Is there any scientific explanation for increasingly violent natural disasters?

The_Absolute

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?

chriscolose

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

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

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

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

Up to 4m people killed in one flood! I just can't fathom a natural disaster on that scale.

turbo

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

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

True or not, none of that has anything to do with the topic in the OP.

mheslep

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

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

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:

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

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

The internet. More media coverage of natural disasters, stories being reported with live footage thanks to the internet.

Evo

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

There is an interesting paper on this topic:
Normalized Hurricane Damage in the United States: 1900–2005
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