Credit NASA
# 10,370
Although it may sound like the plot of a bad made-for-TV sci-fi movie, the threat from solar storms is quite real, and is taken very seriously by governments around the globe. Like great earthquakes (8.0+), and Cat 5 hurricanes, truly destructive solar flares are extremely rare – but they do occur.
A Solar Flare is the brief, sudden release of radiation energy (X-Ray, Gamma Rays, & energetic particles (protons and electrons)) from the surface of the sun, generally in the vicinity of an active sunspot.
Solar flares are rated as either C Class (minor), M Class (Moderate), or X Class (extreme), and while the electromagnetic radiation they release can reach earth in only about 8 minutes time, their effects are mostly limited to disrupting communications and potentially damaging satellites.
A CME (Coronal Mass Ejection) is the ejection of a massive amount of plasma (electrons and protons & small quantities of helium, oxygen, and iron) from the the sun that may last for hours. Some of this plasma falls back into the sun, but trillions of tons can escape and if aimed in their direction, impact surrounding planets.
A CME may arrive on earth – 93 millions miles distant from the sun – anywhere 12 to 72 hours after it is observed, and spark a Geomagnetic Storm. The quicker it arrives, the more powerful it is apt to be.
While they pose no direct physical danger to us on the earth’s surface (we are protected by the earths magnetic field and atmosphere), a large CME can wreak havoc with electronics, power generation, and radio communications. Two recent examples: In 1989 space weather caused a major power outage in Quebec, and in 2003 a solar storm damaged a number of satellites and also caused some power outages in Europe.
Back in 2010 we looked at the granddaddy of all known solar storms, the Carrington Event of 1859, and have since looked at preparations for the next one by our own government, including Solar Storms, CMEs & FEMA & NASA Braces For Solar Disruptions.
In 2009 the National Academy of Sciences produced a 134 page report on the potential damage that another major solar flare could cause in Severe Space Weather Events—Understanding Societal and Economic Impacts. Among their conclusions:
These assessments indicate that severe geomagnetic storms pose the risk for long-term outages to major portions of the North American grid. While a severe storm is a low-probability event, it has the potential for long-duration catastrophic impacts to the power grid and its affected users. The impacts could persist for multiple years with a potential for significant societal impacts and with economic costs that could be measurable in the several trillion dollars per year range.
In November of 2012 the U.S. National Intelligence Council released a report called "Global Trends 2030: Alternative Worlds" that tries to anticipate the global shifts that will likely occur over the next two decades (see Black Swan Events). Making their top 10 list (coming in at #7) was:
7. Solar Geomagnetic Storms
"Solar geomagnetic storms could knock out satellites, the electric grid, and many sensitive electronic devices. The recurrence intervals of crippling solar geomagnetic storms, which are less than a century, now pose a substantial threat because of the world's dependence on electricity," the report says.
And in 2013 Lloyds issued a risk assessment for the insurance industry called Solar storm Risk to the north American electric grid which calls another `Carrington’ class event inevitable, and the effects likely catastrophic, but the timing is unknowable.
While unquestioningly rare events, in 2012 we came unnervingly close to seeing a solar disaster when the largest CME in more than 150 years leapt from the surface of the sun – but fortunately not in Earth’s direction. This from NASA.
Near Miss: The Solar Superstorm of July 2012
July 23, 2014: If an asteroid big enough to knock modern civilization back to the 18th century appeared out of deep space and buzzed the Earth-Moon system, the near-miss would be instant worldwide headline news.
Two years ago, Earth experienced a close shave just as perilous, but most newspapers didn't mention it. The "impactor" was an extreme solar storm, the most powerful in as much as 150+ years.
"If it had hit, we would still be picking up the pieces," says Daniel Baker of the University of Colorado.
A ScienceCast video recounts the near-miss of a solar superstorm in July 2012. Play it
From a preparedness perspective, that wasn’t a `near miss’ . . . it was a `near hit’, and only reinforces the view that a having a major CME impact the earth is just a matter of when, not if.
The UK first added severe space weather to the National Risk Register in 2012 (see updated UK: 2015 Civil Risks Register). Yesterday the UK’s Department for Business Innovation & Skills released a Space Weather Preparedness Strategy PDF report that:
. . . sets out the UK-wide strategy for preparing for, and responding to, the demands of a severe space weather event. It covers the areas which might be affected by the risk, including:
- electrical power
- transport
- satellite navigation and timing
- telecommunications
- government (both at central and local levels)
It also covers how to co-ordinate planning across sectors.
Although UK-centric, this document provides a excellent insight into the planning that governments are putting into mitigating this threat. As this document points out, a CME impact would affect some countries more severely than others, with higher latitude regions at the greatest risk of seeing major damage.
Our dependence upon our modern infrastructure, just in time deliveries, and a continuous supply of electricity makes all of us particularly vulnerable to any sudden interruption. While governments prepare for, and work to harden our infrastructure against, major threats . . . individuals, families, communities, and businesses have a role to play as well.
Which is why agencies here in the United States - like the HHS, CDC, FEMA, Ready.gov and others - work each day to convince citizens of the importance of being prepared for the unexpected, and why I devote a fair amount of this blog to everyday preparedness.
I certainly don’t advocate lying awake at night worrying about solar flares (I certainly don’t!). But I do believe that we all need to be prepared to deal with a variety of disaster scenarios.
The simple truth is, if you are well prepared to deal with an earthquake, pandemic, or a hurricane . . you are automatically in a better position deal with any other disaster, including low probability-high impact events like massive solar storms.
September is National Preparedness Month, and as we do every year, we’ll be devoting a good deal of blog space to that subject. But preparedness isn’t something you should wait to get started on. A solar storm, a great earthquake, or an epic tsunami may not happen again for decades – but it could just as easily happen tomorrow.
For more information on emergency preparedness, some of my preparedness blogs include:
0 komentar:
Posting Komentar