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Paul Hovnanian P.E. · Guest

I>ve got a question about the state of the art in seismographs (if any
of you in So Cal are still alive). After the latest shaker down there,
the news cut over to the USGS HQ to show the obligatory drum style pen
recorders with the squiggly line.

A few years back, a few people in the area of Indonesia were discussing
a major event and posted a couple of traces of their accelerometer
readings. IIRC, these things had time resolutions of milliseconds. No
paper and pen, it was all digital. Various views of the transient were
available, including frequency domain traces (from sub Hz to 100 Hz at
least). I>m guessing that, given an accurate time base (probably sync>d
to GPS), some valuable geological information can be gleaned from
distributed networks of sensors of this sort.

This is a third world country. But we still have paper tape. What is the
state of the art? If we>ve got it, why show everyone the pen and paper
stuff on the news?

--
Paul Hovnanian mailto:Paul@Hovnanian.com
------------------------------------------------------------------
Quidquid latine dictum sit, altum viditur.
(Whatever is said in Latin sounds profound.)

Richard Henry · Guest

On Jul 29, 6:00 pm, "Paul Hovnanian P.E." <p...@hovnanian.com> wrote:
[quote]I>ve got a question about the state of the art in seismographs (if any
of you in So Cal are still alive). After the latest shaker down there,
the news cut over to the USGS HQ to show the obligatory drum style pen
recorders with the squiggly line.

A few years back, a few people in the area of Indonesia were discussing
a major event and posted a couple of traces of their accelerometer
readings. IIRC, these things had time resolutions of milliseconds. No
paper and pen, it was all digital. Various views of the transient were
available, including frequency domain traces (from sub Hz to 100 Hz at
least). I>m guessing that, given an accurate time base (probably sync>d
to GPS), some valuable geological information can be gleaned from
distributed networks of sensors of this sort.

This is a third world country. But we still have paper tape. What is the
state of the art? If we>ve got it, why show everyone the pen and paper
stuff on the news?
[/quote]
Tradition

mpm · Guest

On Jul 29, 9:00ï¿½pm, "Paul Hovnanian P.E." <p...@hovnanian.com> wrote:
[quote]I>ve got a question about the state of the art in seismographs (if any
of you in So Cal are still alive). After the latest shaker down there,
the news cut over to the USGS HQ to show the obligatory drum style pen
recorders with the squiggly line.

A few years back, a few people in the area of Indonesia were discussing
a major event and posted a couple of traces of their accelerometer
readings. IIRC, these things had time resolutions of milliseconds. No
paper and pen, it was all digital. Various views of the transient were
available, including frequency domain traces (from sub Hz to 100 Hz at
least). I>m guessing that, given an accurate time base (probably sync>d
to GPS), some valuable geological information can be gleaned from
distributed networks of sensors of this sort.

This is a third world country. But we still have paper tape. What is the
state of the art? If we>ve got it, why show everyone the pen and paper
stuff on the news? ï¿½ ï¿½

--
Paul Hovnanian ï¿½ ï¿½ mailto:P...@Hovnanian.com
------------------------------------------------------------------
Quidquid latine dictum sit, altum viditur.
(Whatever is said in Latin sounds profound.)
[/quote]
They are paper ballots leftover from the 2000 presidential
election....

krw · Guest

In article <3e51b337-2916-4a7e-ae1f-ff5cc8be53d7
@c65g2000hsa.googlegroups.com>, mpmillard@aol.com says...
[quote]On Jul 29, 9:00?pm, "Paul Hovnanian P.E." <p...@hovnanian.com> wrote:
I>ve got a question about the state of the art in seismographs (if any
of you in So Cal are still alive). After the latest shaker down there,
the news cut over to the USGS HQ to show the obligatory drum style pen
recorders with the squiggly line.

A few years back, a few people in the area of Indonesia were discussing
a major event and posted a couple of traces of their accelerometer
readings. IIRC, these things had time resolutions of milliseconds. No
paper and pen, it was all digital. Various views of the transient were
available, including frequency domain traces (from sub Hz to 100 Hz at
least). I>m guessing that, given an accurate time base (probably sync>d
to GPS), some valuable geological information can be gleaned from
distributed networks of sensors of this sort.

This is a third world country. But we still have paper tape. What is the
state of the art? If we>ve got it, why show everyone the pen and paper
stuff on the news? ? ?

--
Paul Hovnanian ? ? mailto:P...@Hovnanian.com
------------------------------------------------------------------
Quidquid latine dictum sit, altum viditur.
(Whatever is said in Latin sounds profound.)

They are paper ballots leftover from the 2000 presidential
election....
[/quote]
Yeah. No need for paper ballots, since the Demonicrats insisted on
computers.

--
Keith

mpm · Guest

On Jul 30, 1:05ï¿½pm, Rich Grise <r...@example.net> wrote:

[quote]By the time I got outside to check for vandals, or feel the ground if it
was a quake, it was over, but the TeeVee was all "BREAKING NEWS!!!!"
[/quote]

"Breaking News", and nothing actually broke.
Go figure.

-mpm

Rich Grise · Guest

On Tue, 29 Jul 2008 18:00:09 -0700, Paul Hovnanian P.E. wrote:

[quote]I>ve got a question about the state of the art in seismographs (if any of
you in So Cal are still alive).
[/quote]
I felt the earthquake, that was rated a 5.4, in Chino Hills:
http://news.google.com/news?hl=en&tab=wn&ned=us&q=%22chino+hills%22+earthquake&btnG=Search+News
Interestingly, the first "shock" felt like someone had bumped into my RV.
But there was no corresponding noise. I was pondering that, and the
shaking increased until it felt like a couple of vandals shaking the RV.
By the time I got outside to check for vandals, or feel the ground if it
was a quake, it was over, but the TeeVee was all "BREAKING NEWS!!!!"

There were no injuries, no significant reportable damage, but the networks
were loaded with "BREAKING NEWS!!!!" for as much as two hours after it was
over!

One really weird thing is that even though the epicenter was near Chino
Hills, which is about 15 mi. east of me, all of the Hollywood news was
about how intense it was. They almost evacuated Disneyland! I don>t
understand how it could be more intense to my west than it was here,
when I>m half the distance from the epicenter.

I wonder if it>s because:
1. The fault was 7-8 miles deep
2. I>m on rock; LA proper is on sediment, which they say "magnifies" or
maybe "amplifies" the shaking, like a bowl of jello
3. Could the topography have actually focused the waves?

Another thing, it didn>t feel like either P (pressure) waves or T
(transverse) waves; it felt more like ocean waves.

But TWO HOURS of "BREAKING NEWS!!!!" after a 15-second event that didn>t
even do any reportable damage? The hilite of the coverage was the security
film from some liquor store, where the guy feels the first nudge in his
feet, exits the store, and a whole shelf of liquor bottles falls down
sploosh.

So, essentially, ho hum. ;-)

Cheers!
Rich

qrk · Guest

On Tue, 29 Jul 2008 18:00:09 -0700, "Paul Hovnanian P.E."
<paul@hovnanian.com> wrote:

[quote]I>ve got a question about the state of the art in seismographs (if any
of you in So Cal are still alive). After the latest shaker down there,
the news cut over to the USGS HQ to show the obligatory drum style pen
recorders with the squiggly line.

A few years back, a few people in the area of Indonesia were discussing
a major event and posted a couple of traces of their accelerometer
readings. IIRC, these things had time resolutions of milliseconds. No
paper and pen, it was all digital. Various views of the transient were
available, including frequency domain traces (from sub Hz to 100 Hz at
least). I>m guessing that, given an accurate time base (probably sync>d
to GPS), some valuable geological information can be gleaned from
distributed networks of sensors of this sort.

This is a third world country. But we still have paper tape. What is the
state of the art? If we>ve got it, why show everyone the pen and paper
stuff on the news?
[/quote]
http://pasadena.wr.usgs.gov/eqview/cgi-bin/makePublicView.php?EVID=14383980
Looks like digital data to me. This data gets posted minutes after an
event. The poor USGS servers were instantly bogged down right after
the quake.

They probably have drum data as backup or a show & tell for the news
dweebs.

This was a nice slow shaker where I am, about 120 miles (190 km) away.

--
Mark

mpm · Guest

On Jul 30, 6:31ï¿½pm, James Arthur <bogusabd...@verizon.net> wrote:
[quote]Tim Williams wrote:
"Rich Grise" <r...@example.net> wrote in message
news:pan.2008.07.30.18.04.47.327466@example.net...
I felt the earthquake, that was rated a 5.4, in Chino Hills:
http://news.google.com/news?hl=en&tab=wn&ned=us&q=%22chino+hills%22+e...
Interestingly, the first "shock" felt like someone had bumped into my RV.
But there was no corresponding noise. I was pondering that, and the
shaking increased until it felt like a couple of vandals shaking the RV.
By the time I got outside to check for vandals, or feel the ground if it
was a quake, it was over, but the TeeVee was all "BREAKING NEWS!!!!"

5.4? ï¿½BFD, we got one of those around here (relatively speaking) and all it
got was a front page spot. ï¿½'Course, we>re a couple hundred miles away from
the epicenter, and having anything around here is very rare!

My story is, it was around 3 a.m., I was sitting here typing away on the
computer and felt a low frequency oscillation, as if my leg were shaking,
except I know it wasn>t. ï¿½I think it was magnitude 3 something by the time
it got here.

Tim

It can be a big deal. ï¿½The magnitude = total energy released. ï¿½If
concentrated in a small spot, the ground motion can be intense.

I once had my chair literally jump right out from under me, as if
kicked. ï¿½Turned out the quake was 2 or 3-something, but nearby.

Cheers,
James Arthur- Hide quoted text -

- Show quoted text -
[/quote]
My brother went throught the Loma Prieta quake back in '89.
He claims practically everything in the apartment was fine, except the
refrigerator jumped out the bay window. I don>t think he was
kidding, but then, he does have a slight penchant for exaggeration.
I>ve heard similar tales from others. Almost like any heavy object in
just the wrong spot can really lead to trouble.

-mpm

Tim Williams · Guest

"Rich Grise" <rich@example.net> wrote in message
news:pan.2008.07.30.18.04.47.327466@example.net...
[quote]I felt the earthquake, that was rated a 5.4, in Chino Hills:
http://news.google.com/news?hl=en&tab=wn&ned=us&q=%22chino+hills%22+earthquake&btnG=Search+News
Interestingly, the first "shock" felt like someone had bumped into my RV.
But there was no corresponding noise. I was pondering that, and the
shaking increased until it felt like a couple of vandals shaking the RV.
By the time I got outside to check for vandals, or feel the ground if it
was a quake, it was over, but the TeeVee was all "BREAKING NEWS!!!!"
[/quote]
5.4? BFD, we got one of those around here (relatively speaking) and all it
got was a front page spot. 'Course, we>re a couple hundred miles away from
the epicenter, and having anything around here is very rare!

My story is, it was around 3 a.m., I was sitting here typing away on the
computer and felt a low frequency oscillation, as if my leg were shaking,
except I know it wasn>t. I think it was magnitude 3 something by the time
it got here.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

James Arthur · Guest

Tim Williams wrote:
[quote]"Rich Grise" <rich@example.net> wrote in message
news:pan.2008.07.30.18.04.47.327466@example.net...
I felt the earthquake, that was rated a 5.4, in Chino Hills:
http://news.google.com/news?hl=en&tab=wn&ned=us&q=%22chino+hills%22+earthquake&btnG=Search+News
Interestingly, the first "shock" felt like someone had bumped into my RV.
But there was no corresponding noise. I was pondering that, and the
shaking increased until it felt like a couple of vandals shaking the RV.
By the time I got outside to check for vandals, or feel the ground if it
was a quake, it was over, but the TeeVee was all "BREAKING NEWS!!!!"

5.4? BFD, we got one of those around here (relatively speaking) and all it
got was a front page spot. 'Course, we>re a couple hundred miles away from
the epicenter, and having anything around here is very rare!

My story is, it was around 3 a.m., I was sitting here typing away on the
computer and felt a low frequency oscillation, as if my leg were shaking,
except I know it wasn>t. I think it was magnitude 3 something by the time
it got here.

Tim

[/quote]
It can be a big deal. The magnitude = total energy released. If
concentrated in a small spot, the ground motion can be intense.

I once had my chair literally jump right out from under me, as if
kicked. Turned out the quake was 2 or 3-something, but nearby.

Cheers,
James Arthur

Jeff Liebermann · Guest

On Tue, 29 Jul 2008 18:00:09 -0700, "Paul Hovnanian P.E."
<paul@hovnanian.com> wrote:

[quote]What is the
state of the art? If we>ve got it, why show everyone the pen and paper
stuff on the news?
[/quote]
Ever notice that the background noise under the news commentator is
usually a teletype machine? When TV shows a time bomb, it always has
an LED display, never LCD. When TV shows a computer, there are NEVER
any exposed tangle of wired, battery chargers, USB dongles, etc. Argh.

Methinks the high tech seismographs are fiber optic loop/ring
accelerometers. Basically, they>re an interferometer. I>ve only seem
one at the local multiversity, but was not allowed to even exhale next
to the device.

Don Lancaster on seismography (1998) with lots of good references and
broken links:
<http://www.tinaja.com/glib/resbn74.pdf>

"Experiments in laser seismography"
<http://books.google.com/books?id=0uSILcWppmwC&pg=PA245&source=gbs_toc_r&cad=0_0&sig=ACfU3U2DIlC-UmNZ9pO-ZP0RSX6lfn24wQ>

I also found some articles on solid state MEMS low-g accelerometers
for seismography.
<http://www.wtec.org/loyola/mcc/mems_eu/Pages/Chapter-5.html>
My guess(tm) is that this is the high fashion current technolgy as the
laser interferometer is probably too sensisitve to be generally
useful. Just a guess(tm).

Here>s a complete wireless kit with 3 axis accelerometer for $250:
<http://www.vernier.com/labequipment/wdss.html>
I like the idea of taking a roller coaster ride to calibrate and test
it.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Richard Henry · Guest

http://pasadena.wr.usgs.gov/eqview/cgi-bin/makePublicView.php?EVID=14383980

whit3rd · Guest

On Jul 29, 9:00 pm, "Paul Hovnanian P.E." <p...@hovnanian.com> wrote:
[quote]I>ve got a question about the state of the art in seismographs
[after seeing drum recorder on the California quake, and[/quote]
accelerometer readings in old Indonesian quake footage]

Seismometers come in short-period and long-period variants,
and resonance is an important part of the signal/noise
equation: accelerometers pick up lots of out-of-band noise.
A simple accelerometer with millisecond output has to be
a short-period seismometer, suitable for local monitoring only.

The drum recorder is just a visual aid and is maintained as
a photo-opportunity model or as a teaching/display model.
The real recordings, nowadays, are digital for the central office
units, and FM encoded onto analog tape for field units (battery
power for an analog tape drive is ... favorable).

mpm · Guest

On Jul 31, 6:48ï¿½pm, "Paul Hovnanian P.E." <p...@hovnanian.com> wrote:
[quote]qrk wrote:

Backup? Wouldn>t the money be spent more wisely on RAID storage? Same
for show and tell. Even more, people are used to PC displays, computers,
etc. Seeing the USGS using out of date technology makes me wonder if
they really know what they>re doing anymore.
[/quote]
Agreed, but there is something to be said for "low-tech".
Especially if you consider these chart recorders may be installed out
in the boonies, off-grid, etc... I for one could not in good
conscience recommend Vista for such applications. :)

-mpm

Phil Hobbs · Guest

Paul Hovnanian P.E. wrote:
[quote]qrk wrote:
http://pasadena.wr.usgs.gov/eqview/cgi-bin/makePublicView.php?EVID=14383980
Looks like digital data to me. This data gets posted minutes after an
event. The poor USGS servers were instantly bogged down right after
the quake.

They probably have drum data as backup or a show & tell for the news
dweebs.

The labor to maintain and operate pen recorders could be put to better
use elsewhere.
Backup? Wouldn>t the money be spent more wisely on RAID storage? Same
for show and tell. Even more, people are used to PC displays, computers,
etc. Seeing the USGS using out of date technology makes me wonder if
they really know what they>re doing anymore.

Chart recorders make *way* better theatre. That pen wiggling back and[/quote]
forth looks like a frustrated child scribbling on a drawing that didn>t
come out. Perfect.

Part of the problem is that definitions of earthquake magnitude depend
on the frequency passband, which depends on the design of seismographs
and probably on pen recorders too. One way to keep the numbers
comparable is to keep the hardware the same.

The 'Richter' scale quoted by reporters is not the original Richter
scale, but a modified one with a wider passband (and some low-frequency
boost, iirc).

Cheers,

Phil Hobbs


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