what are the ages of volcanic arc volcanoes relative to each other

Chain of stratovolcanoes in western North America

This article is for the volcanic arc. For the namesake mount range see Cascade Range.

Cascades Volcanoes
Mount Rainier from the northeast
Geography
Location	California, Oregon, and Washington, The states, and British Columbia, Canada

The Pour Volcanoes (as well 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 California, a distance of well over 700 miles (1,100 km). The arc formed due to subduction along the Cascadia subduction zone. Although taking its proper name from the Cascade Range, this term is a geologic grouping rather than a geographic one, and the Pour Volcanoes extend north into the Coast Mountains, by the Fraser River which is the northward limit of the Pour Range proper.

Some of the major cities along the length of the arc include Portland, Seattle, and Vancouver, and the population in the region exceeds ten one thousand thousand. All could be potentially affected past volcanic activeness and bang-up subduction-zone earthquakes forth the arc. Because the population of the Pacific Northwest is chop-chop increasing, the Cascade volcanoes are some of the most unsafe, due to their eruptive history and potential for future eruptions, and because they are underlain by weak, hydrothermally altered volcanic rocks that are susceptible to failure. Consequently, Mount Rainier is one of the Decade Volcanoes identified by the International Clan of Volcanology and Chemistry of the Earth'due south Interior (IAVCEI) as existence worthy of detail study, due to the danger it poses to Seattle and Tacoma. Many large, long-runout landslides originating on Cascade volcanoes take engulfed valleys tens of kilometers from their sources, and some of the areas affected at present support large populations.

The Cascade Volcanoes are part of the Pacific Ring of Burn down, the ring of volcanoes and associated mountains around the Pacific Ocean. The Cascade Volcanoes have erupted several times in recorded history. Two most recent were Lassen Peak in 1914 to 1921 and a major eruption of Mountain St. Helens in 1980. Information technology is also the site of Canada's most contempo major eruption most 2,350 years ago at the Mount Meager massif.^[1]

Geology [edit]

The Cascade Arc includes nearly 20 major volcanoes, amid a full of over 4,000 separate volcanic vents including numerous stratovolcanoes, shield volcanoes, lava domes, and cinder cones, along with a few isolated examples of rarer volcanic forms such as tuyas. Volcanism in the arc began about 37 million years ago; however, most of the nowadays-day Cascade volcanoes are less than ii,000,000 years old, and the highest peaks are less than 100,000 years former. Twelve volcanoes in the arc are over 10,000 feet (3,000 m) in meridian, and the two highest, Mount Rainier and Mount Shasta, exceed 14,000 anxiety (four,300 m). Past volume, the 2 largest Cascade volcanoes are the broad shields of Medicine Lake Volcano and Newberry Volcano, which are about 145 cubic miles (600 km^three) and 108 cubic miles (450 kmⁱⁱⁱ) respectively. Glacier Pinnacle is the simply Cascade volcano that is made exclusively of dacite.

Over the last 37 million years, the Cascade Arc has been erupting a chain of volcanoes along the Pacific Northwest.^[ii] Several of the volcanoes in the arc are oft active. The volcanoes of the Cascade Arc share some full general characteristics, just each has its own unique geological traits and history. Lassen Acme in California, which last erupted in 1917, is the southernmost historically active volcano in the arc, while the Mount Meager massif in British Columbia, which erupted nearly two,350 years agone, is by and large considered the northernmost fellow member of the arc. A few isolated volcanic centers northwest of the Mount Meager massif such as the Silverthrone Caldera, which is a circular 20 km (12 mi) wide, deeply dissected caldera complex, may also be the product of Cascadia subduction considering the igneous rocks andesite, basaltic andesite, dacite and rhyolite tin also exist found at these volcanoes as they are elsewhere along the subduction zone.^{[3] [4]} At issue are the current estimates of plate configuration and charge per unit of subduction, but based on the chemical science of these volcanoes, they are also subduction related and therefore part of the Cascade Volcanic Arc.^{[five] [six]} The Pour Volcanic Arc appears to exist segmented; the central portion of the arc is the nearly active and the northern cease least active.

Lavas representing the earliest stage in the development of the Pour Volcanic Arc by and large crop out s of the North Cascades proper, where uplift of the Cascade Range has been less, and a thicker blanket of Cascade Arc volcanic rocks has been preserved. In the Due north Cascades, geologists have not yet identified with any certainty whatever volcanic rocks as old as 35 million years, but remnants of the ancient arc's internal plumbing system persist in the form of plutons, which are the crystallized magma chambers that one time fed the early Pour volcanoes. The greatest mass of exposed Cascade Arc plumbing is the Chilliwack batholith, which makes up much of the northern part of North Cascades National Park and next parts of British Columbia beyond. Individual plutons range in historic period from about 35 one thousand thousand years old to 2.5 million years old. The older rocks invaded by all this magma were affected by the rut.

Around the plutons of the batholith, the older rocks recrystallized. This contact metamorphism produced a fine mesh of interlocking crystals in the sometime rocks, generally strengthening them and making them more resistant to erosion. Where the recrystallization was intense, the rocks took on a new appearance dark, dense and hard. Many rugged peaks in the N Cascades owe their prominence to this baking. The rocks holding up many such Northward Pour giants, as Mountain Shuksan, Mountain Redoubt, Mount Challenger, and Mount Hozomeen, are all partly recrystallized by plutons of the nearby and underlying Chilliwack batholith.

The Garibaldi Volcanic Belt is the northern extension of the Cascade Arc. Volcanoes within the volcanic chugalug are mostly stratovolcanoes along with the residue of the arc, but also include calderas, cinder cones, and minor isolated lava masses. The eruption styles inside the chugalug range from effusive to explosive, with compositions from basalt to rhyolite. Due to repeated continental and alpine glaciations, many of the volcanic deposits in the belt reflect complex interactions between magma limerick, topography, and changing ice configurations. Four volcanoes within the belt appear related to seismic activity since 1975, including: Mount Meager massif, Mount Garibaldi and Mountain Cayley massif.

The Pemberton Volcanic Belt is an eroded volcanic belt northward of the Garibaldi Volcanic Belt, which appears to take formed during the Miocene before fracturing of the northern finish of the Juan de Fuca Plate. The Silverthrone Caldera is the only volcano inside the belt that appears related to seismic activity since 1975.

The Mount Meager massif is the most unstable volcanic massif in Canada. It has dumped dirt and rock several meters deep into the Pemberton Valley at least iii times during the past 7,300 years. Contempo drilling into the Pemberton Valley bed encountered remnants of a debris menstruation that had traveled 50 km (31 mi) from the volcano shortly before it last erupted 2,350 years ago. About i,000,000,000 cubic metres (0.24 cu mi) of stone and sand extended over the width of the valley. Two previous debris flows, about four,450 and 7,300 years ago, sent debris at least 32 km (xx mi) from the volcano. Recently, the volcano has created smaller landslides about every 10 years, including one in 1975 that killed four geologists near Meager Creek. The possibility of the Mount Meager massif roofing stable sections of the Pemberton Valley in a debris menses is estimated at 1 in ii,400 years. There is no sign of volcanic activity with these events. However scientists warn the volcano could release some other massive debris catamenia over populated areas any time without warning.

In the past, Mount Rainier has had large droppings avalanches, and has also produced enormous lahars due to the large amount of glacial ice present. Its lahars have reached all the style to Puget Audio. Around 5,000 years ago, a large clamper of the volcano slid abroad and that debris avalanche helped to produce the massive Osceola Mudflow, which went all the style to the site of nowadays-day Tacoma and due south Seattle. This massive barrage of rock and ice took out the tiptop 1,600 feet (490 m) of Rainier, bringing its height down to effectually 14,100 feet (4,300 m). About 530 to 550 years agone, the Electron Mudflow occurred, although this was not as big-scale every bit the Osceola Mudflow.

While the Cascade volcanic arc (a geological term) includes volcanoes such as the Mount Meager massif and Mount Garibaldi, which lie north of the Fraser River, the Pour Range (a geographic term) is considered to take its northern purlieus at the Fraser.

Human history [edit]

Major Cascade volcano eruptions in the last 4000 years

Native Americans have inhabited the area for thousands of years and developed their ain myths and legends apropos the Cascade volcanoes. Co-ordinate to some of these tales, Mounts Bakery, Jefferson, Shasta and Garibaldi were used as refuge from a nifty flood. Other stories, such equally the Bridge of the Gods tale, had various High Cascades such as Hood and Adams, human action as god-like chiefs who made state of war by throwing fire and stone at each other. St. Helens with its pre-1980 svelte appearance, was regaled as a beautiful maiden for whom Hood and Adams feuded. Among the many stories concerning Mount Baker, ane tells that the volcano was formerly married to Mount Rainier and lived in that vicinity. Then, because of a marital dispute, she picked herself upwardly and marched north to her present position. Native tribes also adult their ain names for the High Cascades and many of the smaller peaks, the about well known to non-natives being Tahoma, the Lushootseed name for Mountain Rainier. Mount Cayley and The Black Tusk are known to the Squamish people who live nearby equally "the Landing Place of the Thunderbird".

Hot springs in the Canadian side of the arc, were originally used and revered by First Nations people. The springs located on Meager Creek are called Teiq ^[vii] in the linguistic communication of the Lillooet people and were the farthest up the Lillooet River. The spirit-beings/wizards known equally "the Transformers" reached them during their journeying into the Lillooet Land, and were a "grooming" place for young First Nations men to larn ability and knowledge. In this area, as well, was establish the blackstone chief'southward caput pipe that is famous of Lillooet artifacts; institute buried in volcanic ash, ane supposes from the 2350 BP eruption of the Mountain Meager massif.

Legends associated with the great volcanoes are many, besides equally with other peaks and geographical features of the arc, including its many hot springs and waterfalls and rock towers and other formations. Stories of Tahoma – today Mount Rainier and the namesake of Tacoma, Washington – allude to great, hidden grottos with sleeping giants, apparitions and other marvels in the volcanoes of Washington, and Mount Shasta in California has long been well known for its associations with everything from Lemurians to aliens to elves and, as everywhere in the arc, Sasquatch or Bigfoot.

Cascadia earthquake sources

In the spring of 1792 British navigator George Vancouver entered Puget Sound and started to give English names to the high mountains he saw. Mount Baker was named for Vancouver's third lieutenant, the graceful Mountain St. Helens for a famous diplomat, Mountain Hood was named in honor of Samuel Hood, 1st Viscount Hood (an admiral of the Royal Navy) and the tallest Cascade, Mountain Rainier, is the namesake of Admiral Peter Rainier. Vancouver's expedition did non, however, name the arc these peaks belonged to. Every bit marine trade in the Strait of Georgia and Puget Sound proceeded in the 1790s and beyond, the summits of Rainier and Baker became familiar to captains and crews (more often than not British and American over all others, but not exclusively).

With the exception of the 1915 eruption of remote Lassen Peak in Northern California, the arc was tranquillity for more than a century. Then, on May 18, 1980, the dramatic eruption of little-known Mount St. Helens shattered the repose and brought the world'southward attending to the arc. Geologists were also concerned that the St. Helens eruption was a sign that long-fallow Pour volcanoes might become agile once more, as in the menstruum from 1800 to 1857 when a total of eight erupted. None have erupted since St. Helens, but precautions are being taken still, such every bit the Mount Rainier Volcano Lahar Warning System in Pierce County, Washington.^[8]

Cascadia subduction zone [edit]

The Cascade Volcanoes were formed by the subduction of the Juan de Fuca, Explorer and the Gorda Plate (remnants of the much larger Farallon Plate) nether the North American Plate forth the Cascadia subduction zone. This is a 680-mile (1,090 km) long error, running l miles (80 km) off the coast of the Pacific Northwest from northern California to Vancouver Island, British Columbia. The plates move at a relative rate of over 0.4 inches (10 mm) per year at a somewhat oblique angle to the subduction zone.

Because of the very large fault area, the Cascadia subduction zone can produce very large earthquakes, magnitude 9.0 or greater, if rupture occurred over its whole area. When the "locked" zone stores upwardly energy for an earthquake, the "transition" zone, although somewhat plastic, can rupture. Thermal and deformation studies indicate that the locked zone is fully locked for threescore km (37 mi) downdip from the deformation front end. Further downdip, there is a transition from fully locked to aseismic sliding.

Unlike most subduction zones worldwide, there is no oceanic trench present forth the continental margin in Cascadia.^[ix] Instead, terranes and the accretionary wedge take been uplifted to grade a series of coast ranges and exotic mountains. A high rate of sedimentation from the outflow of the 3 major rivers (Fraser River, Columbia River, and Klamath River) which cantankerous the Pour Range contributes to farther obscuring the presence of a trench. Even so, in mutual with nigh other subduction zones, the outer margin is slowly being compressed, like to a giant spring. When the stored free energy is of a sudden released by slippage across the fault at irregular intervals, the Cascadia subduction zone tin can create very large earthquakes such equally the Thousand_w  8.7–9.ii Cascadia earthquake of 1700.

Major catastrophic eruptions [edit]

1980 Eruption of Mountain St. Helens [edit]

The 1980 eruption of Mount St. Helens was ane of the nigh closely studied volcanic eruptions in the arc and i of the best studied ever. It was a Plinian style eruption with a VEI=v and was the almost significant to occur in the lower 48 U.Due south. states in recorded history. An earthquake at 8:32 a.chiliad. on May xviii, 1980, caused the unabridged weakened north confront to slide abroad. An ash column rose fifteen miles into the atmosphere and deposited ash in 11 U.S. states. The eruption killed 57 people and thousands of animals and caused more than a billion U.S. dollars in damage.

1914–1917 Eruptions of Lassen Height [edit]

On May 22, 1915, an explosive eruption at Lassen Acme devastated nearby areas and rained volcanic ash as far abroad every bit 200 miles (320 km) to the east.^[ten] A huge column of volcanic ash and gas rose more than than 30,000 anxiety (9,100 thou) into the air and was visible from every bit far away as Eureka, California, 150 miles (240 km) to the west. A pyroclastic menstruum swept down the side of the volcano, devastating a 3-square-mile (7.8 kmⁱⁱ) area. This explosion was the nigh powerful in a 1914–1917 serial of eruptions at Lassen Peak.^[10]

2350 BP (400 BC) Eruption of the Mountain Meager massif [edit]

The Mount Meager massif produced the most contempo major eruption in Canada, sending ash as far abroad as Alberta.^[11] The eruption was similar to the 1980 eruption of Mount St. Helens, sending an ash column approximately twenty km (12 mi) loftier into the stratosphere.^[11] This activeness produced a diverse sequence of volcanic deposits, well exposed in the bluffs along the Lillooet River, which is defined as the Pebble Creek Germination.^[12] The eruption was episodic, occurring from a vent on the north-east side of Plinth Peak.^[7] An unusual, thick apron of welded vitrophyric breccia may represent the explosive collapse of an early lava dome, depositing ash several meters (a dozen or so feet) in thickness near the vent expanse.^[12]

7700 BP (5750 BC) Eruption of Mount Mazama [edit]

The 7,700 BP eruption of Mountain Mazama was a large catastrophic eruption in the U.South. state of Oregon. It began with a large eruption column with pumice and ash that erupted from a unmarried vent. The eruption was so smashing that most of Mount Mazama collapsed to form a caldera and subsequent smaller eruptions occurred as h2o began to fill in the caldera to form Crater Lake. Volcanic ash from the eruption was carried across most of the Pacific Northwest besides as parts of southern Canada.

13100 BP (11,150 BC) Eruption of Glacier Peak [edit]

Near xiii,000 years ago, Glacier Peak generated an unusually strong sequence of eruptions depositing volcanic ash as far abroad as Wyoming.^[13]

Other eruptions [edit]

Silverthrone Caldera [edit]

Most of the Silverthrone Caldera's eruptions in the Pacific Range occurred during the Last Glacial Period and was episodically active during both Pemberton and Garibaldi Volcanic Chugalug stages of volcanism. The caldera is one of the largest of the few calderas in western Canada, measuring about 30 kilometres (19 mi) long (n-southward) and twenty kilometres (12 mi) wide (east-w).^[14] The concluding eruption from Mountain Silverthrone ran upwardly against ice in Chernaud Creek. The lava was dammed by the ice and made a cliff with a waterfall upward confronting information technology. The most recent activity was 1000 years ago.

Mount Garibaldi [edit]

Mountain Garibaldi in the Pacific Range was terminal agile near 10,700 to 9,300 years ago from a cinder cone called Opal Cone. Information technology produced a 15 km (9.3 mi) long broad dacite lava flow with prominent wrinkled ridges. The lava menstruation is unusually long for a silicic lava flow.

Mount Bakery [edit]

Panorama from the northwest of Mount Baker and the Black Buttes

During the mid-19th century, Mount Baker erupted for the kickoff fourth dimension in several thousand years. Fumarole action remains in Sherman Crater, just south of the volcano's summit, became more intense in 1975 and is nonetheless energetic. However, an eruption is non expected in the near future.^[13]

Glacier Peak [edit]

Glacier Peak last erupted about 200–300 years ago and has erupted about six times in the by 4,000 years.^[13]

Mount Rainier [edit]

Mount Rainier last erupted betwixt 1824 and 1854, but many eyewitnesses reported eruptive action in 1858, 1870, 1879, 1882, and in 1894 too. Mount Rainier has created at least four eruptions and many lahars in the past 4,000 years.^[13]

Mount Adams [edit]

Mount Adams was last agile near 1,000 years ago and has created few eruptions during the past several thousand years, resulting in several major lava flows, the most notable being the A. G. Aiken Lava Bed, the Muddy Fork Lava Flows, and the Takh Takh Lava Flow. 1 of the most recent flows issued from South Butte created the four.5-mile (7.2 km) long by 0.5-mile (0.80 km) wide A.Grand. Aiken Lava Bed. Thermal anomalies (hot spots) and gas emissions (including hydrogen sulfide) have occurred especially on the height plateau since the Swell Slide of 1921.^[13]

Mount Hood [edit]

Mount Hood was terminal active about 200 years ago, creating pyroclastic flows, lahars, and a well-known lava dome shut to its superlative called Crater Rock. Between 1856 and 1865, a sequence of steam explosions took place at Mount Hood.^[13]

Newberry Volcano [edit]

A great deal of volcanic activity has occurred at Newberry Volcano, which was last active about 1,300 years ago. It has 1 of the largest collections of cinder cones, lava domes, lava flows and fissures in the world.^[13]

Medicine Lake Volcano [edit]

Medicine Lake Volcano has erupted virtually eight times in the by 4,000 years and was last active about 1,000 years ago when rhyolite and dacite erupted at Glass Mountain and associated vents near the caldera's eastern rim.^[13]

Mountain Shasta [edit]

Mount Shasta last erupted around 1250^[fifteen] and has been the nigh active volcano in California for well-nigh iv,000 years.^[13] Previous claims of a 1786 eruption take been discredited.^[xvi]

Eruptions in the Pour Range [edit]

Eleven of the thirteen volcanoes in the Cascade Range have erupted at to the lowest degree once in the past 4,000 years, and seven accept done so in just the past 200 years.^[13] The Cascade volcanoes have had more than 100 eruptions over the past few chiliad years, many of them explosive eruptions.^[xiii] However, certain Cascade volcanoes can exist dormant for hundreds or thousands of years between eruptions, and therefore the bully risk caused past volcanic activity in the regions is non always readily credible.

When Cascade volcanoes exercise erupt, pyroclastic flows, lava flows, and landslides tin can devastate areas more than than ten miles (16 km) away; and huge mudflows of volcanic ash and debris, called lahars, can inundate valleys more than than 50 miles (lxxx km) downstream. Falling ash from explosive eruptions can disrupt human being activities hundreds of miles downwind, and drifting clouds of fine ash tin cause severe damage to jet shipping even thousands of miles away.

All of the known historical eruptions accept occurred in Washington, Oregon and in Northern California. The two nearly recent were Lassen Superlative in 1914 to 1921 and a major eruption of Mount St. Helens in 1980. Small eruptions of Mount St. Helens have also occurred, most recently in 2008.^[17] In dissimilarity, volcanoes in southern British Columbia, cardinal and southern Oregon are currently dormant. The regions lacking new eruptions keep in bear upon to positions of fracture zones that beginning the Gorda Ridge, Explorer Ridge and the Juan de Fuca Ridge. The volcanoes with historical eruptions include: Mountain Rainier, Glacier Peak, Mount Baker, Mountain Hood, Lassen Peak, and Mount Shasta.

Renewed volcanic activity in the Cascade Arc, such as the 1980 eruption of Mount St. Helens, has offered a neat deal of evidence about the construction of the Cascade Arc. Ane effect of the 1980 eruption was a greater knowledge of the influence of landslides and volcanic evolution in the evolution of volcanic terrain. A vast piece on the north side of Mount St. Helens dropped and formed a jumbled landslide surroundings several kilometers away from the volcano. Pyroclastic flows and lahars moved beyond the countryside. Parallel episodes have also happened at Mount Shasta and other Cascade volcanoes in prehistoric times.

List of volcanoes [edit]

Washington has a majority of the very highest volcanoes, with 4 of the top 6 overall, although Oregon does concur a bulk of the side by side highest peaks. Even though Mount Rainier is the tallest, it is not the largest past volume. Mountain Shasta in California is the largest by volume, followed by Washington's Mount Adams. Mount Rainier is thus the 3rd largest by eruptive volume. Below is a list of the highest Cascade volcanoes:

Name	Elevation		Country/Province	Location	Last eruption
	anxiety	meters		Coordinates
Mount Rainier	14,411	4,392	Washington	46°51′10″N 121°45′37″W  /  46.8528857°Due north 121.7603744°W  / 46.8528857; -121.7603744	November to Dec 1894
Mount Shasta	xiv,162	four,317	California	41°24′33″N 122°xi′42″W  /  41.409196033°N 122.194888358°W  / 41.409196033; -122.194888358	About 1250 Advertisement
Mount Adams	12,280	3,740	Washington	46°12′09″N 121°29′27″W  /  46.202411792°Due north 121.490894694°Due west  / 46.202411792; -121.490894694	Near 950 Advertising
Mount Hood	11,239	3,426	Oregon	45°22′25″Due north 121°41′45″Due west  /  45.373514489°N 121.695918558°Due west  / 45.373514489; -121.695918558	1865 to 1866
Mount Baker	10,781	three,286	Washington	48°46′38″N 121°48′48″Due west  /  48.7773426°Due north 121.8132008°W  / 48.7773426; -121.8132008	September to November 1880
Glacier Tiptop	10,541	3,213	Washington	48°06′45″Due north 121°06′50″W  /  48.112513950°N 121.113804642°W  / 48.112513950; -121.113804642	1700 ± 100 years
Mountain Jefferson	10,497	iii,199	Oregon	44°40′27″N 121°47′58″W  /  44.674300600°N 121.799573611°W  / 44.674300600; -121.799573611	About 950 AD[ commendation needed ]
Lassen Peak	10,457	3,187	California	forty°29′17″N 121°thirty′eighteen″W  /  40.4881731°Due north 121.5050078°West  / forty.4881731; -121.5050078	1914 to 1917
Silverthrone Caldera	10,370	3,160	British Columbia	51°26′00″Due north 126°eighteen′00″W  /  51.43333°N 126.30000°W  / 51.43333; -126.30000	About 100,000 years ago
South Sister (Three Sisters)	10,358	3,157	Oregon	44°06′12″N 121°46′09″W  /  44.1034490°N 121.7692058°W  / 44.1034490; -121.7692058	fifty BC
Northward Sister (Three Sisters)	10,085	3,074	Oregon	44°09′58″N 121°46′21″Due west  /  44.1662273°N 121.7725431°Due west  / 44.1662273; -121.7725431  (Due north Sister)	100,000 yrs ago
Eye Sis (Three Sisters)	10,047	3,062	Oregon	44°08′53″Due north 121°47′02″W  /  44.1481718°N 121.7839312°W  / 44.1481718; -121.7839312  (Heart Sister)	14,000 yrs ago
Mount McLoughlin	9,495	two,894	Oregon	42°26′40″Due north 122°18′56″Westward  /  42.44444°N 122.31556°W  / 42.44444; -122.31556	Well-nigh 30,000 years ago
Mount St. Helens	8,363	ii,549	Washington	46°11′28″N 122°11′xl″W  /  46.1912000°North 122.1944000°W  / 46.1912000; -122.1944000 Coordinates: 46°eleven′28″N 122°eleven′twoscore″West  /  46.1912000°N 122.1944000°Due west  / 46.1912000; -122.1944000	2004-2008

See likewise [edit]

Notes [edit]

1. ^ "Meager". Global Volcanism Programme. Smithsonian Institution.
2. ^ The Cascade Episode Retrieved on 2007-10-03
3. ^ "Silverthrone". Global Volcanism Program. Smithsonian Institution. Retrieved 2008-07-15 .
4. ^ "Washington State Volcanoes and Volcanics". The states Geological Survey . Retrieved 2007-07-16 .
5. ^ "Garibaldi volcanic chugalug". Catalogue of Canadian volcanoes. Geological Survey of Canada. 2008-02-13. Archived from the original on 2006-10-23. Retrieved 2008-05-10 .
6. ^ "Impact of varied slab age and thermal construction on enrichment processes and melting regimes in sub-arc mantle: Case from the Cascadia subduction system" (PDF). Nathan L., A. Krishna Sinha. Archived from the original (PDF) on 2008-12-19. Retrieved 2008-06-xvi .
7. ^ ^{a b} "Mount Meager". Bivouac.com.
8. ^ "Pilot Project: Mount Rainier Volcano Lahar Warning Arrangement". Archived from the original on 2008-05-eleven. Retrieved 2007-10-06 .
9. ^ "Pacific Mountain System – Pour volcanoes". Archived from the original on 2007-05-31. Retrieved 2007-04-12 .
10. ^ ^{a b} USGS: Eruptions of Lassen Peak, California, 1914 to 1917
11. ^ ^{a b} "Mount Meager". Catalogue of Canadian Volcanoes. Archived from the original on 2011-06-04. Retrieved 2007-07-xvi .
12. ^ ^{a b} Volcanology of the 2350 B.P. Eruption of the Mount Meager Volcanic Complex (PDF). Retrieved on 2007-07-16
13. ^ ^{a b c d e f m h i j k} Living With Volcanic Hazard in the Cascades Retrieved on 2007-x-03.
14. ^ Wood, Charles A.; Kienle, Jürgen (2001). Volcanoes of North America: The states and Canada. Cambridge, England: Cambridge Academy Press. ISBN978-0-521-43811-seven. OCLC 27910629.
15. ^ "Shasta: Eruptive History". Global Volcanism Programme. Smithsonian Institution. Retrieved 2021-06-28 .
16. ^ California's Mountain Shasta Loses a Historical Eruption Retrieved on 2021-07-17
17. ^ Mount St. Helens, Washington Eruption 2004 to Current Retrieved on 2007-ten-06.

References [edit]

• Harris, Stephen L. (2005). Burn down Mountains of the W: The Cascade and Mono Lake Volcanoes (3rd ed.) . Mountain Press Publishing Visitor. p. 454. ISBN978-0-87842-220-3.
• Wood, Charles A.; Jürgen Kienle, eds. (1990). Volcanoes of North America. Cambridge University Printing. p. 354. ISBN978-0-521-43811-7.
• Skiing the Cascade Volcanoes – Introduction to the Cascade Volcanoes
• Harris, Stephen L. (1980). Fire & Ice: The Cascade Volcanoes. Seattle, WA: The Mountaineers and Pacific Search Printing. ISBN978-0-89886-009-2.

External links [edit]

• USGS Cascades Volcano Observatory
• Smithsonian Institution Global Volcanism Program

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Source: https://en.wikipedia.org/wiki/Cascade_Volcanoes

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