Volcano alert
Stations reporting last 20 min
Earthquakes within 20 km · 7 days
Lahar rivers vs flood stage
Newest notice from the Cascades Volcano Observatory
The network and the hazard zones
Every seismometer and infrasound array within about 55 km of the summit, coloured by whether it actually sent data in the last 20 minutes, over the USGS lahar hazard zones. Earthquakes from the last 30 days, and the river gauges that would see a lahar arrive.
Hazard zones: Hoblitt and others, 1998, USGS Open-File Report 98-428 (digital data, OFR 2007-1220). They show where lahars have gone and could go; the boundaries are gradual, not sharp lines.
Stations
How each station is doing right now. “Level” is RSAM, the average ground-motion level over the last 10 minutes, compared with the station's own normal over the past week: wind, rivers, storms and people raise it as well as the volcano, so it is a prompt to look, not an alarm.
| Station | Code | Elev ft | Since | Sensors | Last data | Level vs normal |
|---|
Earthquakes
Located earthquakes within 20 km of the summit, from the USGS catalog (the Pacific Northwest Seismic Network locates them). Rainier averages about ten a month; the bars show how this week compares, and every year since 2000.
Per week, last two years
Per year since 2000
Last 30 days
| When (Pacific) | Mag | Depth km | Where |
|---|
The lahar rivers
A lahar arriving at a gauge would look like a wall: the river rising many feet in minutes, far faster than any flood. These are the NOAA river gauges on the Puyallup, Carbon, White and Nisqually, upstream to downstream: the last 7 days, the official forecast (dashed) and the flood lines where NOAA sets them.
Why it matters
People in the hazard zones
People live in Mount Rainier's lahar hazard zones, with over 50,000 employees at about 3,800 businesses (USGS, 2022).
Warning time
Most communities, once a large lahar is detected. Inside the park, residential areas could be reached in about 5 minutes (USGS). More on warning time →
Lahars in the past
Large lahars in the last 5,600 years. The Osceola Mudflow (2–3 km³) reached Puget Sound near Auburn; the Electron Mudflow, about 500 years ago, began as a landslide, with no eruption (USGS).