11:00 AM - 1:00 PM
[U09-P27] Geophysical observation records of Tonga large volcanic eruption by Asia-Pacific network (Pacific21)
Keywords:Pacific21, Broadband seismometer, Atmospheric pressure variation
As for seismological observation, the network operates very broadband (360sec) sensors and most data are distributed to organizations and researchers via telemeters and internet.Some stations have high resolution barometer or geomagnetic sensor at the same location.
Atmospheric pressure variation and meteotsunami excited by large Tonga volcanic eruption are reported globally. Barometer of Pacific21 network also records clear signal with the peak of about 2hPa.
High resolution very broadband seismometers measure the gravity variation and
ground tilt. In our research, ground tilt has high coherency with atmospheric pressure
variation in longer period greater than 40sec by long-term sprectrum stacking analysis.
Atmospheric pressures change clearly with more 20min time width. It ls expected that
the evolution of ground response accurately. The polarity of ground tilting matches
the back azimuth of air pressure wave propagation from Tonga volcano.
In the vertical component of very broadband seismograms, the coupling mode
between atmosphere and solid earth is characterized in long elapse time.
And apparent location dependence also recorded and it will be evaluated.
This presentation introduce geophysical data originated by the Tonga eruption
in the Pacific21 network and ground response due to atmospheric pressure
variation.