Earthquake Analysis 2010

Earthquake Analysis 2010

A comparison of the total of earthquakes for 2010 to the preceding years 2000 – 2009.

(You may download a PDF copy from the QVS Blog)

The general impression that abounds is that 2010 was a particularly bad year for earthquakes and that the global incidence of earthquakes is on the increase. But is this indeed so? I take a look at the figures for 2010 and compare them to earlier years on the basis of numbers (which I do not personally consider a viable method of comparison) and on the basis of energy released which I consider to be a more realistic method.

A description of the data sources I used and the spreadsheets into which the data was loaded can be found at the end of the document together with links detailing the source web sites and to a download of the spreadsheet files.

The final two years comprise data that I have collected using the QVS Data program. Since this data is a mixture of USGS, EMSC and GeoNet (New Zealand) data, all non USGS data was removed leaving only that data which has been supplied by the USGS in the 7 day files available on the Internet. These files are downloaded into the program at 5 minute intervals during the day and thus catch any revisions and/or deletions provided they happen within a 7 day time span. For the most part I consider this to be the case.

To get a figure for energy it was assumed that all earthquakes were of the same scale (which some may not be) since any differences would be minor and should tend to cancel out.

The formula used is:

Es = (10^(4.8+(G2*1.5)))/(10^12)

This gives an energy value in Terajoules and since a magnitude 5 earthquake is 2 TJ of energy this scale has been used throughout. See Wikipedia for information on Joules.



The table above and the information on the calculation was taken from the USGS page on FAQs – Measuring Earthquakes.

The radiated energy can be obtained in various ways. Historically, the radiated energy was estimated empirically (from observations) from magnitude Ms through the Richter formula, log Es = 4.8 + 1.5Ms, where Es is seismic energy in Joules. In this formula, magnitude is measured first, after which the formula is used to obtain Es.

The data is collected into a front sheet in each spreadsheet, and then to a collection in the main spreadsheet. At this point the aggregated values have been converted to Petajoules.
Without further ado the basic figures look like this. First the raw count of earthquakes:



As you can see from the table 2010 beats all years in the decade 2000 to 2009 with the exception of 2007 which was more active for counts but lower for energy. 2008, only just pipped at the post in terms of count, was actually the lowest for energy of all 11 years.

2008 was not considered to be a particularly active year despite the high count. There was not even a magnitude 8 during the year. In fact there were fewer magnitude 7 earthquakes than average as well so it really was a quiet year. This is one of the reasons why I personally take little notice of the counts and prefer to use the energy released.

2004 of course had the magnitude 9 that gave rise to the Indonesian tsunami with such destructive results and great loss of life. But without that one single event 2004 was very quiet. If that single earthquake is removed from the figures it makes a drastic difference to the energy release and makes 2004 the quietest of all the years except 2008.

The next table is the released energy by magnitude band.



Here I have uplifted the calculated Terajoules to Petajoules to fit the display better. In terms of overall energy released 2010 is again higher than all other years except 2004 this time. The interesting thing is that whilst in terms of numbers (count) 2010 is pretty much level pegging with 2008, in terms of release it is only a little over half of the 2004 energy.

Taking a look at the energy per quake (which is not a particularly meaningful figure, just an indicator) we can see that 2010 still scores higher than all year other than 2004 – which is to be expected due to the massive magnitude 9 earthquake in 2004. You can see from the figures that this magnitude 9 released almost twice the amount of energy of the magnitude 8.8 in Chile.



In many respects 2010 can be equated to 2004 in that removing the one single large earthquake in each year then puts each year much lower down the league table, in fact almost at the bottom in each case in terms of energy.


Note that doing this, 2004 and 2010 are almost bottom, with only 2008 – the quiet year – being lower in terms of energy release.


Combined chart of Energy released and earthquake counts.

Looking at the results like this it becomes immediately clear the impact that the single large earthquake in 2004 and 2010 respectively had upon the overall.

Without the one quake in those years the graph looks like this:



It may not be a proper results set, but it does illustrate just how powerful these larger earthquakes are in terms of energy.

Another comparison is average energy per quake. This is possibly a questionable figure in terms of realistic expectation, since you will never get an ‘average’ earthquake, but as a statistic it does give another overview on each earthquake band in each year. First take a look at Magnitude 5 earthquakes.

[atsimg]http://files.abovetopsecret.com/images/member/eff10c73ff5e.gif[/atsimg]

As you can see the average energy of magnitude 5 quakes has fallen over the decade and into 2010.

[atsimg]http://files.abovetopsecret.com/images/member/73a315152006.gif[/atsimg]

I scaled the counts by a factor of 100 so that they did not swamp the graph. Now you can see above the counts alongside the ratio. As you can see the trend of magnitude 5 earthquakes rose up to 2005 and from then on through to present has flattened off. In fact the average is 1705 Magnitude 5 quakes from 2004 to 2010 so at 1813 mag 5 to 5.99 quakes this last year was hardly significant. It is higher against the 1520 for 10 years.

[atsimg]http://files.abovetopsecret.com/images/member/86728a56d57d.gif[/atsimg]

With the energy added you can now see why the overall ratio has fallen, and to be fair pretty much flattened out in the last few years. The average energy for magnitude 5.0 to 5.99 quakes over the 11 year period is 12.1 petajoules per year. 2010 @ 12.5 PJ is right on the mark.
So how about Magnitude 6 quakes?
No real scares here, in fact the magnitude 6 figures are pretty flat for the most part with average ratio of 240 terajoules per quake for the 11 year period. 2001 weighs in at 269, which is only fractionally higher than the 2003 figure, but it has to be said that 2003 and 2010 are the top two. So let’s look at the graphs for these:

[atsimg]http://files.abovetopsecret.com/images/member/d35d28ee45d6.gif[/atsimg]

Now with the counts added:

[atsimg]http://files.abovetopsecret.com/images/member/07ae85122f56.gif[/atsimg]

Even though this line is not as ‘straight’ as the ratios, nevertheless the overall picture is of an even distribution of counts with the average raw counts for the 11 year period as 142. 2010 is not out from the average at all with 143 counted.

So now the energy added:

[atsimg]http://files.abovetopsecret.com/images/member/39155a32b0ec.gif[/atsimg]

Again this is not out of the ordinary as the average for the 11 years is 132 terajoules per magnitude 6 quake and the 2010 value is 142 terajoules.

The overall trend of 6.0 magnitude quakes over the eleven years is down as shown on this graph with a polynomial (4) trend and a linear trend together:

[atsimg]http://files.abovetopsecret.com/images/member/01143b00fee3.gif[/atsimg]

Moving on to Magnitude 7 earthquakes the ration gets interesting especially since 2004 and 2010 come out as the lowest ratios.

[atsimg]http://files.abovetopsecret.com/images/member/9cca6c1d8888.gif[/atsimg]

The ratios are showing a marked downwards trend, in other words the energy release of an average magnitude 7 earthquake appears to have decreased for 2010.

[atsimg]http://files.abovetopsecret.com/images/member/26f0fb5d30d5.gif[/atsimg]

The count of the earthquakes is up, so that would explain the decrease in the ratio.

Provided that the energy released remains roughly an average for the year we can then conclude that magnitude 7 earthquakes are dropping in intensity.

[atsimg]http://files.abovetopsecret.com/images/member/4a159dd015b1.gif[/atsimg]

At a casual glance the energy seems to have dropped down to 2004 and then built back up and levelled off thereafter. Let’s take a look at the energy by itself. This is scaled down by a factor of 10 (making it Exajoules) in this graph and the one above.

[atsimg]http://files.abovetopsecret.com/images/member/94809cfe03db.gif[/atsimg]

Here we see a slight downward linear trend, reflected in the polynomial of course.
Basically then for magnitude 7 earthquakes the count is up. The average for the 11 years is 14 magnitude seven earthquakes per year and 2010 weighs in at 21 – the highest figure in all of the eleven years.

The average energy in Exajoules for the eleven year period is 13.3, and 2010 is only just above that at 14.3. This is dwarfed by 2000 which was 20.9!
In fact in the energy release rankings 2010 is a second division team being only 7th highest out of 11 or if you prefer ranking 5th behind 2009, 2007, 2002 and 2000.

[atsimg]http://files.abovetopsecret.com/images/member/0bd7cb3dfe40.gif[/atsimg]

Curiously again 2004 is the lowest.

Now we come to Magnitude 8. From this point on it is not really feasible to compare years as not every year has a magnitude 8 earthquake. Having said that there are only 2 years without a magnitude 8 so away we go….

[atsimg]http://files.abovetopsecret.com/images/member/fe62991f5c9d.gif[/atsimg]

This is of course being skewed by the Chile earthquake at magnitude 8.8 since that is so very nearly a magnitude 9.

Just as a quick exercise what would this look like if the 8.8 had been a 9 and there were therefore no magnitude 8 quakes in 2010?

[atsimg]http://files.abovetopsecret.com/images/member/10986c3d509f.gif[/atsimg]

That makes quite a difference!

I am going to pass quickly through the next two without comment but I include them for consistency.

[atsimg]http://files.abovetopsecret.com/images/member/f5dbb0e893fe.gif[/atsimg]
[atsimg]http://files.abovetopsecret.com/images/member/04e27ab9d9de.gif[/atsimg]

There is little point in showing a single 9 in the charts so I will now combine the 8 and 9 magnitudes.

[atsimg]http://files.abovetopsecret.com/images/member/7ed999c4afde.gif[/atsimg]

Energy on the left axis and counts on the right axis.

Here is the same graph with a trendline (polynomial 4) for each element.

[atsimg]http://files.abovetopsecret.com/images/member/765d79cf9835.gif[/atsimg]

Either linear or polynomial the trend over the 11 year period is slightly upwards for both number and energy released, but it must be said that the increase is not massive.

[atsimg]http://files.abovetopsecret.com/images/member/b95023b08a61.gif[/img]

The ratios of all the quakes together are below.



Chart of the Energy/Count ratio in Terajoules

This is a pretty minimal trend especially viewed as a linear trend and it could well be imagined that if history repeated itself and the overall energy falls for the next couple of years following the Chile earthquake, the trend could tip downwards.

By removing 2010 from the chart one can see just how easily at these higher magnitudes a small change can have a great influence.



Years 2000 to 2009 only

In conclusion therefore, in my opinion as a non-scientist, I believe that 2010 in terms of earthquakes was not a particularly outstanding year.

Whilst it was the second highest of the eleven years in term of energy released, the energy was well below that of 2004 because the 9.0 was one and a half times bigger than the 8.8 but twice as strong.

[atsimg]http://files.abovetopsecret.com/images/member/c9f3d94d807b.gif[/atsimg]

I believe that much of the ‘unrest’ was occasioned by the Chile earthquake which shook things up a bit and I am reasonably sure that we will see a settling down over the next two or three years.

In theory it should be possible to do this exercise with another provider – for example EMSC and whilst there are times when the EMSC data returns a higher magnitude than the USGS, there are also times when it is the other way round. I believe that the outcome would not be significantly different. It is an exercise I shall be carrying out during 2011.

We are all very grateful to the USGS and other providers of information on seismology for making this available to us. In many respects the freely available information is a part of the cause in my opinion of why the impression that things have got much worse on the earthquake front abounds.

Take for example the LISS helicorder page. This is a great facility, but then there is a deep 6 or 7 and all the recorders go black. Then people start asking why there are so many earthquakes when there is of course only one. You will find a couple of examples from 2010 on my 4Shared site. Here you will also find the spreadsheet files that go with this document.

Earthquake Analysis 2010 folder on 4Shared

A little knowledge is a dangerous thing. So armed with a little knowledge I have produced a web page that anyone can use to learn about how seismographs work and how the epicentre of an earthquake is determined. I have to say that this is put together by me but the content is by IRIS and others. There are some exercises and links to further reading at the end.

[atsimg]http://files.abovetopsecret.com/images/member/26365680dd6e.gif[/atsimg]

PuterMan
The Republic Of No Earthquakes
January 2011

A couple of supplemental charts follow purely for interest. All of these can be found in the spreadsheets.

[atsimg]http://files.abovetopsecret.com/images/member/ad9d9fc53c09.gif[/atsimg]

[atsimg]http://files.abovetopsecret.com/images/member/4a01c672d164.gif[/atsimg]

[atsimg]http://files.abovetopsecret.com/images/member/469226bf3a7f.gif[/atsimg]

Links:

The USGS Centennial Earthquake catalog web page

The Centennial Catalog (Engdahl and Villaseñor, 2002) (2.75MB PDF) is a global catalog of locations and magnitudes of instrumentally recorded earthquakes. It has been updated, and currently extends from 1900 to April 2002. It is being periodically updated as new arrival time data for recent years become available.

The ANSS Catalog Search web page

PDF version of the report

Microsoft Excel 2007 xlsx data

Damn good job puterman! I am proud of you

Fantastic work! I am going to have to back up and study a couple of the charts I found very interesting!

I've been spreading this round my quake buddies... they love it!!

Nice one, PuterMan - the superhero of quake watchers

reply to post by PuterMan


PuterMan you do some of the best work I've ever seen in my lifetime on earthquakes. Not only that, your work is extremely accurate and easily understood by the masses, not just by scientists; and I commend you on that. You do better work than any individual I've ever seen when it comes to earthquake data, as a matter of fact for an individual you do just as good or better work than most governments do in detailing their earthquake data. As a matter of fact I suspect that some of you data will be used by governments all over the world, but unfortunately I doubt that you will get the respect for the work which you most highly deserve.

You claim to be a non-scientist, but that is far from the truth when anyone looks at all of your data that you have processed for all of the masses to look at. You are a true scientist my friend, and never forget that.

What more can be said? The work you have done is incredible.

I've been thinking about it, and wondering what it is that's compelling the general impression that it has gotten so much worse this past year, when looking at your charts is obviously hasn't.

I wonder, do you think it has to do more with the amount of damage and lives lost, vs #'s and energy? In that sense, you could say the instant info at our fingertips has something to do with that also. I think though, between Haiti, Chili to name the biggies, there was just so much damage/tsunamis and death this past year that I think it's why we seem to feel it is worse...and if you look at it in that respect, it is.

Absolutely outstanding. The amount of work you have put in to your analysis is truely impressive.
Further to what Westcoast said, it would be interesting to to compare figures of lives lost and damage costs for those anthropogenic types. Also interesting would be an analysis of frequency and energy release in a given area.
Although your analysis has 5 mag and up, a total release would probably be needed in this instance and of course defining the area would probably be difficult.
If I could give you more than 1 star and flag I would!

Chile just had a pretty decent sized quake. First big one of 2011.

news.yahoo.com...

reply to post by PuterMan


Outstanding work PuterMan!!!

To be fair to all the years though - If you remove the larger quakes from the years 2004 and 2010 on certain graphs - then you should also remove the larger quakes for the other years. :-) . Kinda funny that the 2 7's in Argentina and Chile laid in wait for the New Year.

Just in case you ever think about relocating to the States or if you could work something out via internet - This might be something to look into.

Absolutely awesome work collating this info!

I have one question, which may be just flying over my head since I am a layman... what is the overall conclusion? Am I correct in saying 2010 was a 'normal' year tectonically?

TheRedneck

Very good stuff.

I wonder, how hard would it be to correlate the earthquakes away from the ring of fire and determine their proximity to Lead mines?

Last 3 or 4, Utah, Leeds, Arkansas, Bekistan or something all near Lead mining areas?

Some correlation with lunar cycles and solar / lunar eclipses.

Lots to ask.

Great though. Really makes it easier to understand on scales of energy release, rather than number / magnitude.
A novel approach.

Still shows 2010 as near the top. Wonder what it would look like over the last 100 years.

Wow, now thats some info.

Very interesting work. Thank you. I do wonder though if 2010 and so far, early 2011 seem to be "worse" because of the location of the quakes and not just because of damage or energy released. A lot of us sat up and took notice because some quakes are happening in relatively "quiet" areas. Even though they were small in size and negligible in terms of damage caused, I wonder if these smaller but still noteworthy quakes are an adjustment to the huge ones. If so, I hope we ate just about done with our "adjusting".

reply to post by Anmarie96

If you remove the larger quakes from the years 2004 and 2010 on certain graphs - then you should also remove the larger quakes for the other years. :-)

You are probably right but since the 8.8 and the 9 were so much larger than any other mag 8 quakes I put them together in my mind.

reply to post by TheRedneck


Shall we call it a 'strong' year but not 'abnormal'.

2011 looks like it might be interesting so far!

This in an absolutely extraordinary piece of data collation, presentation and analysis, especially considering that you have been working on your own. Thank you very much for the obviously considerable time, effort and analytical thought you have put into creating this and sharing it with us.

Considering that from the planet's standpoint (if I may put it that way), it is indeed to amount of energy released that matters most, your basis for comparison could not be more valid: rather than mere "numbers" of quakes, energy and the related balance/counterbalance of the immense forces at work are the fundamentals from which all else ultimately derives.

Best regards,

Mike

reply to post by PuterMan


Supposedly this year there will be increased seismic activity all across the world. I have been hearing that psychics are predicting this for 2011.

Has anyone else heard anything like this for 2011? Thanks

reply to post by punctual


Hi punctual and welcome to ATS.

I am afraid that I know nothing of the psychic predictions since, as you may have gathered, I am into the analysis of what has already happened.

There are however earthquake prediction threads here on ATS and this particular one: An Experiment in Alternative Methods of Earthquake Prediction you may find of interest. I believe it deals more with that side of things. It is a long thread - 113 pages at present - so you will have a bit of reading to do!

You could also use the search at the top of each page and see what turns up. Type something in and press return.

OK so energy released is very important, perhaps more so than magnitude number.

So how the heck do you work that formula towards individual earthquakes?

The formula used is: Es = (10^(4.8+(G2*1.5)))/(10^12)

Any chance you could provide some examples of how it works?

Using these ones for a start

Pakistan 18 JAN 2011
Mw = 7.2, mb = 6.7 (153) from neic.usgs.gov...
Me = 7.9 from earthquake.usgs.gov...

North Island NZ 18 JAN 2011
Mw= n/a, mb = 5.0 ( 28) ML = 4.8 ( 34) mblg = 0.0 ( 0) md = 0.0 ( 0) MS = 0.0 ( 0) from neic.usgs.gov...
and how would that come out if the ML was 5.744?

Loyalty islands 13 JAN 2011
Mw= 7.0 mb = 6.6 (255) ML = 0.0 ( 0) mblg = 6.0 ( 2) md = 0.0 ( 0) MS = 7.1 (298) from neic.usgs.gov...
Me = 7.2 from earthquake.usgs.gov...

It seems the most routinely available magnitude type across the board is mb and that Me although used in periods past is no longer in favour.
I hadn't noticed those Energy and Broadband Solutions under Scientific and Technical tab on some individual USGS quake reports before today

and where does Me fit in/relate to what you have done?

Energy Magnitude ( Me ).
The energy magnitude, Me, is computed from the radiated energy using the Choy and Boatwright (1995) formula (eq. 6):

Me = 2/3 log ES - 2.9

where energy is in Newton-meters.

The relationship of Me to MW.
Although Me and MW are magnitudes that describe the size of an earthquake, they are not equivalent. Me, being derived from velocity power spectra, is a measure of seismic potential for damage to anthropogenic structures. MW, being derived from the low-frequency asymptote of displacement spectra, is physically related to the final static displacement of an earthquake. Because they measure different physical properties of an earthquake, there is no a priori reason that they should numerically equal for any given seismic event. The energy magnitude, Me, is an essential complement to moment magnitude, MW, for describing the size and affect of an earthquake rather than an alternative.

Excellent!! Thank you Putermanm for sharing and educating us all in the quake threads. It's always a pleasure to read your posts!!