Earthquake Monitoring

In Countryside Lake live seismic activity monitor

Updates in real time

This seismometer is attached to my lower basement foundation wall which sits upon a concrete footing on really rock solid clay, 

and will detect earthquakes locally and around the globe.

m/s axis on the helicorder shows the velocity of the vibrations in meters per second, measured by a geophone. 

Modern geophones are more sensitive, can capture a wider range of frequencies, and provide more detailed data than the drums used in the past.

The spectrogram below shows the signal strength for each frequency with weak frequencies plotted in dark tones, and strong frequencies brighter. So, yellows represent strong frequencies, and black and dark purples represent weak frequencies.

For the technically inclined, the spectrogram is made by calculating an FFT for each time interval and plotting the results in the vertical column with the signal strength colorized. This way, it shows when signal frequencies start and stop, grow (attack) and decay, and even change in frequency as the source slows down or speeds up.