50-470: Sitkum Glacier is located on the west slopes of Glacier Peak in the U.S. state of Washington . As is true with all the glaciers found on Glacier Peak, Sitkum Glacier is retreating. Sitkum Glacier is immediately south of Scimitar Glacier . This article about a glacier in Washington is a stub . You can help Misplaced Pages by expanding it . Glacier Peak Glacier Peak or Dakobed (known in
100-497: A bridge crossing until it was flooded out by storms in late 2003. The first recorded person to climb the mountain was Thomas Gerdine, along with a group of United States Geological Survey scientists, Sam Strom, A. H. Dubor, and Darcy Bard, in 1897. The climb is Alpine Grade I or II. The easiest ski route is about 5 miles (8.0 km) of walking along the White Chuck River Trail (Forest Service Trail No. 643) and up
150-576: A high ridge, but its volcanic portion extends only 1,600–3,200 feet (500–1,000 m) above the underlying ridge. Another Cascade Arc volcano with similar geomorphology is the Mount Meager massif in southwestern British Columbia , Canada, which is situated on a 1,300 ft (400 m) ridge of nonvolcanic, crystalline and metamorphic rock . Of the five major volcanoes in Washington, only Glacier Peak and Mount St. Helens have had large eruptions in
200-755: A sequence of nine tephra eruptions occurred within a period of less than a few hundred years. Associated with these eruptions were pyroclastic flows. Mixed with snow, ice and water, these formed lahars that raced into three nearby rivers, filling their valleys with deep deposits. Subsequently, the mudflows drained into both the North Fork of the Stillaguamish River (at that time an outlet of the Sauk River ) and Skagit Rivers . In Arlington , 60 miles (97 km) downstream, lahars deposited seven feet of sediment. Subsequent erosion of lahar deposits near Darrington led to
250-639: A single buoyant jet of magma from the Earth's core instead of cracks in the ocean floor. This is reflected in the decreasing age of the islands east to west from Fuerteventura to El Hierro. There are about 60 volcanoes in Ethiopia, located in east Africa. In Southern Ethiopia, the Omo Kibish Rock Formation is composed of layers of tephra and sediment. Within these layers, several fossils have been discovered. In 1967, 2 Homo sapiens fossils were discovered in
300-448: A volcano explodes, biological organisms are killed and their remains are buried within the tephra layer. These fossils are later dated by scientists to determine the age of the fossil and its place within the geologic record. Tephra is any sized or composition pyroclastic material produced by an explosive volcanic eruption and precise geological definitions exist. It consists of a variety of materials, typically glassy particles formed by
350-464: A volcano explodes, it releases a variety of tephra including ash, cinders, and blocks. These layers settle on the land and, over time, sedimentation occurs incorporating these tephra layers into the geologic record. Tephrochronology is a geochronological technique that uses discrete layers of tephra—volcanic ash from a single eruption—to create a chronological framework in which paleoenvironmental or archaeological records can be placed. Often, when
400-477: Is a religious site for locals. It last erupted in 1903. In 2017, new fossil evidence was discovered that determined the date of Paektu Mountain's first eruption, which had been a mystery. A team of scientists directed by Dr. Clive Oppenheimer, British volcanologist , discovered a larch trunk embedded within Paektu Mountain. After radiocarbon dating, the larch was determined to be 264 years old which coincides with
450-461: Is over forty thousand years old and has erupted 11 times since 1800. In South America , there are several historic active volcanoes. In southern Chile , the Chaitén volcano erupted in 2011 adding 160 meters to its rim. Prehistoric weapons and tools, formed from obsidian tephra blocks, were dated at 5,610 years ago and were discovered 400 km away. Due to the location of the subduction zone of
500-453: Is part of a 980-foot-thick (300 m) concentration of past incidents at the volcano that spans the Dusty and Chocolate Creek . In the area at least 2.4 cubic miles (10 km ) of lithic debris are contained. Tephra deposits are for the most part constrained to the left flank of the volcano, and at least nine past incidents have been identified. These form several layers of tephra constructing
550-501: Is the fourth tallest peak in Washington state, and not as much is known about it compared to other volcanoes in the area. Local Native Americans have recognized Glacier Peak and other Washington volcanoes in their histories and stories. When American explorers reached the region, they learned basic information about surrounding landforms, but did not initially understand that Glacier Peak was a volcano. Positioned in Snohomish County ,
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#1733085261689600-574: Is used in broad context within an account by Aristotle of an eruption on Vulcano (Hiera) in Meteorologica . The release of tephra into the troposphere affects the environment physically and chemically. Physically, volcanic blocks damage local flora and human settlements. Ash damages communication and electrical systems, coats forests and plant life, reducing photosynthesis , and pollutes groundwater . Tephra changes below- and above-ground air and water movement. Chemically, tephra release can affect
650-519: The Canary Islands . The most recent El Hierro eruption occurred underwater, in 2011, and caused earthquakes and landslides throughout the Canary Islands. Instead of ash, floating rocks, 'restingolites' were released after every eruption. After the 2011 eruption, fossils of single-celled marine organisms were found in the restingolites verifying the origin theory that Canary Island growth comes from
700-498: The Omo Kibish Formation by Richard Leaky , a paleoanthropologist. After radiocarbon dating, they were determined to be 195 thousand years old. Other mammals discovered in the formation include Hylochoerus meinertzhageni (forest hog) and Cephalophus (antelope). In Asia, several volcanic eruptions are still influencing local cultures today. In North Korea, Paektu Mountain , a stratovolcano, first erupted in 946 AD and
750-467: The Pleistocene epoch, about one million years ago, and since the most recent ice age , it has produced some of the largest and most explosive eruptions in the state. When continental ice sheets retreated from the region, Glacier Peak began to erupt regularly, erupting explosively five times in the past 3,000 years. It has erupted repeatedly during at least six periods; two of these eruptions have been among
800-627: The Roman culture. Also, in Italy, Stromboli volcano , a stratovolcano, last erupted in July 2019. Several volcanic eruptions have been studied in North America . On 18 May 1980, Mount St. Helens , a stratovolcano in Washington state , erupted, spreading five hundred million tons of tephra ash across Washington, Oregon, Montana and Idaho causing earthquakes , rockslides , and megatsunami which severely altered
850-564: The USGS applied to add four more stations, but regulations protecting federal wilderness areas prohibit the use of helicopters that are needed to transport materials; advocacy groups opposed an exemption for the project and filed objections. In 2019, Congress passed the National Volcano Early Warning and Monitoring System Act to authorize more monitoring stations, but did not include funding to construct them. Permits were granted by
900-527: The water cycle . Tephra particles can cause ice crystals to grow in clouds, which increases precipitation . Nearby watersheds and the ocean can experience elevated mineral levels, especially iron , which can cause explosive population growth in plankton communities. This, in turn, can result in eutrophication . In addition to tephrochronology, tephra is used by a variety of scientific disciplines including geology , paleoecology , anthropology , and paleontology , to date fossils, identify dates within
950-578: The 18 most dangerous volcanoes in the United States. When lahars reach populated areas, they can bury structures and people. An example was the Armero tragedy at Nevado del Ruiz where 23,000 died from an enormous mudflow. Lahars from Glacier Peak pose a similar threat to the small communities of Darrington, Arlington, and Concrete with a lesser threat to the larger and rapidly growing towns of Mount Vernon and Burlington , as well as other communities along
1000-481: The 1870s–1890s, searching for resources and rich land. The first white man recorded to observe the mountain—Daniel Lindsley—was an employee of the Northern Pacific Railroad Company searching for possible railroad routes when he saw it in 1870. Despite its elevation of 10,541 feet (3,213 m), Glacier Peak is a small stratovolcano. Its relatively high summit is a consequence of its location atop
1050-590: The 946 AD eruption. Its tree rings are being studied and many new discoveries are being made about North Korea during that time. In northeastern China, a large volcanic eruption in the early Cretaceous caused the fossilization of an entire ecosystem known as the Jehol Biota when powerful pyroclastic flows inundated the area. The deposits include many perfectly preserved fossils of dinosaurs , birds , mammals , reptiles , fish , frogs , plants , and insects . Europe's volcanoes provide unique information about
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#17330852616891100-880: The Sauk-Suiattle dialect of the Lushootseed language as "Tda-ko-buh-ba" or "Takobia" ) is the most isolated of the five major stratovolcanoes (composite volcanoes) of the Cascade Volcanic Arc in the U.S state of Washington . Located in the Glacier Peak Wilderness in Mount Baker–Snoqualmie National Forest , the volcano is visible from the west in Seattle , and from the north in the higher areas of eastern suburbs of Vancouver such as Coquitlam , New Westminster and Port Coquitlam . The volcano
1150-561: The Sitkum Glacier. The trail is reached via Forest Service Road No. 23. The Sitkum Glacier ski route is rated blue to black diamond for both the ascent and the descent. The Seattle-based composer, Alan Hovhaness , dedicated his Symphony no.66 as "Hymn to Glacier Peak": see Symphony no.66 (Hovhaness) . The non-fiction book Encounters with the Archdruid by John McPhee, which portrays the environmental advocacy of David Brower , devotes
1200-563: The U.S. Forest Service in June 2022. Eleven significant glaciers cover Glacier Peak. When C.E. Rusk first saw these glaciers in 1906 they were beginning to retreat, but were still very advanced. The average retreat of Glacier Peak glaciers from the Little Ice Age to the 1958 positions was 5,381 feet (1,640 m). Richard Hubley noted that North Cascade glaciers began to advance in the early 1950s, after 30 years of rapid retreat. The advance
1250-451: The area were mapped, Glacier Peak was left out. In 1850 natives mentioned the volcano to naturalist George Gibbs saying that the volcano had once "smoked". In 1898 the volcano was finally documented on a map. Native Americans also used the area around the Cascades for their agriculture, leading them to often congregate in the region. As a result, gold miners eventually reached the area in
1300-481: The average retreat of eight Glacier Peak glaciers from their recent maximum positions was 1,017 feet (310 m). Milk Lake Glacier, on the north flank of the mountain, melted away altogether in the 1990s. The Pacific Crest Trail passes near Glacier Peak. The Suiattle River crossing is a well-known feature on the Pacific Crest Trail (PCT) as it passes through the area. The Suiattle PCT crossing used to have
1350-499: The cooling of droplets of magma , which may be vesicular, solid or flake-like, and a varying proportions of crystalline and mineral components originating from the mountain and the walls of the vent. As the particles fall to the ground, they are sorted to a certain extent by the wind and gravitational forces and form layers of unconsolidated material. The particles are further moved by ground surface or submarine water flow. The distribution of tephra following an eruption usually involves
1400-711: The current river system with the Stillaguamish River separated from the Sauk/Skagit Rivers. Lahar debris was deposited along both the Skagit and Stillaguamish Rivers all the way to Puget Sound . A small portion of the erupted tephra was deposited locally. However, most of the tephra reached higher levels of the atmosphere, and was transported by the wind hundreds of miles. Deposits from this congregation were as thick as 1 foot (0.30 m) near Chelan and 0.3 inches (7.6 mm) near Missoula, Montana . The table below shows
1450-466: The eastern Pacific's Nazca Plate, there are twenty one active volcanoes in southern Peru . In 2006, fossils, found under a layer of volcanic ash in Peru, were excavated by a team of paleontologists led by Mark D. Uhen, professor at George Mason University. The fossils were identified as 3 different types of archaeocetes, prehistoric whales, and are older than 36.61 million years which, as of 2011, makes them
1500-449: The first of its three main sections to a conflict over mineral prospecting around Glacier Peak. 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 remain as tephra unless hot enough to fuse into pyroclastic rock or tuff . When
1550-499: The fossils record, and learn about prehistoric cultures and ecosystems. For example, carbonatite tephra found at Oldoinyo Lengai (a volcano in the East African Rift Valley) has buried and preserved fossilized footprints of humans near the site of the eruption. Under certain conditions, volcanic blocks can be preserved for billions of years and can travel up to 400 km away from the eruption. Volcanic eruptions around
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1600-485: The history of Italy . One example is Mount Vesuvius , a stratovolcano located in southern Italy, which last erupted in March 1944. Earlier, in 79 AD, in an eruption which lasted 12 to 18 hours, Vesuvius had covered the city of Pompeii in molten lava, ash, pumice, volcanic blocks, and toxic gases. Much of the town was preserved and organic materials fossilized by the volcanic ash, and that has provided valuable information about
1650-467: The largest boulders falling to the ground quickest, therefore closest to the vent, while smaller fragments travel further – ash can often travel for thousands of miles, even circumglobal, as it can stay in the stratosphere for days to weeks following an eruption. When large amounts of tephra accumulate in the atmosphere from massive volcanic eruptions (or from a multitude of smaller eruptions occurring simultaneously), they can reflect light and heat from
1700-399: The largest in Washington. Remnants of past (prehistoric) lava domes are main components of the summit of the volcano, in addition to its false summit, Disappointment Peak. Past pyroclastic flow deposits are easily visible in river valleys near the volcano, likely caused by lava dome collapse, along with ridges found east of the summit consisting of ash cloud remains. On its western flank,
1750-548: The lower Skagit and Stillaguamish Rivers. A 2005 study conducted by the United States Geological Survey identified nine Cascade volcanoes, including Glacier Peak, as "very-high-threat volcanoes with inadequate monitoring". At the time of the study, only one seismometer was installed on Glacier Peak that had not "worked in two years". As of 2023 , the PNSN still operates only one seismometer on Glacier Peak. In 2018,
1800-458: The mountain. Smaller eruptions involving tephra occurred between 6,900 and 5,500 years ago, again between 3,450 and 200 years ago, and as recently as 316 to 90 years ago. On the mountain, about 5,900 ft (1,800 m) up, are three additional cinder cones — one at the head of White Chuck River , one at Dishpan Gap , and one near Indian Pass. The volcano has also created thermal features such as hot springs . There were three hot springs on
1850-568: The mountain: Gamma, Kennedy, and Sulphur, but Kennedy Hot Springs was destroyed and buried in a slide. The volcano is located in Washington , and is one of the five major stratovolcanoes there. Situated in the Cascade Volcanic Arc , the volcano was created by subduction of the oceanic Juan de Fuca Plate under the North American Plate . Convergence between the two continues at a rate of 1.6 inches (4 cm) per year. This range has been volcanically active for about 36 million years, and
1900-561: The past 15,000 years. Since both volcanoes generate magma of dacitic origin, the viscous magma builds up since it cannot flow through the eruptive vent. Gradually, the pressure grows, culminating in an explosion that ejects materials such as tephra , which in its simplest form, is ash . Tephrochronology and radiocarbon dating indicate that Glacier Peak eruptions occurred in 1700 AD ± 100 years, 1300 AD ± 300 years, 900 AD ± 50 years, 200 AD ± 50 years, 850 BC, 3150 BC, and in 3550 BC. The Volcanic Explosivity Index (VEI) for three of these
1950-563: The rocks that make up its volcanoes are between 55 and 42 million years old. Eruptions within the range are irregular and do not occur all at once. In an attempt to organize the volcanoes by age, scientists typically divide them into the High Cascades, younger volcanoes, and the Western Cascades, consisting of the older volcanoes. However, the vents in Washington are all of different ages so none of its volcanoes are included in either of
2000-413: The sections. Around the area, there were many Native Americans, and along with other Washington volcanoes, the mountain was recognized by them as a spirit. When European-American explorers reached the area, they learned about the mountain, though only partially, through local legends. Although the local people described Glacier Peak as a vital part of their storytelling and beliefs, when other volcanoes in
2050-592: The size of the eruption. Tephra fragments are classified by size: The use of tephra layers, which bear their own unique chemistry and character, as temporal marker horizons in archaeological and geological sites, is known as tephrochronology . The word "tephra" and "pyroclast" both derive from Greek : The word τέφρα ( téphra ) means "ash", while pyroclast is derived from the Greek πῦρ ( pyr ), meaning "fire", and κλαστός ( klastós ), meaning "broken in pieces". The word τέφραv (means "ashes")
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2100-404: The sun back through the atmosphere, in some cases causing the temperature to drop, resulting in a temporary " volcanic winter ". The effects of acidic rain and snow, the precipitation caused by tephra discharges into the atmosphere, can be seen for years after the eruptions have stopped. Tephra eruptions can affect ecosystems across millions of square kilometres or even entire continents depending on
2150-476: The three largest eruptions from this sequence. Since these events, Glacier Peak has produced several lahars. The largest mudflows were 5,900 and 1,800 years ago and were associated with dome-building eruptions. In both cases, the lahars traveled down the Skagit River to Puget Sound. The risk of an eruption in any given year is currently estimated as 1 in 1,000. As of 2018 , Glacier Peak is classified as one of
2200-524: The topography of nearby areas. In Yellowstone National Park , eruption-related flooding caused trees to collapse and wash into lake beds where they fossilized. Nearby forests were flooded, removing bark, leaves, and tree limbs. In 2006, the Augustine Volcano in Alaska erupted generating earthquakes, avalanches , and projected tephra ash approximately two hundred and ninety kilometers away. This dome volcano
2250-558: The volcano also has a lahar , or mudflow deposit, which runs for about 22 miles (35 km) into the White Chuck River Valley around 14,000 years ago. Ten other pyroclastic flow deposits are visible, all identified as relatively 10,000 years old. There is also a considerably newer mudflow, about 5,500 years old, which covers an area of 9.3 mi (15 km) between the same river valley, along with two small incidents both under 3,000 years old. Another lahar, of unidentified age,
2300-433: The volcano is only 70 miles (110 km) northeast of downtown Seattle. From locations in northern Seattle and northward, Glacier Peak is closer than the more famous Mount Rainier (Tahoma), but as Glacier Peak is set farther into the Cascades and almost 4,000 feet (1,200 m) shorter, it is much less noticeable than Mount Rainier. Glacier Peak is one of the most active of Washington's volcanoes. The volcano formed during
2350-400: The world have provided valuable scientific information on local ecosystems and ancient cultures. The Waw an Namus volcano is surrounded by an apron of dark tephra, which has a notable color contrast to the surrounding Sahara Desert . Africa's volcanoes have had an impact on the fossil record. Geographically a part of Africa, El Hierro is a shield volcano and the youngest and smallest of
2400-435: Was 2 to 4, small compared to the 5 of the 1980 eruption of Mount St. Helens . They were characterized mainly by a central vent eruption, followed by an explosive eruption. These eruptions varied in outcome; some produced lahars , some pyroclastic flows , and others lava domes . The volcano has had one eruption with a VEI of 2, one with a VEI of 4, and possibly another with a VEI of 3. A little more than 13,000 years ago,
2450-493: Was in response to a sharp rise in winter precipitation and a decline in summer temperature beginning in 1944. Ten of the fifteen glaciers around Glacier Peak advanced, including all of the glaciers directly on the mountain's slopes. Advances of Glacier Peak glaciers ranged from 50 to 1,575 feet (15 to 480 m) and culminated in 1978. All eleven Glacier Peak glaciers that advanced during the 1950–79 period emplaced identifiable maximum advance terminal moraines. From 1984 to 2005,
2500-573: Was rich in oxyhornblende dacite ; and continued for 30 km (19 mi) into the Sauk River . There are also ash cloud deposits on the opposite eastern flank of the volcano. Studies of the mountain have to date been unable to find any correspondence with pyroclastic flows, but several past mudflows have been identified. In the Dusty Creek, located by the mountain, there is a lahar at least 98 ft (30 m) thick, containing pyroclastic flow deposits and other mudflows. However, this large mudflow
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