gem global earthquake history; albini [dec 2012]

Tools for compiling theGlobal Earthquake HistoryPaola Albini1 | Roger M.W. Musson2 | Antonio A. Gomez Capera1 | Mario Locati1 | Andrea Rovida1 |Massimiliano Stucchi1 | Daniele Viganò1 |

1 Istituto Nazionale di Geofisica e Vulcanologia, INGV, Milano, Italy2 British Geological Survey, BGS, Edinburgh, UK

Global Earthquake History: the project

‣ Three main goals:‒ Global Historical Earthquake Archive-GHEA‒ Global Large Historical Earthquake Catalogue-GLHECAT‒ IT Infrastructure and website

‣ Fulfilled by establishing an innovative set of methodological and technological tools

‣ Time coverage: 1000-1903

‣ Magnitude range : ≥7 (at the outset of the project)

Global Earthquake History: the project (cont)

Study A Study B Study C Study D

Global Historical EarthquakeArchive

Global Large Historical Earthquake Catalogue

Earthquake 1 Earthquake 2

Selection criteria

The Global Historical Earthquake Archive - GHEA

Overall goal in compiling the Global Historical Earthquake Archive:‣ To identify, collect and critically organise the best and most

recent information available for earthquakes in the time-window 1000-1903 and magnitude equal to or higher than 7

‣ Information not from primary sources, but from published material, such as:‒ Papers, reports, and volumes‒ Sets of Macroseismic Data Points‒ Parametric Catalogues

GHE Archive: from Studies to Records-1833 Nyalam eq

Szeliga et al., 2010

Martin & Szeliga, 2010

Bilham, 1995

Ambraseys & Douglas, 2004

Bhatia et al., 1999

GHE Archive: from Studies to Records-1833 Nyalam eq

China SSB & FU, 1990b

Min Ziqun, 1995

GHE Archive: from Studies to Records-1833 Nyalam eq

• M values range from 7.6 to 8.0

• Epicentral location varies considerably

• The solution by the Chinese catalogue, Min Ziqun, 1995 (highlight in yellow) is adopted

• NB: in bordering areas the comprehensive vision of the GEH Archive can suggest new insights

GHE Archive and Number of Records per Earthquake

Multiplicity of Studies for each Earthquake

GHE Archive in Numbers

The Archive contains:

‣ 236 studies ‣ critically analysed and inventoried‣ selected (thousands of pages scanned)

‣ 994 earthquakes

‣ 3,154 records compiled (in the database underlying the Archive)

‣ 17 fakes

GHE Archive in Numbers (cont)

The Archive contains also:

‣ 77 studies in the Archive containing Macroseismic Data Points

‣ 12, 282 Macroseismic Data Points re-compiled from 69 studies for a total of 292 (out of 994) earthquakes

GHE Archive and Number of Macroseismic Data Points

292 earthquakes with 12,582 macroseismic data

The Global Large Historical Earthquake Catalogue - GLHECAT

Overall goal in compiling the Catalogue:‣ The material upon which GLHE Catalogue is built is supplied by

the GHE Archive, selected because of‒ public availability‒ clarity and reliability

‣ The Archive content was analysed on a region-by-region and in most cases an earthquake-by-earthquake basis

‣ The Catalogue results from comparing the sets of parameters available for each earthquake and selecting the best-attested (checked against the studies and their data)

GLHE Catalogue in Numbers

The Catalogue contains:‣ 827 earthquakes (out of 994 in the GHE Archive)‣ 110 earthquakes with M<7 (mostly in intraplate areas)‣ 167 earthquakes not included (a magnitude <7 was assigned)

‣ 92 studies (out of the 236 archived) supplying the parameters

GLHE Catalogue in Time

32 earthquakes

GLHE Catalogue in Time

37 earthquakes

GLHE Catalogue in Time

101 earthquakes

GLHE Catalogue in Time

132 earthquakes

GLHE Catalogue in Time

209 earthquakes

GLHE Catalogue in Time

316 earthquakes

GLHE Catalogue in Time 1000-1903

827 earthquakes

NOAA Catalogue 1000-1903 and M≥7

371 earthquakes

GLHE Catalogue 1000-1903 M≥7

717 earthquakes

GLHE Catalogue vs NOAA Catalogue, Himalayas (1)

11 eqs in NOAA Catalogue vs 20 eqs in GLHE Catalogue

Differences in location

GLHE Catalogue vs NOAA Catalogue, Himalayas (2)

Comparison between Magnitudes

GLHE Catalogue vs NOAA Catalogue, Himalayas (3)

GLHE Catalogue vs NOAA Catalogue, Indonesia

NOAA Catalogue: 6 earthquakes GLHE Catalogue: 75 earthquakes

The IT Infrastructure and Website: accessing the Archive

Accessing the Archive (cont)

The archive is accessed by means of a website where a two depth level approach has been implemented:‣ a general view with the list of all earthquakes‣ a detailed view with all the archived items on an earthquake

Global Earthquake History

Study A Study B Study C Study D

Global Historical EarthquakeArchive

Global Large Historical Earthquake Catalogue

Earthquake 1 Earthquake 2

Selection criteria

Global Earthquake History: an “alive and kicking” Archive

‣ The Global Historical Earthquake Archive provides a complete (so far as is possible) account of the global situation in historical seismology, with all existing studies collected together in a syncretic way, retrievable either by earthquake or region.

‣ The Global Large Historical Earthquake Catalogue is the best global historical catalogue of large earthquakes presently available with the best parameters selected, duplications and fakes removed, and new earthquakes discovered.

‣ The full title of the project is “Tools for compiling a Global Earthquake History”: the history itself is not yet fully written, and, as should be clear, much writing remains to be done.