Zao Volcano
Updated: 28 avril. 2024 22:24 GMT -
comlex volcano 1841 m / 6,040 ft
Honshu (Japon), 38.14°N / 140.44°E
Condition actuelle: normal / en sommeil (1 sur 5)
Honshu (Japon), 38.14°N / 140.44°E
Condition actuelle: normal / en sommeil (1 sur 5)
Last update: 21 déc. 2021 (Smithsonian / USGS Weekly Volcanic Activity Report)
Zao (or Zaozan, Zaosan) volcano is the most active volcano of northern Honshu and consists of a group of stratovolcanoes forming the crest of the divide between the Pacific Ocean and the Japan Sea.
The older parts of the complex are Ryuzan volcano in the west and Byobu and Fubo volcanoes forming the southern group. Zao volcano proper (Chuo-Zao) is the youngest edifice and forms the central part of the group. One of its youngest summit lava domes is Goshiki-dake, which contains the active Okama crater, the source of most of the frequent historical eruptions recorded since the 8th century AD.
Okama crater contains a colorful, strongly acidic crater lake (pH 1.3).
[smaller] [larger]
Eruptions du volcan Zao: 1940, 1939 (?), 1927 (?), 1905, 1897 (?), 1896, 1895, 1895, 1894, 1890 (?), 1873, 1867, 1833, 1831, 1830, 1822, 1821, 1809, 1806, 1804, 1796, 1794, 1694, 1670, 1669, 1668, 1641, 1630, 1623-24, 1622, 1620, 1400 ± 100 years (radiocarbon), 1350 (?), 1331-33 (?), 1230, 1227, 1183, 884, 773 (?), 300 AD ± 200 (RC), 1600 BC (?, RC), 2000 BC ± 500 (tephrochronology), 2300 BC ± 75 (RC), 2600 BC ± 200 (RC), 3350 BC ± 50 (RC), 3850 BC ± 200 (RC), 4150 BC ± 200 (RC), 5500 BC (?, RC), 5600 BC (?, RC), 7600 BC (?, RC)
Derniers séismes proches
Heure | Mag. / Profondeur | Distance / Lieu | |||
17 avril 11:34 (GMT +9) | 2.5 142 km | 17 km au sud-ouest | Japan: SOUTHERN MIYAGI PREF | Info |
Introduction
The Pleistocene Ryuzan volcano forms the western Zao group (Nishi-Zao), and Byobu and Fubo volcanoes form the southern Zao group (Minami-Zao). The complex was constructed over granitic basement rocks as high as 1500 m and thus has a relatively small volume. The 7 cu km Zao volcano proper forms the central ao group (Chuo-Zao), a volcanic complex topped by several lava domes and the Goshiki-dake tuff cone, aligned along a NW-SE trend. Several episodes of edifice collapse produced debris avalanches during the Pleistocene.Zao Volcano Photos
Le lac vert du cratère Okama du volcan Zao, NE Honshu, Japon (Photo: Tom Pfeiffer)
Lac de cratère Okama, volcan Zao, Japon (Photo: Tom Pfeiffer)
Ravines d'érosion sur les pentes extérieures du cratère intérieur contenant le lac Okama, volcan Zao, Japon (Photo: Tom Pfeiffer)
Coulées de lave et couches pyroclastiques exposées dans les parois du cratère du volcan Zao (Photo: Tom Pfeiffer)
Eruptions du volcan Zao
1992 earthquake
A M 4.7 earthquake occurred at 17h58 local time on 1 September a few kilometers ESE of the summit. There were no visible changes.
A M 4.7 earthquake occurred at 17h58 local time on 1 September a few kilometers ESE of the summit. There were no visible changes.
1990 seismic swarm
In July 1990, many small earthquakes were detected below the summit of Zao volcano.
(GVP)
In July 1990, many small earthquakes were detected below the summit of Zao volcano.
(GVP)
1867 phreatic eruption and fatalities
On 21 Oct 1867, a phreatic eruption caused an overflow of muddy water from Okama crater lake, which killed 3 bathers who were in the hot springs at the foot of Goshiki-dake. ...plus d'info
On 21 Oct 1867, a phreatic eruption caused an overflow of muddy water from Okama crater lake, which killed 3 bathers who were in the hot springs at the foot of Goshiki-dake. ...plus d'info