Solar Grand Minima & the New Madrid Seismic Zone

I recently reviewed a white paper by former director of meteorology for the Weather Channel, Joseph D’Aleo, on the potential effects global cooling could have on agriculture, in light of a recent flurry of discussion about the potential for a new mini ice age.

In the basement, we began to discuss other things which have been correlated with changes and solar activity, and earthquakes came to mind.  In recent years, we had seen several studies, one Japanese study in particular, which looked at the relationship between strong earthquakes and the activity of the Sun as it enters its minimum phase.  This study concluded that it appeared that the number of strong earthquakes globally increased during solar minima.

An additional more recent and specific study also piqued our interest--a paper published in 2015 in the Journal “Concepts in Global Tectonics” by John Casey and Dong Choi -- which looked specifically at earthquakes in the New Madrid Seismic Zone in the United States, and deep solar minima.  This region, located in the interior of the United States, stretches southwest from New Madrid, Missouri and encompasses parts of the states of Illinois, Indiana, Missouri, Arkansas, Kentucky, Tennessee, and Mississippi. Quakes in continental interiors typically have high fatality rates.

This region had 4 major 8.0+ magnitude earthquakes from December 1811-February 1812, during the Dalton Minimum (which included the “Year Without a Summer” of 1816), as well as during other periods of intense seismic activity during solar grand minima.

According to Casey and Choi, the past four strong periods of earthquake activity in this zone have all occurred during periods of very low solar activity-- during the Sporer (1450), Maunder (1699), Dalton (1811-12), and Centennial (1895) Grand Minima.

THE NEW MADRID SEISMIC ZONE

I did some digging to try to confirm some of this history, since it is a rather interesting association.

The New Madrid Seismic Zone, or NMSZ, is thought to be relatively young, 64,000 years old.  

 

NMSZBig.gif

 

The faults responsible for the New Madrid Seismic Zone are found within a subsurface geological feature known as the Reelfoot Rift, formed during the breakup of the supercontinent Rodinia about 750 million years ago

Archaeological studies (like artifacts from sand blows and C-14 dating) show that quakes similar in magnitude to the 1811-12 period also likely occurred in the year 300 and 900, although with less certainty, with better indications of similar activity in 1450. There are indications of prehistoric quakes, but given the greater uncertainty about exact dates, we will focus on the relatively more recent events.

The 900 event has been noted to have a margin of error of +/- 100 years.  But this could put it closer to the Oort minimum of 1040-1080.

There was also possibly a major event in 1380 indicated by a large sand blow in the area.  This would be around the time of the Wolf Minimum.  

There are also indications, although with some amount of uncertainty about the date precision, of a 1450 strong seismic event. This was the time of the Sporer Minimum.  While the later quakes are more reliably dated, this is already somewhat interesting.

As Thomas Gold points out in his book, “The Deep Hot Biosphere,” human anecdotal reports actually do help in verifying the accuracy of geological and other observations which indicate strong quake activity.  In the case of the NMSZ quakes of 1811-1812, this even inspired artwork.

 

New_Madrid_Erdbeben.jpg

A woodcut showing depicting aftermath of 1811-1812 NMSZ quakes

 

Tree ring studies conducted on the oldest trees growing in Reelfoot Lake, a lake created after the series of major quakes of 1811-1812, found evidence of this series in the form of tree stem fractures followed by rapid growth after the area was flooded with water, whereas cores taken from similar trees in the St. Francis sunklands showed slowed growth in the half century that followed 1812. Both of these different indicators in different locations in the NMSZ were interpreted as clear signals of the 1811–1812 earthquake series in tree rings.

Because the tree ring record in Reelfoot Lake and the St. Francis sunklands extend back to A.D. 1682 and A.D. 1321 respectively, researchers interpreted the lack of similar signals elsewhere in the chronology as evidence against large New Madrid earthquakes between those years and 1811.

The geological indications of the 1450 quake are closer to Reelfoot Lake, in northwest Tennessee, perhaps not reflected in the tree growth patterns of the St. Francis sunklands, in northeast Arkansas, for this reason.

 

Reelfoot_Lake.jpg

Reelfoot Lake, NMSZ.  Credit:  © Jeremy Atherton, 2001

 

GRAND SOLAR MINIMA AND THE NMSZ

So, while we may not have a completely accurate reading of some of the earliest possible quake activity, from the late 1600’s on, it does appear that the correlation with deep solar minima holds true, and even relatively weaker earthquake activity correlates with relatively weaker minima.  Here are a list of some of the most significant minima we know of:

 

Event

Start

End

Homeric minimum

950BC

800BC

Oort minimum

1040

1080

Wolf minimum

1280

1350

Spörer Minimum

1450

1550

Maunder Minimum

1645

1715

Dalton Minimum

1790

1820

 

And as far as well-documented NMSZ strong seismic activity, we have:

--The earliest well documented major quake-- 1699 (during the MAUNDER MINIMUM)

--Then the 1811-1812 series (during the DALTON MINIMUM)

--The next largest quake-- on Oct. 31, 1895, a 6.6 quake (during the “CENTENNIAL MINIMUM”-- a relatively less major but significant dip in solar activity)

And as mentioned before, we have reason to believe that there might have been significant events around the time of the Oort, Wolf, and Sporer minima, although with a lesser degree of certainty.

 

Sunspot_Numbers.png

 

The 20th century has not seen much strong activity in the NMSZ, aside from a 5.4 quake in 1968, which interestingly occurred during Solar Cycle 20, which, while it was nowhere near a grand minimum, had a relatively low number of sunspots for the century.  Since then, there has only been one earthquake greater than magnitude 5, a 5.4 quake in the nearby Wabash Valley Seismic Zone in 2008.

The USGS recently issued a fact sheet reiterating the estimate of a 10% chance of a New Madrid earthquake of magnitude comparable to those of 1811–1812 within the next 50 years, and a greater chance of a magnitude 6.0 earthquake in the same time frame.

This particular fact sheet discusses how the region has continued to have small quake activity (> mag. 2.5) since the major quakes of 1811-1812.  It says the fact that this activity has not diminished shows that it does not simply reflect aftershocks from those quakes.  

In July 2014, the USGS increased the risk assessment for the New Madrid area.

These recently issued risk assessments are mostly interesting because the USGS is notoriously extremely hesitant and conservative about making “earthquake forecasts.”

 MORE EVIDENCE FOR A SOLAR-QUAKE CONNECTION

As mentioned, these indications are also reminiscent of a study which the Basement Team looked into several years ago, done by Japanese researchers who showed that higher magnitude earthquakes appear to occur in greater numbers during the period in which the Sun enters a minimum.

In a paper published in 2011 entitled "Possible Correlation Between Solar Activity and Global Seismicity," researchers from Kyushu University took 4,108 large, shallow quakes which occurred from 1963-2010 and compared them with the phases of the last four solar cycles.  They showed that for each magnitude range, there were consistently more earthquakes during the declining phase of the solar cycle compared with the ascending phase, and this was most pronounced for the largest earthquakes.

solar cycles and earthquakes-blue.png

The reason behind this type of association is not clear, but there is certainly reason to investigate further.

A SENSITIVE QUESTION?

Other areas in the United States, specifically on the West Coast, are said to be “overdue” for major quakes.  Recently the New Yorker published an article called “The Earthquake that Will Devastate Seattle,” about the fact that the Cascadia Subduction Zone is ripe with potential to generate a big quake.

But why would the NMSZ not respond to the 11-year solar cycle changes, but only grand minima?  Perhaps we can speculate that it is that this area is actually less sensitive to these changes, but still resonates with them, requiring greater dips in solar activity to unleash its earthquake potential.  Unlike the West Coast of the United States, or a country like Japan, located on the infamous “Ring of Fire,” the NMSZ has continuous but very weak seismic activity.  Perhaps the very deep minima are required to trigger strong earthquakes in this area, albeit by a process we still do not fully understand.  If this is the case, the forecasts of a deep solar minimum to come in the near future are all the more reason to pay attention to the New Madrid Seismic Zone.

What we do know is that all of this evidence gives us all the more reason to proceed with a Galactic Science Driver and Strategic Defense of Earth policy before we face a real disaster, literally right in the middle of our country, for which we will be sorely unprepared.

 


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