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22-20. Assessing slope instability and tsunamigenic hazards of island volcanoes to coastal areas in the U.S. and its territories 

Tsunamis generated by the collapse of volcanic edifices are a potentially high impact hazard. A multidisciplinary project across several USGS programs will enhance the understanding of hazards resulting from instability of island volcanoes and potential subsequent tsunami generation. The overarching goal is to improve the resilience of coastal and island communities.  

Description of the Research Opportunity

Tsunamis generated by volcanic edifice collapses are a low probability (~5% of all recorded tsunamis; Grezio et al., 2017), but a potentially high impact hazard (Day, 2015). The January 2022 Hunga-Tonga-Hunga Ha’apai eruption in the southwest Pacific Ocean generated tsunami waves that traveled across the Pacific Ocean and made landfall in 11 countries (Lynett et al., 2022). This event serves as a reminder of the significant hazards posed by instability of island volcanoes and potential subsequent generation of volcanic tsunamis (e.g., Costa et al., 2021; Ramalho et al., 2015; Zorn et al., 2022). These tsunamis pose a significant hazard to coastal areas in the continental U.S., Alaska, Hawai‘i, and the U.S. territories (American Samoa, Commonwealth of the Northern Mariana Islands, Guam U.S. Virgin Islands, Puerto Rico).  

Volcanic tsunamis can be generated by several different processes (Paris, 2015) with edifice instability and collapse in the subaerial or submarine environment being among the most significant (McGuire, 2006). For example, flank collapse in Anak Krakatau (Indonesia) in December 2018 that resulted in 457 fatalities (Grilli et al., 2019), the Canary and Cape Verde Islands in the Atlantic Ocean (Paris et al., 2018), and at Augustine Volcano in the Cook Inlet, Alaska (Waythomas et al., 2009). The 1792 tsunami caused by flank collapse of the Mayuyama Dome at Unzen Volcano on the island of Kyushu, Japan resulted in more than 15,000 fatalities (Higaki et al., 2023).  

There are several major knowledge gaps that limit the ability to assess and quantify the hazards posed by volcanic tsunamis. For example, which island volcanoes have potentially unstable flanks? What is the recurrence of volcanic tsunamis? How does the collapse of a volcanic edifice generate tsunamis and influence slope stability of the remaining edifice? How can volcanic tsunamis be included into probabilistic tsunami hazard assessments?   

To overcome some of these critical knowledge gaps, we propose a multidisciplinary project across several USGS programs within the Natural Hazards Mission Area (Volcano Hazards, Landslide Hazards, Coastal and Marine Hazards). Research collaborations with the USGS Volcano Disaster Assistance Program (VDAP) and other federal agencies (for example, NOAA's tsunami warning centers) are encouraged.  

The main objective of the fellowship is to improve the understanding of hazards resulting from instability of island volcanoes and the potential generation of tsunamis. Research can include a variety of field-based observations, remote sensing, and computational methods. Science objectives that the Mendenhall Fellow might work towards include:  

  • Conduct an inventory of volcanoes in the Pacific and Atlantic Oceans (including the Caribbean Sea) that pose significant tsunami threats to US interests. Develop hazard ranking schemes based on characteristics such as the volcano’s eruptive and tsunami generation history, the volcano’s flank steepness and its elevation relative to the distance from the sea, and the degree of hydrothermal alteration in the edifice (Zorn et al., 2022).  

  • Calculate the potential volumes of rock that can slide into the ocean using field-based and high-resolution imagery remote sensing methods (InSAR, hyperspectral), geologic maps, information on rock properties, digital elevation models, and slope stability models such as the USGS 3D slope-stability model, Scoops3D (Reid et al., 2015). Improve processing pipelines for integrating slope stability results into lahar and debris flow models.   

  • Determine how volcano flank failure and mass movement simulations are best used as input to models of volcanic tsunami generation and of near-field and ocean basin-scale wave propagation, providing specific hazard assessment information for US coastal communities. 

The overarching goal of this project is to improve resilience of coastal and island communities by providing them the needed information to better site critical infrastructure, and conserve and manage vital resources and habitats, while minimizing their risk from exposure to natural hazards. One of the expected outcomes of the project is to aid agencies responsible for monitoring tsunamis around the world to incorporate warnings for tsunamis generated by volcanic sources. 

Interested applicants are strongly encouraged to contact the Research Advisor(s) early in the application process to discuss project ideas. 



Costa, P.J., Dawson, S., Ramalho, R.S., Engel, M., et al., 2021. A review on onshore tsunami deposits along the Atlantic coasts. Earth-Science Reviews, 212, p.103441.  

Day, S.J., 2015. Volcanic tsunamis. In The Encyclopedia of Volcanoes. Academic Press, 993-1009.  

Grezio, A., Babeyko, A., Baptista, M.A., Behrens, J., et al., 2017. Probabilistic tsunami hazard analysis: multiple sources and global applications. Reviews of Geophysics, 55, 1158-1198.  

Grilli, S.T., Tappin, D.R., Carey, S., Watt, S.F., et al., 2019. Modelling of the tsunami from the December 22, 2018 lateral collapse of Anak Krakatau volcano in the Sunda Straits, Indonesia. Scientific reports, 9, p.11946.  

Higaki, D., Hirota, K., Dang, K., Nakai, S., et al., 2023. Landslides and countermeasures in Western Japan: Historical largest landslide in Unzen and earthquake-induced landslides in Aso, and rain-Induced landslides in Hiroshima. In Progress in Landslide Research and Technology, V.1, 287-307. Cham: Springer International Publishing.  

Lynett, P., McCann, M., Zhou, Z., Renteria, W., et al., 2022. Diverse tsunamigenesis triggered by the Hunga Tonga-Hunga Ha’apai eruption. Nature, 609, 728-733.  

McGuire, W.J., 2006. Lateral collapse and tsunamigenic potential of marine volcanoes. Geological Society, London, Special Publications, 269, 121-140.  

Paris, R., 2015. Source mechanisms of volcanic tsunamis. Philosophical Transactions of the Royal Society A, 373, p.20140380.   

Paris, R., Ramalho, R.S., Madeira, J., Ávila, S., et al., 2018. Mega-tsunami conglomerates and flank collapses of ocean island volcanoes. Marine Geology, 395, 168-187.   

Ramalho, R.S., Winckler, G., Madeira, J., Helffrich, G.R., et al., 2015. Hazard potential of volcanic flank collapses raised by new megatsunami evidence. Science Advances, 1, p.e1500456.   

Reid, M.E., Christian, S.B., Brien, D.L. and Henderson, S., 2015. Scoops3D–software to analyze three-dimensional slope stability throughout a digital landscape. US Geological Survey Techniques and Methods, 14-A1, 218.  

Waythomas, C.F., Watts, P., Shi, F. and Kirby, J.T., 2009. Pacific Basin tsunami hazards associated with mass flows in the Aleutian arc of Alaska. Quaternary Science Reviews, 28, 1006-1019.   

Zorn, E.U., Orynbaikyzy, A., Plank, S., Babeyko, A., et al., 2022. Identification and ranking of subaerial volcanic tsunami hazard sources in Southeast Asia. Natural Hazards and Earth System Sciences, 22, 3083-3104.  


Proposed Duty Station(s)

Moffett Field, California.  


Areas of PhD

Geology, geophysics, fluid dynamics, oceanography, engineering or related fields (candidates holding a Ph.D. in other disciplines, but with extensive knowledge and skills relevant to the Research Opportunity may be considered).  



Applicants must meet the following qualification:  Research Geologist, Research Geophysicist, Research Oceanographer, Research Physicist  

(This type of research is performed by those who have backgrounds for the occupations stated above.  However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)