Contact | RSS | EN | DE | EL | ES | FR | IT | RU

Katmai Volcano

Updated: 29 mars. 2024 11:07 GMT -
Stratovolcano with central caldera 2047 m / 6716 ft
Alaska Peninsula, USA, 58.28°N / -154.95°W
Condition actuelle: normal / en sommeil (1 sur 5)
Last update: 12 nov. 2023 (Volcanic Ash Advisory)

A large stratovolcano in Alaska, near the Novarupta vent, that erupted in 1912 with the largest volcanic eruption in the 20th century, 10 times the size of the 1980 eruption of Mt. St. Helens.

[smaller] [larger]
Style éruptif tipique: Explosive
Eruptions du volcan Katmai: 1912 (Plinian eruption: the largest in the 20th century!)

Derniers séismes proches

HeureMag. / ProfondeurDistance / Lieu
20 mars 09:54 (Anchorage)
20 mars. 17:54 GMT
1.2

3.5 km
25 km au sud-ouest États-Unis, 179 km à l'ouest de Kodiak, Kodiak Island, Alaska Info
lundi, 18 mars 2024 GMT (1 séisme)
18 mars 05:31 (Anchorage)
18 mars. 13:31 GMT
1.2

4 km
17 km au nord-est 94 km NNW of Karluk, Alaska Info
vendredi, 15 mars 2024 GMT (1 séisme)
15 mars 08:19 (Anchorage)
15 mars. 16:19 GMT
0.9

4.1 km
23 km à l'est 85 km N of Karluk, Alaska Info
jeudi, 28 mars 2024 GMT (1 séisme)
27 mars 22:29 (Anchorage)
28 mars. 06:29 GMT
0.8

2.2 km
25 km au sud-ouest 85 km NW of Karluk, Alaska Info
lundi, 18 mars 2024 GMT (1 séisme)
17 mars 23:35 (Anchorage)
18 mars. 07:35 GMT
0.7

2.2 km
2.1 km au sud 82 km NNW of Karluk, Alaska Info
mardi, 19 mars 2024 GMT (1 séisme)
19 mars 01:08 (Anchorage)
19 mars. 09:08 GMT
0.6

1.1 km
24 km au sud-ouest États-Unis, 177 km à l'ouest de Kodiak, Kodiak Island, Alaska Info

Introduction

Katmai volcano is a large stratovolcano about 10 km in diameter with a central lake-filled caldera whose rim is about 4.2 by 2.5 km in area. The caldera rim has a maximum elevation of 2047 m and in 1975 the lake surface was at an elevation of about 1236 m. The estimated elevation of the caldera floor is about 995 m.
The volcano is one of five stratovolcanoes near the Novarupta dome, which was the source of the large Plinian eruption in 1912. The eruption produced voluminous pyroclastic flows and counts as the largest eruption in the 20th century.
Much of the volcano is mantled by snow and ice and several valley glaciers radiate out from the flanks and three glaciers originating from the upper caldera walls descend into the crater to the lake
Katmai volcano is built on the sedimentary rocks of the Naknek Formation of Late Jurassic age, which are exposed just west of the caldera rim at an elevation of about 1520 m, as well as north and southeast of the crater.
(from: Alaska Volcano Observatory's website).

The June 1912 eruption of Novarupta Volcano altered the Katmai area dramatically. Severe earthquakes rocked the area for a week before Novarupta exploded with cataclysmic force. Enormous quantities of hot, glowing pumice and ash were ejected from Novarupta and nearby fissures. This material flowed over the terrain, destroying all life in its path. Trees up slope were snapped off and carbonized by the blasts of hot wind and gas. For several days ash, pumice, and gas were ejected and a haze darkened the sky over most of the Northern Hemisphere. When it was over, more than 40 square miles of lush green land lay buried beneath volcanic deposits as much as 700 feet deep. At nearby Kodiak, for two days a person could not see a lantern held at arm's length. Acid rain caused clothes to disintegrate on clotheslines in distant Vancouver, Canada. The eruption was ten times more forceful than the 1980 eruption of Mount St. Helens. In the valleys of Knife Creek and the Ukak River, innumerable small holes and cracks developed in the volcanic ash deposits, permitting gas and steam from the heated groundwater to escape. It was an apparently unnamed valley whehn the 20th century's most dramatic volcanic episode took place. Robert Griggs, exploring the volcano's aftermath for the National Geographic Society in 1916, stared awestruck off Katmai Pass across the valley's roaring landscape riddled by thousands of steam vents. The Valley of Ten Thousand Smokes, Griggs named it.
(from: U. S. National Park Service Website, Geology Fieldnotes - Katmai National Park and Preserve, Alaska, April 2000, posted on CVO's website at: vulcan.wr.usgs.gov/Volcanoes/Alaska/description_1912_eruption_novarupta.html)

Latest satellite images

Katmai satellite image sat1Katmai satellite image sat2

Sur cette page: