Open AccessScaling Law of Earthquake Source Time‐Function
Author(s) -
Aki Keiiti
Publication year - 1972
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1972.tb02356.x
Subject(s) - seismology , geology , scaling , scaling law , slip (aerodynamics) , earthquake simulation , earthquake prediction , geodesy , physics , mathematics , geometry , thermodynamics
Summary Further evidences support the scaling law of far‐field seismic spectrum based upon the ω‐square model (Aki) for earthquakes with M S > 6 and for periods T > 10s. Recent observations, however, unequivocally require the modification of the above law for periods T < 10s. Unfortunately, the presently available data are not sufficient for a unique revision of the scaling law. We propose two alternatives and discuss their implications and consequences. In either case, we have to conclude that a large earthquake and a small one are substantially different. One interesting feature of the ω‐square model appears to be unaffected by the required revision; that is, the spectral density of the fault‐slip time‐function for periods T < 5s takes the same absolute value, independent of magnitude, for earthquakes greater than M s = 65. This result has important consequences in earthquake engineering because the seismic motion in the vicinity of an earthquake fault will scale as the fault‐slip motion.