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Is there any scientific explanation for increasingly violent natural disasters?

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The_Absolute
#1
Nov14-09, 10:52 PM
P: 182
Shortly after the year 2001, to now, there have been more increasingly violent earthquakes, hurricanes, tsunamis, tornadoes, etc... than in any other decade in history. I wanted to know if there is a natural, geological, and meteorological explanation for this. Not too long ago, there were Two massive earthquakes, happening on different continents, within less than 15 minutes apart from each other. What gives?
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chriscolose
#2
Nov14-09, 11:03 PM
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Not that I know this for sure, but the claim that "there have been more increasingly violent earthquakes, hurricanes, tsunamis, tornadoes, etc... than in any other decade in history" sounds pretty dicey. Where do you get this from? How good is the data for this, especially for older times?
Ophiolite
#3
Nov15-09, 06:12 AM
P: 274
Seven points:

1. A major disadvantage of the human cognitive system is its difficulty in recognising long term patterns, or of envisaging at a 'gut level' that things could be different from what they are now. Earthquakes, volcanic eruptions, harsh winters, violent storms, etc are stochastic processes and so, from time to time, we will have noticeably more or less of these. We are likely in such a phase at present.

2. Weather related phenomena may be tied either to global warming, or periodic events such as an El Nino.

3. There is some evidence that earthquakes may occur in series. The details are being worked out at present.

4. There are more people around today than thirty, fifty, or one hundred years ago, so more people are affected by any single event.

5. There are vastly better sensing systems for things such as earthquakes or weather patterns. (I recall that there are around twice as many seismic stations operational today than fifteen years ago, for example. Or consider improved Earth observation satellites.)

6. We now have 24 hour news channels. "Life proceeds normally for inhabitants of small Italian village" is not a headline that will work. The media are hungry for disasters. [Place photographer with scene of maximum devastation in background. Shake camera to simulate aftershock. Use portable fan to give impression of growing wind strength, etc.]

7. As Chriscolose said - and this may be the most important one - are there more natural disasters? How are we assessing them? What does it take to qualify?

Andre
#4
Nov15-09, 07:56 AM
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Is there any scientific explanation for increasingly violent natural disasters?

If you check the volcanic sulphur markers in the Greenland (GISP-2))ice cores, it appears that there are prolongued periods of high volcanic activity alltenated with quiet periods. It's specially noted the increased volanic activity during the last stage of the last glacial transition and the early holocene, suggesting that there might be some relation. After that time, for instance, both the -now dormant- volcanic Eifel in Germany and Massif Central in France had been quite active then.
Evo
#5
Nov15-09, 12:55 PM
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Quote Quote by The_Absolute View Post
Shortly after the year 2001, to now, there have been more increasingly violent earthquakes, hurricanes, tsunamis, tornadoes, etc... than in any other decade in history. I wanted to know if there is a natural, geological, and meteorological explanation for this. Not too long ago, there were Two massive earthquakes, happening on different continents, within less than 15 minutes apart from each other. What gives?
None of this is true. As has ben mentioned, people are living in areas of the world they haven't before, in greater concentrations, with more media coverage, measurents are being taken where they haven't been before. This is why someone would mistakenly assume that hurricanes, etc... have gotten worse, or that there are worse earthquakes. One simply has to look back on disasters like Vesuvius and Krakatoa to realize that we've had nothing of that nature happen in the last hundred years.

Ten deadliest natural disasters
Note: This list excludes diseases and famines, which would otherwise occupy the entire list.

Rank Year Event Location Date Death Toll (Estimate)
1. 1931 China floods China July-November 1931 1000000–4000000*[1]
2. 1887 Yellow River flood China September-October 1887 900000–2000000
3. 1556 Shaanxi earthquake Shaanxi Province China January 23 1556 830000
4. 1970 Bhola cyclone Bangladesh November 13 1970 500000
5. 2004 Indian Ocean earthquake/tsunami Indian Ocean December 26 2004 443929
6. 526 Antioch earthquake Antioch Byzantine Empire May 20 526 250000
7. 1976 Tangshan earthquake Tangshan Hebei China July 28 1976 242 000
8. 1920 Haiyuan earthquake Haiyuan Ningxia-Gansu China December 26 1920 240000
9. 1839 India Cyclone India November 25 1839 300000
10. 1975 Banqiao Dam flood Zhumadian Henan Province China August 7 1975 90000–230000

* Estimate by Nova's sources are close to 4 million and yet Encarta's sources report as few as 1 million. Expert estimates report wide variance.

http://en.wikipedia.org/wiki/List_of..._by_death_toll
mheslep
#6
Nov15-09, 08:27 PM
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Quote Quote by Evo View Post
1. 1931 China floods China July-November 1931 10000004000000*[1]
Up to 4m people killed in one flood! I just can't fathom a natural disaster on that scale.
turbo
#7
Nov15-09, 08:49 PM
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With the digital information explosion, it is FAR easier to get video and stills of destruction from remote places, and it happens almost immediately. With minimal research, a bit of fact-checking and some production time, the piece could be on the TV and Internet news sites in an hour or two - or perhaps instantly with a raw streaming feed.

In the mid-1800s news didn't travel like that, and it was often quite stale. Lack of immediacy relegates current events to "history" which is less likely to sell papers. If yours is the first paper in London to announce a big earthquake in central China, you might sell more issues than your competitors that day. As more news comes in and death-tolls are announced, the story not only falls below the fold pretty quickly, but it gets buried inside the paper. Old news doesn't sell papers or ad-space.

Today's news outlets thrive on hyperbole, and put stuff out with a "context" that is often quite limited. Ex: "The last two hurricanes to hit New Orleans were the strongest to hit in 50 years." Such a statement might be true, but hurricanes are pretty quirky storms and trying to show some kind of trend based on a couple of observations (small-sample statistics) would be quite suspect.

There probably weren't many people living in the region centered on the New Madrid fault in 1811-1812. If such a quake occurred today in a dense urban area, the loss of human life could be staggering.
russ_watters
#8
Nov16-09, 06:54 PM
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Quote Quote by mheslep View Post
Up to 4m people killed in one flood! I just can't fathom a natural disaster on that scale.
And the disease and famine incidents in the past few hundred years or so have been up to two orders of magnitude worse!
russ_watters
#9
Nov16-09, 06:55 PM
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Quote Quote by Xnn View Post
I will not comment about earthquakes and tsumani's.
However, there has been an increase in extreme precipitation
events due to global warming/greenhouse gases.
True or not, none of that has anything to do with the topic in the OP.
mheslep
#10
Nov16-09, 07:03 PM
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Quote Quote by russ_watters View Post
And the disease and famine incidents in the past few hundred years or so have been up to two orders of magnitude worse!
Sure, as have the wars. It's the timescale that struck me - wiping out all those people a day or even in minutes.
Count Iblis
#11
Nov16-09, 07:06 PM
P: 2,158
We also have many people living in big cities. To get a disaster, all you need is intense rain for a longer time than we are used to now. You don't need to think about extreme events like cyclones. If it simply rains a bit more intensely and a bit longer than usual, the drainage system won't be able to handle it and you get flooding. Due to Global Warming, the average rainfall has to increase (because higher temperatures means higher evaporation rate and on average, as much rain has to fall as is evaporating from the oceans).

A good example:

http://en.wikipedia.org/wiki/Maharashtra_floods_of_2005
mheslep
#12
Nov16-09, 07:09 PM
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Quote Quote by russ_watters View Post
True or not, none of that has anything to do with the topic in the OP.
Good point. The OP was concerning natural disasters, not a noticeable (or not) signal in storm intensity which may be very different things, as Emanuel also points out:

Quote Quote by Emanuel
7.) Q: Does this mean that we are seeing more hurricane-caused damage in the U.S. and elsewhere?

A: There is a huge upward trend in hurricane damage in the U.S., but all or almost all of this is due to increasing coastal population and building in hurricane-prone areas. When this increase in population and wealth is accounted for, there is no discernible trend left in the hurricane damage data. Nor would we expect to see any, in spite of the increase in global hurricane power. The reason is a simple matter of statistics: There are far too few hurricane landfalls to be able to discern any trend. Consider that, up until Katrina, Hurricane Andrew was the costliest hurricane in U.S. history. But it occurred in an inactive year; there were only 7 hurricanes and tropical storms. Data on U.S. landfalling storms is only about 2 tenths of one percent of data we have on global hurricanes over their whole lifetimes. Thus while we can already detect trends in data for global hurricane activity considering the whole life of each storm, we estimate that it would take at least another 50 years to detect any long-term trend in U.S. landfalling hurricane statistics, so powerful is the role of chance in these numbers.

8.) Q: I gather from this last discussion that it would be absurd to attribute the Katrina disaster to global warming?

A: Yes, it would be absurd.
http://wind.mit.edu/~emanuel/anthro2.htm
Not sure I'm in bounds posting the above from the author's website, but it seems appropriate given the earlier reference to his Nature article.
mheslep
#13
Nov16-09, 07:25 PM
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Quote Quote by Count Iblis View Post
We also have many people living in big cities. To get a disaster, all you need is intense rain for a longer time than we are used to now. You don't need to think about extreme events like cyclones. If it simply rains a bit more intensely and a bit longer than usual, the drainage system won't be able to handle it and you get flooding. Due to Global Warming, the average rainfall has to increase (because higher temperatures means higher evaporation rate and on average, as much rain has to fall as is evaporating from the oceans).

A good example:

http://en.wikipedia.org/wiki/Maharashtra_floods_of_2005
The little I understand from the theory, if its correct, says that most enhanced rainfall would be over the oceans. Do you know differently?
DrClapeyron
#14
Nov16-09, 11:04 PM
P: 128
The internet. More media coverage of natural disasters, stories being reported with live footage thanks to the internet.
Evo
#15
Nov18-09, 07:17 PM
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I felt that the discussion started by Xnn warrented it's own thread.

Anyone have a catchier title?

http://physicsforums.com/showthread.php?t=356048
joelupchurch
#16
Nov19-09, 12:37 AM
P: 149
There is an interesting paper on this topic:
Normalized Hurricane Damage in the United States: 19002005
Natural Hazards Rev. Volume 9, Issue 1, pp. 29-42 (February 2008)

http://www.nhc.noaa.gov/pdf/NormalizedHurricane2008.pdf

There is another article, but not peer reviewed, which covers both hurricanes and earthquakes.

Top Ten Historical Hurricanes and Earthquakes in the U.S.: What Would They Cost Today?
http://www.air-worldwide.com/Publica...84&e=ac_112009


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