Data and methodology
How reports are collected, corrected, translated and presented.
Last updated: 29 August 2026On this page
Earthquake reports
Live bulletins and newer catalogue records are received through P2PQuake and reconciled with JMA information. Selected historical records from 2000–2014 may instead come from the USGS ComCat catalogue and are identified as USGS on their report pages. The original bulletins and their revisions are retained. Corrections update the same event instead of silently creating a replacement.
Times are presented in Japan Standard Time. Magnitude, depth, hypocentre, maximum Shindo and tsunami status are copied or normalised from source reports; they are not independently forecast by JISHINDESU.
Station observations
Values shown for cities and stations are actual reported observations. JISHINDESU does not estimate Shindo at the user's address. Distances are calculated from geographic coordinates; hypocentral distance also includes the reported depth.
Romanised names come from official multilingual JMA datasets or curated mappings tied to a known JMA code. The service does not guess arbitrary kanji readings.
Latency and availability
JISHINDESU normally receives a newly published P2PQuake bulletin within seconds, but the confirmed JMA report itself may be issued several minutes after the earthquake. Network failures, source outages and later corrections can increase this delay.
OpenFreeMap provides the interactive map background using OpenMapTiles and OpenStreetMap data. Attribution remains visible on every map. Images shared on social media use a simplified map of Japan to show the reported epicentre.
Optional earthquake notifications
Anonymous Web Push sends only fresh, confirmed reports when an actual station observation in any of up to eight selected municipalities reaches the Shindo threshold chosen for that place. If several places match the same earthquake, the subscription receives one notification based on the strongest matching observation. It is not JMA Earthquake Early Warning, a forecast or an independently issued warning. Corrections are deduplicated so the same event does not repeatedly alert the same subscription.
Each precise map point selects the nearest supported JMA observation area and stays only in notification settings on that device so the linked report can calculate station distances. The server-side subscription stores the resolved municipality codes and their thresholds, but not precise coordinates or user-defined place names; those details are not included in the push payload. Notification delivery can be delayed or fail because it depends on source data, the JISHINDESU server, the browser push service, network connectivity and device settings.
Processing pipeline and event status
For live and newer reports, the publication path is: JMA source bulletin → P2PQuake delivery → JISHINDESU normalisation and reconciliation → event page, map and statistics. The separate historical import follows: USGS ComCat record → JISHINDESU normalisation → event page. Preliminary, confirmed, corrected and cancelled states describe the current source record; a correction updates the reconciled event rather than creating an unrelated earthquake.
Statistics count unique catalogue events from 2015 onward for a JST day, month or year. Averages use only records where the measured value exists, and current periods are explicitly incomplete.