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On the estimation of seismic intensity in earthquake early warning systems
Author(s) -
Yamamoto Shunroku,
Rydelek Paul,
Horiuchi Shigeki,
Wu Changjiang,
Nakamura Hiromitsu
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl033034
Subject(s) - seismology , magnitude (astronomy) , geology , earthquake magnitude , peak ground acceleration , intensity (physics) , earthquake warning system , warning system , earthquake scenario , earthquake simulation , earthquake prediction , earthquake casualty estimation , seismic microzonation , seismic hazard , seismic wave , ground motion , computer science , physics , telecommunications , quantum mechanics , geometry , mathematics , astronomy , scaling
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.