IAG-IASPEI 2017

講演情報

Oral

Joint Symposia » J02. Recent large and destructive earthquakes

[J02-4] Recent large earthquakes IV

2017年8月2日(水) 16:30 〜 18:00 Intl Conf Room (301) (Kobe International Conference Center 3F, Room 301)

Chairs: Shin-Chan Han (University of Newcastle) , Thorne Lay (University of California Santa Cruz)

17:15 〜 17:30

[J02-4-04] From Sumatra 2004 to Today, through Tohoku-Oki 2011: what we learn about Tsunami detection by ionospheric sounding

Giovanni Occhipinti1, Lucie Rolland2, Julian Eisenbeis1, Shingo Watada3, Pierdavide Coisson1, Jonathan Makela4, Philippe Lognonné1, Hélène Hebert5 (1.Institut de Physique du Globe de Paris, Paris, France, 2.Géoazur - Université Nice Sophia Antipolis, Valbonne, France, 3.Earthquake Research Institute, University of Tokyo, Tokyo, Japan, 4.University of Illinois, Urbana, IL, United States, 5.Commissariat Energie Atomique, Arpajon, France)

The tsunamigenic Tohoku earthquake (2011) strongly affirms, after the 26 December 2004, the necessity to open new paradigms in oceanic monitoring. Detection of ionospheric anomalies following the Sumatra event demonstrated that ionosphere is sensitive to earthquake and tsunami propagation: ground and oceanic vertical displacement induces acoustic-gravity waves propagating within the neutral atmosphere and detectable in the ionosphere. Observations supported by modelling proved that tsunamigenic ionospheric anomalies are deterministic and reproducible. Tsunami signature in the ionosphere is routinely detected and we show here perturbations of total electron content (TEC) measured by GPS and following tsunamigenic eartquakes from 2004 to 2011, nominally, Sumatra (26 December, 2004 and 12 September, 2007), Chile (14 November, 2007), Samoa (29 September, 2009) and the Tohoku-Oki (11 Mars, 2011). Additionally, new exciting measurements in the far-field were performed by Airglow measurement in Hawaii, showing IGWs induced by the Tohoku tsunami in the Pacific Ocean, as well as by two new recent tsunamis: the Queen Charlotte (27 October, 2013, Mw 7,7) and Chili (16 September, 2015, Mw 8.2). The detection of those two new events strongly confirms the potential interest and perspective of the tsunami monitoring by airglow camera, ground-located or potentially onboard on satellite. Observations close to the epicenter, performed by GPS networks located in Sumatra, Chile and Japan, highlight the first TEC perturbation observed within the first 10min after the seismic rupture. This perturbation contains informations about the ground displacement, as well as the consequent sea surface displacement resulting in the tsunami. In this talk we present all this new observations in the ionosphere and we discuss, under the light of modelling, the potential role of ionospheric sounding in the oceanic monitoring and future tsunami warning system.
Works presented here @ www.ipgp.fr/~ninto