[ RadSafe ] FW: [GeigerCounterEnthusiasts] volcano report from Iceland's top volcanologist / geology, chemistry, petrology -- it could get worse

[Roger Helbig]

From: GeigerCounterEnthusiasts at yahoogroups.com
[mailto:GeigerCounterEnthusiasts at yahoogroups.com] On Behalf Of Robert Merkin
Sent: Sunday, April 18, 2010 3:02 PM
To: GeigerCounterEnthusiasts at yahoogroups.com
Subject: [GeigerCounterEnthusiasts] volcano report from Iceland's top
volcanologist / geology, chemistry, petrology -- it could get worse

 

Geiger Counter enthusiast Bob Merkin said

 

I e-mailed 

 

Dr. Morten Schioldan Riishuus

Nordic Senior Researcher

Nordic Vulcanological Center 

University of Iceland

 

about radiation measurements of the Eyjafjallajökull eruption. This must be
the busiest guy in Iceland this week, but he generously took the time to
reply.

 

Note his worry about the nearby Katla, "the most vicious volcano in
Iceland." He says the two are believed to be connected at depth, and
historically, one's eruption has often triggered the other. Katla is usually
worse. 

 

BBC called it Eyjafjallajökull, but this refers to the entire system of
volcano and glacier (jökull). Dr. Riishuus refers to the volcano only as
Eyjafjalla.

 

============

 

I am unaware of such radiation measurements having been performed on this
eruption plume.

 

Data released by the Earth Science Institute concerning the eruption can be
found here

 

http://www.earthice.hi.is/page/ies_Eyjafjallajokull_eruption?247,112

 

More information - including chemistry - can be found in the icelandic
version of the web page above. I can inform that the composition of the ash
is silica oversaturated trachyandesite. So, intermediate to evolved. In
comparison, the ash and lava flows from the earlier flank eruption at
fimmvorduhals was alkali olivine basaltic (transitional to slightly
undersaturated). So, much more primitive in composition than what is
presently being erupted from the summit crater. The source for the basaltic
magma erupted at fimmvorduhals is deep-seated (15-20 km), while the
trachyandesite is very shallow (2-3 km).

 

Provided that the eruption will be over by summer, it will surely be
interesting for you to come to Iceland and study the effects of these
eruptions. Of major concern is that the eruption will be long-lasted and/or
that it will trigger its bigger neighbor, Katla, the most vicious volcano in
Iceland. The two systems seem connected at depth, and historically
Eyjafjalla eruptions have been followed by more devastating Katla eruptions.

 

Best wishes,

 

Morten Riishuus