Richland CERT

Richland CERT
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Friday, January 21, 2011

GREAT CENTRAL U.S. SHAKEOUT

FEMA is running a Earthquake drill for the Central U.S. on April 28, 2011 at 10:15 am.
DROP - COVER - HOLD ON
Disaster preparation is the key to survival. In this case an ounce of prevention can make the difference between life and death. Read the following article.

1812 New Madrid earthquake

The 1811-1812 New Madrid Earthquakes (pronounced /nuː ˈmædrɨd/) were an intense intraplate earthquake series beginning with an initial pair of very large earthquakes on December 16, 1811. These earthquakes, as well as the seismic zone of their occurrence, were named for the Mississippi River town of New Madrid, Louisiana Territory, now Missouri.
There are estimates that the earthquakes were felt strongly over roughly 130,000 square kilometers (50,000 square miles), and moderately across nearly 3 million square kilometers (1 million square miles). The historic 1906 San Francisco earthquake, by comparison, was felt moderately over roughly 16,000 square kilometers (6,000 square miles).

Earthquakes

  • December 16, 1811, 0815 UTC (2:15 a.m.); (M ~7.2 – 8.1[1]) epicenter in northeast Arkansas. It caused only slight damage to man-made structures, mainly because of the sparse population in the epicentral area. The future location of Memphis, Tennessee experienced level IX shaking on the Mercalli intensity scale. A seismic seiche propagated upriver and Little Prairie was heavily damaged by soil liquefaction[2]
  • December 16, 1811, 1415 UTC (8:15 a.m.); (M ~7.2–8.1) epicenter in northeast Arkansas. This shock followed the first earthquake by six hours and was similar in intensity.[1]
  • January 23, 1812, 1500 UTC (9 a.m.); (M ~7.0–7.8[1]) epicenter in the Missouri Bootheel. The meizoseismal area was characterized by general ground warping, ejections, fissuring, severe landslides, and caving of stream banks. Johnson and Schweig attributed this earthquake to a rupture on the New Madrid North Fault. This may have placed strain on the Reelfoot Fault.[2]
  • February 7, 1812, 0945 UTC (4:45 a.m.); (M ~7.4–8.0[1]) epicenter near New Madrid, Missouri. New Madrid was destroyed. At St. Louis, Missouri, many houses were severely damaged, and their chimneys were toppled. This shock was definitively attributed to the Reelfoot Fault by Johnston and Schweig. Uplift along a segment of this reverse fault created temporary waterfalls on the Mississippi at Kentucky Bend, created waves that propagated upstream, and caused the formation of Reelfoot Lake by obstructing streams in Lake County, Tennessee.[2]
Susan Hough, a seismologist of the United States Geological Survey (USGS), has recently estimated the earthquakes' magnitudes as "right around magnitude 7. Possibly a bit below, possibly a bit above, but not as big as 7.5."[3]

Effects

Some sections of the Mississippi River appeared to run backward for a short time.[2] Sand blows were common throughout the area, and can still be seen from the air in cultivated fields. The shockwaves propagated efficiently through midwestern bedrock. Residents as far away as Pittsburgh and Norfolk were awakened by intense shaking.[4] Church bells were reported to ring as far as Boston, Massachusetts and York, Ontario (now Toronto), and sidewalks were reported to have been cracked and broken in Washington, D.C.[5] There were also reports of toppled chimneys in Maine.[citation needed]
Eliza Bryan[6] in New Madrid, Territory of Missouri, wrote the following eyewitness account in March, 1812.
On the 16th of December, 1811, about two o'clock, a.m., we were visited by a violent shock of an earthquake, accompanied by a very awful noise resembling loud but distant thunder, but more hoarse and vibrating, which was followed in a few minutes by the complete saturation of the atmosphere, with sulphurious vapor, causing total darkness. The screams of the affrighted inhabitants running to and fro, not knowing where to go, or what to do — the cries of the fowls and beasts of every species — the cracking of trees falling, and the roaring of the Mississippi — the current of which was retrograde for a few minutes, owing as is supposed, to an irruption in its bed — formed a scene truly horrible.
The Shaker diarist Samuel Swan McClelland described the effects of the earthquake on the Shaker settlement at West Union (Busro), Indiana, where the earthquakes contributed to the temporary abandonment of the westernmost Shaker community.[7]

Disaster relief

A request, dated January 13, 1814, by William Clark, the governor of Missouri Territory (the territory was renamed soon after the quake to eliminate confusion with the new state of Louisiana), asked for federal relief for the "inhabitants of New Madrid County." This was possibly the first example of a request for disaster relief from the U.S. Federal government.

 Geology

The underlying cause of New Madrid earthquakes is not well understood, but modern faulting seems to be related to an ancient geologic feature buried under the Mississippi River alluvial plain, known as the Reelfoot Rift
The New Madrid Seismic Zone is made up of reactivated faults that formed when what is now North America began to split or rift apart during the breakup of the supercontinent Rodinia in the Neoproterozoic Era (about 750 million years ago). Faults were created along the rift and igneous rocks formed from magma that was being pushed towards the surface. The resulting rift system failed but has remained as an aulacogen (a scar or zone of weakness) deep underground. Another unsuccessful attempt at rifting 200 million years ago created additional faults, which made the area weaker. The resulting geological structures make up the Reelfoot Rift, and have since been deeply buried by younger sediments. But the ancient faults appear to have made the rocks deep in the Earth's crust in the New Madrid area mechanically weaker than much of the rest of North America.
This weakness, possibly combined with focusing effects from mechanically stronger igneous rocks nearby, allows the relatively small east-west compressive forces that exist in the North American plate to reactivate old faults, making the area prone to earthquakes.[8]
Since other rifts are known to occur in North America's stress environment but not all are associated with modern earthquakes, (for example the Midcontinent Rift System that stretches from Minnesota to Kansas), other processes could be at work to locally increase mechanical stress on the New Madrid faults. Stress changes associated with bending of the lithosphere caused by the melting of continental glaciers at the end of the last Ice Age, has been considered to play a role,[9] as well as downward pull from sinking igneous rock bodies below the fault.[10] It has also been suggested that some form of heating in the lithosphere below the area may be making deep rocks more plastic, which concentrates compressive stress in the shallower subsurface area where the faulting occurs.[11] There may be local stress from a change in the flow of the mantle beneath the NMSZ, caused by the sinking Farallon Plate, according to one model.[12]
When epicenters of modern earthquakes are plotted on a map, three trends become apparent. First is the general northeast-southwest trend paralleling the trend of the Reelfoot Rift, in Arkansas, south of where the epicenters turn northwest. This is a right-lateral strike-slip fault system parallel to the Reelfoot Rift.
The second is the southeast to northwest trend that occurs just southwest of New Madrid. This trend is a stepover thrust fault known as the Reelfoot Fault, associated with the Tiptonville dome and the impoundment of Reelfoot Lake. Epicenter locations on this fault are more spread out because the fault surface is inclined and dips into the ground, towards the south, at around forty degrees. Slip is towards the northeast. Motion on this fault in the 1811-1812 series created waterfalls on the Mississippi.
The third line, extending northeast from the northwestern end of the Reelfoot Fault is another right-lateral strike-slip fault, termed New Madrid North.

 Seismic Zone

The epicenters of over 4,000 earthquakes can be identified from seismic measurements taken since 1974. It can be seen that the earthquakes originate from the seismic activity of the Reelfoot Rift. The zone which is colored in red on the map is called the New Madrid Seismic Zone.

 Recent earthquakes

4000 earthquake reports since 1974
The zone remains active today. In recent decades minor earthquakes have continued.[5] New forecasts estimate a 7 to 10 percent chance, in the next 50 years, of a repeat of a major earthquake like those that occurred in 1811–1812, which likely had magnitudes of between 7.5 and 8.0. There is a 25 to 40 percent chance, in a 50-year time span, of a magnitude 6.0 or greater earthquake.[13]

 Recurrence potential

In a report filed in November 2008, The U.S. Federal Emergency Management Agency warned that a serious earthquake in the New Madrid Seismic Zone could result in "the highest economic losses due to a natural disaster in the United States," further predicting "widespread and catastrophic" damage across Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri and particularly Tennessee, where a 7.7 magnitude quake or greater would cause damage to tens of thousands of structures affecting water distribution, transportation systems, and other vital infrastructure.[14]
The potential for the recurrence of large earthquakes and their impact today on densely populated cities in and around the seismic zone has prompted research devoted to understanding in the New Madrid Seismic Zone. By studying evidence of past quakes and closely monitoring ground motion and current earthquake activity, scientists attempt to understand their causes and recurrence intervals.
The lack of apparent land movement along the New Madrid fault system has long puzzled scientists. In 2009 two studies based on eight years of GPS measurements indicated that the faults were moving at no more than 0.2 millimetres (0.0079 in) a year.[15] This contrasts to the rate of slippage on the San Andreas Fault which averages up to 37 millimetres (1.5 in) a year across California.[16]

What to Do Before an Earthquake

Earthquakes strike suddenly, violently and without warning. Identifying potential hazards ahead of time and advance planning can reduce the dangers of serious injury or loss of life from an earthquake. Repairing deep plaster cracks in ceilings and foundations, anchoring overhead lighting fixtures to the ceiling, and following local seismic building standards, will help reduce the impact of earthquakes.

Six Ways to Plan Ahead

  1. Check for Hazards in the Home
    • Fasten shelves securely to walls.
    • Place large or heavy objects on lower shelves.
    • Store breakable items such as bottled foods, glass, and china in low, closed cabinets with latches.
    • Hang heavy items such as pictures and mirrors away from beds, couches, and anywhere people sit.
    • Brace overhead light fixtures.
    • Repair defective electrical wiring and leaky gas connections. These are potential fire risks.
    • Secure a water heater by strapping it to the wall studs and bolting it to the floor.
    • Repair any deep cracks in ceilings or foundations. Get expert advice if there are signs of structural defects.
    • Store weed killers, pesticides, and flammable products securely in closed cabinets with latches and on bottom shelves.
  2. Identify Safe Places Indoors and Outdoors
    • Under sturdy furniture such as a heavy desk or table.
    • Against an inside wall.
    • Away from where glass could shatter around windows, mirrors, pictures, or where heavy bookcases or other heavy furniture could fall over.
    • In the open, away from buildings, trees, telephone and electrical lines, overpasses, or elevated expressways.
  3. Educate Yourself and Family Members
    • Contact your local emergency management office or American Red Cross chapter for more information on earthquakes. Also read the "How-To Series" for information on how to protect your property from earthquakes.
    • Teach children how and when to call 9-1-1, police, or fire department and which radio station to tune to for emergency information.
    • Teach all family members how and when to turn off gas, electricity, and water.
  4. Have Disaster Supplies on Hand
    • Flashlight and extra batteries.
    • Portable battery-operated radio and extra batteries.
    • First aid kit and manual.
    • Emergency food and water.
    • Nonelectric can opener.
    • Essential medicines.
    • Cash and credit cards.
    • Sturdy shoes.
  5. Develop an Emergency Communication Plan
    • In case family members are separated from one another during an earthquake (a real possibility during the day when adults are at work and children are at school), develop a plan for reuniting after the disaster.
    • Ask an out-of-state relative or friend to serve as the "family contact." After a disaster, it's often easier to call long distance. Make sure everyone in the family knows the name, address, and phone number of the contact person.
  6. Help Your Community Get Ready
    • Publish a special section in your local newspaper with emergency information on earthquakes. Localize the information by printing the phone numbers of local emergency services offices, the American Red Cross, and hospitals.
    • Conduct a week-long series on locating hazards in the home.
    • Work with local emergency services and American Red Cross officials to prepare special reports for people with mobility impairments on what to do during an earthquake.
    • Provide tips on conducting earthquake drills in the home.
    • Interview representatives of the gas, electric, and water companies about shutting off utilities.
    • Work together in your community to apply your knowledge to building codes, retrofitting programs, hazard hunts, and neighborhood and family emergency plans.

Know Your Earthquake Terms

Familiarize yourself with these terms to help identify an earthquake hazard:
Aftershock
An earthquake of similar or lesser intensity that follows the main earthquake.
Earthquake
A sudden slipping or movement of a portion of the earth’s crust, accompanied and followed by a series of vibrations.
Epicenter
The place on the earth’s surface directly above the point on the fault where the earthquake rupture began. Once fault slippage begins, it expands along the fault during the earthquake and can extend hundreds of miles before stopping.
Fault
The fracture across which displacement has occurred during an earthquake. The slippage may range from less than an inch to more than 10 yards in a severe earthquake.
Magnitude
The amount of energy released during an earthquake, which is computed from the amplitude of the seismic waves. A magnitude of 7.0 on the Richter Scale indicates an extremely strong earthquake. Each whole number on the scale represents an increase of about 30 times more energy released than the previous whole number represents. Therefore, an earthquake measuring 6.0 is about 30 times more powerful than one measuring 5.0.
Seismic Waves
Vibrations that travel outward from the earthquake fault at speeds of several miles per second. Although fault slippage directly under a structure can cause considerable damage, the vibrations of seismic waves cause most of the destruction during earthquakes.



What to Do Before a Thunderstorm

To prepare for a thunderstorm, you should do the following:
  • Remove dead or rotting trees and branches that could fall and cause injury or damage during a severe thunderstorm.
  • "If thunder roars, go indoors" because no place outside is safe when lightning is in the area. We want everyone to stay indoors until 30 minutes have passed after they hear the last clap of thunder.
Summary of Lightning Safety Tips for Inside the Home
  • Avoid contact with corded phones
  • Avoid contact with electrical equipment or cords. If you plan to unplug any electronic equipment, do so well before the storm arrives.
  • Avoid contact with plumbing. Do not wash your hands, do not take a shower, do not wash dishes, and do not do laundry.
  • Stay away from windows and doors, and stay off porches.
  • Do not lie on concrete floors and do not lean against concrete walls.
The following are guidelines for what you should do if a thunderstorm is likely in your area:
  • Postpone outdoor activities.
  • Get inside a home, building, or hard top automobile (not a convertible). Although you may be injured if lightning strikes your car, you are much safer inside a vehicle than outside.
  • Remember, rubber-soled shoes and rubber tires provide NO protection from lightning. However, the steel frame of a hard-topped vehicle provides increased protection if you are not touching metal.
  • Secure outdoor objects that could blow away or cause damage.
  • Shutter windows and secure outside doors. If shutters are not available, close window blinds, shades, or curtains.
  • Avoid showering or bathing. Plumbing and bathroom fixtures can conduct electricity.
  • Use a corded telephone only for emergencies. Cordless and cellular telephones are safe to use.
  • Unplug appliances and other electrical items such as computers and turn off air conditioners. Power surges from lightning can cause serious damage.
  • Use your battery-operated NOAA Weather Radio for updates from local officials.
Avoid the following:
  • Natural lightning rods such as a tall, isolated tree in an open area.
  • Hilltops, open fields, the beach, or a boat on the water.
  • Isolated sheds or other small structures in open areas.
  • Anything metal—tractors, farm equipment, motorcycles, golf carts, golf clubs, and bicycles.

Know Your Thunderstorms and Lightning Terms

Familiarize yourself with these terms to help identify an thunderstorm hazard:
Severe Thunderstorm Watch
Tells you when and where severe thunderstorms are likely to occur. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio, or television for information.
Severe Thunderstorm Warning
Issued when severe weather has been reported by spotters or indicated by radar. Warnings indicate imminent danger to life and property to those in the path of the storm.



What to do Before a Tornado

Be alert to changing weather conditions.
  • Listen to NOAA Weather Radio or to commercial radio or television newscasts for the latest information.
  • Look for approaching storms
  • Look for the following danger signs:
    • Dark, often greenish sky
    • Large hail
    • A large, dark, low-lying cloud (particularly if rotating)
    • Loud roar, similar to a freight train.
If you see approaching storms or any of the danger signs, be prepared to take shelter immediately.


Know Your Tornado Terms

Familiarize yourself with these terms to help identify a tornado hazard:
Tornado Watch
Tornadoes are possible. Remain alert for approaching storms. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio, or television for information.
Tornado Warning
A tornado has been sighted or indicated by weather radar. Take shelter immediately.


Before a Flood

To prepare for a flood, you should:
  • Avoid building in a floodprone area unless you elevate and reinforce your home.
  • Elevate the furnace, water heater, and electric panel if susceptible to flooding.
  • Install "check valves" in sewer traps to prevent floodwater from backing up into the drains of your home.
  • Contact community officials to find out if they are planning to construct barriers (levees, beams, floodwalls) to stop floodwater from entering the homes in your area.
  • Seal the walls in your basement with waterproofing compounds to avoid seepage.

Flood: Know Your Terms

Familiarize yourself with these terms to help identify a flood hazard:
Flood Watch:
Flooding is possible. Tune in to NOAA Weather Radio, commercial radio, or television for information.
Flash Flood Watch:
Flash flooding is possible. Be prepared to move to higher ground; listen to NOAA Weather Radio, commercial radio, or television for information.
Flood Warning:
Flooding is occurring or will occur soon; if advised to evacuate, do so immediately.
Flash Flood Warning:
A flash flood is occurring; seek higher ground on foot immediately.


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