# Time window to constrain the corner value of the global seismic-moment distribution

## TL;DR

This paper investigates how the length of earthquake recording periods influences the ability to accurately estimate the maximum possible earthquake size, using global seismic data and modified Gutenberg-Richter models.

## Contribution

It introduces a method to constrain the tail of the seismic-moment distribution by analyzing the time window of earthquake data and its impact on the estimated maximum earthquake magnitude.

## Key findings

- Current data allow a wide range of maximum magnitude estimates.
- Future data will significantly narrow the estimated maximum magnitude range.
- The estimated corner magnitude will decrease with more data, contrary to previous claims.

## Abstract

It is well accepted that, at the global scale, the Gutenberg-Richter (GR) law describing the distribution of earthquake magnitude or seismic moment has to be modified at the tail to properly account for the most extreme events. It is debated, though, how much additional time of earthquake recording will be necessary to properly constrain this tail. Using the global CMT catalog, we study how three modifications of the GR law that incorporate a corner-value parameter are compatible with the size of the largest observed earthquake in a given time window. Current data lead to a rather large range of parameter values (e.g., corner magnitude from 8.6 to 10.2 for the so-called tapered GR distribution). Updating this estimation in the future will strongly depend on the maximum magnitude observed, but, under reasonable assumptions, the range will be substantially reduced by the end of this century, contrary to claims in previous literature.