PSN-L Email List Message
Subject: Large eruption in Chile
From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@.........
Date: Sat, 03 May 2008 19:30:59 +0000
There is a large eruption in Chile, the ash plume has reached 16 km
yesterday when the eruption did start. The current information that I
have is limited, but this is what I got on the volcano postlist
42.833S, 72.646W; summit elev. 1,122 m
All times are local (=3D UTC - 4 hours)
Later updates from multiple sources have indicated that the 2
May 2008 eruption at Minchinm=E1vida (Vnum 1508-04) was incorrectly
attributed. The volcano that erupted was an adjacent caldera, Chaiten
(1508-041). A Volcanic Ash Advisory stated that ash rose to altitudes
in the range of 45,000-55,000 feet [13.7-16.7 km].
Chaiten lies slightly to the W of Minchinmavida. Chaiten
volcano lacks any known modern eruptions but a radiocarbon date on its
tephra (CHA1) yields a date of 7,430 BC (plus or minus 75 years).
Since my message this morning much news (in Spanish and
English) has emerged about today's eruption at Chaiten, correcting the
earlier confusion regarding the name and including numerous photos of
impressive plumes. One report said 1,500 people were evacuated in
Chile. What follows after the Geologic Summary are relevant portions
of reports by others. My thanks to this listserve's Kimberly Genareau
and these other contributors.
Geologic Summary. Chait=E9n is a small, glacier-free
late-Pleistocene caldera with a Holocene lava dome located 10 km NE of
the town of Chait=E9n on the Gulf of Corcovado. The north side of the
rhyolitic, 962-m-high obsidian lava dome occupying the 3.5-km-wide
caldera is unvegetated. Obsidian cobbles from this dome found in the
Blanco River are the source of prehistorical artifacts from
archaeological sites along the Pacific coast as far as 400 km away
from the volcano to the north and south. The caldera is breached on
the SW side by a river that drains to the bay of Chait=E9n, and the high
point on its southern rim reaches 1,122 m. Two small lakes occupy the
caldera floor on the west and north sides of the lava dome. Moreno
(1985 pers. comm.) noted that the nearby volcano of Yelcho listed by
the International Association of Volcanology and Chemistry of the
Earth's Interior (1973) does not exist.
Also, given the pictures that I have seen on the news. It can be save to
assume that this eruption is not small.
More news here,
This volcano last erupted in 7420 BC =B1 75 years. So it has lied dormant
for a long time now.
More information on the volcano here,
If this is a really big eruption, it might create issues for the nearby
countries. At least part of the south part of the planet.
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