What was the worst Natural Disaster in U.S history?

[EDR1222]

Due to the extreme Death toll, the Galveston storm has to the worst. I am not sure about some of the other events, but the Okeechobee Hurricane of 1928 also resulted in tremendous loss of life.

[Aslkahuna]

Earthquakes along the San Andreas are typically shallow as is usually the case for strike slip faults. The deeper shocks are usually associated with thrust faults or subduction zone mega-thrust faults. Scientists have recently recreated the strong shaking associated with the 1906 earthquake and they have also refined the epicentral location to a point 2 miles west of the San Francisco Zoo or just off shore. Should be noted that there was a MM6.0 foreshock about a minute or two before the main shock.

Steve

[zlaxier]

There is no doubt a 7.8 in the SF-Oakland Bay area would have devastating consequences, and I would be the first to say I hope it never happens (although we all know that in time it will)... claiming its damage (a 7.8) would "dwarf" the 90,000 sq. miles of devastation Katrina left in her wake, goes beyond hyperbole.

Yes, it would dwarf it. The average single family home in the Bay area costs $600,000. The gulf coast real estate that was wrecked cost a small fraction of that.

A 7.8 in San Francisco will dwarf Katrina in economic damages by multiples. It's simple math. The property is worth more. And there's a lot more stuff to damage because of the population density.

Also, There is a major difference between a 6.9 and a 7.8. Earthquakes go up in intensity on a logorithmic scale. A 7.8 is many many times more intense than a 6.9.

[Aslkahuna]

To be specific, a 7.8 is 29 times the energy release of a 6.9. The 1906 shock came from a rupture that was 300 miles long with a swath of severely damaging intensities at least 100 miles wide. However, the fault at no time is much more than 50 or so miles inland through much of the length of the rupture. In 1906, the total population of the area affected was under 500000-today it's 8 million. The 1906 economic losses resulted in a major Depression in the US and San Francisco is still a major financial center on the West Coast (and home to the Pacific Stock Exchange). But consider this, as bad as a 7.8 along the San Andreas would be, imagine how much worse a 7.5 on the Elysian Park Fault which runs directly under downtown L.A. would be.

Steve

[Dionne]

The entire story has yet to be told on Katrina. Cleary our death toll from Katrina was well under Galveston. It is my understanding that Galveston required mass burial/burning of fatalities. Men were forced into involuntary servitude during the cleanup on Galveston. Just imagine if Katrina had made landfall 50 miles to the west? We sure wouldn't be worried about rebuilding anything.

[GalvestonDuck]

Eh, I'm biased, so why vote?

[Audrey2Katrina]

Yes, it would dwarf it. The average single family home in the Bay area costs $600,000. The gulf coast real estate that was wrecked cost a small fraction of that.

A 7.8 in San Francisco will dwarf Katrina in economic damages by multiples

Sorry, neither Stanford University (and I assume they know the area pretty well and their study is based on an 8.3) nor the USGS agree with you so we'll have to agree to disagree. And yes, thank you I'm quite familiar with a logarithmic scale--and FWIW the 1989 quake was a 7.1 not a 6.9--big difference there as well. Besides this is speculation that is almost morbid. If we're going to talk about how BIG a disaster has the potential to be, let's talk a recurrence of the New Madrid Earthquake of 1811-12 and the economic impact that would have from Chicago down to Memphis

From the USGS:

"On the basis of the large area of damage (600,000 square kilometers), the widespread area of perceptibility (5,000,000 square kilometers), and the complex physiographic changes that occurred, the Mississippi River valley earthquakes of 1811-1812 rank as some of the largest in the United States since its settlement by Europeans. The area of strong shaking associated with these shocks is two to three times larger than that of the 1964 Alaska earthquake and 10 times larger than that of the 1906 San Francisco earthquake."

--One could talk about a major hitting NYC... there are a lot of hypotheticals; the property values of Florida are also much higher than in the areas hit by Katrina--Heck one could hypothesize that IF the area stricken by Katrina HAD the property values of Florida, or a population density of So. California, or NYC, the death toll and damage total would indeed be multiples of what it alread is--and considering the damage figures now (from $80 B to as high as $125B) one can only imagine what they'd be if the property values were adjusted to such levels...if...if...if...The thread is about reality in opinions about the worst natural disaster in US History, not speculative what-ifs.

Reality is bad enough, I'd prefer not bickering over hypothetical scenarios.

A2K

[Audrey2Katrina]

imagine how much worse a 7.5 on the Elysian Park Fault which runs directly under downtown L.A. would be.

Exactly my point... besides... my vote was probably the same as that of our estimable Duck!

A2K

[Jim Cantore]

There are alot of natrual disasters that are quite possible but yet to happen that the thought of them sends chills down your spine

[zlaxier]

Sorry, I believe this would dwarf Katrina.

More than 300,000 people left homeless. Thousands of buildings collapsed or damaged beyond repair. As much as $200 billion in economic losses. Two major airports knocked out. Freeways crumbled and sunken. Mass transit disrupted. Water pipelines shattered. An untold number of fires fueled by broken gas lines.

Picture one of America's greatest cities, perched on a peninsula, cut off when bridge approaches fail. Commuting all but stops. Ships and military airlifts become the bearers of emergency food and supplies. Tent cities and makeshift trailer parks persist for months as a region already chronically short of housing struggles to rebuild.

Across the bay from San Francisco and the San Andreas looms another disaster-in-waiting: the Hayward Fault coursing through a dense urbanscape including Oakland and Berkeley.

The Hayward is much shorter and couldn't generate as big a rumble as the San Andreas. Yet, a Hayward rupture could be nearly as destructive because 400,000 people live on top of the fault, many on artificial land created over decades by filling in edges of the bay. "Made ground," as it was called in 1906, shakes the worst in an earthquake.

"These areas typically are right at water level, water saturated, lots of sandy material," says Mary Lou Zoback, a scientist with the USGS in Menlo Park. "They behave like quicksand and lose their strength. Whole houses and apartment buildings can tip over."

The process, called liquefaction, struck San Francisco's marina and financial districts in 1989. It caused a double-deck freeway section to collapse in Oakland. In a repeat of 1906, almost the entire perimeter of San Francisco and large stretches of the East Bay would liquefy. Farther south, pieces of Alameda, San Leandro, Hayward and Fremont are built on fill.

The USGS rates "very high" the chances that all the land under Foster City, population 29,500, would liquefy.

Designating a building "earthquake resistant" — the modern standard — means it won't collapse. It doesn't mean business as usual. "The public thinks it means no damage," says Richard McCarthy, executive director of the California Seismic Safety Commission. "It means you and I get out of that building alive, but the next day they start tearing it down."

Most older brick and masonry buildings — the main rubble piles from big earthquakes — have been reinforced. Still vulnerable, however, is one of San Francisco's signature housing styles: multistory wood-frame apartments above ground-floor garages or glass commercial storefronts.

"We don't know how many could collapse, certainly hundreds, maybe thousands," says Laurence Kornfield, one of San Francisco's chief building inspectors. "These are very important buildings to the city — visually and culturally." Many are rent-controlled, and landlords have little incentive to retrofit them because they can't pass the costs on to tenants.

As for pre-1970s concrete buildings, including many high-rises, the city is "just beginning to understand the scope of the risk," Kornfield says. Retrofitting can eat up three-quarters of the cost of replacing such a building, but the alternative is grim. "In a concrete collapse, pretty much everybody inside will end up in the pile of debris," he says.

http://www.usatoday.com/news/nation/200 ... over_x.htm

[Extremeweatherguy]

I think a major hurricane in NYC or a Cat. 5 in Houston/Galveston or Miami (downtown) would be worse than a 7.8 earthquake in San Francisco.

[Jim Cantore]

I think a major hurricane in NYC or a Cat. 5 in Houston/Galveston or Miami (downtown) would be worse than a 7.8 earthquake in San Francisco.

or a slow moving cat 3-5 into New Orleans, with the levees the way they are now??????

[jasons2k]

In terms of hypotheticals, an explosion of the Yellowstone Caldera would take the cake. But this thread isn't about hypothetical scenarios....

I think Galveston 1900 wins, hands-down. Some have commented that it didn't have much of a historical impact on par with Katrina, but I challenge those to thoroughly read the history of what 1900 did -- not just to Galveston but to the nation at the time.

Yes, Katrina displaced a lot of people and was quite a deadly hurricane in its own right. But 8,000 - 12,000 deaths with NO warning is the ultimate tragedy.

[Brent]

In terms of hypotheticals, an explosion of the Yellowstone Caldera would take the cake. But this thread isn't about hypothetical scenarios....

I was about to bring that up...

[Aslkahuna]

Actually, according to the USGS site the Moment Magnitude of the 1989 Lome Prieta was 6.9. The last big shock on the Hayward was in 1868 and it's estimated to have been around 7.0. Also of concern is the complex faulting south of the Hayward on the east side of San Jose extending down to where the Calaveras takes off from the San Andreas in Hollister.

Steve

[Audrey2Katrina]

Sorry, I believe this would dwarf Katrina.

You really want to make an argument over speculation don't you?

Well, sorry, but from your own source I cite the CRUX of the argument:

More than 300,000 people left homeless. Thousands of buildings collapsed or damaged beyond repair. As much as $200 billion in economic losses.

From your own source: USA TODAY:

"the Federal Emergency Management Agency (FEMA), told a Senate committee last week that 400,000 to 600,000 displaced households in Louisiana and Mississippi alone will "need to find long-term housing."

http://www.usatoday.com/news/nation/2005-10-11-homeless-cover_x.htm

I also note your article (an alarmist worst-case speculation by a journalist as opposed to my stated conducted study by a major university right there in the area) referred to "estimated" $200 billion in "economic losses" as opposed to factual estimated damage--the former much more vague and taking into account a lot more than just insurance claims and infrastructural repair. Using your own "economic loss" tally, As it is now, the official damage estimates for Katrina run as high as $125 billion NOW, and total "economic losses" could be as high as that very $200 Billion figure your article cites.

http://www.usatoday.com/news/nation/2005-09-18-bush-plan-analysis_x.htm

Now I'm already aware that the "damage" total will in all likelihood fall short of that humongous figure; but IF you're talking "economic losses", well, in your own words, do the math: Congress has already appropriated approximately $70 Billion in Katrina related costs, and anothe $40 Billion is waiting in the wings... add that to the Insured estimates that have already exceeded $40 Billion, and the "at least" matching cost to the private sector, and another matching figure in infrastructure to the 90,000 sq. miles of damaged area, and--well, you get a figure in "economic losses" pretty much equaling, if not exceeding your own sources estimates for the Bay area.

This "dwarfs" Katrina? Not even in citing the very sources you've used is this the case. It MAY match it... maybe not--but hardly dwarfs it. Like I said originally-- hyperbole. All that other stuff is geological data that is really superfluous to the figures already presented.

Now you can continue to post further your opinions on the matter, as you are certainly entitled to them; but the raw facts do not support your position. Aside from all this, you persist in speculating on a hypothetical case that could "dwarf" Katrina. Hey, you know what? I agree with you that there ARE literally dozens of "potential" scenarios that COULD dwarf Katrina--and I've listed a few--it's just that a 7.8 in S.F. is NOT one of them--even by a study by one of the areas most prestigious universities as opposed to a journalists parsing of words hither and yon intertwined with data from USGS and other sources attempting to lend credibility to that position. Intellectual and Academic honesty belies the "dwarf" scenario en toto.

Finally, I reiterate, this is not a thread titled: "What COULD BE the worst natural disaster in US History?"... It's what do you think IS the worst natural disaster, and the operative word, to cite a former president, is IS.

Now based on the opinions, at least so far, the majority here sees it as Katrina--all speculation aside. Frankly, I disagree with that consensus as human LIFE is priority one IMHO, and that gives Galveston the nod, (I have consistently put human life as priority one) but others see multifarious other factors including a death toll potentially in the thousands AND economic impact over a vast area--so be it--it's just a poll of opinions. The SF quake of 1906 would be in my top 10... probably after Galveston, Katrina, and the Dust Bowl. Speculating on what COULD be the worst is really a topic for another thread. If you wish to start one, I suggest you ask the moderators to OK a poll on speculation--it might be an interesting poll. There are a LOT of disasters out there waiting to happen as Floyd adroitly points out. It's just that this is not the topic of this thread. With that comment, I call a truce and we'll just have to disagree on this matter. If you wish to continue to disagree, have a good time; but I'll return to reading coments on REALITY, and leave all this speculation for another thread.

PAX!

A2K

[Audrey2Katrina]

In terms of hypotheticals, an explosion of the Yellowstone Caldera would take the cake. But this thread isn't about hypothetical scenarios....

Absolutely! Although there is something about a huge east coast Tsunami if there were a major shift somewhere along the Canary Island (Or is it Azores?) zone. But the point is well taken--it's not about hypotheticals, and I agree with your assessment.

A2K

[wxmann_91]

Ya know what would dwarf Katrina? 9.0 quake near Puerto Rico that sends a teletsunami propagating across the Atlantic, Caribbean, and GOM.

[Audrey2Katrina]

Actually, according to the USGS site the Moment Magnitude of the 1989 Lome Prieta was 6.9.

Granted, the 6.9 is the MM, and the 7.1 is the surface magnitude. Is there a thread in here on Earthquakes? As I really don't want to have this issue (earthquakes and speculation) to hijack the central theme here, and I appreciate your input in here on this matter--always room to learn more. There is an excellent "handbook" by the USGS on Bay area quakes:

http://pubs.usgs.gov/gip/2005/15/

For anyone interested!

A2K

[jasons2k]

In terms of hypotheticals, an explosion of the Yellowstone Caldera would take the cake. But this thread isn't about hypothetical scenarios....

Absolutely! Although there is something about a huge east coast Tsunami if there were a major shift somewhere along the Canary Island (Or is it Azores?) zone. But the point is well taken--it's not about hypotheticals, and I agree with your assessment.

A2K

Yep, that's also very true. But I would consider the Canary Island Tsunami, along with a devastating asteroid or massive solar flare or whatever in the category of a global disaster. In terms of a US disaster, the Yellowstone Caldera would dwarf any worst-case earthquake (i.e., New Madrid or SFO) or any worst-case hurricane (i,e., NYC or Tampa). Millions would perish if Yellowstone ever blew its top. OK, enuf from me about hypotheticals...

I also strongly agree with your point above that loss of life is the number one priority and the true measuring stick in terms of what is a "disaster". Economic losses and displaced persons aside, human life cannot be replaced. And FWIW the NWS warned LA and MS two full days before Katrina's landfall most of the area would be "uninhabitable for weeks, perhaps longer" and "water shortages will make human suffering incredible by modern standards". I know we've all seen this but I cite it to point out those in Galveston didn't have "fair warning", if you will, of what was about the hit them. A large portion of the population simply had no choice but to drown, including a disproportionate amount on children.

If one values life more than property, no other disaster comes close.