Lisbon, Portugal, during the great earthquake of 1 November 1755. This copper engraving, made that year, shows the city in ruins and in flames. Tsunamis rush upon the shore, destroying the wharfs. The engraving is also noteworthy in showing a harbor with highly disturbed water which sank many ships. Passengers in the left foreground show signs of panic. Original in: Museu da Cidade, Lisbon. Reproduced in: O Terramoto de 1755, Testamunhos Britanicos (The Lisbon Earthquake of 1755, British Accounts.) Lisbon: British Historical Society of Portugal, 1990.
Once Upon A Star...
June 15, 763 BC was likely a very nice day in ancient Greece. – The Dark Ages had ended, trade with the Near East, Italy and Egypt was flourishing and Greece’s economic recovery was afoot. – The ease of life’s daily burdens left plenty of time to contemplate the heavens and the newly adopted Phoenician alphabet gave scholars the perfect tool with which to record that day’s solar eclipse.
During this period bloomed an intellectual revolution; classical philosophy, theater and poetry were born. It is also from this time that we retain the first written records of earthquake occurrences, yet for many years, advances in the arts would continue to outpace the physical sciences.
In the centuries that followed, for example, earthquakes were alternately attributed to air (vapors) in the cavities of the Earth, tension between the earth and water, episodes of dryness and wetness and even underground thunderstorms.  The shape of the Earth itself was still open to debate until the end of the sixth century B.C. when Pythagoras, for aesthetic reasons, decided that the Earth was neither flat nor cylindrical nor rectangular, but spherical like the Sun and the Moon.  Finally, it wasn't until our time, during the latter half of the twentieth century, that researchers would begin to theorize about a possible link between earthquakes and the sun. 
What follows is a brief introduction to their latest findings.
Sun-Earth Seismic Connection
A close inspection of sunspot activity records dating back to the seventh century reveals that solar activity follows a predictable 11-year cycle of minima and maxima.
Combining the data of these 11-year solar cycles with earthquake totals recorded during the same time period reveals that seismic activity has closely followed solar activity for centuries.
Not only is there a direct relation, but it was found that more earthquakes occur during the height of sunspot activity.
Number of earthquakes in the Mediterranean area summed over the 11-year solar cycles (solid line) and solar activity in the maxima of the solar cycles (broken line) in the period 296-1000 AD; 3-point running means.
Since the twentieth century, the global number of strong (with magnitude 7 or greater) earthquakes per year was studied to determine if a relation existed with sunspot cycles today.
Average number of earthquakes (solid line, left scale) and solar activity (broken line, right scale) in the 11-year solar cycle for the period 1900-1999.
Not only did this research reaffirm the earthquake-solar activity connection, it revealed that the significantly greater probability of earthquake occurrence was due to the arrival of high speed solar streams at the Earth.
The working theory as to why these streams cause earthquakes is a somewhat complicated process to explain and is best done scientifically by Gousheva et al :
The possible mechanism includes deposition of solar wind energy into the polar ionosphere where it drives ionospheric convection and auroral electrojets, generating in turn atmospheric gravity waves that interact with neutral winds and deposit their momentum in the neutral atmosphere, increasing the transfer of air masses and disturbing the pressure balance on tectonic plates.
Interestingly, no clear relation was found between solar activity and earthquake size, confirming the assertion that all earthquakes start in a similar fashion, but some grow bigger than others.
It was also determined that both the day of arrival of high speed solar wind and the day following right after it are “special” concerning earthquake appearance.
The origin of these high-speed solar winds will be examined after a brief detour to determine if a connection exists between solar activity and volcanic eruptions.
Sun-Earth Volcanic Connection
It stands to reason that if the Sun is geoeffective with regard to earthquakes that it might also have an effect on volcanic activity.
The short answer is: it does.
Specifically, there is a high correlation of duration of eruptive days and dates of short-moving sunspots.
Changing of the duration of volcanically eruptive days with the excluded linear trend (solid line) and dates of short-living sunspots (dashed line) in accordance with the data of A.Stoyko’s works (1969).
But not all volcanoes are alike. They are generally divided into two types: mud volcanoes and magmatic volcanoes.
All mud (M-type) volcanoes of the world are located in the zones of subduction and collision and, consequently, reflect the activity of compression processes of the Earth.
Location scheme of mud (M-type) volcanoes and subduction zones of the world.
Data from more than 300 mud volcano eruptions around the world were used to determine that mud volcano activity (that typically occurs in a 9-12 year cycle) corresponds with the 11-year cycles in solar activity.
Comparison of solar and mud (M-type) volcano activities diagrams.
Magmatic volcanoes are further divided into geodynamical types. Each type of volcano reflects the activity of various processes:
• C-type volcanoes characterize the compression processes of Earth (due to subduction.)
• R-type volcanoes characterize the tension processes of Earth (due to spreading.)
C-type magmatic volcanoes were found to occur in 6, 10 and 22-year cycles of hyperactivity.
Comparison of C-type magmatic volcanoes activity diagrams and solar activity.
As follows the graph above, the periods of C-type volcanoes hyperactivity coincide with the 11-year cycles in solar hyperactivity.
Comparison of R-type magmatic volcanoes activity diagrams and solar activity.
R-type magmatic volcanoes were found to occur in 15-year and 22-year activation cycles.
As suspected, the comparison of R-type volcano activity diagrams with the solar activity diagram caused contrary conclusions. With the increase of solar activity there decreases R-type volcanic activity.
The theory by which solar activity affects volcanoes is explained by Khain and Khalilov :
When solar activity increases, the corpuscular emission and solar magnetic field strength increase rapidly as well, inducing ring currents in various layers of Earth, particularly, in lithosphere and asthenosphere. Currents in asthenosphere appeared as a result of solar activity increase cause mantle heating, its plasticity growth and as a result convection currents acceleration. Convection currents acceleration leads to spreading acceleration, and increase of mantle temperature – to its heat expansion while Earth extension is taken place due to spreading. In the periods of solar activity decrease the ring currents magnitude inducing in the mantle, decreases as well and as a result there decreases temperature and Earth compression, accompanying by the process of subduction.
The study concluded that in periods of solar activity increase, there increases the activity of volcanoes in the Earth's compression zones, while in periods of solar activity decrease there increases the activity of tension zone volcanoes that should cause periodical change of the Earth’s radius.
Evidently, 22-year cycles became apparent in all geodynamic types of volcanoes and it seems that they are genetically coherent by the influence of a single factor – the 22-year cycle of solar activity consisting of two 11-year cycles.
We can conclude that 11-year and 22-year cycles, the most typical for solar activity, have a direct influence upon the Earth’s processes, including volcanism and seismicity.
Now, let’s return to an examination of their main influence, the source of high-speed solar winds: solar coronal holes and coronal mass ejections (CMEs).
Two Threats (CMEs and Coronal Holes)
Solar streams are more prevalent during two discernable times: (1) during the maximum of the 11-year sunspot cycle and (2) during the descending phase of the sunspot cycle when coronal holes are present.
Yearly average values of the sunspot number, R, and the geomagnetic index, aa.
The greatest Earth effects occur when coronal holes face the Earth and when CMEs are traveling at speed.
Solar winds are considered high speed when their velocities are no less than 500 kilometers per second.
To illustrate the effects solar weather can have on the Earth, let’s take a look at two major events in recent history.
Carrington Event of 1859
At 11:18 AM on the cloudless morning of Thursday, September 1, 1859, 33-year-old Richard Carrington—widely acknowledged to be one of England's foremost solar astronomers—was in his well-appointed private observatory. Just as usual on every sunny day, his telescope was projecting an 11-inch-wide image of the sun on a screen, and Carrington skillfully drew the sunspots he saw.
Sunspots of September 1, 1859 as sketched by Richard Carrington.
On that morning, he was capturing the likeness of an enormous group of sunspots. Suddenly, before his eyes, two brilliant beads of blinding white light appeared over the sunspots, intensified rapidly, and became kidney-shaped. Realizing that he was witnessing something unprecedented and "being somewhat flurried by the surprise," Carrington later wrote, "I hastily ran to call someone to witness the exhibition with me. On returning within 60 seconds, I was mortified to find that it was already much changed and enfeebled." He and his witness watched the white spots contract to mere pinpoints and disappear.
It was 11:23 AM. Only five minutes had passed.
Just before dawn the next day, skies all over planet Earth erupted in red, green, and purple auroras so brilliant that newspapers could be read as easily as in daylight. Indeed, stunning auroras pulsated even at near tropical latitudes over Cuba, the Bahamas, Jamaica, El Salvador, and Hawaii.
Even more disconcerting, telegraph systems worldwide went haywire. Spark discharges shocked telegraph operators and set the telegraph paper on fire. Even when telegraphers disconnected the batteries powering the lines, aurora-induced electric currents in the wires still allowed messages to be transmitted.
"What Carrington saw was a white-light solar flare—a magnetic explosion on the sun," explains David Hathaway, solar physics team lead at NASA's Marshall Space Flight Center in Huntsville, Alabama.
Now we know that solar flares happen frequently, especially during solar sunspot maximum. Most betray their existence by releasing X-rays (recorded by X-ray telescopes in space) and radio noise (recorded by radio telescopes in space and on Earth). In Carrington's day, however, there were no X-ray satellites or radio telescopes. No one knew flares existed until that September morning when one super-flare produced enough light to rival the brightness of the sun itself.
"It's rare that one can actually see the brightening of the solar surface," says Hathaway. "It takes a lot of energy to heat up the surface of the sun!"
The explosion produced not only a surge of visible light but also a mammoth cloud of charged particles and detached magnetic loops—a "CME"—and hurled that cloud directly toward Earth. The next morning when the CME arrived, it crashed into Earth's magnetic field, causing the global bubble of magnetism that surrounds our planet to shake and quiver. Researchers call this a "geomagnetic storm." Rapidly moving fields induced enormous electric currents that surged through telegraph lines and disrupted communications. 
Halloween Storms of 2003
As researched by Gopalswamy et al , the violent solar eruptions of October-November 2003 (see figure below,) are one of the best observed outbreaks of intense solar activity to date. These events, referred to as the Halloween Storms, are extreme in both their solar properties and terrestrial consequences.
Two of the eruptions recorded at this time arrived at Earth in less than a day. Historically, only 13 such “fast transit” events, including the Carrington event described above, have been observed. Remarkably, the two fast transit events in October 2003 occurred on consecutive days.
An overview plot showing (from top to bottom) the GOES X-ray flares, CME height-time plots, the SEP flux (>10 MeV protons), the 1 AU solar wind speed from ACE, and the Dst index. The nominal quiet condition is marked by the horizonal dashed lines. The solid lines in the CME height-time plots represent halo CMEs.
Several aspects of the Halloween Storms displayed extreme behavior:
• The size of the Sun’s active region
• The potential energy generated
• Flare occurrence rate and peak intensity
• Coronal Mass Ejection (CME) speed and intensity
• Shock occurrence rate
• Solar Energetic Particle (SEP) occurrence rate and peak intensity
• The geomagnetic storm intensity
As expected, this outbreak of strong solar activity resulted in a broad spectrum of space weather impacts. About 59% of the reporting spacecraft and about 18% of the onboard instrument groups were affected by these storms. Most Earth-orbiting spacecraft were put into safe mode to protect them from the particle radiation that was emitted.
Major societal impacts also occurred:
• About 50,000 people in southern Sweden (Malmoe) experienced a blackout when the oil in a transformer heated up by 10 degrees
• Surge currents were observed in Swedish pipelines
• Several occurrences were noted of degradation and outage of GPS systems
• Teams climbing Mount Everest experienced interference on high-frequency radio communication paths
Near-Earth effects were no less extreme:
• The total electron content in the ionosphere over the US mainland increased tenfold during 30-31 October
• The solar energetic particle event on 28 October caused a significant (50-70%) depletion of the ozone layer at the northern polar cap
• Airline passengers flying at a significant latitude and altitude were exposed to an approximate 37% increase in solar radiation dose (with pregnant women being particularly vulnerable)
• Longer airline flights could subject passengers to a significant dose of radiation
Prediction of strong interplanetary coronal mass ejections (ICMEs) is of paramount importance to critical power infrastructures.
Just how important has already been the discussion of various articles grouped under the tag of EMP.
The main reasons why the Halloween Storms were so dangerous are two-fold:
In 2003, the average time-of-arrival errors from space weather forecast centers was 9.26 hours.
Overall, the strongest ICME impact events of 29 and 30 October 2003 were the most poorly predicted.
Due to the nature of its potential impact, space weather prediction evokes two schools of thought as to its best delivery.
One’s sugar coated and the other right between the eyes…
1- graph of real numbers of earthquakes of compression rims of the Earth with M≥5; 2-circumflexing graph of seismic activity of compression rims of the Earth with M≥5; 3-forecast part of the graph of seismic activity of compression rims of the Earth; 4-lines connecting the minimal indexes of solar and seismic activities and showing the delay of seismic activity against solar; 5-graph of volcanic activity of compression rims of the Earth; 6-forecast part of the graph of volcanic activity of compression rims of the Earth; 7-drawing up of volcanic activity graph for zones of type C; 8-drawing up of seismic activity graph for zones of type C.
X-ray-emitting CMEs, earthquakes and volcanic eruptions are each set to peak in number again in (you guessed it) 2012 through 2015.
Their 2012 totals are expected to exceed those of the Halloween Storms.
The areas of particular vulnerability on Earth lie in what are called the compression zones, where subduction of the tectonic plates occurs.
The map of geodynamic zones of Earth. 1 – compression zones of Earth – type C; 2 – ocean internal plate zones – type OI. 3 – continental rift zones – type CP; 4 – ocean rift zones – type OR.
The USGS Earthquake Hazards Programs provides detailed maps of worldwide subduction zones at http://earthquake.usgs.gov/research/data/slab/.
There is some good news here. - A useful predictor of harmful CMEs has been found.
Type II solar radio bursts of a long-wavelength (decameter-hectometer) have been associated with CMEs that are much faster and wider than average; the types of CMEs that are potentially more geoeffective.
Sign up to receive NOAA’s free space weather alerts by email or SMS (texted to your cell phone.)
Here are examples of space weather alerts that occurred this week on 18 and 20 March 2010:
Space Weather Message Code: ALTTP2
Serial Number: 694
Issue Time: 2010 Mar 18 2357 UTC
ALERT: Type II Radio Emission
Begin Time: 2010 Mar 18 2311 UTC
Estimated Velocity: 776 km/s
Space Weather Message Code: ALTK04
Serial Number: 1436
Issue Time: 2010 Mar 20 0839 UTC
ALERT: Geomagnetic K-index of 4
Threshold Reached: 2010 Mar 20 0838 UTC
Synoptic Period: 0600-0900 UTC
Active Warning: No
Space weather generated by the Sun can cause increased radiation, earthquakes and volcanic eruptions on Earth.
Solar weather for the current sunspot cycle 24 is forecast to set new record totals for these events, each peaking in 2012.
How bad will it get? Could the peak days trigger cataclysmic events on the Earth as depicted in the movie 2012? At this time, we simply don’t know.
If so, to quote another student of the Sun, “That will be a very bad solar hair day.”
Oh, and just in case you were wondering…
That was sugar-coated.
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This article drew heavily from the following three research papers, each of which are an excellent source of further study [PDFs]: