Known Geologic Events at Mount Rainier
The purpose of this page is to list all known, dated gelogic events at Mount Rainier, including lahars, debris flows, large rockfalls, large avalanches, rockfalls, and other events. This list is currently being compiled, so if you find errors or a missing event, please
let Scott know.
Database ID#: 178
Date: Sunday, August 10, 2025
Location: South Tahoma Glacier
Glacier Name: South Tahoma Glacier
Drainage Basin: Tahoma Creek
Event Type: Debris Flow
Weather:
Dry, Hot (high temp at Paradise 74.9), did have 1.28 inches of rain at Paradise on 8/6.
Season: Dry
Notes:
Debris flow occurred on Tahoma Creek from the South Tahoma Glacier at approximately 6:38 PM, detected by the Debris Flow Detection System (Alert Level 2). Detection:
https://rsam.morageology.com/view_spectra_time.php?ds=1754876486&ts=10&te=30
UPDATE FROM USGS:
Posted by: Alex Iezzi (aiezzi@usgs.gov), Mon Aug 11, 2025 03:16 (0316 UTC)
--
A small debris flow occurred in Tahoma Creek at Mount Rainier on 8/10/2025. The most convincing preliminary onset time I have is ~01:36 UTC (8/11/2025), which is obtained from clear infrasound array detections at station COPP. These types of small debris flows are common for Rainier, with the last one happening August 15, 2023 for Tahoma Creek, and a few weeks ago there were some even smaller ones in Kautz Creek.
Seismic:
Stations RER, TABR, and TAVI show really nice signals for this event, as seen in the hour long record section and spectrogram. Station TABR is ~50 m from the channel and shows lingering higher stream flow/sediment content that continues as of writing. Station TAVI shows multiple pulses that do not appear higher up in the channel (e.g. RER or TABR). A quick comparison shows that, at least from seismic amplitudes, the event was quite comparable in size to the 2023 flow.
Infrasound:
Clear infrasound was detected at stations COPP (with backazimuth sweep down channel), TAVI, and TABR (nice seismoacoustic coherence)
Laser Rangefinder:
The laser rangefinder at TABR very nicely caught the timing of the flow arrival at that part of the channel at ~01:50 (around the same time the 2023 flow took to get there). Note: This plot shows the oblique distance from the laser rangefinder, so I have to convert to a change in height.
Notes:
- The park geologist went out to survey the flow and noted that it was a hyper-concentrated flow along the westside road and has shared a lot of photos with us. They will try to make more observations tomorrow.
- Multiple sets of temporary seismic nodes are out there, as well as multiple game cameras and a campaign infrasound array so we should get a lot of really great data!
- The telemetry link at ARAT has been struggling (which WOW flows through) and both were unfortunately not telemetering at the time of the flow but we should be able to recover that data and fill in the gaps.
Estimated Velocity:
Estimated Peak Flow:
Estimated Volume:
References:
Data references:
Beason, S.R., 2012, Small glacial outburst flood occurs on Mount Rainier - October 27, 2012: Unpublished National Park Service Science Brief, 3 p.
Beason, S.R., et al., in prep, Glacial outburst floods and debris flows from the South Tahoma Glacier, Mount Rainier National Park, Washington: August and September, 2015: National Park Service Natural Resource Report NPS/MORA/NRR-2015/XXX.
Copeland, E.A., 2010, Recent periglacial debris flows from Mount Rainier, Washington: M.S. Thesis, Oregon State University, 125 p.
Copeland, E.A., P.M. Kennard, A.W. Nolin, S.T. Lanscaster and G.E. Grant, 2008, Initiation of recent debris flows on Mount Rainier, Washington: A climate warming signal? American Geophysical Union Fall Meeting, San Francisco, CA.
Crandell, D.R., 1971, Postglacial lahars from Mt. Rainier volcano, Washington: U.S. Geological Survey Professional Paper 677, 75 p.
Donovan, K.H.M, 2005, An investigation into the 2003 Van Trump Creek debris flow, Mt. Rainier, Washington, United States of America: BSc Geological Hazards Thesis, University of Portsmouth (UK), 58 p.
Driedger, C.L. and A.G. Fountain, 1989, Glacier outburst floods at Mout Rainier, Washington State, USA: Anals of Glaciology, Vol. 13, 5 p.
Hodge, S., 1972, The movement and basal conditions of the Nisqually Glacier, Mount Rainier: Ph.D Thesis, Univeristy of Washington, xxx p.
Legg, N.T., 2013, Debris flows in glaciated catchments: A case study on Mount Rainier, Washington: M.S. Thesis, Oregon State University, 162 p.
Legg, N.T., A.J. Meigs, G.E. Grant and P.M. Kennard, 2014, Debris flow initiation in proglacial gullies on Mount Rainier, Washington: Geomorphology, Vol. 226, p. 249-260.
Richardson D., 1968, Glacier outburst floods in the Pacific Northwest: U.S. Geological Survey Professional Paper 600-D, D79-D86.
Samora, B., 1991, Chronology of flood events as noted in the superintendent's annual reports 1940-1991, Unpublished Internal Document, Mount Rainier National Park, WA, 13 p.
Scott, K.M., J.W. Vallance, and P.T. Pringle, 1995, Sedimentology, behavior, and hazards of debris flows at Mount Rainier, Washington: United States Geological Survey Professional Paper 1547, 56 p.
Vallance, J.W., C.L. Driedger and W.E. Scott, 2002, Diversion of meltwater from Kautz Glacier initiates small debris flows near Van Trump Park, Mount Rainier, Washington: Washington Geology, Vol. 30, No. 1/2, p. 17-19.
Vallance, J.W., M.L. Cunico and S.P. Schilling, 2003, Debris-flow hazards caused by hydrologic events at Mount Rainier, Washington: United States Geological Survey Open-File Report 2003-368, 4 p.
Walder, J.S. and C.L. Driedger, 1994, Geomorphic changed caused by outburst floods and debris flows at Mount Rainier, Washington, with emphasis on Tahoma Creek valley: U.S. Geological Survey Water-Resources Investigations Report 93-4093, 100 p.
Walder, J.S. and C.L. Driedger, 1994, Rapid geomorphic change caused by glacial outburst floods and debris flows along Tahoma Creek, Mount Rainier, Washington, USA: Arctic and Alpine Research, Vol. 26, No. 4, p. 319-327.
Walder, J.S. and C.L. Driedger, 1995, Frequent outburst floods from South Tahoma Glacier, Mount Rainier, USA: relation to debris flows, meterological origin and implications for subglacial hydrology: Journal of Glaciology, Vol. 41, No. 137, 11 p.