Thomas C Pierson, Ph.D.

Biography

Thomas Pierson completed his Masters and Ph.D. degrees in geology at the University of Washington (1972 and 1977), followed by a post-doctoral fellowship with the New Zealand Forest Service, Forest Research Institute (1977-80). He has been a research scientist at the USGS Cascades Volcano Observatory since 1981, with four of those years serving concurrently as Vancouver Project Office Chief (WRD) and Associate Scientist in Charge at the Observatory (WRD/GD). Since 1996 he has also been Adjunct Professor of Geology at Portland State University, supervising Masters students and occasionally teaching.  Tom's field-based research focuses primarily on volcano hazards involving the mobilization and rapid movement of rock debris, ice, and water mixtures down the flanks of volcanoes—lahars, debris avalanches, and floods.  His work examines the magnitude, frequency, initiation mechanisms, timing, and flow behavior of such sediment-water flows, but it also aims to refine the sedimentologic interpretation of the volcaniclastic deposits left by these flows, in order to better understand and assess the potential for future hazards in volcanic areas. Tom is particularly interested in using hazard assessment information gleaned from volcanic deposits to inform and educate emergency managers, public officials, and vulnerable communities about volcanic hazards. Research projects and disaster responses have taken him to restless volcanoes in the Cascades, Alaska, Japan, the Philippines, New Zealand, Ecuador, Colombia, Chile, and Mexico.  He has authored over 75 published articles, reports, and book chapters.

 

Published articles and book chapters, and academic theses:

 

1.  Pierson, T.C., 1970, Petrogenesis and emplacement of the alkaline intrusion at Cuttingsville, Vermont:  A re-evaluation:  B.A. Thesis, Middlebury College, 41 p.

 

2.  Pierson, T.C., 1972, Petrologic and tectonic relationships of Cretaceous sandstones in the Harts Pass area, North Cascade Mountains, Washington:  M.S. Thesis, University of Washington, 37 p.

 

3.  Laurent, R., and Pierson, T.C., 1973, Petrology of alkaline rocks from Cuttingsville and the Shelburne Peninsula, Vermont:  Canadian Journal of Earth Science, v.10, p.1244-1256. 

 

4.  Pierson, T.C., 1977, Factors controlling debris-flow initiation on forested hillslopes in the Oregon Coast Range:  Ph.D. Dissertation, University of Washington, 166 p.

 

5.  Pierson, T.C., and Mosley, M.P., 1978, Erosion and deposition by debris flows in the Bullock Creek catchment, Mount Thomas State Forest, North Canterbury:  N.Z. Forest Service, Protection Forestry Div., Geohydrology Report No. 162, 19 p.

 

6.  Pierson, T.C., 1980, Preliminary landscape zonation for stream protection and hillslope stability maintenance, Granville State Forest 47, Westland:  N.Z. Forest Service, Protection Forestry Div., Geohydrology Report No. 179, 6 p. plus maps.

 

7.  Pierson, T.C., 1980, Erosion and deposition by debris flows at Mount Thomas, North Canterbury, New Zealand:  Earth Surface Processes, v.5, p.227-247.

 

8.  Pierson, T.C., 1980, Piezometric response to rainstorms in forested hillslope drainage depressions:  Journal of Hydrology (New Zealand), v.19, p.1-10.

 

9.  Pierson, T.C., 1980, Debris flows -- An important process in high country gully erosion:  Review 39, Journal of the Tussock Grasslands and Mountain Lands Institute (New Zealand), December, p.3-14.

 

10.  Pierson, T.C., 1981, Dominant particle support mechanisms in debris flows at Mount Thomas, New Zealand, and implications for flow mobility:  Sedimentology, v.28, p. 49-60.

 

11.  Pierson, T.C., 1982, Classification and hydrological characteristics of scree slope deposits in the northern Craigieburn Range, New Zealand:  Journal of Hydrology (New Zealand), v.21, p.34-60.

 

12.  Pierson, T.C., 1982, Flow behavior of two major lahars triggered by the May 18, 1980, eruption of Mount St. Helens, Washington:  Symposium on Erosion Control in Volcanic Areas, Proceedings:  Public Works Research Institute, Japan, Technical Memorandum No. 1908, p. 99-129.

 

13.  Pierson, T.C., 1983, Soil pipes and slope stability:  Quarterly Journal of Engineering Geology, London, v.16, p.1-11.

 

14.  Pierson, T.C., 1983, Flow behavior of two major lahars triggered by the May 18, 1980, eruption of Mount St. Helens, Washington, in Proc. Symposium on Erosion Control in Volcanic Areas:  Public Works Research Institute (Japan), Tech. Memorandum No. 1908, p.99-129.

 

15.  Waitt, R.B., Jr., Pierson, T.C., MacLeod, N.S., Janda, R.J., Voight, B., and Holcomb, R.T., 1983, Eruption-triggered avalanche, flood, and lahar at Mount St. Helens:  Effects of winter snowpack:  Science, v.221, p.1394-1397.

 

16.  Gallino, G.L., and Pierson, T.C., 1984, The 1980 Polallie Creek debris flow and subsequent dam-break flood, East Fork Hood River basin, Oregon:  U.S., Geological Survey Open File Report 84-578, 37 p.

 

17.  Pierson, T.C., 1985, Effects of slurry composition on debris-flow dynamics, Rudd Canyon, Utah, in Bowles, D.D., ed., Delineation of Landslide, Flash Flood, and Debris-Flow Hazards in Utah:  Utah Water Research Laboratory, General Series UWRL/G-85/03, Logan, Utah, p.132-152.

 

18.  Pierson, T.C., 1985, Initiation and flow behavior of the 1980 Pine Creek and Muddy River lahars, Mount St. Helens, Washington:  Geological Society of America Bulletin, v.96, p.1056-1069.

 

19.  Pierson, T.C., 1985, Field techniques for measuring debris-flow dynamics, in Proc. International Symposium on Erosion, Debris Flow, and Disaster Prevention:  Tsukuba, Japan, p.203-207.

 

20.  Pierson, T.C., and Scott, K.M., 1985, Downstream dilution of a lahar: transition from debris flow to hyperconcentrated streamflow:  Water Resources Research, v.21, p.1511-1524.

 

21.  Gallino, G.L., and Pierson, T.C., 1985, Polallie Creek debris flow and subsequent dam-break flood of 1980, East Fork Hood River Basin, Oregon:  U.S. Geological Survey Water-Supply Paper 2273, 22 p.

 

22.  Pierson, T.C., 1986, Flow behavior of channelized debris flows, Mount St. Helens, Washington, in Abrahams, A.D., ed., Hillslope Processes:  Boston, Allen and Unwin, p.269-296.

 

23.  Pierson, T.C., 1986, Mobilization and flow of the 1980 eruption-triggered lahars -- eastside drainages, in Guidebook to 1986 American Geomorphological Field Conference -- Mount St. Helens:  CispusCenter, Randle, Washington, p.35-39.

 

24.  Pierson, T.C., and Costa, J.E., 1987, A rheologic classification of subaerial sediment-water flows, in Costa, J.E., and Wieczorek, G.F., eds., Debris Flows/Avalanches:  Process, Recognition, and Mitigation:  Geological Society of America, Reviews in Engineering Geology, v.7, p.1-12.

 

25.  Thouret, J.C., Janda, R.J., Pierson, T.C., Calvache, M.L., and Cendrero, A., 1987, L'eruption du 13 novembre 1985 au Nevado del Ruiz (Cordillere Centrale, Colombie):  interactions entre le dynamisme eruptif, la fusion glaciaire et la genese d'ecoulements volcano-glaciaires:  C.R. Acad. Sci. Paris, v.305 (series II), p.505-509.

 

26.  Pierson, T.C., 1987, Debris flow and landslide hazard assessment, in Kresch, D.L., Flood hazard assessment of the Hoh River at Olympic National Park Ranger Station, Washington:  U.S. Geological Survey Water Resources Investigations Report 86-4198, p.18-20.

                       

27.  Pierson, T.C., 1989, Hazardous hydrologic consequences of volcanic eruptions and goals for mitigative action -- an overview, in Starosolszky, O., and Melder, O.M., eds., Hydrology of Disasters: Proc. World Meteorological Organization Technical Conference, Geneva, November, 1988:  London, James and James, p.220-236.

 

28.  Pierson, T.C., Janda, R.J., Thouret, J.C., and Borrero, C.A., 1990, Perturbation and melting of snow and ice by the 13 November 1985 eruption of Nevado del Ruiz, Colombia, and consequent mobilization, flow, and deposition of lahars:  Journal of Volcanology and Geothermal Research, v.41, p.17-66.

 

29.  Major, Jon J., and Pierson, T.C., 1990, Rheological analysis of fine-grained natural debris-flow material, in Proceedings of the International Symposium on Hydraulics/Hydrology of Arid Lands, July 30-Aug. 2, 1990, San Diego, CA:  American Soc. of Civil Engineers, New York, p.225-231.

 

30.  Ellen, S.D., Iverson, R.M., and Pierson, T.C., 1991, Map showing the distribution of debris flows during the New Year's Eve storm of 1987-1988 in southeastern Oahu, Hawaii:  U.S. Geological Survey Open-File Report 91-129.

 

31.  Wright, T.L., and Pierson, T.C., 1992, Living with volcanoes: a summary of the U.S. Geological Survey's Volcano Hazards Program:  U.S. Geological Survey Circular 1073, 57 p. 

 

32.  Pierson, T.C., Ellen, S.D., and Iverson, R.M., 1992, Spatial and temporal distribution of shallow landsliding during intense rainfall, southeastern Oahu, Hawaii, in Bell, D.H. (ed.), Landslides:  Proceedings of the Sixth International Symposium on Landslides, 10-14 February 1992, Christchurch, New Zealand, p. 1393-1398.

 

33.  Major, J.J., and Pierson, T.C., 1992, Debris-flow rheology: experimental analysis of fine-grained slurries:  Water Resources Research, v. 28, p. 841-857.

 

34.  Pierson, T.C., Janda, R.J., Umbal, J.V., and Daag, A.S., 1992, Immediate and long-term hazards from lahars and excess sedimentation in rivers draining Mt. Pinatubo, Philippines:  U.S. Geological Survey Water-Resources Investigations Report 92-4039, 35 p. and 1 plate.

 

35.  Pierson, T.C., 1992, Rainfall-triggered lahars at Mt. Pinatubo, Philippines, following the June 1991 eruption:  Landslide News (Japan Landslide Society), No. 6, p. 6-9.

 

36.  Arattano, M., Savage, W.Z., and Pierson, T.C., 1993, Application of kinematic wave theory to a debris flow at Lower Rudd Canyon, Farmington, Utah, in Novosad, S. and Wagner, P. (eds.) Landslides:  Proceedings of the Seventh International Conference and Field Workshop on Landslides in Czech and Slovak Republics, 28 August--15 September, 1993, Balkema, Rotterdam, p.123-130.

 

37.  Pierson, T.C., and Janda, R.J., 1994, Volcanic mixed avalanches:  a distinct eruption-triggered mass-flow process at snow-clad volcanoes:  Geological Society of America Bulletin, v. 106, p. 1351-1358.

 

38.  Waitt, R.B., Gardner, C.A., Pierson, T.C., Major, J.J., and Neal, C.A., 1994, Unusual ice diamicts emplaced during 15 December 1989 eruption of Redoubt Volcano, Alaska:  Journal of Volcanology and Geothermal Research, v. 62, p. 409-428. 

 

39.  Waitt, R.B., and Pierson, T.C., 1994, The 1980 (mostly) and earlier explosive eruptions of Mount St. Helens volcano, in Swanson, D.A., and Haugerud, R.A., eds., Geologic field trips in the Pacific Northwest:  1994 Geological Society of America Annual Meeting, v. 2, Chap. I, p. 2I.1-2I.36.

 

40.  Pierson, T.C., 1995, Flow characteristics of large eruption-triggered debris flows at snow-clad volcanoes: constraints for debris-flow models:  Journal of Volcanology and Geothermal Research, v. 66, p. 283-294.

 

41.  Wolfe, E.W., and Pierson, T.C., 1995, Volcanic-hazard zonation for Mount St. Helens, Washington, 1995:  U.S. Geological Survey Open-File Report 95-497, 12 p. plus map. 

 

42.  Pierson, T.C., Daag, A.S., Delos Reyes, P.J., Regalado, M.T.M., Solidum, R.U., and Tubianosa, B.S.,  1996, Flow and deposition of posteruption hot lahars on the east side of Mount Pinatubo, July-October 1991, in Newhall, C.G., and Punongbayan, R.S., eds., Fire and mud: eruptions and lahars of Mount Pinatubo, Philippines:  Philippine Institute of Volcanology and Seismology, Quezon City and University of Washington Press, Seattle, p. 921‑950. 

 

43.  Janda, R..J., Daag, A.S., Delos Reyes, P.J., Newhall, C.G., Pierson, T.C., Punongbayan, R.S., Rodolfo, K.S., and Umbal, J.V.,  1996, Assessment and response to lahar hazard around Mount Pinatubo, 1991‑93, in Newhall, C.G., and Punongbayan, R.S., eds., Fire and mud: eruptions and lahars of Mount Pinatubo, Philippines:  Philippine Institute of Volcanology and Seismology, Quezon City and University of Washington Press, Seattle,  p. 107‑139. 

 

44.  Scott, W.E., Pierson, T.C., Schilling, S.P., Costa, J.E., Gardner, C.A., Vallance, J.W., and Major, J.J., 1997, Volcano hazards in the Mount Hood Region, Oregon:  U.S. Geological Survey Open-File Report 97-89, 14 p.

 

45.  Pierson, T.C., and Driedger, C., Who's keeping watch over Pacific Northwest volcanoes?:  U.S. Geological Survey Open-File Report 97-125. 

 

46.  Pierson, T.C., 1998, An empirical method for estimating travel times for wet volcanic mass flows:  Bulletin of Volcanology, v. 60, p. 98-109.

 

47.  Pierson, T.C., ed., 1999, Hydrologic consequences of hot rock--snowpack interactions at Mount St. Helens Volcano, Washington, 1982-84:  US Geological Survey Professional Paper 1586, 117p.

 

48.  Pierson, T.C., and Waitt, R.B., 1999, Hydrologic consequences of hot rock--snowpack interactions at Mount St. Helens Volcano, Washington, 1982-1984, in Pierson, T.C., ed., Hydrologic consequences of hot rock--snowpack interactions at Mount St. Helens Volcano, Washington, 1982-84:  US Geological Survey Professional Paper 1586, p. 1-8.

 

49.  Pierson, T.C., 1999, Transformation of water flood to debris flow following the eruption-triggered transient-lake breakout from the crater on March 19,1982,  in Pierson, T.C., ed., Hydrologic consequences of hot rock--snowpack interactions at Mount St. Helens Volcano, Washington, 1982-84:  US Geological Survey Professional Paper 1586, p. 19-36.

 

50.  Pierson, T.C., and Waitt, R.B., 1999, Dome-collapse rockslide and multiple sediment-water flows generated by a small explosive eruption on February 2-3, 1983, in Pierson, T.C., ed., Hydrologic consequences of hot rock--snowpack interactions at Mount St. Helens Volcano, Washington, 1982-84:  US Geological Survey Professional Paper 1586, p. 53-68.

 

51.  Major, J.J., Pierson, T.C., Dinehart, R.L., and Costa, J.E.,  2000,  Sediment yield following severe volcanic disturbance—A two-decade perspective from Mount St. Helens:  Geology, v. 28, p. 819-822.

 

52.  Gardner, C.A., Scott, W.E., Major, J.J., and Pierson, T.C., 2000, Mount Hood—History and hazards of Oregon’s most recently active volcano:  U.S. Geological Survey Fact Sheet 060-00, 4 p.

 

53.  Pierson, T.C., 2002, Evaluation of lahar mitigation proposals at Mt. Ruapehu:  New Zealand Dept. of Conservation, DOC Science Internal Series 63, 18 p.

 

54.  Wilcock, P.R., Schmidt, J.C., Wolman, M.G., Dietrich, W.E., DeWitt, D., Doyle, M.W., Grant, G.E., Iverson, R.M., Montgomery, D.R., Pierson, T.C., Schilling, S.P., and Wilson, R.C., 2003, When models meet managers:  Examples from geomorphology, in Wilcock, P.R., and Iverson, R.M., eds., Prediction in Geomorphology:  Geophysical Monograph 135, American Geophysical Union, Washington, DC, p. 27-40.

 

55.  Mothes, P., Hall, M.L., Andrade, D., Samaniego, P., Pierson, T.C., Ruiz, A.G., and Yepes, H., 2004, Character, stratigraphy, and magnitude of historical lahars of Cotopaxi volcano (Ecuador):  Acta Vulcanologica, v. 16, p. 85-108.

 

56.  Pierson, Thomas C., 2005, Distinguishing between debris flows and floods from field evidence in small watersheds:  USGS Fact Sheet 2004-3142, 4 p.

 

57.  Pierson, Thomas C., 2005, Hyperconcentrated flow—transitional process between water flow and debris flow, Chapter 8 in Jakob, Matthias, and Hungr, Oldrich (eds), Debris-flow Hazards and Related Phenomena:  Springer/Praxis, Chichester, UK, p. 159-202.

 

58.  Major, Jon J., Pierson, Thomas C., and Scott, Kevin M., 2005, Debris flows at Mount St. Helens, Washington, USA, Chapter 27 in Jakob, Matthias, and Hungr, Oldrich (eds), Debris-flow Hazards and Related Phenomena:  Springer/Praxis, Chichester, UK, p. 685-731.

 

59.  Pierson, Thomas C., 2005, More on the challenges of natural hazards (Forum section):  EOS, Transactions of the American Geophysical Union, v. 86, no. 13 (29 March 2005), p. 134.

 

60.  Pierson, Thomas C., 2007, Tree-ring dating of young lahar- and flood-deposit landforms downstream of volcanoes in the southern Washington and northern Oregon Cascades:  Earth Surface Processes and Landforms, v. 32, p. 811-831. 

 

61.  Pierson, T.C., Scott, W.E., Vallance, J.W., and Pringle, P.T., 2009, Eruption-related lahars and sedimentation response downstream of Mount Hood:  Field guide to volcaniclastic deposits along the Sandy River, Oregon, in O’Connor, J.E., Dorsey, R.J., and Madin, I.P., eds., Volcanoes to Vineyards:  Geologic Field Trips through the Dynamic Landscape of the Pacific Northwest:  Geological Society of America Field Guide 15, p. 229-244.

 

62.  Pringle, P.T., Pierson, T.C., Cameron, K.A., and Sheppard, P.R., 2010, Late eighteenth century Old Maid eruption and lahars at Mount Hood, Oregon (USA) dated with tree rings and historical observations, in Stoffel, M., Bollschweiler, M., Butler, D.R., and Luckman, B.H., eds., Tree-Rings and Natural Hazards: A State of the Art (Advances in Global Change Research 41):  Berlin, Springer-Verlag,  p. 487-491. 

 

63.  Vallance, J.W., Gardner, C.A., Scott, W.E., Iverson, R.M., and Pierson, T.C., 2010, Mount St. Helens: A 30-year legacy of volcanism:  Eos, Transactions of the American Geophysical Union, v. 91, no. 19, p. 169-170.

 

64.  Pallister, J.S., Major, J.J., Pierson, T.C., Hoblitt, R.P., Lowenstern, J.B., Eichelberger, J.C., Lara, L., Moreno, H., Muñoz, J., Castro, J.M., Iroumé, A., Andreoli, A., Jones, J., Swanson, F., and Crisafulli, C., 2010, Interdisciplinary studies of eruption at Chaitén volcano, Chile:  Eos, Transactions of the American Geophysical Union, v. 91, no. 42, p. 381-382.

 

65.  Pierson, T.C., Pringle, P.T., and Cameron, K.C., 2011, Magnitude and timing of downstream channel aggradation in response to a dome-building eruption at Mount Hood, Oregon:  Geological Society of America Bulletin, v. 123, p. 3-20.

 

66.  Waythomas, C.F., Pierson, T.C., Major, J.J., and Scott, W.E., 2012, Preliminary observations of voluminous ice-rich and water-rich lahars generated during the 2009 eruption of Redoubt Volcano, Alaska:  U.S. Geological Survey Open-File Report 2012-1078, 42 p.

 

67.  Pierson, T.C., 2013, Using age of colonizing Douglas-fir for the dating of young geomorphic surfaces:  a case study. In:  Schneuwly-Bollschweiler, M., Stoffel, M., Rudolf-Miklau, F. (eds.),  Dating Torrential Processes on Fans and Cones: Methods and Their Application for Hazard and Risk Assessment: Springer, Dordrecht, The Netherlands, 203-210.

 

68.  Pierson, T.C., Driedger, C., and Tilling, R.I., 2013, Volcano crisis response at Yellowstone Volcanic Complex—After Action Report for Exercise Held at Salt Lake City, Utah, November 15, 2011:  U.S. Geological Survey Open-File Report 2013-1018, 31 p.

 

69.  Pierson, T.C., Major, J.J., Amigo, Á., and Moreno, H., 2013, Acute sedimentation response to rainfall following the explosive phase of the 2008–2009 eruption of Chaitén volcano, Chile:  Bulletin of Volcanology, v. 75, art. no. 723, DOI 10.1007/s00445-013-0723-4.

 

70.  Major, J.J., Pierson, T.C., Hoblitt, R.P., and Moreno, H., 2013, Pyroclastic density currents associated with the 2008-2009 eruption of Chaitén volcano (Chile)—forest disturbances, deposits, and dynamics:  Andean Geology, v. 40 (2), p. 324-358.

 

71.  Lara, L.E., Moreno, R., Amigo, Á, Hoblitt, R.P., and Pierson, T.C., 2013, Late Holocene history of Chaitén volcano:  New evidence for a 17th-century eruption:  Andean Geology, v. 40 (2), p. 249-261.

 

 

 72.  Waythomas, C.F., Pierson, T.C., Major, J.J., and Scott, W.E., 2013, Voluminous ice-rich lahars generated during the 2009 eruption of Redoubt Volcano, Alaska:  Journal of Volcanology and Geothermal Research, v. 259, p. 389-413.

 

 

73.  Pierson, T.C., and Major, J.J., 2014, Hydrogeomorphic effects of explosive volcanic eruption on drainage basins:  Annual Review of Earth and Planetary Sciences, v. 42, p. 469–507.

 

 74.  Pierson, T.C., Wood, N.J., and Driedger, C.L., 2014, Reducing risk from lahar hazards: concepts, case studies, and roles for scientists:  Journal of Applied Volcanology 3:16 [http://www.appliedvolc.com/content/3/1/16].

 

75.  Pierson, Tom, 2015, What if you had been at Lahar Viewpoint on May 18, 1980?:  Rumblings, issue 9, March/April, 2015:  Mount St. Helens Institute online newsletter [http://mshinstitute.org/images/pdf/Rumblings_Issue_9.pdf].

 

76.  Pierson, Thomas C., Evarts, Russell C., and Bard, Joseph A., 2016, Landslides in the Western Columbia Gorge, Skamania County, Washington:  U.S. Geological Survey Scientific Investigations Map 3358, scale 1:12,000, 22 p., http://dx.doi.org/10.3133/sim3358.

 

77.  Major, J. J., D. Bertin, T. C. Pierson, Á. Amigo, A. Iroumé, H. Ulloa, and J. Castro, 2016, Extraordinary sediment delivery and rapid geomorphic response following the 2008–2009 eruption of Chaitén Volcano, Chile: Water Resour. Res., 52, doi:10.1002/2015WR018250.

 

78.  Hu, X., Wang, T., Pierson, T.C., Lu, Z., Kim, J., and Cecere, T., 2016, Detecting seasonal landslide movement within the Cascade landslide complex (Washington) using time-series SAR imagery:  Remote Sensing of Environment, v. 187, p. 49–61, http://dx.doi.org/10.1016/j.rse.2016.10.006.

 

79.  Pierson, T.C., Mangan, M.T., Lara Pulgar, L.E., Amigo Ramos, Álvaro, 2017, United States-Chile binational exchange for volcanic risk reduction, 2015—Activities and benefits: U.S. Geological Survey Circular 1432, 43 p., https://doi.org/10.3133/cir1432.

 

80.  Pierson, T.C., 2017, Volcanoes, landslides, and angry gods—A Pacific Northwest connection:  Volcano Watch,  May 25, 2017, on Hawaiian Volcano Observatory website, https://volcanoes.usgs.gov/observatories/hvo/hvo_volcano_watch.html?vwid=1198.