Super-eruption
このような文書を目にしました。
真偽不明だが、VSI所長の名前はあってる。
http://www.vsi.esdm.go.id/general_info/staff.html
> PRESS RELEASE April 5, 2005
> LAKE TOBA WILL NOT ERUPT IN THE NEAR FUTURE
>
>
> Regarding a news wire of some mass media of the prospect of a Toba Lake
> biggest super volcano eruption quoting Professor Ray Cas of Monash
> University School of Geosciences of Australia, on Science-AFP through
> Yahoo at April 1, 2005, the Directorate of Volcanology and Geological
> Hazard Mitigation, Directorate General of Geology and Mineral Resources,
> Ministry of Energy and Mineral Resources, Republic of Indonesia, has some
> comments as follows:
>
> 1. Toba Lake at West Sumatra, Indonesia, is an Holocene volcano-tectonic
> structure caldera. It is a biggest caldera in the world. Geologiclly, it
> was formed by combination of tectonic structure and magmatic eruption
> prosesses in the pre-historical, Holocene. Ignimbrite series of the
> products surrounding the lake have shown many lithological ignmbrite
> colling units, which is indicated that the series came out from several
> central vents with different ages.
>
> 2. Toba Lake is not an active volcano, although it sites on Sumatra
> faultline running western part of Sumatra itself. There are some worries
> among scientists in the world, that there are some instances worldwide in
> which large subduction quakes do trigger eruptions. However, there are
> many more instances in which no eruption is triggered. Actually, there are
> no recent volcanic or seismic activity in Toba Lake, except a little
> fumarole field at the southern tip of Samosir Island.
>
> 3. Directorate of Volcanology and Geological Hazard Mitigation (previously
> VSI, Volcanological Survey of Indonesia), has a seismometer network at
> Sorikmarapi (the nearest active volcano to the Toba Lake), Marapi,
> Tandikat, Talang, Kerinci, Kaba and Dempo active volcanoes along side of
> the Sumatra faultline. The seismographs recorded the 9.0 magnitude quake
> on December 26, 2004, and the 8.7 magnitude quake on Monday March 28,
> 2005, but there are no significant local tectonic and volcanic tremors
> recorded following and or even trigerred unrest on those volcanoes till
> this day. There is no any reports of changes from people around the lake.
> Yes, it was recalled that in the 1988 there was concern that the water
> levels in the lake were dropping. The most recent study of a doctorate
> degree of Gajah Mada University turned out that the water levels were
> dropping becaused of overuse of water for hydroelectric generation power
> plant.
>
> 4. It is obviously worth for anyone to check and look at the data to deal
> with the potentially any geological catastrophes prediction in the world.
>
> 5. It is called to the people living around the Toba Lake to stay calm and
> not to be worried by the prediction without data resources available.
>
> Director,
>
> Ir. Yousana O.P. Siagian
>
> ------------------
> Directorate of Volcanology & Geological Hazard Mitigation
> Volcanological Survey of Indonesia - VSI
> Jalan Diponegoro 57 Bandung, Indonesia 40122
> Tel 62 22 720 2606
> Fax 62 22 720 2761 |
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