Posted on 04/04/2018 8:24:32 AM PDT by C19fan
WHO CARES ?
Yeah, you’re right - we’ll have to go with ‘both’... running around like crazy people AND scamming us for grants to study the ‘issue’...
The earthquake in Virginia in 2011 was a 5.8, at least according to the USGS. It was also rated a VII ( very strong) on the Modified Mercalli scale.
Ah. I pulled that number from Wikipedia.
Thanks for the correction!
No problem. I was about 40 miles from the epicenter when it hit and it was an interesting experience. It felt like a train was hitting the building I was in, and the 500,000 gallon elevated water storage tank behind my office building was noticeably swaying. You could hear the water sloshing around inside it from more than 500 feet away.
The house I was living in at the time was about 30 miles from the epicenter and we suffered some a small amount of foundation damage and some cracked drywall inside, but all-in-all we made out [pretty well. My family has since moved a little further south and we currently live about 12 miles from the epicenter. Quite a few houses in Louisa, Fluvanna, Orange and Culpeper Counties suffered significant damage.
According to USGS, the 2011 Virginia earthquake was felt by more people in North America than any other earthquake on record (estimated at something like 60,000,000+ people) - from as far south Atlanta, Georgia, as far north as to Quebec City, Quebec, as far west as Illinois and as far east as New Brunswick.
Based on reading I have done since that quake, apparently eastern earthquakes tend to affect a much larger surface area than those in the west, which tend to be more concentrated.
Urban removal project
I live in Alexandria. On that day I was home, and the neighbors were doing some renovation work. At first, I thought one of their demo trucks were rolling by. But soon our house began shaking violently. All the pots and pans in the kitchen crashed onto the floor. I grabbed our then baby granddaughter from her crib and called for everyone to get out of the house. I shouted for my oldest grandson to wake my wife; she’s deaf and was napping upstairs. No need! Our bed was shaking so hard it woke her!
We went outside with all the other neighbors. They had no idea what was going on. I’ve been to California and I knew it was an earthquake.
The prior year, a 5.0 hit Ontario August 23rd at 1:40pm. I was working at the time near BWI Airport in Maryland. Our 4-story building shook. I thought, again, it was a big truck passing by. We learned later that it was that earthquake.
Actually the disaster in New Orleans is the ignorance of the Corp of Engineers and insurance.
1. The Corp of Engineers has built levees from St. Louis to Venice, Louisiana about 80 miles South of New Orleans. All the sediments that in the past from the Spring flood no longer go out into the marsh and swamp both North and South and East and West of New Orleans. These sediments replenished the marsh and swamp and it acted as a natural barrier to storms. Today all that sediment goes to the mouth of the river and down the continental shelf into the deep of the Gulf of Mexico. The storm levees the Corp of Engineers built around New Orleans were simply sub standard. The Corp of Engineers also dug the Ship Channel which is a straight shot from the Gulf of Mexico into the heart of New Orleans. It is also a straight shot for flood waters if a levee breaks.
2. Then there is the idiocy of Federal subsidized insurance in flood zones. Whole communities were built in areas that should have never been developed. Only the Federal insurance made this possible. It was swamp and should have been left as swamp.
3.Also to blame is the New Orleans public utility commission. The largest river in the United States flows past New Orleans. They choose to pump ground water instead of using river water for New Orleans. It is cheaper to clean up the ground water than river water to make it suitable for people. As a result the former swamp that was about 1 foot above sea level is in places 8 feet below sea level due to ground subsidence due to extraction of water from the underlying aquifers. That former swamp was no longer swamp but the home of about 300 thousand people due to federal insurance.
This was a man made disaster.
If one has a bit of time to play with google earth look at the Atchafalaya Delta south of Morgan City, Louisiana. The Atchafalaya is a distributor river of the Mississippi. It does not have the constraints of the levees that are on the Mississippi. That delta is growing and healthy. Then look at the Mississippi delta below New Orleans. The difference is stark. The Mississippi Delta is eroding. It no longer gets the sediments that keep it stable.
ps
Circa 1966 my old Geology Professor Dr. Doney said in class, “I do not know when it will happen but New Orleans will flood by Hurricane or Mississipi River levee break.”
I am well aware that earthquakes east of the Rockies are felt throughout a wider area than on the west coast. That's why the 1811–12 quakes on the the New Madrid fault were the most widely felt in US history, and why everyone wishing that California slides into the sea when the Big One hits are in for a rude awakening when the New Madrid gets froggy again.
It's true that western formations are relatively younger than on the east coast, though some rocks in the San Bernardino Mountains are 1,800 million years old. It seems to me that the barrier to the distance the shock wave travels is more a function of the number of faults, though the former may affect the latter. In any case since the faults in question are located right in New York City, I don't think it's an issue anyway.
Actually, the 2011 quake in Virginia was the most widely felt earrhquake in U.S. history; at least that is what the USGS says.
Also, I consider $100,000,000 worth of damage in a county with a total population of 34,000 people to be a pretty decent sized disaster - and that was just Louisa County, Virginia. Damage to buildings and structures was reported as far away as Brooklyn, NY.
Tsunami by US continental margin landslide off the Mid-Atlantic states???
“I consider $100,000,000 worth of damage in a county with a total population of 34,000 people to be a pretty decent sized disaster -“
As opposed to $39 billion for the same sized quake in New York City? Or maybe the same sized 1987 Whittier Narrows earthquake which caused two to three times that much destruction.
You may have actually understated the monetary losses in Virginia by up to a factor of three. However the destruction was described as “Minor and moderate damage to buildings was widespread.” That’s not a catastrophic impact by any stretch of the imagination.
In any event, my main objection was to the idea that no city “could take a 5 level quake.” East Coast, West Coast, whatever. If this report is accurate and NYC is going to be devastated by such a quake it’s because of construction not being designed for such an earthquake, not any inherent feature of the local seismic activity.
Well, watching “Piggy” Hogg implode has eaten into my supply, and payday is tomorrow. . . (grin)
And what are/were the populations of NYC and Whittier, CA?
Well, the $100M figure was, as I stated in my post, for damage only within Louisa County, Virginia.
The total cost of all damage in Virginia probably was about 3 times that.
If an office building in the Town of Culpeper essentially collapsing, and an entire high school being destroyed is considered “minor to moderate” damage then yes, I guess the damage was only minor to moderate. And those were not the only buildings which were either destroyed or damaged beyond repair.
All in all, I think we were fortunate that the epicenter of the 2011 earthquake was in a mostly rural area. Had it been centered in Washington, DC, Richmond, VA or even Charlottesville I suspect the monetary damage would have been in the billions, and I doubt we would have made it through without some fatalities and/or serious injuries. We were actually quite fortunate, but it most certainly was not a “nothing” event. At the time it hit, I knew a couple of people living in Culpeper who were original from SoCal. At first they were quite dismissive of the quake, but as the true extent of the damage became more clear, they admitted to having had their perspectives on “small” east-coast earthquakes changed.
The Whitter Narrows Earthquake was over thirty years ago. The population of Whittier at the time was about 78,000. 123 homes and 1,347 apartments were destroyed, and an additional 513 homes and 2,040 apartments were damaged. Adjusting for inflation, the damage was about $780 million.
So by the numbers the relative damage was about the same as the more recent event in Virginia as a factor of population. Since Whittier was at the epicenter, the impact was greater there than in areas of Southern California as distant from the source as those which had the worst damage in Virginia. Which is the point. I’ve acknowledged that tremors travel father back east. This article was about NYC being at the epicenter. Even so, shaking was felt throughout southern California up to San Luis Obispo and east to Las Vegas, some 260 miles away.
The worst damage in Whittier was in the old sections of town dating back to the 1920s. Showing that construction is going to be the biggest factor in a major quake in New York. We have addressed seismic issues much more so obviously than places the only get earthquakes every few decades at most. It’s crazy to deny that construction is the biggest factor.
By the way, I spoke to someone many years ago rode out the Northbridge earthquake about a mile or two from the epicenter. Like me, he had experienced earthquakes here in Southern California all his life. He said that being so close to the epicenter totally changed his view of earthquakes too.
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