INGV           ALomax Scientific

Mw9 Tohoku, Japan Earthquake and Tsunami, 11 March 2011, 05:46 UTC

Rapid mainshock location, magnitude and tsunami potential determinations in real-time at INGV

Anthony Lomax - ALomax Scientific, Mouans-Sartoux, France.,

Alberto Michelini - Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy,

INGV Global Earthquake Monitor real-time display at origin time + 15min

During the earthquake and tsunami in Japan, the Global Earthquake Monitor implementing the rapid magnitude and tsunami warning algorithms described in our recent papers (see below) was running in real-time at the INGV seismic center in Rome.

The earthquake monitor first located the M9 mainshock at origin time (OT) +3min, and indicated:

While the tsunami warning information at OT+8min would not have aided response along the nearby Japanese coasts, we note that the Mwpd=8.8 magnitude and T0=170s duration estimates provided early information on the true size and extent of the earthquake rupture; these rapid measures should be useful during future large earthquakes for regional tsunami warning, and early shakemap, finite-fault and tsunami forecast modeling.

Selected screen-shots of the real-time monitor display:
mpeg movie of the monitor display during the event:
INGV realtime monitor:


Lomax, A. and A. Michelini (2011), Tsunami early warning using earthquake rupture duration and P-wave dominant period: the importance of length and depth of faulting, Geophys. Journal Int., first published on-line Jan. 20, 2011, DOI: 10.1111/j.1365-246X.2010.04916.x. (further information)

Lomax, A. and A. Michelini (2009), Tsunami early warning using earthquake rupture duration, Geophys. Res. Lett., 36, L09306, doi:10.1029/2009GL037223. (further information)

Lomax, A. and A. Michelini (2009), Mwpd: A Duration-Amplitude Procedure for Rapid Determination of Earthquake Magnitude and Tsunamigenic Potential from P Waveforms, Geophys. J. Int.,176, 200-214. (further information)