Looking at Valhall's charts something came to mind...

There is another thread here on ATS about asteroid near misses increasing that seems to make the same mistake.

When it comes to natural events, people seems to stumble over the common falacy that increasing numbers of an event on record mean the actualy events are increasing in frequency. This is not the only possibility.

The reason near miss asteroids and earthquakes are increasing over time based on the data is because humans are taking more measurments and accounting for more of them. As sky watchers and seismographs grow in number more of these natural events are noticed.

To get a REAL idea if the actual event are increasing in number you have to have a data control to avoid the fact that with time more measurement are being made.

I highly reccomend that rather than just taking all quakes ON RECORD you take known seismographic stations that are 50 years old or so and look just at those. That way you can be more certain you're not just looking at increased frequency of measuments.

the only reason i cannot accept your explanation fully is that five years ago, a major quake (5.0+) was a big time news event to hear about. now we hear about one in the middle east monthly, volcanoes all over the globe are reporting more activity, theres increased activity in the yellowstone caldera. sorry, but it just doesnt add up to 'more monitoring'.

[Edited on 3/3/2004 by nativeokie]

Originally posted by forsakenwayfarer
the only reason i cannot accept your explanation fully is that five years ago, a major quake (5.0+) was a big time news event to hear about. now we hear about one in the middle east monthly, volcanoes all over the globe are reporting more activity, theres increased activity in the yellowstone caldera. sorry, but it just doesnt add up to 'more monitoring'.

If you disagree with thats, fine. I actualy wasn't trying to provide proof of an average level of earth quakes. A matter of fact aside from trying to prove a negetive, you just can't prove we are having more because there aren't record far enough back into history. Rather, i was pointing out a flaw in the use of data.

The earth is a very dynamic system. We have no base line measurment to judge increasing frequency. Taking all the USGA data though isn't really going to show you anything though since it lacks a base line and has increasing mesurments.

At best one might come up with a theory for WHY quakes are increasing and try to build experiments to that theory.

If you look at quakes in just qualitative terms throughout history though, you'll see some monsters here and there, and occasional records of lesser ones.

And of course perhaps quakes are increasing in frequency... but there just isn't the evidence for it.

Quest,

Your theory holds for the lower magnitude earthquakes. That is why I do not look at anything below 4.0 and that is why I haven't bothered going back and looking at anything prior to NEIC's earliest data (1974). That is also why I break the data into ranges. Your theory does not hold for higher magnitude quakes, and especially in the period we are looking at (74 to present).

SO...that is why I always have a chart with all quakes 4.0 and up, and then also break them down.

Originally posted by Valhall
Quest,

Your theory holds for the lower magnitude earthquakes. That is why I do not look at anything below 4.0 and that is why I haven't bothered going back and looking at anything prior to NEIC's earliest data (1974). That is also why I break the data into ranges. Your theory does not hold for higher magnitude quakes, and especially in the period we are looking at (74 to present).

SO...that is why I always have a chart with all quakes 4.0 and up, and then also break them down.

Maybe you misunderstood. I'm saying all the USGS data is time bias, that goes for any magnitude. The only way to get close to an unbias data set if you took the total number of USGS monitoring stations and used it to normalize the quake data.

Currently the USGS doesn't even have a list of all thier stations or thier operation start date, so basicly, the USGS data on their website can't tell us anything cept information on each specific quake.

Well, actually, it doesn't matter if we can determine the total number of stations, we can normalize to the total number of REPORTING stations. Because it does not change our data to normalize to a station that has never reported (see my point?) So, I will look over the NEIC data and see how difficult it would be for me to get a running total of stations for each year and we'll take a looksee at the data then?

What say?

Originally posted by Valhall
Well, actually, it doesn't matter if we can determine the total number of stations, we can normalize to the total number of REPORTING stations. Because it does not change our data to normalize to a station that has never reported (see my point?) So, I will look over the NEIC data and see how difficult it would be for me to get a running total of stations for each year and we'll take a looksee at the data then?

What say?

Sounds good, i actualy sent a request to the USGS yesterday asking for station data. I asked for at least the total number of operational stations per year, and even more details if they can.

There is no point is them posting data without posting enough of it to be useful.

Good deal Please share the feedback you get, and if you don't get any - hit them again, because there is no station data that accompanies the NEIC data...so my hands are tied unless we get this information.

BUT, I will say this. Though it is given that this will "adjust" the data. I'm betting big money that you are surprised at how little it affects it. At least over the time period my charts are for. We may see some stepwise adjustment somewhere in the 90's, but it is not going to level the years out by any means. That's my prediction.

Quest,

Actually, what’s you’re asking for from the USGS is not going to answer the question.

Example:

Say the USGS has had a station in Davis, CA since 1973. This station is found to have picked up every 6.0 quake in the world from 1973 to date.

Now, in, say, 1993 we add a station in Nepal. And this station picks up every 6.0 quake from 1993 to date.

Now, for this thought experiment we say that the number of 6.0’s picked up by the Davis station from 1993 to date exactly equals the number of 6.0’s picked up by the Nepal station. In fact, they are the identical quakes for each station.

If you now normalize the number of 6.0 quakes based on the number of stations, you have produced an erroneous picture…basically you would be halving the number of 6.0 events from 1993 to date, when, in fact, they are just as if the Nepal station had never been brought online.

In order to account for the addition of measurements, the data must be analyzed against a snapshot of stations recording events in 1973 (the beginning of NEIC data for my charts). Then, on a quake-by-quake basis, you have to look at whether that event was recorded by any of the stations present in 1973. If it was, you don’t add any other reporting stations. It is only when you find a quake that has a recording by ONLY a new station brought online.

This is a major analysis job. I am more than willing to assist in this, because 1. I’m a seismic junkie. 2. I’m an analytical freak, and 3. I want to know the TRUTH.

Here is my suggestion to you:

u2u Advisor and submit a request for a Research Project to determine whether seismic activity is, in fact, increasing, or whether it is a matter of improved/increased measurements. Name yourself as team lead. Before, submitting this request select four members you believe would be beneficial to your team and u2u them asking them if they would participate in your project. Once you have a team of 4 or 5 people (including yourself), then u2u Advisor.

I’ll tell you now, that I will participate if you choose to have me as a member.

Gotta be a malfunction. 17:22 Zulu...Acticity off the charts..

Confirmation requested through U2U

IRIS is not showing this. Please give link or more information.

Thanks

sorry, we posted over each other, didn't see the second post with the link.

That's wild! And that the two (relatively close in proximity) are showing the same behaviour pretty much rules out that the seismo is malfunctioning.

Wonder what this is and why it is not reported on IRIS, USGS, or EMSC???