Angie Diefenbach


I work for the Volcano Disaster Assistance Program (VDAP), a partnership between the USGS and the Office of U.S. Foreign Disaster Assistance (OFDA) of the U.S. Agency for International Development (USAID). My job is multifaceted and involves crises response, research, teaching, monitoring, and hazards communication and outreach. My research focuses on image analysis techniques to monitor active volcanoes. I utilize various platforms, from Unmanned Aircraft Systems (UAS) “drones” to helicopters to satellites to acquire images and a technique called photogrammetry to create high-resolution topographic models of volcanoes. During eruptions I create successive models to measure volumes and effusion rates of lava domes and flows for hazard mitigation and scientific investigation. I am the primary data analyst for VDAP’s International Volcano Activity Notification System (IVANS) where I prepare synoptic hazard analyses of developing volcanic unrest and eruptions and communicate information to government officials and international aid agencies through situation reports. I also work with partner observatories to develop frameworks for monitoring, mapping, and mitigation strategies through national-scale volcanic threat assessments. Additionally, I teach international workshops on photogrammetry and UAS techniques and for the Center for the Study of Active Volcanoes (CSAV) international training program.



Since 2010: Volcano Disaster Assistance Program, Cascades Volcano Observatory, USAID-USGS

2007-2010: Volcano Hazards Program, Cascades Volcano Observatory, USGS

2005-2007: Western Washington University, M.S. Geology

  • Thesis title: Oblique photogrammetric analysis of the dome-building eruption of Mount St. Helens, 2004-2007
  • Graduate Teaching Assistant and Geology Department GIS Specialist (2006-2007)
  • National Science Foundation, GK-12 Catalyst for Reform, Fellow (2005-2006)

2005-2005: NAGT intern, Cascades Volcano Observatory, USGS

2004-2006: UNAVCO – NSF Earthscope Plate Boundary Observatory, Field Engineer and Permitting Specialist, PNW Office

1999-2004: Central Washington University, B.S. Geology with Environmental Studies minor

  • Geochemistry Laboratory Research Assistant and Geology Department Clerical Assistant (2002-2004)
  • Member, Sigma Gamma Epsilon (National Geology Honor Society) CWU, Eta Zeta Chapter (2001-2004)
  • Ronald E. McNair Scholar (2001-2003). Thesis title: Comparison of water chemistry of streams draining deforested, regrowth, and old growth portions of land in the Salmon la Sac area, Washington State
  • Study Abroad, University of Queensland, Brisbane, Australia (2001)
  • Washington State Promise Scholar (1999-2002)



USGS National Geological and Geophysical Data Preservation Program Award (2016)

WWU Innovations in Technology Graduate Thesis Award (2007)

Northwest Geological Society Outstanding Student Presentation Award (2004)

Outstanding Student Award, CWU Center for Excellence in Leadership (2003)



Neal, C.A., Brantley, S.R., Antolik, L., Babb, J., Burgess, M., Calles, K., Cappos, M., Chang, J.C., Conway, S., Desmither, L., Dotray, P., Elias, T., Fukunaga, P., Fuke, S., Johanson, I.A., Kamibayashi, K., Kauahikaua, J., Lee, R.L., Pekalib, S., Miklius, A., Million, W., Moniz, C.J., Nadeau, P.A., Okubo, P., Parcheta, C., Patrick, M.P., Shiro, B., Swanson, D.A., Tollett, W., Trusdell, F., Younger, E.F., Zoeller, M.H., Montgomery-Brown, E.K., Anderson, K.R., Poland, M.P., Ball, J., Bard, J., Coombs, M., Dietterich, H.R., Kern, C., Thelen, W.A., Cervelli, P.F., Orr, T., Houghton, B.F., Gansecki, C., Hazlett, R., Lundgren, P., Diefenbach, A.K., Lerner, A.H., Waite, G., Kelly, P., Clor, L., Werner, C., Mulliken, K., Fisher, G (2018). The 2018 rift eruption and summit collapse of Kīlauea Volcano: Science, doi:10.1126/science.aav7046

Singer, B.S., Le Mevel, H., Licciardi, J.M., Cordova, L., Tikoff, B., Garibaldi, N., Anderson, N.L., Diefenbach, A.K., Feigl, K.L. (2018). Geomorphic expression of rapid Holocene silicic magma reservoir growth beneath Laguna del Maule, Chile: Science Advances,

Ewert, J.W., Diefenbach, A.K., Ramsey, D.W. (2018). 2018 update to the U.S. Geological Survey national volcanic threat assessment: USGS Scientific Investigations Report 2018-5140

Battaglia, M., Lisowski, M., Dzurisin, D., Poland, M. P., Schilling, S., Diefenbach, A., Wynn, J. (2018). Mass addition at Mount St. Helens, Washington, inferred from repeated gravity surveys. Journal of Geophysical Research: Solid Earth, 123, 1856–1874.

Evans, W.C., Bergfeld, D., Neal, C.A., McGimsey, R.G., Werner, C.A., Waythomas, C.F., Lewicki, J.L., Lopez, T., Mangan, M.T., Miller, T.P., Diefenbach, A., Schaefer, J., Coombs, M.L., Wang, B., Nicolaysen, K., Izbekov, P., Maharrey, Z., Huebner, M., Hunt, A.G., Fitzpatrick, J., and Freeburg, G. (2015). Aleutian Arc geothermal fluids: chemical analyses of waters and gases sampled in association with the Alaska Volcano Observatory, U.S. Geological Survey Data Release,

Diefenbach, A.K., Wood, N.J., Ewert, J.W. (2015). Variations in community exposure to lahar hazards from multiple volcanoes in Washington State (USA): Journal of Applied Volcanology,

Diefenbach, A.K., Bull, K.F., Wessels, R.L., McGimsey, R.G. (2013). Photogrammetric monitoring of lava dome growth during the 2009 eruption of Redoubt Volcano: Journal of Volcanology and Geothermal Research,

Pallister, J.S., Diefenbach, A.K., Burton, W.C., Munoz, J., Griswold, J.P, Lara, L.E., Lowenstern, J.B., and Valenzuela, C.E. (2013). The Chaiten rhyolite lava dome: Eruption sequence, lava dome volumes, rapid effusion rates and source of the rhyolite magma: Andean Geology,

Bull, K.F., Anderson, S.W., Diefenbach, A.K., Wessels, R.L., and Henton, S.M. (2013). Emplacement of the final lava dome of the 2009 eruption of Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research,

Diefenbach, A.K., Crider, J.G., Schilling, S.P., and Dzurisin, D. (2012). Rapid, low-cost photogrammetry to monitor volcanic eruptions: an example from Mount St. Helens, Washington, USA, Bulletin of Volcanology, v. 74, no. 2, p. 579-587,

Schaefer, J.R., Bull, K., Cameron, C., Coombs, M., Diefenbach, A., Lopez, T., McNutt, S., Neal, C., Payne, A., Power, J., Schneider, D., Scott, W., Snedigar, S., Thompson, G., Wallace, K., Waythomas, C., Webley, P., and Werner, C. (2012). The 2009 eruption of Redoubt Volcano, Alaska: Alaska DGGS Report of Investigations 2011-5, 45 p.

Diefenbach, A.K., Guffanti, M., and Ewert, J.W. (2009). Chronology and references of volcanic eruptions and selected unrest in the United States, 1980-2008: U.S. Geological Survey Open-File Report 2009-1118, 85 p.

Guffanti, M., Diefenbach, A.K., Ewert, J.W., Ramsey, D.W., Cervelli, P.F., and Schilling, S.P. (2009). Volcano monitoring instrumentation in the United States, 2008: U.S. Geological Survey Open File Report 2009-1165, 41 p.