• Tag Archives seismograph
  • Seismograph – Part 2

    We will get back to the topic of urban noise in another blog… This blog is all about what does an earthquake look like on my RaspberryShake?

    Sadly, because I have been so focused on cleaning up the urban noise, I have not been 100% diligent in taking screenshots and noting down the quakes that I have seen, so here are the few I have….

    This is from a different bit of software that I can run at my house.
    The plot is from the Pi and it is a small quake off the coast of San Francisco. I don’t remember what magnitude it was. Something around M2 from poor memory.

    This is the M5.6 in Montana the other day.
    This screenshot also shows very clearly why I want to reduce the urban noise, it makes recording the quakes a lot clearer.
    This quake is a bit interesting as it shows a bigger rumble after the quake started.

    This is the big M7.8 at the Solomon Islands a while back.
    I really like this trace as it clearly shows the P-Waves that come (not always, but usually with the big ones) some time latter, this is the quiver of the planet from such a big shake.
    The P-Waves actually come through the planet, not over like the quake.
    These P-Waves are important for us to understand lots of different parameters of the quake and the planet.

    I hope I get time to list some nice resources that are out on the web about all these different waves and why they matter.
    I never was much for geology at school, but this thing has me all excited to learn stuff that just never made sense back then.

    This one shows a very small quake (M1.6 from memory) just down the road from us at The Salton Sea.

    Last one….. As I was writing this blog, I looked at the current trace and it shows three perhaps four quakes…. I have never seen that many in one hit. Just amazing on the timing.
    They are all small ones, M1.48, M1.3 and M1.18 in Northern California.
    But, it beautifully shows the range of quakes that I can see from my back yard. it shows how well and very interesting the device is.

    As I said, its one of my favorite Kickstarter projects. I think now you can get a bit of a sense why.

    BTW, The guys have another project in the works at the moment, the new one has more features and is more expensive. I would love to back it, but just don’t have the money.
    Thankfully they are going to pass down to us as many of the software features as they can, one of which I am most excited about, and that is an email feature. I will automatically get an email when my sensor picks up a quake. That will make having the system a lot more exciting.

  • Seismograph – Part 1

    My names thebaldgeek and I am addicted to Kickstarter.
    I have not said it before.

    One of the best projects I have ever backed is a Raspberry Pi seismograph.
    For no reason, I have always been interested in earthquakes. Hard to recall when I first started to tinker with building one (I think I was 12 years old and we lived in a Brisbane suburb called ‘The Gap’).
    Anyway, no need to repeat it, but we all know I also love me some Raspberry Pi.

    So, when this one came along, it was an immediate and automatic backer.
    To their credit, they delivered. Not only on time and on budget, but these guys set the gold standard (in my books) for how a Kickstarter campaign should be run.
    Great product and great communication with their backers. You could honestly feel their excitement for us.

    Ok, so it arrived and I very quickly powered it up. Worked first time out of the box and I was about the 11th person in the world to get it going (which is not bad considering they themselves had about 9 running).

    So, what is it and how has it all been going?

    It’s a Pi with a very low noise amplifier hooked to a special microphone.
    That’s it in a nutshell.

    I can get some more close up photos if it’s needed, but this really is it.
    Plastic box to hold all the bits nice and square which is really important, and the guts. Extra love given since they engraved my name in it.

    The transducer is on the bottom, the silver can with the gray and blue wires. They are twisted together to reduce noise. They can not be very long as they will pick up noise.
    They go into the blue circuit board and that is the low noise amplifier and converter. It converts the analog signal from the ground vibrations to the computer data stream (serial 3.3v Pi).
    You can separate the blue board from the Pi. More on why you might want to do this as we progress through these blogs.
    The Pi needs 5 volts DC at around 2 amps. Since the Wifi causes interference to the very faint earth signals, I opt not to use it and so have a standard ethernet cable going out to the unit in the yard.

    Lastly, you run their software which understands their data stream and it turns it into a few different data streams. The most common on my website (and groov) is a page that shows the current wave.

    It looks like this;

    So what are we looking at.
    Ok, so the times are in UTC. That’s the earthquake standard. It just is.
    The different color lines don’t mean anything. They just use a different color for each 15 minutes of each hour, so 4 quarters, 4 colors. It helps break up each strip. Black, red, blue, green. And they repeat the same for the next hour(s).
    There are no quakes on that screen shot (will get to that in a bit).
    So, what’s the noise then?
    You have heard the saying ‘the throb of the city’ (or words to that effect)…. Well, that’s what you are seeing here.
    It’s quiet up the top, that’s my night, then as day breaks you see the signal become bigger. That is traffic and wind.
    Yeah, as the wind blows, the trees sway and the noise of their branches is passed into the ground.
    The big jaggies? No idea. Big trucks. Garbage truck. Mail truck. UPS delivery truck. Next door neighbour jumping off a ladder after changing a light bulb. Who knows.
    Its weird. I listened for trucks and then tried to see them on the plot and I quickly found that if it sounds loud, it might be smooth and stuff that sounded soft, set the rumble line a wobbling.

    There is a whole world under our feet that we are oblivious to.
    Much fun.