Don Goyo hasn’t done anything too surprising lately and I have only been checking the cams, not the daily CENAPRED bulletins. Today, I did read the bulletin, and they started off discussing tremor at the volcano – usually they list the number of exhalations it has had. That’s very interesting.
Here it is in English:
September 1 11:00 am (16:00 GMT September 1)
In the last 24 hours, the monitoring system of Popocatepetl recorded several episodes of low-to-moderate amplitude harmonic and high frequency tremor, between 00:30 and 06:00 h (GMT). Similar signals were also detected between 11:22 and 12:30 h (GMT). Additionally, 10 low intensity exhalations were detected, accompanied by steam, gas and small ammounts of ash, being displaced towards west-southwest. Around 02:30 h (GMT) light ash fall was reported at Tetela del Volcán and Ocuituco, both towns located in the southwest sector of the volcano.
During the period covered by this report, and depending on the atmospheric conditions, a continuous steam, gas and ash emission has been observed. (see image 1); (see image 2).
Image 2 is beautiful enough to show on its own:
As this amateur understands things, harmonic tremor indicates magma movement. I’m not sure what high-amplitude tremor signifies – other than that it, too, has to do with magma movement, not steam or tectonic causes.
The presence of tremor, combined with reports of ashfall in nearby communities, and a much darker appearing summit area on the current Tlamacas webcam, indicate Popo is wide awake, feeling its oats a bit, and well worth watching closely now.
The SSN webicorder PPIG is not the seismograph CENAPRED has shown in their bulletins, but it is close enough to the volcano to be interesting. There is low-level stuff on it right now, just as the scientists have mentioned, but it isn’t jumping, which is reassuring.