I am a naturalist, educated in physics, who worked in industry as a sound and vibration engineer for many years. I enjoy observing things that go on around me in the natural world. Many of my interests relate to natural and man-made sources of sound and vibration out in the environment but I throw in a few observations and posts on other subjects that catch my attention too.
Murmurs from the Earth…Whispers from the Sky is the more analytical half of my personal blogosphere. My quiet, more reflective side used to express itself at The Quiet Way, now closed. My reflective side now posts black and white photographs at landscapes and other abstractions. In all of them I share some of the things around me that I have found interesting. I hope you enjoy them…comments are welcomed.
Murmurs from the Earth... 
Sir,
First, Merry Christmas!
I ran across your weblog while searching for information to complete a Lehman Seismograph which I am building with my 6th grade math and science students.
I must tell you that I became engrossed with your posts at The Quiet Way and they have distracted me from my search for the information I think I need to complete the seismograph.
But I wonder if I may shoot a few questions your way regarding your seismometer?
I’d like to know how long your boom is and whether you gave any thought to the boom’s center of mass when you determined where and how to attach the suspension wire.
I also would be interested to know the height of your support tower and the distance between the boom pivot point and the suspension point at the top of the tower.
Finally, I note that most builders of Lehman instruments suspend the boom and inertial mass from an inverted U shape of steel pipe as it appears in the original Walker article. But I am wondering if there is any reason why an un-guyed monopole of maybe 1″ pipe, or even a square steel tube welded to a flat steel plate wouldn’t work just fine?
I would be grateful for any assistance you are willing to offer.
Christopher Dahle
6th Grade Math and Science
Ortega Middle School
Alamosa, Colorado
Merry Christmas Christopher,
Thanks for your comments and questions. I’ll send you an email with the information you requested, a couple of small photographs, and a couple of other suggestions.
Mic
Thanks again Mic for your detailed and very helpful suggestions. My ADC arrived today and excepting a few nuts and bolts and a final decision on what to do about an amplifier, I finished rounding up all the parts this afternoon.
I’m looking forward to playing with the ADC. I’ve never had access to anything like it before.
Happy New Year,
Chris
Hi, This is a great page. I am always looking for good examples of sound recordings for classes in underwater acoutsics but air acoustics often work well. Would you consider posting or sharing some of your recordings you use in your examples?
Regards,
Bud Vincent
Research Associate Professor]
Ocean Engineering
University of Rhode Island
Bud,
Thank you for commenting. I would be happy to send you some recordings if I can find them and will contact you via email regarding the specifics.
Mic
Found this interesting! I love the tagline you wrote listening to murmurs of the earth, poetic!Thanks for stopping by my blog.
Congratulations Mic. Really an amazing Web site for all of us that enjoy nature like part of us!!
Was amazin to find the almost the same questions than I have to build my Lehman seismometer!!
first question
I’d like to know how long your boom is and whether you gave any thought to the boom’s center of mass when you determined where and how to attach the suspension wire.
Second question
I also would be interested to know the height of your support tower and the distance between the boom pivot point and the suspension point at the top of the tower.
Third question
Is there some procedure about ..How to find the correct damping point??? I am not sure but maybe the free oscillation period have to be about 60% minor after damping???
I am amateur solar observer, and visual deep sky observer too. I live in Cochabamba Bolivia South America
Many thanks for Your help and Congratulations for Your inspiring Web site!!
Gonzalo
Hello Gonzalo. Thank you for your kind comments. I will try to answer your questions but you have asked them at an unusually busy time for me. Please be patient as it may be a few days until can reply.
Hello, very interesting blog, superb. If You have time visit me too, regards from Poland, Em
Thank You for visiting my blog and Liking my Artworks !!! 🙂 * Cynthia
You are welcome, Cynthia! I enjoyed the visit and your work! If you have any interest in Black & White photography, I invite you to take a look at my images at http://lightmonkey1.wordpress.com.
Greetings, fellow Earth-listener! I’ve been enjoying your seismology and Quiet Way blogs for quite some time now — both are a most welcome and gentle gift to the madness that is the Internet. I couldn’t find your email address, hence this comment to you… I’m an artist/seismologist and thought you might be interested in a project that I’ve been working on in Maine, exploring ways to make Earth’s seismic sounds audible. In its current incarnation, I have a seismometer under my studio streaming near-real-time audio onto the internet (see http://www.earthsound.com) and broadcasting into my neighborhood over a micro-power FM radio station. Sometimes listening is exhilarating (I enjoy drifting off to sleep to the soothing sounds of the planet’s microseismic background), sometimes heartbreaking (last week’s devastating quake in Nepal, man-made fracking quakes in OK, for example), and always fascinating. There is much we can learn from listening to Earth — about the planet, our relationship to it, and what it means to be a human being.
I appreciate the fine work you’re doing in increasing our awareness and appreciation of the beauty of Earth.
with best wishes,
jt
Thank you for your kind comments, jt. Your audification project is very neat! Being able to listen to seismic signals gives a much better connection to the data than a graphic ever can. Just a great project!
I love Black And White Photography !!! Beautiful !!! 🙂 * Cynthia
Fantastic blog … where I can find interests I share. I am sure you know about Zhang Heng’s seismograph, 132 AC, a prodigious masterpiece !
Thank you, Gilles. Good to hear that you found some things of interest here. And yes, I am aware of but, I must admit, not really familiar with the Zhang Heng earthquake indicator.
I just built a Seismograph equipped with a DataQ-145. I cannot get the voltage output over .100 when reading it with Windaq. Your screenshot is showing 2 plus volt, question, is that directly from your coil or has it been amplified? What is the ohms of your coil? Mine is 128, does that seem low? My coil is homemade with salvaged wire, 1″ wide X 1.5″ diameter , yours looked thinner and larger in diameter. Thanks for any help.
Hello, Greg. All of the output displays show the output from the amplifier. My coil is roughly 10,000 turns of #34 magnet wire (0.0073 inch dia) wound on a 1 inch wooden dowel. The coil is formed between Lexan disks roughly 3 inches in diameter. The width is probably around 0.63 inch. The amplifier I use has a gain of around 10,000. I really have not made any electrical measurements of the components, e.g. coil resistance, amplifier gain, etc. so I can’t help you much there. With the coil and amplifier I have, I can easily get close to +/-10 volts output to the Dataq DI-145 in response to walking up next to the seismometer on the concrete floor of my basement or to a large earthquake somewhere in the world. Don’t know if that helps explain where you are at with yours…I probably should try to do some electrical measurements on it sometime. My main interest has been with detection and arrival times. For that I only need a big enough signal and reasonably accurate timing.
Thanks for the quick reply. The amplified output display now makes sense. It inspired me to look into building an amplifier. What I’ve come up with is a “poor man’s” alternative, using the PC’s sound card, powered speakers, and Audacity (open source, cross-platform software for recording and editing sounds).
I’m sending the seismograph’s coil output to the PC’s microphone input. Audacity then takes the signal and sends to out to the speaker. From there it is sent to the DataQ-145 to be converted to digital to be processed by jAmaseis.
As I type this it sound convoluted, however at least now I can see my activity in jAmseis as I walk nearby. Thanks again
You’re welcome. Your approach is interesting. I have heard of people using audio equipment for amplifiers but I don’t how successfully. I you find that you are not picking up earthquakes one thing is to remember that the signals of interest are at very low frequencies. I don’t know what kind of signal conditioning and/or amplifier rolloff on the low end occurs in audio equipment. Sounds like you are on your way if you can see your activity in jAmaSeis! Good luck!
Hello Mic!! This is Jaxson Ellington from Central Christian school. Thank you for coming and sharing with us! I really learned a lot about seismology and the Great Circle. I think it is awesome that you can do, teach and understand all of this stuff about seismology. Thank you again for coming and sharing!
Dear Mic,
I hope you´re having a good day. Thank you so much for coming to our school to show us all of the cool seismology information. Your presentation was great and easy to follow.
Sincerely,
Lucas
Hey Mic, this is Dorian from Central Christian I’m in 7th Grade and I learned how the seismograph works it was cool.
Hello, Jaxson. I enjoyed sharing with you and your class. Thank you for commenting on my web site. ~Mic.
Hi, Lucas. I’m happy to hear that you enjoyed my presentation. I enjoyed taking part in your class. ~Mic.
Hey Dorian. Thanks for letting me know. You may have gathered from my presentation that I think they are pretty cool too. Good to hear from you. ~Mic.