In detail, the value of 3D‐source characterization depends on the user’s chosen alert threshold, tectonic regime, and faulting style. If a line‐source representation is used and magnitude is calculated from the estimated length, then incorrect length estimates significantly degrade alert region accuracy. We find that alert regions determined using 3D‐source representations of correct magnitude and faulting mechanism are generally more accurate than those obtained using line sources. Using scenario crustal and subduction interface sources, we (1) identify the most influential source geometry parameters for an EEW algorithm’s shaking forecast, and (2) assess the intensity alert thresholds and magnitude ranges for which more detailed source characterization affects alert accuracy. We investigate conditions under which this information produces sufficiently better intensity estimates to potentially improve alerting. Several geodetic EEW algorithms under development would provide 3D finite‐fault information. From this information, ShakeAlert calculates shaking intensity and alerts locations where shaking estimates exceed a threshold.
![real 3d earthquake information real 3d earthquake information](https://ichef.bbci.co.uk/images/ic/1920x1080/p052zw0b.jpg)
West Coast EEW system, ShakeAlert, currently uses two algorithms based on seismic data to characterize the earthquake’s location, magnitude, and origin time, treating it as a point or line source.
![real 3d earthquake information real 3d earthquake information](https://storage.googleapis.com/wzukusers/user-34845901/images/5cd884912723etlMy9gL/piles_medium_d600.jpg)
EEW systems aim to alert users to impending shaking before it reaches them. We identify aspects of finite‐source parameterization that strongly affect the accuracy of estimated ground motion for earthquake early warning (EEW).