Atmospheric boundary waves excited by the tsunami generation related to the 2011 great Tohoku-Oki earthquake

Abstract

Atmospheric pressure changes caused by the 2011 Off the Pacific Coast of Tohoku, Japan earthquake (Mw = 9.0) are investigated. Sensitive microbarographs in and around Japan recorded unequivocal signals associated with the tsunami. We identify them as atmospheric boundary waves excited by the uplift and subsidence of the ocean surface, on the basis of the waveform characteristics as well as similarity with the data from ocean‐bottom pressure gauges. Potential usefulness of an observation network of atmospheric pressure is discussed regarding the improvement of the tsunami warning system.

Ionospheric signatures of the April 25, 2015 Nepal earthquake and the relative role of compression and advection for Doppler sounding of infrasound in the ionosphere

“…Good understanding of the ionospheric response to acoustic gravity waves excited by tsunamis could be potentially used in the tsunami early-warning systems since the infrasound waves propagate at larger velocities (~330 m/s) than tsunamis (~200 m/s at deep water). So, if the epicenter is sufficiently far in the sea, the related ionospheric disturbances can be detected before the tsunami arrival to the seacoast [Rolland et al 2010;Liu et al 2006b;Arai et al 2011;Shinagawa et al 2013]. It is, however, crucial to properly distinguish the co-seismic (co-tsunami) ionospheric disturbances from fluctuations caused by other kinds of forcing from below, e.g., acoustic gravity waves from severe weather systems , mountain waves, etc., and from above, e.g., geomagnetic and solar activity [Laštovička 2006;Liu et al 1996;Šindelářová et al 2009], and the meteorite falls [Brown et al 2013] and artificial re-entries [Yamamoto et al 2011].…”

Low-Frequency Atmospheric Gravity Waves from Vertical Tectonic Deformation During Two Recent Chilean Megathrust Events: the 2010 Maule (Mw8.8), and 2014 Iquique (Mw8.2) Earthquakes

“…It is to be mentioned here that similar observations of low-frequency atmospheric waves have been recorded after three megathrust events, since the 1964 Alaskan earthquake (Mw = 9.2) [16,17], the 2004 Sumatra-Andaman earthquake (Mw = 9.2) [18,19], and the 2011 great Off-Tohoku earthquake (Mw = 9.0) [20,21]. In the present article, we try to find the evidence of observations for low-frequency gravity waves propagating from each of the source regions of the above two great earthquakes through the atmosphere to some of these microbarograph stations.…”

“…The Tsunami arrival was with a height of 0.35 -0.18 m at 3 hours and a half later than the gravity waves, indicating the Tsunami speed in these cases was between 220 and 239 m/sec. This means that the acoustic arrival might be used as early warning for Tsunami arrival [20,21], although the Tsunami amplitudes this time were not high enough to issue urgent warning at far-field stations. After the 2014 Iquique earthquake, on the other hand, Tsunami waves arrived at several sites within 4 hours along the western coast of Chile up to a height of 0.7 -2.0 m [31].…”

Interaction of Solid Earth, Atmosphere, and Ionosphere

“…A microbarograph in Oshu city, Iwate, successfully recorded infrasounds excited in the sea directly above the rupture area (Arai et al, 2011). This is considered to have propagated along the surfaceatmosphere boundary as the Lamb wave.…”