Sources & credits
Sumendi is not an authoritative source and must never be used for a safety decision. It gathers the volcanic activity that volcano observatories publish and shows it on one map. For anything that matters, go to the responsible observatory — every state displayed links back to its original publication.
The comparative colour Sumendi assigns to each volcano is its own editorial reading, not an official alert level. There is no worldwide alert scale: each country has its own, and mapping one onto another is a judgement, not an equivalence. The value published by the source is always shown alongside, in its original language.
An absence of data is an absence of data. Most volcanoes on Earth are not covered by an observatory publishing a standing alert level. They appear grey. That does not mean they are quiet.
Volcano catalogue
Positions, names, types, elevations and last known eruptions come from theVolcanoes of the World database of the Global Volcanism Program, Smithsonian Institution. The GVP volcano number is the identifier every source in Sumendi is matched onto.
The Smithsonian allows personal, educational and other non-commercial uses of its content.Sumendi is and will remain non-commercial: no advertising, nothing for sale, and no promotion of any product or service.
Activity sources
| Source | What it publishes | Coverage |
|---|---|---|
| Smithsonian / USGS Weekly Volcanic Activity Report | A weekly bulletin of volcanoes in activity, with a narrative report for each | Worldwide, about 26 volcanoes a week |
| GeoNet — GNS Science | Volcanic Alert Level 0–5, and the aviation colour code | New Zealand, 12 monitored areas |
| USGS Volcano Hazards Program | Volcano Alert Level and aviation colour code | United States, 70 monitored entries across five observatories |
| Japan Meteorological Agency | 噴火警戒レベル — volcanic alert levels, published in Japanese | Japan, 41 volcanoes carrying a level |
| PHIVOLCS — via GeoRiskPH | Volcano Alert Level 0–5, with the date each level came into force | Philippines, the 5 instrumented volcanoes |
| IPGP — OVPF, OVSG, OVSM | Niveau d'alerte ORSEC — the alert level declared by the préfecture on each observatory's advice, restated in every bulletin and published in French | France, the 3 monitored volcanoes |
| IGP — CENVUL | Nivel de alerta volcánica — a four-colour alert with its official meaning, served from a public API and published in Spanish | Peru, 14 monitored volcanoes |
| VMGD — Vanuatu | Volcanic Alert Level 0–5, with the date each level was last bulletined | Vanuatu, 7 monitored volcanoes |
Alert wordings are never translated. Translating a level would reinterpret it, and would pass Sumendi's editorial reading off as the observatory's own words.
Satellite thermal activity
Hot-spot detections come from MIROVA — Middle InfraRed Observation of Volcanic Activity, run by the Earth Science Department of the University of Turin. MIROVA watches 176 volcanoes with MODIS, VIIRS, Sentinel-2 and Landsat-8, and publishes the Volcanic Radiative Power it measures at each satellite overpass.
A thermal reading is a measurement, not an alert level. It says how much heat a satellite saw, in megawatts — not how dangerous a volcano is. Sumendi shows it as a separate dimension, with its own halo on the map and its own block on the card, and it never changes the colour of a volcano. A volcano can radiate tens of megawatts while its observatory publishes a normal alert level, and both statements are true.
And no detection is not a quiet volcano. Cloud hides a hot spot, and a phreatic or ash-only eruption has no thermal signature at all. When the card says nothing was detected, it means a satellite passed over and measured nothing — which is a different statement from having no data. For that same reason the halo on the map stands for a detection within the last ten days, not for one today: a blank pass under cloud would otherwise put out a halo the weather had lit. The card always shows the most recent reading first, and dates the remembered one below it.
MIROVA's terms: free to copy, share and quote for non-commercial purposes with attribution, and not to be altered or transformed. The value is therefore shown in megawatts with MIROVA's own band name, never rescaled into a wording of Sumendi's.
Satellite sulfur dioxide
The optional SO₂ layer shows imagery from NASA's Global Imagery Browse Services (GIBS): the sulfur dioxide column in the lower troposphere, measured by the OMPS instrument on the NOAA-20 satellite, in Dobson units. It shows the previous day's composite, in UTC.
This layer is not tied to any volcano. It is a picture of the whole planet: coal-fired power stations, smelters and city pollution appear on it as well as volcanic plumes. Sumendi never attaches a value from it to a volcano, and it never changes a volcano's colour.
And no SO₂ is not a quiet volcano. The instrument measures sunlight, so it sees nothing at night, and nothing at high latitudes in winter. Isolated specks of 1 to 4 DU scattered across the globe are measurement noise; a plume shows as a continuous patch that brightens towards its core.
We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS).
Basemap
Map data from OpenStreetMap contributors, under the Open Database License. Tiles and styles by OpenFreeMap. Elevation from the Terrain Tiles dataset on AWS.
Legal notice
Contact: contact@volcanicactivity.com.
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Sumendi has no account, no form, no advertising and no analytics, and sets no cookie of its own. The only thing it keeps in your browser is whether the map panel is open. Serving the pages means Cloudflare receives your IP address; loading the map tiles and the elevation data means OpenFreeMap and Amazon Web Services receive it too, as any web server does. Turning on the SO₂ layer means NASA receives it as well; while that layer is off, no request is made to NASA.