Mount Shasta volcan

stratovolcan 4,322 m / 14,179 ft

Condition actuelle: normal / en sommeil (1 sur 5)
Mount Shasta volcano seen from Lassen Peak
Mount Shasta volcano seen from Lassen Peak

Mt Shasta dans le comté de Siskiyou, du Nord de la Californie, est le deuxième plus grand volcan de la chaîne des Cascades. Mont Shasta Monte majestueusement près de 10 000 pieds (3000 m) au-dessus du terrain environnant car il n'est pas connecté à une montagne voisine. Il a un volume estimé de 350 km3 qui rend le volcan plus volumineux dans l'Arc volcanique des Cascades.
La montagne impressionnante et belle a attiré l'attention des poètes, auteurs, ufo-observateurs et est considéré comme un centre de pouvoir spirituel par beaucoup.

Géologiquement, Shasta est remarquable pour un glissement de terrain géant qui supprimé tout le côté nord du volcan entre environ 300 000 à 360 000 ans. Avec un volume estimé de 6,5 km cube, c'est un des avalanches plus connus sur terre. La diapositive coulait vers dans la vallée de Shasta où la rivière Shasta traverse maintenant le dépôt de flux de débris long 28 miles (45 km).
La dernière éruption confirmée de Mt Shasta qui s'est passé en 1786 et a été observée par l'exporer La Pérouse de son navire.

Montrer carte interactive
Style éruptif tipique: Explosive
Eruptions du volcan Mount Shasta: 1786, 1250(?), 1200(?), 850(?), 150(?), 50 AD (?), 150 BC (?), 550 BC ± 500, 650 BC ± 1000, 850 BC (?), 1150 BC (?), 2050 BC (?), 2550 BC (?), 3050 BC (?), 4050 BC (?), 6650 BC (?), 7250 BC (?), 7350 BC (?), 7420 BC ± 300, 7650 BC ± 100, 7750 BC (?), 8050 BC (?)

HeureMag. / ProfondeurDistance/Lieu
vendredi, 24. septembre 2021 02:46 GMT (1 séisme)
23 sept. 2021 19:46 (GMT -7) (24. sept. 2021 02:46 GMT)
1.9

5.6 km
26 km (16 mi)
9km SSE of McCloud, CA
mercredi, 22. septembre 2021 09:24 GMT (3 séismes)
22 sept. 2021 02:24 (GMT -7) (22. sept. 2021 09:24 GMT)
1.9

11 km
18 km (11 mi)
6km NE of Dunsmuir, CA
22 sept. 2021 01:56 (GMT -7) (22. sept. 2021 08:56 GMT)
1.7

12 km
18 km (11 mi)
6km W of McCloud, CA
22 sept. 2021 01:55 (GMT -7) (22. sept. 2021 08:55 GMT)
1.8

11 km
18 km (11 mi)
6km NE of Dunsmuir, CA
lundi, 13. septembre 2021 13:39 GMT (1 séisme)
13 sept. 2021 06:39 (GMT -7) (13. sept. 2021 13:39 GMT)
1.8

1.8 km
15 km (9.3 mi)
15km NE of McCloud, CA

Introduction

Mt Shasta volcano has a complex summit that consists of four overlapping volcanic cones, including the main summit and the prominent satellite cone of 12,330-foot (3,760 m) Shastina with its visible conical form. Shastina has a fully intact summit crater indicating that Shastina developed after the last ice age.
There are 7 named glaciers on Mount Shasta. The 4 largest (Whitney, Bolam, Hotlum, and Wintun) radiate down from high on the main summit cone to below 10,000 feet (3,000 m) primarily on the north and east sides. Whitney Glacier is the longest and the Hotlum is the most voluminous glacier in the state of California. 3 of the smaller named glaciers occupy depressions near and above 11,000 feet (3,400 m) on the south and southeast sides, including the Watkins, Konwakiton, and Mud Creek Glaciers.
The oldest remaining parts of Mount Shasta's are exposed at Sargents Ridge on the south side of the mountain. Andesitic lavas from the Sargents Ridge vent cover the Everitt Hill shield at Mount Shasta's southern foot.
The second oldest cone to form is exposed south of Mount Shasta's current summit and is called Misery Hill. It was formed 15,000 to 20,000 years ago from andesite flows and was later intruded by a hornblende dacite dome.
Since the end of the last ice age, Shastina cone was built by mostly pyroxene andesite lava flows. Some 9,500 years ago, these flows reached about 6.8 miles (10.9 km) south and 3 miles (4.8 km) north of the area now occupied by nearby Black Butte. Pyroclastic flows from Shastina and the then forming Black Butte dacite lava dome complex to the west covered 110 km2, including large parts of what is now Mount Shasta, California and Weed, California.
The last cone of Mt Shasta to form, and the highest, is the Hotlum Cone, which formed about 8,000 years ago. It is named after the Hotlum glacier on its northern face; its longest lava flow, the 500 feet (150 m) thick Military Pass flow, extends 5.5 miles (8.9 km) down its northwest face. Since the creation of the Hotlum Cone, a dacite dome intruded the cone and now forms the summit. The rock at the 600 feet (180 m) wide summit crater has been extensively altered by sulfurous hot springs and fumaroles there.
In the last 8,000 years, the Hotlum Cone has erupted at least eight or nine times. About 200 years ago the last significant Mount Shasta eruption came from this cone and created a pyroclastic flow, a hot lahar (mudflow), and three cold lahars, which streamed 7.5 miles (12.1 km) down Mount Shasta's east flank via Ash Creek. A separate hot lahar went 12 miles (19 km) down Mud Creek. This eruption was observed by the explorer La Pérouse, from his ship off the California coast, in 1786.
---
Source: GVP and Wikipedia


See also: Sentinel hub | Landsat 8
Montrer plus
Découvrez notre app gratuite !
Volcanoes & Earthquakes - new app for Android
Android | Version iOS

Plus sur VolcanoDiscovery

Why is there advertising on this site?
Support us - Help us upgrade our services!
We truly love working to bring you the latest volcano and earthquake data from around the world. Maintaining our website and our free apps does require, however, considerable time and resources.
We need financing to increase hard- and software capacity as well as support our editor team. We're aiming to achieve uninterrupted service wherever an earthquake or volcano eruption unfolds, and your donations can make it happen! Every donation will be highly appreciated. If you find the information useful and would like to support our team in integrating further features, write great content, and in upgrading our soft- and hardware, please make a donation (PayPal or Online credit card payment).

Planned features:
  • Improved multilanguage support
  • Tsunami alerts
  • Faster responsiveness
Thanks to your past donations, these features have been added recently:
  • Earthquake archive from 1900 onwards
  • Detailed quake stats
  • Additional seismic data sources
Download and Upgrade the Volcanoes & Earthquakes app to get one of the fastest seismic and volcano alerts online:
Android | IOS
Thank you!
Copyright: VolcanoDiscovery ou autres sources indiquées.
Utilisation des documents: Les textes, les images et les vidéos de ce site internet sont protégées par copyright. Toute reproduction et tout usage sans accord préalable ne sont pas autorisés. Si vous désirez acquérir pour certains documents (photos, vidéos, textes ou autres) le droit de reproduction, d'édition et, plus généralement, de toute utilisation destinée à un usage public, qu'elle soit commerciale ou pas, vous êtes priés de nous contacter.