The Source Time Function To Estimate The Earthquake Radiation Energy

Radiated(seismic) energy, being a fundamental yet still not very well measured parameter of seismic source, has long been attractive to seismologists worldwide. In this thesis, we discuss how to estimate radiated energy based on source time functions obtained directly from seismograms. We use simple geometric form functions(trapezoid, triangle) as a simplified representation of the actual source time functions and estimate radiated energy with these simpler functions. Further discussions show that our estimate agrees well with the energy result calculated by NEIC, our result can be even closer to the NEIC result when we take into account multiple sub-events and use other simple geometric form functions (i.e. asymmetric triangle).The scaling law between reduced energy and seismic moment is now under heated discussion. To resolve this question requires more observational data, especially local and regional data. We collect observation reports of three earthquake sequences occurred in Yunnan Province and investigate the scaling law between reduced energy and seismic moment with these reports. We adopt Andrews(1986) method which is based on Brune's model to calculate radiated energy. Our results show that reduced energy rises with seismic moment as to earthquakes smaller than M_L4, but to earthquakes larger than M_L4, it seems reduced energy doesn't vary with seismic moment.Main contents of this thesis:1. Introduce concepts of radiated energy, seismic moment, apparent stress and reduced energy.2. Review traditional methods and basic principles of energy calculation; introduce some major research progress in relative fields.3. Introduce the definition of source time function; analyze various calculation methods using source time function.4. Present a method of estimating radiated energy using simplified source time...