CRISIS/MAP

FLASH REPORT · EQ

M4.8 earthquake — Off the east Coast of Chiba Prefecture

Published Updated
JMA SHINDO 4GDACS GREEN

An earthquake occurred at Off the east Coast of Chiba Prefecture. JMA reports magnitude 4.8, a depth of 30 km, maximum observed intensity of Shindo 4. GDACS currently provides a Green alert and rapid-impact estimates.

At a glance

Occurred
Aug 29, 2026, 15:17 UTC
Location
Off the east Coast of Chiba Prefecture
Magnitude
JMA M4.8 · GDACS M4.7
Depth
JMA 30 km · GDACS 35 km
Maximum observed intensity
JMA Shindo 4
GDACS alert
GREEN
Off the east Coast of Chiba Prefecture GDACS rapid-impact intensity geometry is an estimate, not observed JMA shaking.

What we know

OBSERVED SHAKING — JMA

Japan Meteorological Agency observations

Maximum observed seismic intensity: JMA Shindo 4.

JMA magnitude: 4.8.

JMA depth: 30 km.

ESTIMATED IMPACT — GDACS

Global Disaster Alert and Coordination System

Current GDACS alert: Green.

GDACS rapid-impact intensity geometry is an estimate, not observed JMA shaking.

Report history

  1. A newly associated source was added to the report; GDACS changed the alert to Green; GDACS revised event details; GDACS detailed geometry was added or revised.

  2. JMA revised earthquake measurements.

  3. Flash Report published from JMA earthquake information reporting maximum observed intensity of Shindo 4.

Sources

CrisisMap presents source-labelled information and is not the original authority for these measurements.

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