I wonder if it is something to do with changes to the Earth’s magnetic field causing the magma pressure to increase at known crustal ‘weak’ spots? Apparently the north magnetic pole is wandering off towards Siberia, while the southern one is hardly moving. Perhaps it is a combination of this and small changes to the sun’s magnetic field which creates more of these events.

Anyone heard how Yellowstone is doing?

http://www.theregister.co.uk/2009/11/03/africa_unzipped/

I was just being facetious about the Cosmic Rays (not about the prayer, though).

Any accuracy to it? I donno… Never was all that great at angular momentum problems and it doesn’t get any easier when it is a 10 body problem with 10000 perturbations from smaller bodies, oh, and bit of relativity seasoning just for good measure. A real planetary mechanics physicist would need to address it, IMHO. The correlation is there, the causality is not demonstrated. YMMV. Read All Directions before attempting assembly. May cause drowsiness. Do not operate heavy equipment while using product … 8-)

Link to discussion of topic and containing link to Ian Wilson paper here:

http://chiefio.wordpress.com/2009/03/09/are-we-quaking/

Has a live map of recent quakes on it. Maybe I’ll a volcano’s link too…

If the GCR’s trigger the release, then there is a lag time to be worked out because of the early 1980′s and 1990′s clusters occuring during solar maximum (or GCR minimum).
One might try that the lack of Solar Activity causes them not to be released on a regular basis, until the pressures become too much and they pop ever more violently.
It’s food for thought as this point.

Laki(VEI6), in Iceland kicked off the Dalton with Sourfriere & Mayon coming around 1812 before Tambora(VEI7), but note also at Volcansim Blog down a few posts more evidence for unrecorded eruptions, e.g., 1809.

We are due a couple VEI6 erruptions per century, a couple VEI7 per millenium. It seems, looking at the USGS survey, that many volcanos await awakening. Perhaps, for the solar ramp? And what about the recent Santa Cruz Is. earthquake swarm?

I’ve looked for this at length before. The best I could find was the following. I think I got it at NASA. Sorry, I didn’t save the link just a picture of the data, so you need to google:

Jaroslav Strestik: Geophysica Institute AS CR Czech Republic
jstr@ig.cas.cz

Possible correlation between solar and volcanic activity in a long term scale.
Proc. ISCS 2003 Symposia 23-28 June 2003: Tatranska Lomnica, Slovakia
Solar variability as an input to the Earths environment.

He claims a 21 year running average correlates to the sun cycle with increases at extended minimums.

Well, obviously the increased cosmic ray flux is triggering the volcanoes.

I do admit I prayed for cold weather but only the minimum amount, mind you. However, with the current level of insanity and corruption, the reset required may be rather hard. May only the ninnies suffer.

Yes, I find your graph very interesting. Eyeballing is persuasive; I wonder about a more rigourous analysis. I also wonder if their is any relationship to other solar cycles.

Of course, there is no mechanism even well speculated let alone shown, even if the correlation is there. Could these be tidal forces from the planets equivalent to those miniscule ones found in the sun? I can’t wait for the heat of Leif’s knowledge to hit that vaporous thought.
==================================

I

http://www.robertb.darkhorizons.org/SSNvsVOL.JPG

Is a rough graph I did some time back. 1st symbol is a small black dot, a 4 on the http://volcano.si.edu/world/largeeruptions.cfm scale used.
Multiple volcanic eruptions use other symbols in addition to the black dot, and the higher the dot on a 4 -8 – 12 rung, the bigger the eruption.
The can occur and cluster anytime, but show tendency to prefer the minimums of solar cycles.
What other circumstances encourage more volcanic activity escapes me.
Maybe someone has a more in-depth analysis”.

Thanks for the graph.

I have collected some other publications on the subject but I have to retrieve them from another computer.

If interesting I will post them.

So while they appear random over shorter timescales they are not over longer timescales.

In general terms, the longer a volcano doesn’t erupt the more likely it will erupt soon. The same probably applies to the size of eruptions.

The 20th century had just one very large (VI6+) eruption compared to at least three in the 19th century and and similar numbers in what we know of previous centuries. Which means a very large eruption will come sooner rather than later (in terms of long term averages).

It has also been nearly 2 decades since a large eruption (Pinatubo size) occured, which is also an unusual long time.

So we due for both more large and very large eruptions. Lets hope we don’t get multiple eruptions at the same time.