FAQ
South America coverage
Select South America in Settings to load the past 30 days of USGS earthquake reports within 60°S–15°N and 95°W–25°W. This includes Chile, Peru, the Andes and a broad offshore margin, as well as nearby border areas. The regional window is not a country boundary. Location names are currently English-only and times remain JST. Sharing uses region=sa. Japan-only weather and tsunami features remain hidden; earthquake selection, playback and location tools work as in the other non-Japan regions.
Africa and Australia & Oceania
Africa covers 40°S–38°N, 25°W–65°E, including Madagascar and nearby waters. Australia & Oceania covers 55°S–30°N, from 110°E eastward across the date line to 120°W, including New Zealand and Pacific islands. Both use the past 30 days of USGS reports; smaller earthquakes may be missing. These broad windows overlap neighboring regions. Names are English-only, times are JST, and Japan-only weather and tsunami features remain hidden. Shared URLs use region=af and region=oc.
Middle East coverage
Choose Middle East in Settings for EMSC earthquake data covering 12–43°N and 25–65°E: Türkiye, the Levant, the Arabian Peninsula, Iraq, Iran, and nearby waters and border areas. This view uses the past 30 days of available reports, without merging feeds. Location names remain in English and times are shown in JST. The earthquake list, timeline, location tools, and sharing work as in other regions; Japan-only features remain hidden. Regional boundaries intentionally overlap Europe & Mediterranean.
Region and data sources
In Settings, choose Japan, North America, Europe & Mediterranean, East & Southeast Asia, Middle East, South America, Africa, or Australia & Oceania independently of the interface language. Europe & Mediterranean uses the EMSC catalogue (25–72°N, 25°W–45°E, including nearby offshore areas). East & Southeast Asia uses USGS within 12°S–55°N, 73–150°E, including Japan, Vietnam, the Philippines, and nearby offshore and border areas. It does not merge feeds; the separate Japan view may show smaller events absent from USGS. East & Southeast Asia location names remain in English. Each non-Japan feed covers the past 30 days. Coverage of smaller earthquakes varies by country. The app loads separate earthquake datasets rather than merging them: Japan uses the P2PQuake API; the North America view uses the USGS GeoJSON feed. North America coverage includes Canada, the United States, Mexico, Central America, the Caribbean, Alaska, Hawaii, and nearby waters. Boundaries are broad geographic windows, not country borders. Times remain Japan Standard Time (JST) in every region.
North America quick views
Overview, Alaska, and Hawaii buttons reposition and zoom the map without filtering the earthquake list or timeline or changing the selected earthquake. On desktop they sit below the previous/next event controls; they are hidden on phones. These shortcuts are exclusive to the North America view.
Regional features and location names
When any non-Japan region is selected, earthquake marker location names are currently available only in English, even with the Japanese interface. North American event details link to the original USGS report; Japanese shindo and tsunami-status fields are not displayed. Japan-only typhoon, radar, lightning, wind, five-day forecast, and Weather timeline controls are hidden in every non-Japan region. North America, East & Southeast Asia, South America, Africa, and Australia & Oceania reports link to USGS; Europe & Mediterranean and Middle East reports link to EMSC. Returning to Japan restores its controls and saved layer/timeline choices. Automatic JMA tsunami coastlines are available only in Japan mode.
Sharing your region
Header and event share links include the region, map style, zoom, map center, supported weather-layer states, and selected earthquake when present. The shared map position takes priority over centering on the selected earthquake. Region selection is also remembered in this browser.
What is Jishinwatch?
Jishinwatch is an educational earthquake map for Japan, North America, Europe & Mediterranean, East & Southeast Asia, the Middle East, South America, Africa, and Australia & Oceania. It helps residents, students, and observers explore recent earthquake activity on a full-page map with timeline replay, magnitude colors, maximum reported intensity, optional tectonic overlays, and current typhoon data when available.
Where does the earthquake data come from?
For Japan, Jishinwatch uses recent earthquake information from the P2PQuake API. The North America and East & Southeast Asia use USGS GeoJSON data, and Europe & Mediterranean and the Middle East use the EMSC catalogue. Each region loads its own dataset; feeds are not merged. Official warnings, advisories, and emergency guidance should always come from the Japan Meteorological Agency and local authorities.
Is Jishinwatch an official warning service?
No. Jishinwatch is not an official alerting, warning, or evacuation service. It is intended for education, awareness, and visual exploration of recent earthquake data.
How often does the earthquake feed update?
The app checks for new earthquake data automatically based on the refresh cycle selected in Settings. Users can also refresh the list manually from the earthquake list controls.
What does magnitude mean?
Magnitude describes the size of an earthquake at its source. Larger numbers generally represent much larger releases of energy, and Jishinwatch uses marker size and color to make magnitude easier to compare visually.
What is maximum reported intensity?
Maximum reported intensity is the strongest shaking intensity reported by available observation points for an event. It is not an average of every reporting location.
Why can magnitude and intensity feel different?
Magnitude describes the earthquake itself, while intensity describes shaking experienced at specific locations. Depth, distance, local ground conditions, and the earthquake mechanism can all affect reported intensity.
What are the purple dots shown after selecting an earthquake?
Purple dots represent intensity reporting locations available for the selected event. The number inside each dot shows the reported intensity at that location.
What does the typhoon overlay show?
The typhoon overlay shows current Japan Meteorological Agency typhoon data when available. The red dot marks the current center, dotted lines connect projected forecast centers, forecast circles show possible future position areas, and the key shows when the data was issued in JST. This is for quick visual reference only; always use official JMA information for warnings and decisions.
What does the timeline do?
The timeline replays the currently displayed earthquakes in the order they occurred, helping users understand recent activity as a sequence instead of only as a list.
Can I share a specific earthquake?
Yes. Use the Share button on an event to copy a link that opens the map centered on that earthquake with its tooltip and intensity reporting points visible.
Does the location button store my location?
The location button requests browser location permission and shows your position as a blue dot. It measures the approximate distance to the latest earthquake in the displayed dataset, not the nearest earthquake, with a green connecting line. Selecting another earthquake updates the distance and line. Click empty map space to turn measurement off; dragging preserves it. The acquired position is reused in memory until you refresh or close the page. While locating, “Locating Your Position” stays visible. Temporary failures retry for up to 30 seconds; permission denial stops immediately. If unsuccessful, check location permissions and try again later. Mobile location access generally requires HTTPS. The last successful coordinates are also saved locally in browser settings; clear site data to remove them. Review location tags before sharing links or images.
Why might my location not work?
Browser privacy settings, operating system permissions, network conditions, or an in-app browser can prevent location from resolving. If location access times out, try a standard browser and confirm that location permission is allowed.
How does the five-day forecast use my location?
In Japan mode, enable Radar and open 5 Day Forecast. Location permission is requested when you open it. The panel shows tomorrow and the following four days for the JMA forecast area containing your location, with temperatures from a representative station. It is not a street-level forecast. The blue dot and tag identify the location; missing values appear as dashes. If permission or data is unavailable, follow the message and use Retry.
Where does the wind layer come from, and why might it differ from a typhoon marker?
Wind uses hourly 10-metre forecast wind speed and direction from Open-Meteo, interpolated into animated particles in your browser. It is not a JMA wind observation layer. The wide-area grid is supplemented with finer samples near loaded active typhoons, and data is cached for 30 minutes to reduce requests. JMA typhoon positions and modelled winds can have different valid times and centers; check the Wind Key timestamps. We do not shift the wind artificially to match a marker. Wind is available only in Japan mode, works without location permission, and can animate alone or with radar and lightning on the Weather timeline. If wind data cannot load, the key displays an unavailable message.
Can I save or share an image of my map?
Yes. Select the camera icon beside Share to preview the current map with its visible layers and tags, then choose Save Image or, on supported browsers, Share Image. Controls and menus are excluded; branding, capture time and data attribution are included. Animations become a still image. Check the preview for personal location information before sharing. Share Image requires browser support for file sharing and normally HTTPS, so it may not appear on a local-network HTTP address. You can still use Save Image. To share an interactive view rather than a fixed image, use the header’s regular Share button.
Can I hide earthquakes to view weather layers?
Yes. Use the concentric-circle button at the top of the desktop controls, or Earthquakes at the top of the mobile Layers menu. The event list remains available. Turn the layer back on or select a list event to restore it. Automatic refreshes respect the hidden state and do not recenter the map. Earthquakes are visible again by default on a new page load.