Earthquake location accuracy

Abstract

Earthquake location catalogs are not an exact representation of the true earthquake locations. They contain random error, for example from errors in the arrival time picks, as well as systematic biases. The most important source of systematic errors in earthquake locations is the inherent coupling of earthquake locations to the seismic velocity structure of the Earth. Random errors may be accounted for in formal uncertainty estimates, but systematic biases are not, and must be considered based on knowledge about how the earthquakes were located. In this chapter we discuss earthquake location methods and methods for estimating formal uncertainties, systematic biases in earthquake location catalogs, and give readers guidance on how to identify good-quality earthquake locations.