Tuesday, January 23, 2018

About Today's Not So Gentle Seismic Reminder


Although today's 7.9M quake off the Alaskan coast produced only minor damage and a minuscule tsunami, the clock continues to tick inexorably towards the next great earthquake or seismic event.  
The only questions are where, and when it will happen.
Last September, on day 3 of National Preparedness Month, we looked at the seismic risks in the United States in #NatlPrep: Half Of All Americans Need An Earthquake Plan. As the USGS map above illustrates, tens of millions of Americans live or work in earthquake zones.

While the `big one' in California (see Dr. Lucy Jones: `Imagine America Without Los Angeles’) is perhaps the most anticipated major disaster of all time, there are other areas in the continental United States equally ripe for a big quake.
  • FEMA and the U.S. government recently conducted a huge drill (see FEMA: Cascadia Rising 2016)  involving 20,000 people from both the United States and Canada, in order to prepare for a catastrophic M9.0 quake & tsunami off the Pacific coast. 
  • And in 2011 – during the bicentennial of the four great New Madrid earthquakes of 1811-12 – FEMA and other federal agencies mounted the largest National Level Exercise (NLE) to that date, revolving around a catastrophic earthquake occurring in the New Madrid Seismic Zone (NMSZ) that would involve eight Central U.S. States.
In recent years Oklahoma has see a huge upsurge in seismic activity (see M5.6 Quake In Northern Oklahoma), while northern Alabama, Georgia and Eastern Tennessee - and even New York City and parts of New England  - can experience infrequent, but strong temblors (see USGS: Eastern Earthquakes - Rare But Powerful).

Perhaps least appreciated is the seismic history of South Carolina, which in 1886 was struck by an (Est. 7.3-7.6 magnitude) quake that devastated much of Charleston, South Carolina. Shaking was felt as far north as Boston, south to Cuba, and west as far as New Orleans.

An earthquake of that size today, in the same area, it is estimated would produce:
  • 45,000 injuries
  • 9,000 hospitalizations
  • 900  fatalities
  • 200,000 displaced or homeless persons
  • 20 billion dollars in Damage
While we tend to think first of local threats, other - often distant - seismic events can directly affect people and populations even thousands of miles away.  Earthquakes, volcanoes, tsunamis and even asteroid strikes can have far reaching effects.

Alaska's 1964 earthquake produced significant tsunami effects both locally, and thousands of miles away, killing 5 in Oregon and 13 in California. Chile's 1960 Valdivia earthquake sent a train of tsunamis across the Pacific, causing heavy damage and loss of life in Hawaii, Japan, and beyond (see NOAA Report).


When Mount Pinatubo erupted in the Philippines in 1991, within a year its aerosol cloud had dispersed around the globe, resulting in `an overall cooling of perhaps as large as -0.4°C over large parts of the Earth in 1992-93’ (see USGS The Atmospheric Impact of the 1991 Mount Pinatubo Eruption).

In 1816, an even greater global cooling event occurred following the 1815 eruption of  Mt. Tambora in Indonesia - killing 80,000 people from the direct effects - and thousands more globally as crops failed during the `year without a summer'.

Going back even further, to 1783 when the Craters of Laki in Iceland erupted and over the next 8 months spewed clouds of clouds of deadly hydrofluoric acid & Sulphur Dioxide, killing over half of Iceland’s livestock and roughly 25% of their human population.
These noxious clouds drifted over Europe, and resulted in widespread crop failures and thousands of deaths from direct exposure to these fumes (see Mortality in England during the 1783–4 Laki Craters eruption). There are also anecdotal reports that suggest this eruption had short-term global climate impacts as well.
More recently, in the spring of 2010, the relatively small eruption of Iceland’s Eyjafjallaj√∂kull volcano sent thick plumes of ash into the atmosphere, closing many air corridors in Europe and disrupting travel for 6 days, illustrating just how vulnerable our modern world still remains to geologic events.  
An estimated 100,000 flights were affected, at a cost of over 1.7 billion dollars.  That said, not every volcanic eruption produces large ash plumes. 

Simply put, you don't have to live or work in an earthquake zone or in the shadow a volcano to be impacted by the effects of one of these seismic disasters.
Physical effects aside, the economic effects of a great earthquake or volcanic eruption can be huge, and widespread. 
Imagine an M8.0 New Madrid quake collapsing major bridges that cross the Mississippi river, buckling the Midwest's railroad tracks and interstate highways, and taking out the dozens of critical natural gas pipelines that snake through that region.
A quake of that size could impact the transportation of food, the delivery of energy (power, gas, coal, etc.), the national power grid, and the nation's economy in ways we can only partially imagine.
While we can't prevent the next big quake from happening, we can prepare for it.
For starters - and as a bare minimum - every household should have a disaster plan, a good first aid kit (and the knowledge to use it), an emergency battery operated NWS weather radio, and emergency supplies to last a minimum of 72 hours during a disaster.

While 72 hours is an admirable start, I wouldn't feel comfortable with it. Here in the United States many agencies and organizations recommend that households work towards having a 10-to-14 day supply of food, water, and emergency supplies on hand. 
In When 72 Hours Isn’t Enough, I highlighted  a colorful, easy-to-follow, 100 page `survival guide’ released by Los Angeles County, that covers everything from earthquake and tsunami preparedness, to getting ready for a pandemic.
While admittedly California-threat specific, this useful guide may be downloaded here (6.5 Mbyte PDF).
Despite the abundant seismic risk to the nation (not to mention hurricanes, floods, tornadoes, blizzards, power outages, etc.), according to FEMA: 60% Of Americans Not Practicing For Disasters. Which means there are probably 100 million Americans living in seismically active zones who are not prepared for an earthquake.
My best advice:  Don’t be one of them.  
For more on earthquake preparedness, both here in the United States, and around the world, you may wish to revisit:

Japan's Earthquake Preparedness Messaging - Tokyo's X Day
USGS: Induced Earthquakes Raise Chances of Damaging Shaking in 2016
California Quakes : Concrete Concerns
Estimating The Economic Impact Of A San Andreas Quake
USGS/OGS Joint Statement On Increased Earthquake Threat To Oklahoma

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