Earthquakes are short-lived phenomena; over within a couple of minutes at most, and every earthquake is history, albeit recent history, by the time it can be studied.
This report provides a careful account of the challenges of compiling a robust global historical archive and catalogue (1000-1903), on the one hand managing basic source materials often scattered and obscure, and in a plethora of different languages and scripts, and on the other hand dealing with existing secondary studies which vary hugely in quality and organisation.
Te report touches upon the main outputs of the Global Earthquake History (GEH) project namely:
- The Global Historical Earthquake Archive (GHEA). This archive brings together the current state-of-the-art in historical seismology, and allows the user to see what material is available for any earthquake or any region. It underpins the earthquake catalogue that is the second product of GEH, and provides a starting point for future studies of historical earthquakes.
The Analysis of the Archive Contents by Geographical Area, a thorough and comprehensive investigation of materials available for twelve geographical regions, which have filled in a number of gaps in the record that existed prior to the project.
The Global Historical Earthquake Catalogue (M >=7.0, 1000-1903), a Global Parametric Catalogue for earthquakes above magnitude 7 for the period 1000-1903. This was to match the Global Instrumental Catalogue for GEM, which begins in 1904 with M >= 7, by critically merging and carefully selecting the most reliable input datasets stored in the Global Archive.
The reports also covers the methodology and the approach used to estimate the completeness of the catalogue for the purpose of hazard assessment. It also expands on the IT infrastrcuture built to access data at different levels: 1) a general view with the list of all earthquakes and 2) a more detailed view showing all the archived items about a selected earthquake. A final chapter is dedicated to future maintenance, expansion in time, and expansion in scope, that will support further work to improve understanding of historical seismicity (much needed in some regions).