eggs from Scotland and Germany were shipped to U. S. hatcheries. Behnke believed all life forms of brown trout—anadromous and lacustrine—were imported into the U. S. and intermingled genetically to create what he calls the American generic brown trout and a single subspecies the North European brown trout. In April 1884, the U. S. Fish Commission released 4900 brown trout fry into the Baldwin River, a tributary of the Pere Marquette River in Michigan; this was the first release of brown trout into U. S. waters. Between 1884 and 1890, brown trout were introduced into suitable habitats throughout the U. S. By 1900, 38 states and two territories had received stocks of brown trout, their adaptability resulted in most of these introductions establishing wild, self-sustaining populations.
The fish is not considered to be endangered, although, in some cases, individual stocks are under various degrees of stress through habitat degradation and artificial propagation leading to introgression. Increased frequency of excessively warm water
A lake is an area filled with water, localized in a basin, surrounded by land, apart from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, therefore are distinct from lagoons, are larger and deeper than ponds, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which are flowing. Most lakes streams. Natural lakes are found in mountainous areas, rift zones, areas with ongoing glaciation. Other lakes are found along the courses of mature rivers. In some parts of the world there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will fill in with sediments or spill out of the basin containing them. Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, or for aesthetic, recreational purposes, or other activities.
The word lake comes from Middle English lake, from Old English lacu, from Proto-Germanic *lakō, from the Proto-Indo-European root *leǵ-. Cognates include Dutch laak, Middle Low German lāke as in: de:Wolfslake, de:Butterlake, German Lache, Icelandic lækur. Related are the English words leak and leach. There is considerable uncertainty about defining the difference between lakes and ponds, no current internationally accepted definition of either term across scientific disciplines or political boundaries exists. For example, limnologists have defined lakes as water bodies which are a larger version of a pond, which can have wave action on the shoreline or where wind-induced turbulence plays a major role in mixing the water column. None of these definitions excludes ponds and all are difficult to measure. For this reason, simple size-based definitions are used to separate ponds and lakes. Definitions for lake range in minimum sizes for a body of water from 2 hectares to 8 hectares. Charles Elton, one of the founders of ecology, regarded lakes as waterbodies of 40 hectares or more.
The term lake is used to describe a feature such as Lake Eyre, a dry basin most of the time but may become filled under seasonal conditions of heavy rainfall. In common usage, many lakes bear names ending with the word pond, a lesser number of names ending with lake are in quasi-technical fact, ponds. One textbook illustrates this point with the following: "In Newfoundland, for example every lake is called a pond, whereas in Wisconsin every pond is called a lake."One hydrology book proposes to define the term "lake" as a body of water with the following five characteristics: it or fills one or several basins connected by straits has the same water level in all parts it does not have regular intrusion of seawater a considerable portion of the sediment suspended in the water is captured by the basins the area measured at the mean water level exceeds an arbitrarily chosen threshold With the exception of the seawater intrusion criterion, the others have been accepted or elaborated upon by other hydrology publications.
The majority of lakes on Earth are freshwater, most lie in the Northern Hemisphere at higher latitudes. Canada, with a deranged drainage system has an estimated 31,752 lakes larger than 3 square kilometres and an unknown total number of lakes, but is estimated to be at least 2 million. Finland has larger, of which 56,000 are large. Most lakes have at least one natural outflow in the form of a river or stream, which maintain a lake's average level by allowing the drainage of excess water; some lakes do not have a natural outflow and lose water by evaporation or underground seepage or both. They are termed endorheic lakes. Many lakes are artificial and are constructed for hydro-electric power generation, aesthetic purposes, recreational purposes, industrial use, agricultural use or domestic water supply. Evidence of extraterrestrial lakes exists. Globally, lakes are outnumbered by ponds: of an estimated 304 million standing water bodies worldwide, 91% are 1 hectare or less in area. Small lakes are much more numerous than large lakes: in terms of area, one-third of the world's standing water is represented by lakes and ponds of 10 hectares or less.
However, large lakes account for much of the area of standing water with 122 large lakes of 1,000 square kilometres or more representing about 29% of the total global area of standing inland water. Hutchinson in 1957 published a monograph, regarded as a landmark discussion and classification of all major lake types, their origin, morphometric characteristics, distribution; as summarized and discussed by these researchers, Hutchinson presented in it a comprehensive analysis of the origin of lakes and proposed what is a accepted classification of lakes according to their origin. This