Shanaka L de Silva

Shanaka L de Silva is a British-American geologist, academic and author. He is Sri Lankan by birth but grew up in England where he completed his education. He then moved to the US where he is a professor of geology and geophysics at Oregon State University.

de Silva is most known for his research into how volcanoes develop and erupt and the risks that they pose, primarily focusing on the largest explosive volcanic eruptions on the planet. He has conducted research on volcanoes in many locations including South America, Indonesia, Japan, China/DPRK and Saudi Arabia. Among his authored works are his publications in academic journals, including the Journal of Volcanology and Geothermal Research, Nature, and Journal of Petrology as well as books such as Volcanoes of the Central Andes.

Education de Silva earned his BSc (Hons). in Geology from the University of Southampton in 1983. In 1987, he went on to receive a PhD in Earth Sciences from the Open University in the United Kingdom.

In 2014, de Silva was invited to give expert testimony to the 113th Congress, Natural Resources Sub-Committee on "Volcano Hazards: Exploring the National Preparation and Response Strategy".

Works de Silva has contributed to various publications, including books, throughout his career. In 1991, he co-authored a catalog on Andean volcanoes, featuring detailed information, satellite images, figures, and descriptions of 44 major, potentially active volcanoes in the region.

Research As part of his volcanism research, de Silva has studied the largest and most explosive volcanoes on Earth, large calderas or supervolcanoes. His 1989 research discovered the Altiplano-Puna Volcanic Complex in the Andes, attributing its formation to large-scale crustal melting caused by crustal thickening and subduction-related magma heat, leading to significant silicic magmatism and extensive ignimbrite eruptions. His work establishes that the formation of complex calderas are the result of crustal processes driven by elevated mantle heat, leading to crustal softening, magma formation, and large-scale volcanic eruptions, thereby redefining such calderas as tectonomagmatic phenomena rather than purely volcanic events. This theme of research has been applied to many other calderas, around the world, including Toba, Sumatra, to help understand their development, evolution and future hazards. In 2007 he contributed to a review that integrated data from volcanic and plutonic rocks to understand them as part of a continuum, proposing that volcanic rocks represent erupted melt-rich regions from crystal-rich reservoirs that later solidify into plutons, ultimately aiming to better understand Earth's magmatic processes and crustal formation.

In 2020, de Silva's team presented an analysis of the eruptive history of Changbaishan-Tianchi volcano, confirming three eruptions including the Generalized Millennium Eruption of 946 CE, while also providing new age estimates and insights into the nature of these eruptions. Additionally, he is serving as the Principal Investigator of a project to establish the current state of the active Cerro Blanco caldera magmatic system in Argentina and its potential to erupt again. He is also the Co-Principal Investigator (Co-PI) of a project, aiming to advance techniques for dating explosive volcanic eruptions in the Asia-Pacific region within the last million years.

Awards and honors 1994–1995 – Educational Excellence Award Indiana State University 2004–2005 – Departmental Excellence in Teaching, University of North Dakota 2011 – Fellow, Geological Society of America 2020 – Research Fellow, Alexander von Humboldt Foundation