On the estimation of seismic intensity in earthquake early warning systems
Article first published online: 3 APR 2008
Copyright 2008 by the American Geophysical Union.
Geophysical Research Letters
Volume 35, Issue 7, April 2008
How to Cite
2008), On the estimation of seismic intensity in earthquake early warning systems, Geophys. Res. Lett., 35, L07302, doi:10.1029/2007GL033034., , , , and (
- Issue published online: 3 APR 2008
- Article first published online: 3 APR 2008
- Manuscript Accepted: 3 MAR 2008
- Manuscript Revised: 15 FEB 2008
- Manuscript Received: 23 DEC 2007
- early warning;
- seismic intensity;
- ground shaking
 The infamous Tokai Earthquake, which by some accounts is overdue, is expected to be a magnitude ≥ 8 event that will cause unprecedented damage in regions of Japan. To mitigate hazards from large earthquakes in Japan, an earthquake early warning (EEW) system was developed that is able to determine hypocentral locations from P-arrival data within a few seconds and then transmit this information before the onset of large ground motions from the later arrival of S-waves. We introduced a new source parameter for seismic intensity magnitude that can be estimated from the real-time P-wave data during the early stages of fault rupture for most earthquakes M ≥ 6.5. The use of this parameter results in a significant improvement in the uncertainty in the estimated seismic intensity compared to estimates derived from earthquake magnitude. A pre-established relation between the P- and S-wave seismic intensity therefore enables an EEW system to issue a rapid and reasonably reliable prediction of the amount of ground shaking that may be expected from the damaging S-waves.