No Magnitude, No Glory !!
Abstract
Surface waves emitted after large earthquakes are known to induce, by dynamic coupling, atmospheric infrasonic waves propagating upward through the neutral and ionized atmosphere. Those waves have been detected in the past at ionospheric heights using a variety of techniques, such as HF Doppler sounding or GPS receivers. The HF Doppler technique, particularly sensitive to the ionospheric signature of Rayleigh waves is used here to show ionospheric perturbations consistent with the propagation of Rayleigh wave phases R1 and R2 following the Sumatra earthquake on the 28 March 2005 (M = 8.6). This is in our knowledge the first time that the phase R2 is detected by ionospheric sounding. In addition, we prove here that the ionospheric signature of R2 is also observed by over-the-horizon (OTH) Radar (Occhipinti et al., 2010). Adding the OTH Radar to the list of the "ionospheric seismometers" we finally introduce the ionospheric magnitude and we apply it to 65 events observed by "ionospheric seismometers".
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2014
- Bibcode:
- 2014AGUFMNH33C..06O
- Keywords:
-
- 1220 Atmosphere monitoring with geodetic techniques;
- GEODESY AND GRAVITY;
- 2435 Ionospheric disturbances;
- IONOSPHERE;
- 4341 Early warning systems;
- NATURAL HAZARDS;
- 7944 Ionospheric effects on radio waves;
- SPACE WEATHER