One hundred plus years of recomputed surface wave magnitude of shallow global earthquakes

Abstract

Among the multitude of magnitude scales developed to measure the size of an earthquake, the surface wave magnitude Ms is the only magnitude type that can be computed since the dawn of modern observational seismology (beginning of the 20th century) for most shallow earthquakes worldwide. This is possible thanks to the work of station operators, analysts and researchers that performed measurements of surface wave amplitudes and periods on analogue instruments well before the development of recent digital seismological practice. As a result of a monumental undertaking to digitize such pre-1971 measurements from printed bulletins and integrate them in parametric data form into the database of the International Seismological Centre (ISC, http://www.isc.ac.uk, last access: August 2021), we are able to recompute Ms using a large set of stations and obtain it for the first time for several hundred earthquakes. We summarize the work started at the ISC in 2010 which aims to provide the seismological and broader geoscience community with a revised Ms dataset (i.e., catalogue as well as the underlying station data) starting from December 1904 up to the last complete year reviewed by the ISC (currently 2018). This Ms dataset is available at the ISC Dataset Repository at 10.31905/0N4HOS2D.