Jumping, Jumping, Jumping, Kids Get Your Jump On!

Jumping, Jumping, Jumping, Kids Get Your Jump On!  This morning we experimented with our #RaspberryShake (Station #RAD87) by creating our own “earthquakes” – we jumped in front of the #seismograph several times.  We are investigating how local site conditions affect the #amplitude and #shape of the waves we see recorded on the #helicorder (see picture below).

Each time we moved the RS seismograph, it created a large amplitude spike (shown as black arrows).  First, we moved the RS seismograph to an open space on the hardwood floor, then we jumped for 10 seconds and again for 20 seconds (shown by the green arrows at times 14:22 and 14:23).  Second, we placed a pillow under the RS seismograph and jumped for 20 seconds again (time 14:25).  Lastly, we put two sheets of bubble wrap under the RS and jumped for 20 more seconds (time 14:26).  Once we finished jumping, we moved the RS back to its original position.

Image#1 – Raspberry Shake Station RAD87’s helicorder display.  Shown are the high amplitude events when we were moving the seismograph (black arrows) and when we were jumping in front of the instrument (green arrows).


Image#2 – An extracted seismogram showing the different waves detected by the RS.  The first group of waves begin with a movement down (shown by the black arrow), this movement is associated with jumping because the ground first moves down.  The second group of waves first moves up because we are picking the instrument up to move it.  Note that both groups of waves have several up-and-down peaks which show us how the instrument was moving, relative to the ground, during that time period.


Unfortunately the SWARM software stopped the peaks/troughs once they reach a certain amplitude, so we cannot observe the difference (1) jumping with the seismograph on hardwood vs. a pillow vs. on bubblewrap, and (2) between jumping vs. moving the seismograph.

Next steps are to re-design the experiment so that the software doesn’t change our display on the helicorder.  Scientific-inquiry is a iterative process, re-design and try again 🙂

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