...Meichen Liu; Yihe Huang; Jeroen Ritsema ABSTRACT Although the Brune source model describes earthquake moment release as a single pulse, it is widely used in studies of complex earthquakes with multiple episodes of high moment release (i.e., multiple subevents). In this study, we investigate how...

... the accelerograms recorded at short distances from the fault traces. Applying Brune's model, we have determined important source parameters, such as rise time, stress drop, offset, and particle velocity. Generally, the earthquake is characterized as having had two distinct fault segments. The southern segment...

... to be used in microseismic studies for characterizing the size of an event and calculating its moment magnitude. For non-double-couple sources, the proportional relationship between body-wave amplitude and seismic moment in the Brune model breaks down. So under such situations, the Brune model...

... parameters. The source spectrum of the simulated rupture process using the hierarchical patch model generally follows the Brune model. However, the source spectrum underestimates the Brune model near the corner frequencies when the event size grows over M w 5.5. This spectral shape is consistent...

... of the Georgia Strait earthquake is in good agreement with the Brune point-source model, with a stress drop of approximately 45 bars. The apparent source spectrum of the slightly larger Duvall earthquake is in reasonable agreement with the Brune model, with a stress drop of about 70 bars; however, for the Duvall...

... and larger magnitude dependence than the Brune model. Variance reduction threshold, frequency bandwidth, and time‐window length, if chosen within an appropriate parameter range, have limited influence on source parameter measurement. For both methods, wave type, attenuation correction, and spectral...

... by Brune (1970) , a new method of estimating f c , based on the phase fitting of Fourier spectra of the Brune’s seismic pulse related to S ‐waves, called Fourier phase spectra fitting (FPS), is proposed and evaluated in this study. The method can be applied in cases in which Brune’s model may...

... similarity. Observed characteristics of S -wave spectra in ENA are fully explained as simple consequences of directivity effects entailed by the classical crack rupture model (Kostrov, 1964; Madariaga, 1976), with “normal” effective stresses of the order of 100 bars and fractional stress drop (Brune, 1970...

..., methods that assumed a Boatwright model tended to have lower Ω 0 and somewhat higher f c compared to those assuming a Brune model, although resulting Δ σ estimates are similar. When compared to the overall validation study results, the fitting approach alone may account for between 5% and 90% (25...

..., recorded at rupture distances from 1 to 200 km. Empirically derived source spectra for California earthquakes are generally inconsistent with the spectral shape implied by a Brune (“omega-squared”) point-source model. This is manifested by magnitude- and frequency-dependence of the Brune model parameters...

...—that parameterize an earthquake’s complexity relative to the standard Brune model and strongly correlate with the estimate discrepancies. We find that the observed systematic magnitude–stress‐drop trends may reflect underlying changes in STF complexity, not necessarily trends in actual stress drop. Both the decay...

... )=−1.72+0.43 M with a standard deviation of 0.19 in log10 units, based on the values obtained from the study earthquakes. The apparent source spectra of most M 6+ earthquakes can be modeled using a simple Brune point‐source model. For a few of the M 6+ earthquakes, notably those in California, we observed...