The sun affects space weather, but does it cause earthquakes?

Many have wondered whether solar activity can be linked to earthquakes, but a recent study found no direct relationship between the two.

Scientists assembled historical records of the Sun’s interaction with Earth, looking at sunspots, solar wind, and magnetic storms. They then compared these with historical records of earthquake occurrence. They found no significant pattern between solar activity and more or larger earthquakes. There is no demonstrated way to use space data to predict future earthquakes.

The study was recently published in the journal Geophysical Research Letters. The research was conducted by Jeffrey Love with the USGS and Jeremy Thomas from Northwest Research Associates. The earthquake data were from the USGS, the sunspot data were from NOAA, the solar wind data were from NASA, and the geomagnetic data were from the British Geological Survey and Geoscience Australia.

The Author’s Perspective

“This research was conducted to advance our understanding of natural science and to test how the Sun affects Earth, ultimately helping protect the safety of our communities,” said USGS research geophysicist Jeffrey Love. “Even though we did not find a significant correlation between space measurements and earthquakes, we recognize that the Sun affects Earth in other ways. The USGS is dedicated to studying these natural phenomena, some of which are hazardous for a modern and technologically dependent society.”

“Of course it is always conceivable that some new and unexpected discovery will be made in the future, but it is also essential that we objectively evaluate the data and information that we have available now,” continued Love. “Just because one might think that a pattern exists does not mean that one actually exists. We need clear evidence to be convinced.”

Types of Solar and Space Activity

Everyone is familiar with weather systems on Earth like rain, wind, and snow. But space can also have a “weather” of sorts. The Sun’s behavior changes over time and this can cause the space environment surrounding Earth to change as well.

Magnetic storms, for example, are periods of time when Earth’s magnetic field is unusually active. How do they occur? The Sun is always emitting a wind of electrically charged particles, and when that happens abruptly, it can cause a magnetic storm.

Space weather can have important consequences for our lives on Earth’s surface. Large magnetic storms can cause the loss of radio communications, reduce the accuracy of GPS systems, damage satellite electronics and affect satellite opera­tions, increase pipeline corrosion, and induce voltage surges in electric power grids, causing blackouts. It is during magnetic storms that beautiful aurora borealis — or “northern lights” — are visible at high latitudes.

Now let’s talk about sunspots. A sunspot is a visibly dark region on the solar surface that corresponds to a concentration of solar magnetic energy and activity. If and when a large sunspot emerges on the face of the Sun, there is an increased chance for abrupt emission of strong solar wind velocity, and this can result in large magnetic storm at Earth. The number of sunspots waxes and wanes over the course of an 11-year solar cycle. The current cycle is unusually tame, but it could still change over the next few years.

Haitian woman carrying supplies amid the destruction from the January 2010 Haiti earthquake.

USGS Role 

The USGS Geomagnetism Program operates 14 observatories around the United States and its territories, which provide real-time ground-based measurements of the variable geomagnetic field. These measurements are used internally by the USGS, and they are used by partners in the United States National Space Weather Program, including NOAA, NASA, and the U.S. Air Force, to track the intensity of the magnetic storms generated by the Sun and its interaction with the Earth. The USGS Geomagnetism Program has also been working cooperatively with private industries that are affected by space weather and geomagnetic activity, including electric-power grid companies and the oil and gas drilling industry.

Can We Predict Earthquakes?

So far, the answer is no. Despite frequent claims to the contrary, no reliable short-term earthquake prediction method has ever been developed. Nor do scientists expect to develop a method in the foreseeable future.

However, based on scientific data, probabilities can be calculated for future earthquakes. For example, comprehensive assessments of long-term earthquake rates in California tell us there is roughly a 2-in-3 chance that a magnitude 6.7 or larger earthquake will strike in the next 30 years in the greater San Francisco Bay Area. Within the State of California as a whole, earthquakes this large are virtually certain (a 99 percent probability) in that same time frame.

Knowing the likelihood of future earthquakes allows prudent actions to be taken to mitigate their effects, no matter when they may happen to strike.

Listen to a podcast on earthquake prediction with Mike Blanpied, Associate Coordinator of the USGS Earthquake Hazards Program.

Climate Change and Solar Storms

Are solar storms related to climate change? Find out the answer by watching USGS Climate Connections.

The arc of light heading towards the earth is a coronal mass ejection, which impacts the earth's magnetic field (shown in purple), causing magnetic storms.

Everyone is familiar with weather systems on Earth like rain, wind and snow. But space weather – variable conditions in the space surrounding Earth – has important consequences for our lives inside Earth’s atmosphere.

Solar activity occurring miles outside Earth’s atmosphere, for example, can trigger magnetic storms on Earth. These storms are visually stunning, but they can set our modern infrastructure spinning.

On Jan. 19, scientists saw a solar flare in an active region of the Sun, along with a concentrated blast of solar-wind plasma and magnetic field lines known as a coronal mass ejection that burst from the Sun’s surface and appeared to be headed for Earth.

When these solar winds met Earth’s magnetic field, the interaction created one of the largest magnetic storms on Earth recorded in the past few years. The storm peaked on Jan. 24, just as another storm began.

“These new storms, and the storm we witnessed on Sept 26, 2011, indicate the up-tick in activity coming with the Earth’s ascent into the next solar maximum,” said USGS geophysicist Jeffrey Love.” This solar maximum is the period of greatest activity in the solar cycle of the Sun, and it is predicted to occur sometime in 2013, which will increase the amount of magnetic storms on Earth.

Magnetic storms, said Love, are a space weather phenomenon responsible for the breathtaking lights of the aurora borealis, but also sometimes for the disruption of technology and infrastructure our modern society depends on. Large magnetic storms, for example, can interrupt radio communication, interfere with global-positioning systems, disrupt oil and gas well drilling, damage satellites and affect their operations, and even cause electrical blackouts by inducing voltage surges in electric power grids. Storms can also affects airline activity — as a result of last weekend’s  storm, both Air Canada and Delta Air Lines rerouted flights over the Arctic bound for Asia as a precautionary measure. Although the storm began on the 19th of January, it did not peak until January 24th.

While this particular storm had minor consequences on Earth, other large storms can be crippling, Love said. He noted that the largest storm of the 20^th century occurred in March, 1989, accompanied by auroras that could be seen as far south as Texas, and sent electric currents into Earth’s crust that made their way into the high-voltage Canadian Hydro-Quebec power grid. This caused the transformer to fail and left more than 6 million people without power for 9 hours. The same storm also damaged and disrupted the operation of satellites, GPS systems, and radio communication systems used by the United States military.

While large, the 1989 storm pales in comparison to one that occurred in September 1859 and is the largest storm in recorded history. Scientists estimate that the economic impact to the United States from a storm of the same size in today’s society could exceed $1 trillion as a result of the technological systems it could disrupt.

The USGS, a partner in the multi-agency National Space Weather Program, collects data that can help us understand how magnetic storms may impact the United States. Constant monitoring of Earth’s magnetic field allows us to better assess the impact of these phenomena on Earth’s surface. To do this, the USGS Geomagnetism Program maintains 14 observatories around the United States and its territories, which provide ground-based measurements of changes in the magnetic field. These measurements are being used by the NOAA Space Weather Prediction Center and the US Air Force Weather Agencyto track the intensity of the magnetic storm generated by this solar activity.

Absolutes, variations and proton buildings at Cayey magnetic observatory, Puerto Rico.

In addition to providing data to its customers, the USGS produces models of the Earth’s magnetic field that are used in a host of applications, including GPS receivers, military and civilian navigational systems, and in research for studies of the effects of geomagnetic storms on the ionosphere (a shell of electrons and electrically charged atoms and molecules surrounding Earth), atmosphere, and near-space environment.

• Visit the USGS Geomagnetism Program home page.
• Are solar storms related to climate change? Find out the answer by watching USGS Climate Connections.
• Learn more with the USGS Calendar.