Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] Earthquake near Sendai



I suspect it is not different from calibrating instruments in decibels. One measurable total released energy is probably used as a standard of reference. But this is only a guess.

Ludwik
=============================================================


On Mar 11, 2011, at 1:43 PM, Bob Sciamanda wrote:

How does one calibrate a seismometer in Richters?
Where does one get a standard “One Richter” earthquake? :~)

From: curtis osterhoudt
Sent: Friday, March 11, 2011 12:08 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] Earthquake near Sendai
Best of luck to him, and to all of the Japanese people (and others in the
Pacific. There was another, perhaps even more deadly, and much smaller quake
in
China, too).


I noticed a few teachable moments while watching BBC coverage of the quake
and
subsequent tsunami:

* Footage of an aircraft boarding tube at Sendai Airport showed it
standing
up to an onslaught of debris-laden water quite well. The support structure
and
wheel at its tip didn't buckle, even when apparently hit by a large volume
of
water and some "minor" debris. However, when the water level reached the
level
of the ramp itself, it apparently temporarily floated it, which allowed the
support structure to quickly collapse. I'm not sure how they're engineered,
but
this one stood up impressively for a long time.
* An interview with a British geologist (I think -- he specifically
stated
that he wasn't a seismologist) led to two interesting statements: He said
(and
I'm paraphrasing), "Yes, we expect aftershocks, maybe several which are an
order
of magnitude smaller than the main quake. Well, not, an order of magnitude
smaller. Maybe of strength 7 and smaller." I found that particularly
interesting, because there _seems_ to be quite a confusion as to exactly
what
the logarithmic Moment-Magnitude-Scale means.

* In the same interview with the same geologist, the interviewer asked,
"We
had the strong Christchurch quake recently, too. Why so many strong quakes?"
to
which the geologist replied, quite rightly, "I don't think anyone can really
answer that." It strikes me that, even if a class couldn't really
appreciate
the intricacies of such a discussion, an introduction to things like
power-law
scalings and their ilk could be apropos at such a time.






________________________________
From: ludwik kowalski <kowalskil@mail.montclair.edu>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Fri, March 11, 2011 9:51:18 AM
Subject: [Phys-l] Earthquake near Sendai

I was in Sendai in 2005, working on a cold-fusion-related project, for about
eight weeks. That is where I experienced a small earthquake. We have them
all
the time, said my host, Professor Kasagi. I am still waiting to hear from
him;
he and his wife live in Sendai.

Ludwik

http://csam.montclair.edu/~kowalski/life/intro.html



_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l
Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
treborsci@verizon.net
http://mysite.verizon.net/res12merh/



_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

Ludwik

http://csam.montclair.edu/~kowalski/life/intro.html