Wednesday, September 02, 2009

Invisible Sun, Cont'd   [Jonah Goldberg]

A really boring e-mail:

You surprise me, Goldberg. You don't often see a right-wing ideologue with an interest in hard science.

Anyway, here's a fact for you:

Between 1860 and the present, global average temperatures have gone up by about .60 degrees C. ( That doesn't seem like a lot, but only 6 degrees C separate us from the last Ice Age.)

Why has this occurred? Well, most scientists think it is because of the widespread burning of fossil fuels, brought on by the expansions of industrial activity.

We can't do much about sunspots (which may cause some level of climate change) , but we can do something about fossil fuel consumption. And we should.

A not-boring e-mail:

Jonah.

Volcanic activity has long been implicated in cooling the Earth, but there are reasons to suspect we should not treat volcanic activity and sunspot cycles as independent of each other.

Statistical studies have found a strong correlation between seismic activity and solar cycles:

"The distribution of great earthquake occurrence times with respect to the 11-yr solar sunspot cycle is nonrandom at the 99.4% level. A bimodal distribution of phases is found, with increased event frequency found for the years approaching sunspot minima (as now), and with a second population found associated with sunspot maxima. A pronounced deficit of events is found for the intervening times, when solar activity is most rapidly rising, and then most rapidly falling."
http://adsabs.harvard.edu/abs/2007AGUFM.S33C1473S

In less technical terms, great earthquakes almost always occur during the periods of minimum or maximum activity of a sunspot cycle.

Here are a couple of questions that I'd love to have the answers to:

1) "Do volcanic eruptions correlate with solar cycles in the same way that earthquakes do?"

It seems logical that the answer to this question would be "Yes". Earthquakes and volcanic activity are, after all, related. Detailed statistical data on volcanic eruptions seem to only be available for the rather recent past, though, so there may not be enough data available to answer this.

2) "Do longer solar minima and maxima lead to more and/or larger quakes?"

It seems probable that the answer to this would be also be "Yes". This question could probably be answered from an analysis of available data, but I've found no such analysis to date.

What about the climate tie-in?

One postulated mechanism whereby solar activity might change the Earth's climate goes something like this:

1) Climate change correlates with solar cycles.
2) There are indications of significant volcanic activity around the time of past climate shifts.
3) Solar activity change -> Increased volcanic activity -> Cooling

So far as I know, no causal link has ever been found, or even proposed, for the observed correlation between seismic activity and solar cycles. If we are entering a cooling period, the next few years seem likely to provide some insight.

Update: Because one never has enough opportunities to say "magma." From a reader:

There are no known aspects of sunspots that could couple to the internal dynamics of the Earth. At least not known to me; somebody may have printed something on it since I graduated, but I think I'd have heard about it.

There is more magnetic activity during sunspots, but not NEARLY enough to move magma around.

09/02 04:31 PMShare