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#: 145
Date: Monday, August 5, 2019
Location: South Tahoma Glacier
Glacier Name: South Tahoma Glacier
Drainage Basin: Tahoma Creek
Event Type: Debris Flow
Weather:
See: http://dfh.morageology.com/view_dfh.php?d=2019-08-05
Season: Dry
Notes:
***** PRELIMINARY FINDINGS, UPDATED 2019-08-07 15:09:00 *****
A debris flow occurred on Monday, August 5, 2019, in Tahoma Creek on the southwest side of Mount Rainier National Park. The event occurred between approximately 6:44 pm and 8:10 pm. Preliminary findings and analysis of satellite imagery indicate that the origination of this event is likely from a sudden and catastrophic change in the primary outlet stream from terminus of the South Tahoma Glacier. This change caused a surge of water to go over loose, unconsolidated sediment-rich areas immediately downstream, which quickly turned the flow of water into a debris flow.
This event was initially detected by the park geologist on his way into the park—observing Tahoma Creek’s extreme sediment-rich character on Tuesday morning, August 6th, 2019. After viewing the seismic records from Emerald Ridge, and consultation with geoscientists at the USGS Cascades Volcano Observatory, the park temporarily closed the Westside Road to visitor and staff access while geologic investigations were undertaken by the park’s Geology and Imminent Threats Team. Geologists onboard the park’s contract A-Star B3 helicopter conducted aerial reconnaissance of the area on Tuesday afternoon and quickly identified the source and runout areas, and checked the South Tahoma Glacier for possible additional outburst geologic hazards. All of the park visitors and staff in the area were accounted for by Tuesday afternoon, but park staff will continue to monitor visitor use in the area.
The passage of Monday’s debris flow was recorded by the Emerald Ridge seismograph, which recorded a total of four individual surges. The debris flows washed downstream past the Tahoma Creek suspension bridge and deposited a great deal of material adjacent to the Westside Road, where the park had undertaken road stabilization measures over the past few years. These log and rock stabilization measures performed spectacularly well and likely saved severe damage to the roadway itself.
Individual Debris flow surge times:
http://service.iris.edu/irisws/timeseries/1/query?net=UW&sta=RER&cha=EHZ&start=2019-08-06T01:40:00&end=2019-08-06T03:20:00&format=plot&loc=--
UTC, Date = 08/06/2019:
DF1: Start 01:44:38 | Peak 02:00:00 | End 02:05:25 | Rank 4 | 20.78 min
DF2: Start 02:05:26 | Peak 02:10:43 | End 02:15:48 | Rank 2 | 10.37 min
DF3: Start 02:15:49 | Peak 02:20:00 | End 02:30:56 | Rank 3 | 15.12 min
DF4: Start 02:30:57 | Peak 02:38:47 | End 03:10:04 | Rank 1 | 39.12 min
TOTAL: Start 01:44:38 | End 03:10:04 | 85.26 min (1:25:26)
PDT, Date = 08/05/2019:
DF1: Start 18:44:38 | Peak 19:00:00 | End 19:05:25 | Rank 4 | 20.78 min
DF2: Start 19:05:26 | Peak 19:10:43 | End 19:15:48 | Rank 2 | 10.37 min
DF3: Start 19:15:49 | Peak 19:20:00 | End 19:30:56 | Rank 3 | 15.12 min
DF4: Start 19:30:57 | Peak 19:38:47 | End 20:10:04 | Rank 1 | 39.12 min
TOTAL: Start 18:44:38 | End 20:10:04 | 85.26 min (1:25:26)
**** EVENT NOTES SUBJECT TO CHANGE ****
Estimated Velocity: Downstream areas might have a velocity estimate based on runup elevations
Estimated Peak Flow:
Estimated Volume: To be determined by analysis of worldview satellite imagery
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.