On JMA earthquake data

( Please don't contact with JMA on this page )

Event list(1994/10/4-2001/3/24) : M was revised by JMA in April 2001

JMA seismic station list (on 2016/Jul/8)
JMA hypocenter format on 2016 April 01
JMA hypocenter format (old)
JMA observation data format
JMA mechanism data format
JMA Intensity scale

The history of JMA seismic network and systems

 1987            :  EPOS (Tokyo center)
 1990            :  ETOS (Sendai local center)
 1991            :  ETOS (Sapporo local center)
 1992            :  ETOS (Fukuoka local center)
 1993            :  ETOS (Osaka local center)
 1994 to 1995 : Tsunami system of Tokyo and all local centers( including Okinawa ETOS in 1995)
                     the seismic network for tsunami forecast Sapporo(95 Jan.10) Tokyo EPOS2(95 April)
 1997 Octber  : Unified system (all centers) the unified seismic network with universities'
 1998 to now  : Basic network ( Hi-net ) the basic seismic network for earthquake research
                      supported by the ministry of Education and Science and it will be completed in 2002.
 1999            : Travel time table wes extended  at depth to 700km
 2003 Oct.     : Magnitude of most small events were revised in the JMA catalogue including past events.
                  : Tokyo EPOS3

 L-Adess : Local Automated Data Editing and Switching System
 EPOS    : Earthquake Phenomena Observation System
 ETOS    : Earthquake and Tsunami Observation System

I didn't revised the history of JMA seismic obserbation after 2004.

JMA adopted the new Geodetic coordinate system, JGD200(ITRF94) on 2005 Feb. 01. And all old hypocenters were changed, not redetermined by new location data of stations.
The most recent JMA catalog is edited on 2016 Aug. 17.
The hypocenters from 1923 to 1976 June were redetermined.

Katsumata, A.,2001,Magnitude determination of deep-focus earthquakes in and around Japan with regional velocity-amplitude data,EPS,53,333-346.
Katsumata, A.,1999,Attenuation function of displacement amplitude for magnitude calculation,Pap. Meteor. and Geophys.,50,1-14.
Masakazu Ohtake and Yuzo Ishikawa,1995,Seismic networks in Japan,J.Phys. Earth,1995,43,563-584.

Please tell us your comment !
This Page is written by YI