Over the coming weeks and months, we will be sharing data products from our Super Typhoon Bopha data set. Bopha began as a tropical storm east of our array in Palau, and intensified as it narrowly missed Palau on its way to the Philippines. ISLA staff were recently in Palau to upgrade an IMS infrasound station (International Monitoring System). The last of the field crew, (including yours truly) completed the work and left just 2 days before the arrival of Typhoon Bopha. We will be presenting products from this exciting data set recorded with our newly upgraded system.
More information on the array
This is the first of our data products. This audio file is 24 hrs of data from 00:00:00 UTC on December 2, 2012. It has been sped up by a factor of 2200 resulting in a ~39 second clip.
From 0-10 seconds you can hear the typhoon approach the island
Around 12 seconds, signal from the high period surf becomes noticeable
Around 30 seconds, signal from long period surf becomes noticeable
We recommend playing this track several times, and using different EQ settings. We have been having fun playing it on different systems with different frequency responses.
For those interested in waveforms, this signal has been band-pass filtered from 40Hz to 6kHz after being sped up by a factor of 2200. This maps the 0.2 Hz microbarom (ocean storm) peak to 440Hz (a concert A).