Earthquakes Are Not Increasing In Frequency

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posted on Sep, 27 2010 @ 06:13 PM
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Many times I have seen the claim made that 2010 has been a very bad year for earthquakes, and that the number we are having is abnormal. I have planned on investigating this for a while now, but was not able to get around to it until recently. I first looked at whether or not the number of larger quakes are increasing. For my sample I looked at all 6.0 + earthquakes that occurred between January 1 and September 26 for the past twenty years. I then divided these into three groups, 6.0 - 6.9, 7.0 - 7.9, and 8.0 -8.9. These are the graphs and statistics that this data produced.







These graphs show that the number of 6.0 + quakes have remained stable for the past twenty years. While there is the expected variation between years, these differences are not significant as can be seen from the F-scores and p-values. I also decided to include the R-square value to further show that there is no correlation between the number of earthquakes and the year.

After looking at large earthquakes I decided to look at another claim that has been made, that while we may not be having more major earthquakes this year, we are having more total earthquakes this year. For this, I once again got my data from USGS. This sample was comprised of every earthquake over 1.0 that has happened between January 1 and September 26 for the past 10 years.



Once again, the variation between years is not significant. The number of earthquakes that have occurred this year are not anomalous in any way. In fact we have had fewer earthquakes this year than previous years, although this is not significant. Once again the F-score, p-value, and R-square all support what the graph shows.

In conclusion, the frequency of total and major earthquakes have not been on the rise this year. What we have seen for this year is consistent with earthquake activity for at least the past 20 years. While I am sure there are those out there who will not be swayed by this post, hopefully others will see that the people who claim this year is significant for earthquakes are nothing more than fearmongers or are simply creating fake evidence to support their pet theory.




posted on Sep, 27 2010 @ 06:58 PM
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Earthquake events might not be - but if you check out Puterman's quake on energy released you'll find this is definitely on the up.

Having just gone through the 7.1 here in NZ (I was 10km from epicentre) it sure FEELS like there are more!


Puterman's great thread is here:

Is Escalating Earthquake Energy being concealed by scientific platitudes? : www.abovetopsecret.com...



posted on Sep, 27 2010 @ 08:28 PM
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I beg to differ

45to47south.wordpress.com...

Been working on it for 2 months now, and gone back 100 years.

Good effort on your part
, though just looking at 20 years doesn't give a true picture because its the whole of the last 20 years that the number of earthquakes has increased overall.
And just using USGS data alone you lose 20% of events that actually happened, I can see from your 7.0-7.9 chart that you are way down on the real numbers and there are issues with magnitude types, USGS use both Mw and mb which can make a big difference when you get down to the low mag 6's, a lot of them are actually 5's



posted on Sep, 27 2010 @ 08:45 PM
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reply to post by muzzy
 


The problem with going back 100 years is that our ability to detect earthquakes was not anywhere near where it is now. Technology has increased, not to mention that there are areas that weren't populated then are now. So, of course it will look like there were fewer earthquakes then. Also, the reason why the numbers are low is because I am not looking at entire years, only January 1 to September 26 so I can actually make a comparison to 2010. This topic was more to dispel the claims that 2010 has been a particularly bad year for earthquakes and that frequency is steadily increasing. What I have shown is that frequency has remained constant for 20 years and that 2010 is no different than any other year. I would be more than willing to look back further, except it would not be an accurate comparison due to the factors I have already mentioned.



posted on Sep, 27 2010 @ 09:06 PM
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Of course, you probably won't get as many flags as a "ZOMG EARTH QUAKES INCREASING NIBURU INCOMING" thread, but sound scientific research and I always appreciate that. The only thing that is increasing (and ultimately, the reason why so many perceive there to be more earthquakes this year) is that the social network (Twitter & Facebook, mainly) has gone global to a full extent. This allows people to post information real time information and to reach other people. Even in the poorest areas I think you would be challenged to go 100 miles and not find someone with access to the internet. While this isn't as exciting as some of the more end of the world types push, it's the main reason why we perceive an increase in earthquakes.



posted on Sep, 27 2010 @ 10:53 PM
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reply to post by Xcalibur254
 
and to post by zcflint05
 



I disagree again.
Just because USGS did not exist before 1972 doesn't mean that earthquakes didn't happen


A lot of historical information is held by the chinese and the japanese and they can also provide long distance data from the other side of the pacific ocean due to tsunamis from way way back.

With 24 x 7+ quakes in 2010 and 3 months to go its still the 3rd equal highest in the last 20 years 2007 - 30, 2008 - 29, 1995 - 24, 2010 - 24 (9 months).
Going back the full 100 years it comes in 4th equal (with 1995) after 1957 - 25 in 3rd place.

The technology argument doesn't explain the rise in numbers, explain why is 1957 so high? explain 1943 and 1946 which had equal to or 1 more quakes than you have for 2010 now. If it was down to technolgy then all the years prior to the computer age would be down low?, its not the case, even the 1980's were low numbers, just when everyone was getting digitally wound up, especially the Universities who did/do a lot of the seismic data gathering.
A quick overview of the "decades" graphs clearly shows technology has nothing to do with it.



edit on 27-9-2010 by muzzy because: beacuse I think while I type and thought of something else duh



posted on Sep, 27 2010 @ 11:47 PM
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reply to post by muzzy
 

Rather than looking at calendar years, doesn't make more sense to look at time spans? Today (Sept. 27) was the 270th day of the year so let's use that span for a comparison. Gotta start somewhere.

The USGS database shows 18 earthquakes >=7.0 for 2010. I would be very curious about the locations of the 24 you cite but for now, I will continue with the USGS data since it should be self consistent.
11/1/1989-7/27/1990 268 days 17 earthquakes
04/7/1995-1/01/1996 269 days 19 earthquakes
07/3/1995-2/25/1996 237 days 18 earthquakes
10/3/1995-6/17/1996 258 days 19 earthquakes
08/1/2007-4/12/2008 255 days 19 earthquakes

Yes, it's been busy 270 days this year but not unheard of, There doesn't appear to be a trend, just some spikes with 1995-1996 being most prominent.

Can you provide the database for the 24 quakes you cite? I'd be interested to run a similar study using it. It seems to be very different from the USGS catalog which shows; 18 in 2007, 12 in 2008, and 20 in 1995.

============
Your blog says:

1940-2004 the main cross referencing used is ANSS and local networks such as Geonet of New Zealand.

From the description of the ANSS catalog itself:

As a further illustration, consider these histograms of the number of events in the ANSS catalog at various magnitude levels. These plots were generated for every 5 years between 1940 and 1995. One can see the relatively low numbers of events in 1940-1960, and the sudden increase in 1965. This represents the increase in USGS earthquake monitoring efforts as well as the routine reporting of magnitude from the NEIC. Another burst can be seen in 1975 as many of the NEHRP-funded networks began to come online. Beginning in the 1980s, events at the higher magnitude levels begin to show some stability. For example, here are year-by-year histograms for the 1980s and 1990s, showing the variations in numbers of events of magnitude 4 and higher. While the number of magnitude 4.0-4.9 events gradually evolves, the number of magnitude 5 and higher events has remained relatively stable on the year to year basis.



The ANSS brings together the earthquake catalogs of its member institutions in the composite catalog. Users should be aware of the potential problems due to variations in location thresholds and methodologies from agency to agency and due to temporal variations in network configurations.

www.ncedc.org...

There is a marked increase in the contributors to the catalog which coincides with the increase in located earthquakes.

You have also used catalogs of "destructive earthquakes" do you think all earthquake are destructive? Even those which occur distant from population centers? How can those earthquakes make it into such catalogs?

The reason for an apparent increase is an increase in the ability to record earthquakes. It's not the quality of the technology as much as the numbers of station contributing, as well as changes in standards.

edit on 9/28/2010 by Phage because: (no reason given)



posted on Sep, 28 2010 @ 12:12 PM
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Originally posted by Phage
reply to post by muzzy
 

Rather than looking at calendar years, doesn't make more sense to look at time spans? Today (Sept. 27) was the 270th day of the year so let's use that span for a comparison. Gotta start somewhere.

That would skew the results, take 1955 for example, all the quakes were in the months Feb, March, April and May, there were none in the 2nd part of the year. You could do that if you want, as long as the data parameters are consistant you can run out results on anything. I set my parameters very strickly, 7.0 Mag is the bottom line, no using 6.9's. If you don't be strict then it can get really skewed.The one luxury I have allowed is using all the various magnitude types, I had to do this because over the years the types of magnitudes used on the lists changed, Mw is todays prefered type, but back in the 1980's Ms was the prefered type, and Me was all the rage at one time. So if it says 7.0 I have used it, if it says 6.9 its out, no matter what type of magnitude the 6.9 is.


The USGS database shows 18 earthquakes >=7.0 for 2010. I would be very curious about the locations of the 24 you cite but for now,

Under each years map there is a small icon which when clicked opens a page with all the earthquakes on the map, the highest magnitude, lat, long date/time, depth, location and source, At the moment this feature only goes back to 1953, I'm currently adding that data, going backwards.
2010 currently reads
Magnitude, Date(y/m/d) Time(hh:mm:ss), Latitude, Longitude, Depth, Location, Source
7.1Mw, 2010/1/3 22:36:27.9, -8.799, 157.346, 25, Solomon Islands, usgs
7.3Ms, 2010/1/12 21:53:10, 18.443, -72.571, 13, Port-au-Prince, Haiti, usgs
7.0Mw, 2010/2/26 20:31:26.5, 25.931, 128.427, 22, Rhyuku Islands, Japan, usgs
8.8Mw, 2010/2/27 6:34:14, -35.846, -72.719, 35, o/s Maule, Chile, usgs
7.0Ms, 2010/3/11 14:39:44, -34.92, -71.95, 11, Liberator Bernardo O'Higgins, Chile, usgs
7.2Mw, 2010/3/11 14:55:28, -34.25, -71.9, 20, Liberator Bernardo O'Higgins, Chile, geofon
7.2Mw, 2010/4/4 22:40:41, 32.128, -115.303, 10, Baja California, Mexico, usgs
7.7Mw, 2010/4/6 22:14:2, 2.36, 97.132, 31, o/s Sumatra, Indonesia, usgs
7.1Mw, 2010/4/11 9:40:29, -10.85, 161.15, 51, Solomon Islands, geofon
7.1Ms, 2010/4/13 23:49:38, 33.271, 96.627, 10, Yushu, China, cea
7.2Mw, 2010/5/9 5:59:44, 3.67, 96.1, 56, o/s Northern Sumatra, Indonesia, geofon
7.4Mw, 2010/5/27 17:14:48, -13.7, 166.68, 49, Vanuatu Islands, geofon
7.7Mw, 2010/6/12 19:26:50, 7.702, 91.975, 35, Nicobar islands, Indian Ocean, usgs
7.1Ms, 2010/6/16 3:16:28, -2.171, 136.549, 18, Papua, Indonesia, usgs
7.1Ms, 2010/7/18 13:4:11, -6, 150.436, 42, New Britain, PNG, usgs
7.3Ms, 2010/7/18 13:35:2, -6.019, 150.497, 57.6, New Britain, PNG, usgs
7.3Mw, 2010/7/23 22:8:11, 6.699, 123.475, 612.2, Moro Gulf, Philippines, usgs
7.6Mw, 2010/7/23 22:51:12, 6.47, 123.532, 583.8, Moro Gulf, Philippines, usgs
7.4Mw, 2010/7/23 15:9:, 6.792, 123.282, 631.2, Moro Gulf, Philippines, usgs
7.0Mw, 2010/8/4 22:1:43.89, -5.768, 150.776, 44, New Britain, Papua New Guinea, usgs
7.5Mw, 2010/8/10 5:23:47, -17.59, 167.978, 35, Vanuatu Islands, usgs
7.1Mw, 2010/8/12 11:54:16, -1.26, -77.312, 211, Pastaza, Ecuador, usgs
7.2Mw, 2010/8/13 21:19:32, 12.409, 141.487, 4.7, W of Marianas Islands, usgs
7.1Mw, 2010/9/3 16:35:42, -43.55, 172.18, 10, Darfield, Canterbury, New Zealand, geonet



Can you provide the database for the 24 quakes you cite? I'd be interested to run a similar study using it. It seems to be very different from the USGS catalog which shows; 18 in 2007, 12 in 2008, and 20 in 1995.

As mentioned above and shown on the list there are numerous sources for the data, not just one Network.The overall data is on the maps regarding multiple magnitudes recoreded for each event where available. There is no use just picking one source, as they all miss some quakes. Do you just watch one TV News channel and believe everything they say?


Your blog says:

1940-2004 the main cross referencing used is ANSS and local networks such as Geonet of New Zealand.

You have also used catalogs of "destructive earthquakes" do you think all earthquake are destructive? Even those which occur distant from population centers? How can those earthquakes make it into such catalogs?

I have used the iisee source to "find" mag 7 and higher quakes only, not just destructive. There are many "destructive" quakes in the destructive quakes catalogue below 7.0 Mag which I have not used.


The reason for an apparent increase is an increase in the ability to record earthquakes. It's not the quality of the technology as much as the numbers of station contributing, as well as changes in standards.

that still doesn't explain the spikes in 1943, 1946 and 1957. I understand what you are saying, and what you quoted from ANSS, and that would apply to quakes of less than 5.0 magnitude. Quakes of less than 4 were rarely recorded before 1942, but 7's have always been noted, and thats what we are talking about.
ANSS catalog isn't one of the most comprehensive around, but is handy to pick up the odd one that the others missed, particularily for Alaska., The NOAA catalog is far superior.









edit on 28-9-2010 by muzzy because: spelling: missing a s, d, t, and spelt channel wrong



posted on Sep, 28 2010 @ 12:20 PM
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reply to post by Xcalibur254
 


Actually, they are. Total number of earthquakes (all categories) 1990 was 16,600. This number has risen gradually to 30,000 in 2008. That's nearly double. You are cherry picking information. How are things at NASA?www.infoplease.com...



posted on Sep, 28 2010 @ 12:43 PM
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reply to post by astrogolf
 

Only the number of 5's is consistant on those charts.
So what does that say? That there has been no increase in earthquakes?
No it says the number of 5's has remained consistsant, while smaller and larger quakes have increased in number.
The lower ones due to improved monitering, the larger one due to what?? thats the big question.

Also a LOT of 5's are aftershocks of bigger quakes, so 5's are useless to build research on on their own.



posted on Sep, 28 2010 @ 02:38 PM
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We could argue till the cows come home about the numbers, but you have to ask yourself why would they downplay the numbers if they are increasing?.
My conclusion is to save spending money on upgrading infrastucture and building codes to decent earthquake resistant standards..
Where does the US Govt Federal Reserve get its info.regarding the risks? USGS of course.

You can watch current events and keep an eye on volcano's about to erupt all you want, but if you don't take the info and do something about it, then whats the point?

A lot can be learned from history.
After the Hawkes Bay 1931 quake here in NZ the building codes were drastically changed for the better.
But there is still some chain dragging going on, the recent Darfield, NZ 7.1Mw quake exposed the slack uptake of lessons learned from the past on the part of the Authorities, "it won't happen here" or " we don't get big quakes", so the older buildings without masonary reinforcement collapsed in a heap of rubble.

I don't usually get involved in political discussions ( they are all wankers) but this is a prime case of where the people elected to protect us are just not doing their job. In fact they are lying to us.



posted on Sep, 28 2010 @ 02:59 PM
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reply to post by Phage
 


Actually you make total sense. If you were going to get an average number of earthquakes, why would you use our arbitrary measurement of Jan 1 to Dec 31. Obviously earthquakes don't think on terms of years like we do. Additionally, geological time periods are expressed in terms of millenia, not years. So in order to get an accurate picture, you'd have to have millions of years of data. 100 years in terms of geology is a blink of an eye.

This entire argument on both sides is pointless.



posted on Sep, 28 2010 @ 03:17 PM
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reply to post by dbloch7986
 


Give me another few months and we can compare centuries


Rome wasn't built in a day, but it fell down pretty quickly.



posted on Sep, 28 2010 @ 03:37 PM
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reply to post by muzzy
 

I don't understand your point. Using a specific span of time does not "skew" the data, it provides an accurate representation of earthquake frequency for a period of time rather than an arbitrary deliniation of time. If a span of 365 days is used similar results are found. If a span of 730 days is used similar results are found. You use 1955 as an example. All of your data for 1955 comes from NOAA. A total of 6 earthquakes. You yourself say "There is no use just picking one source, as they all miss some quakes." Why do you believe that the data from NOAA for 1955 is complete? Why do you think all earthquakes which occurred were included? The NOAA database includes earthquakes which meet at least one of the following criteria:

Moderate damage (approximately $1 million or more), 10 or more deaths, Magnitude 7.5 or greater, Modified Mercalli Intensity X or greater, or the earthquake generated a tsunami.
It does not include all 7+ earthquakes. If it did not meet one of the above criteria it isn't there. How can you consider such incomplete data useful for any sort of statistical analysis? Do you have some reason to believe that there were only 6 large earthquakes on Earth in 1955, or that all of them met the above criteria? How do you know there were none in the later part of the year? Think about those criteria for a moment. Monetary damage, number of deaths, Mercalli scale.. All of these would tend to increase over time due to increasing development and population so the number of earthquakes included would also increase.

You claim that 7.0 is a "strict" cutoff yet it is arbitrary because you use different scales. For statistical analysis it is invalid because it is inconsistent. For example, your data includes earthquakes recorded as 6.9Mw and 6.7Mw (3/11/10). Your "luxury" of disregarding the scale skews the data. As I'm sure you are aware the Mw scale does not only "downgrade" earthquakes, it can produce higher values than Ms as well (1960 Chile for example; 9.5Mw, 8.6Ms) so an earthquake which does not qualify under Ms, may qualify under Mw. You are "having your cake and eating it too".

The caveat from ANSS (what you call your "main cross reference") does not apply only to earthquakes of 5.0 and less. The explanation makes that clear. It concerns standards and reporting procedures. The catalog shows few 7s and 8s prior to 1960, then suddenly between 1960 and 1965 the numbers suddenly increase. Why is that?

For global events, magnitudes are not routinely reported until the early 1960s. This means, for example, that the largest earthquake observed - the 1960 Chilean earthquake (Mw 9.5) - appears in this catalog without an associated magnitude.

So running a search for magnitude 7+ earthquakes on ANSS will miss many. It provides incomplete data. Incomplete data cannot be used for statistical purposes.

Let's look at those "spikes" (keeping in mind the criteria for the NOAA database). 1957; 6 of those earthquakes were located in the Aleutian Islands and occurred within days of each other, a single "event". 1943, you didn't provide the datasource. 1946, you didn't provide the datasource. Can I "explain" the spikes? Not other than to say that there are obviously periods of time which are more active than others. But no trend.

edit on 9/28/2010 by Phage because: (no reason given)



posted on Sep, 28 2010 @ 05:17 PM
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reply to post by Phage
 


The part reporting will only show that part of it, so its skewed towards the years where there were more quakes at the start rather than throughout the year.
Take it on decades if you want, the graphs are there.

1955 shows the NAOO as the source as that source is the backbone of the data available, I cross checked against ANSS and iisee and they listed the same data as NAOO. There were no other quakes in that year over 7.0.

The NAOO data base uses whatever criteria you give it, not just what you said, this is the search page
www.ngdc.noaa.gov...

As I said ANSS is just a cross reference to NAOO, ie before USGS became the main outlet for data to the public. ANSS have probably provided a dozen quakes in 100 years that the others didn't have.

The data sources are there for 1943 and 1946, on the map, click on individual icons for the details. It takes time for the icons to load especially on dial up.


You claim that 7.0 is a "strict" cutoff yet it is arbitrary because you use different scales. For statistical analysis it is invalid because it is inconsistent. For example, your data includes earthquakes recorded as 6.9Mw and 6.7Mw (3/11/10). Your "luxury" of disregarding the scale skews the data. As I'm sure you are aware the Mw scale does not only "downgrade" earthquakes, it can produce higher values than Ms as well (1960 Chile for example; 9.5Mw, 8.6Ms) so an earthquake which does not qualify under Ms, may qualify under Mw. You are "having your cake and eating it too".


Wherever available I have given the other magnitudes on the pop up balloon for each quake for comparison.
You can't just dismiss a "very strong" quake because USGS decided "oh on this one we'll use mb instead of Mw", and the mb is less than 7.0, they still chop and change when reporting todays quakes. ie they manipulate the data themselves. I know there are reasons behind this, saturation of the graph and so on over a certain magnitude, and thats why ML got replaced.


As I said before, I haven't done the text pages back before 1950 yet.

The text pages are just to give an overview, the real data is in the popup balloons, including a description of some quakes damage etc.

You can check all the data behind the 100 years if you want, I gave the search links in the side column. Its an ardious process to filter out duplicated events once you combine all the data.
And I certainly don't dismiss a 7+ mag quake from the list if it is an aftershock, like the Aluetian ones in 1957 you allude to, take 1951 and the 2 x 8.3 and 7.1 and 7.3.Taiwan quakes series, one event ... yeah right. A swarm is different than a main event and aftershocks, therefore a swarm gets listed by individual events ( if they meet the criteria)



posted on Sep, 28 2010 @ 05:21 PM
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reply to post by muzzy
 

ANSS shows nothing (zero, zilch, zip) for 1955.

Your search parameters are:

* catalog=ANSS
* start_time=1955/01/01,00:00:00
* end_time=1955/12/31,00:00:00
* minimum_magnitude=7.0
* maximum_magnitude=10
* event_type=E

No matches to your search criteria


What does that tell us? Nothing. Once again:

For global events, magnitudes are not routinely reported until the early 1960s.

That means that even if the earthquake is in the catalog, it can show a magnitude of 0. Useless for your purposes. You have no way of knowing if there were other earthquakes of 7 or greater.



The NAOO data base uses whatever criteria you give it, not just what you said, this is the search page

Incorrect.
From the top of the search page:

The Significant Earthquake Database contains information on destructive earthquakes from 2150 B.C. to the present that meet at least one of the following criteria: Moderate damage (approximately $1 million or more), 10 or more deaths, Magnitude 7.5 or greater, Modified Mercalli Intensity X or greater, or the earthquake generated a tsunami.

www.ngdc.noaa.gov...
Check 1975. NOAA shows only 11 earthquakes. USGS shows 15. Why is that?

The data is not usable for statistical purposes.


The USGS policy is to be as consistent as possible in the use of the Mw scale. You are arbitrary in your use of scales.

Different methods of estimating magnitude will be used, depending upon the time elapsed since the earthquake’s occurrence. Preliminary estimates of magnitude should not be included in statements if revised, preferred estimates of magnitude exist. If several different magnitude estimates are available, the reported magnitude should be moment magnitude, if available. Moment magnitude is the preferred magnitude for all earthquakes listed in USGS catalogs. All other magnitudes should be preserved in the database, but routine searches of the catalogs should list only the preferred magnitude. For historical earthquakes, the preferred magnitude will be the best estimate of the moment magnitude (see attached Appendix 2 – Magnitudes of Significant Earthquakes). This estimate, however, should not simply be a conversion from some other historical magnitude scale, but an estimate obtained using supplementary information (ground rupture, macroseismic data, etc.).

earthquake.usgs.gov...

edit on 9/28/2010 by Phage because: (no reason given)



posted on Sep, 29 2010 @ 01:52 AM
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reply to post by Phage
 


Thats why you have to use multiple sources to collect and confirm your data. Just go through the Recent Quakes on USGS and Geofon and see how many quakes USGS have missed, and thats with all the new digital equipment available!.

USGS are hopeless at picking quakes out of the South Pacific and South Atlantic, let alone Russia and China. I'm sure its politically motivated.
1975

ANSS shows 13 events for 1975 when I downloaded it back on Sunday, ‎20 ‎June ‎2010, ‏‎5:31:40 p.m.
year,month,day,hour,minute,seconds,lat,long,depth,mag,type
1975, 2, 2, 8, 43, 39, 53.113, 173.497, 10, 7.6, Ms
1975, 2, 4, 11, 36, 7, 40.641, 122.58, 33, 7.4, Ms
1975, 5, 10, 14, 27, 39, -38.183, -73.232, 6, 7.7, Ms
1975, 5, 26, 9, 11, 52, 35.997, -17.649, 33, 7.9, Ms
1975, 6, 10, 13, 47, 15, 43.024, 147.734, 15, 7, Ms
1975, 7, 20, 14, 37, 40, -6.59, 155.054, 49, 7.9, Ms
1975, 7, 20, 19, 54, 28, -7.104, 155.152, 44, 7.7, Ms
1975, 10, 1, 3, 29, 59, -4.882, 102.198, 33, 7, Ms
1975, 10, 6, 22, 24, 16, -12.519, 166.499, 54, 7, Ms
1975, 10, 11, 14, 35, 15, -24.894, -175.119, 9, 7.8, Ms
1975, 10, 31, 8, 28, 3, 12.54, 125.993, 50, 7.2, Ms
1975, 11, 29, 14, 47, 40, 19.339, -155.004, 9.15, 7.2, Ms
1975, 12, 26, 15, 56, 39, -16.265, -172.467, 33, 7.8, Ms

NAOO shows 13 quakes
ref,tsu,year,month, day, hour, minute, second,depth,lat, long, Ms, mb, location
4680, n/a, 1975, 2, 2, 8, 43, 39.1, 10, 53.11, 173.5, 7.6, 6.1, Near Islands, Aluetians, USA
4681, n/a, 1975, 2, 4, 11, 36, 7.5, 33, 40.64, 122.58, 7.4, 6.4, Liaoning, China
4690, n/a, 1975, 5, 10, 14, 27, 38.7, 6, -38.18, -73.23, 7.7, 6.5, Bio Bio, Chile
4691, Yes, 1975, 5, 26, 9, 11, 51.5, 33, 35.997, -17.649, 7.9, 6.7, Madeira/Atlantic Ocean
6449, Yes, 1975, 6, 10, 13, 47, 14.5, 15, 43.024, 147.734, 7.0, 5.8, Kuril Trench, Russia
4694, Yes, 1975, 7, 20, 14, 37, 39.9, 49, -6.59, 155.054, 7.9, 6.6, Bougainville, PNG
4695, n/a, 1975, 7, 20, 19, 54, 27.7, 44, -7.104, 155.152, 7.7, 6.1, Bougainville, PNG
, n/a, 1975, 10, 1, 32958.9, , , 33, -4.882, 102.198, 7.0, 6.2, Mentawai Trough, Indonesia
, n/a, 1975, 10, 6, 222416.2, , , 54, -12.519, 166.499, 7.0, 6.6, Vanuatau
4702, n/a, 1975, 10, 11, 14, 35, 15, 9, -24.894, -175.119, 7.8, 7.0, Kermadec-Tonga Trench
4703, Yes, 1975, 10, 31, 8, 28, 2.6, 50, 12.54, 125.993, 7.6, 6.4, Philippine Trench
4704, Yes, 1975, 11, 29, 14, 47, 40.4, 5, 19.334, -155.024, 7.1, 6.0, Hawaii, USA
4705, Yes, 1975, 12, 26, 15, 56, 38.7, 33, -16.265, -172.467, 7.8, 6.4, Tonga Trench/Samoa


USGS data I have has 15 events
year,month,day,lat,long, mag
1975,02,02, 53.11, 173.5, 7.6
1975,02,04, 40.64, 122.58, 7.0
1975,05,10, -38.18, -73.23, 7.8
1975,05,26, 36., -17.65, 8.1
1975,06,10, 43.02, 147.73, 7.0
1975,07,10, 06.51, 126.64, 7.0
1975,07,20, -06.59, 155.05, 7.9
1975,07,20, -07.1, 155.15, 7.7
1975,10,01, -04.88, 102.2, 7.0
1975,10,06, -12.52, 166.5, 7.0
1975,10,11, -24.89, -175.12, 7.8
1975,10,31, 12.54, 125.99, 7.6
1975,11,01, 13.84, 144.75, 7.1
1975,11,29, 19.33, -155.02, 7.2
1975,12,26, -16.26, -172.47, 7.8

iisee has 13
source,year,month,day,hour,minute,lat,long,mag,location, S=Ms reading
U, 1975, 2, 2, 8, 43, , 53.11, 173.5, 7.6, USA:Near Is.(Aleutians)(I=9) 7.4S
C, 1975, 2, 4, 19, 36, local, 40.7, 122.8, 7.3, China:Liaoning[Haicheng earthquake ](I=9+)fault 7.2S
NGR, 1975, 5, 10, 14, 27, , -38.03, -72.78, 7.7, Chile(I=8) 7.6S
GR, 1975, 5, 26, 9, 11, , 36, -17.65, 8.1, Azores 7.8S
J a, 1975, 6, 10, 22, 47, local, 43.18, 147.36, 7, Shikotan Island offshore earthquake with tsunami(Mt=7.9)6.8S
GRT, 1975, 7, 20, 14, 37, , -6.59, 155.05, 7.9, Papua New Guinea:Bougainville Is.(I=8) 7.6S
GRT, 1975, 7, 20, 19, 54, , -7.1, 155.15, 7.7, Papua New Guinea(I=7) 7.5S
MG, 1975, 10, 3, 5, 14, , 30.3, 66.3, 7, Pakistan-Iran border
GR, 1975, 10, 11, 14, 35, , -24.89, -175.12, 7.8, Tonga 7.7S
GRT, 1975, 10, 31, 8, 28, , 12.54, 125.99, 7.6, Philippines(Samar):Calbayog 7.4S
GR, 1975, 11, 1, 1, 17, , 13.84, 144.75, 7.1, Marianas:Guam 7.1B
UT, 1975, 11, 29, 14, 48, , 19.3, -155, 7.2, USA:Hawaii[Kalapana EQ](I=8)
GT, 1975, 12, 26, 15, 56, , -16.26, -172.47, 7.8, Tonga(I=5) 7.5S



the end result after filtering is 15 events
Magnitude, Date(y/m/d) Time(hh:mm:ss), Latitude, Longitude, Depth, Location, Source
7.6, 1975/2/2 8:43:39.1, 53.11, 173.5, 10, Near Islands, Aluetians, USA, noaa
7.4, 1975/2/4 11:36:7.5, 40.64, 122.58, 33, Liaoning, China, noaa
7.7, 1975/5/10 14:27:38.7, -38.18, -73.23, 6, Bio Bio, Chile, noaa
7.9, 1975/5/26 9:11:51.5, 35.997, -17.649, 33, Madeira/Atlantic Ocean, noaa
7.0, 1975/6/10 13:47:14.5, 43.024, 147.734, 15, Kuril Trench, Russia, noaa
7.9, 1975/7/20 14:37:39.9, -6.59, 155.054, 49, Bougainville, PNG, noaa
7.7, 1975/7/20 19:54:27.7, -7.104, 155.152, 44, Bougainville, PNG, noaa
7.0, 1975/10/1 3:29:58.9, -4.882, 102.198, 33, Mentawai Trough, Indonesia, usgs
7.0, 1975/10/3 5:14:00, 30.3, 66.3, 11, Pakistan-Afganistan border, iisee
7.0, 1975/10/6 22:24:16.2, -12.519, 166.499, 54, Vanuatu, usgs
7.8, 1975/10/11 14:35:15, -24.894, -175.119, 9, Kermadec-Tonga Trench, noaa
7.6, 1975/10/31 8:28:2.6, 12.54, 125.993, 50, Philippine Trench, noaa
7.1, 1975/11/1 1:17:00, 13.84, 144.75, 113, Marianas Islands, iisee
7.1, 1975/11/29 14:47:40.4, 19.334, -155.024, 5, Hawaii, USA, noaa
7.8, 1975/12/26 15:56:38.7, -16.265, -172.467, 33, Tonga Trench/Samoa, noaa

whats the problem?

Note: you can see I didn't use the usgs or iisee 8.1 for the Azores quake, because these are composite magnitudes (Unkown type)..
iisee often gives a real magnitude type as well, in this case 7.8Ms. But I used 7.9 as both NAOO and ANSS had 7.9 (Ms)





edit on 29-9-2010 by muzzy because: (no reason given)



posted on Sep, 29 2010 @ 03:54 AM
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reply to post by muzzy
 

Your listing from NOAA shows two entries with no ID. I don't know what that means but I don't get those quakes listed in my search results. Also, the timestamps for those two entries do not seem to be formatted correctly.

My point in showing the discrepancy in the NOAA and USGS data was to demonstrate that the NOAA data does not include all earthquakes, it is pre-filtered. For more recent data (since 1973, using the USGS database) it is possible to determine which earthquakes have been filtered. (According to my search, there are four for 1975). For earlier earthquakes it is not.

The problem is (as I have said) that, no matter what the source is, the older the data is the less reliable it is. Add to this that you are using a source (NOAA) which is known to filter known earthquakes and it makes matters worse. You use data saying that there were 6 large earthquakes worldwide in 1955. You have no way of knowing if that figure is accurate or not. All you know is that there were 3 earthquakes of 7.5 or greater, 2 with reported tsunami, and 1 with property damage over $1 million dollars. You know nothing about any earthquakes between 7.0 and 7.5 which did not meet the other criteria. The data for 1955 is not reliable. There could very well have been almost any number of earthquakes greater than 7.0 and less than 7.5 which did not create a tsunami, did not result in more than 10 deaths, and did not result in significant property damage. There are 4 cases of that occurring in 1975.

The IISEE catalog suffers from the same problem. It is prefiltered and there is no way of determining what earthquakes are missing from it. In fact the filtering seems more arbitrary than that of NOAA and the compiler is very aware of its shortcomings (iisee.kenken.go.jp...). For example; in 1980 IISEE lists only 4 earthquakes, USGS lists 13 (NOAA lists 5). Filtered data. If it isn't reliable when there is a cross reference, how can it be reliable when there isn't (pre 1973)?

The data you are using, pre-1973 is not complete. This is obvious. Since it is not complete it cannot be used for your purposes. Incomplete data from 60 years ago cannot be compared to current, much more complete, data. For data which can be considered to be quite reliable (1973 on), there is no trend showing an increase in earthquakes of 7.0 and greater, over any time span. There are some notable spikes and there are some notable slumps in this time period but with a linear regression curve (based on calendar years) showing an R^2 of .046, there is no trend indicated. Nor is there a trend found when using frequency/timespan comparisons.

edit on 9/29/2010 by Phage because: (no reason given)



posted on Sep, 29 2010 @ 01:00 PM
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reply to post by Phage
 

I had a look back at my list for NAOO for 1970-1970 and I see that I had combined NAOO with USGS by the stage I saved the file. So the two on the list that have no ref number were in fact USGS sourced events. So thats correct there were 11 quakes reported by NAOO for 1975.
It doesn't matter, the end result is the same.

I think Utsu has done a great job compiling his data, often he marks some quakes where he is unsure whether they are duplicated, so I filter the ones out that do not match with NAOO or the others.

I don't see how you can tow the USGS and BGS line so readily when there is clear evidence that they based their statements on incomplete data?.
The Chilean (dgfuc) and Peruvian (cndg) databases also added approx 20 quakes to the 100 year data that the others didn't have.
So am I supposed to dismiss these just because they are not from the big boys?, no I don't think so.

All you can do is take whats available and draw conclusions from that.

USGS is not the pinnacle of global earthquake recording by any means. They can't even get the number of quakes in 2010 right.
so why would I believe what they say about the numbers not increasing?



posted on Sep, 29 2010 @ 01:08 PM
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oops wrong thread ~ deleted


edit on 29-9-2010 by muzzy because: (no reason given)






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