Drew T. Downs
I am a research geologist with the Hawaiian Volcano Observatory and my main areas of research revolve around constructing geologic maps and unraveling the eruptive histories of volcanoes. To do this, I use a multidisciplinary approach using field studies, physical volcanology, geochronology, geochemistry, petrology, remote sensing, and many more techniques.
I have worked on volcanoes and volcanic fields in a variety of settings, including subduction-related arc volcanoes within New Zealand and the southern Cascades of California, the monogenetic volcanic field of of Harrat Rahat in Saudi Arabia, and unraveling the eruptive history and processes of volcanic rocks of the Hawaiian Islands.
Throughout my research career I have participated in studies on explosive and effusive volcanism ranging from high-silica rhyolites and trachytes to basaltic lava flows. Unraveling the eruptive history preserved at the surface to understanding deeper volcanic processes has led me to use a wide variety of techniques, such as field studies, physical volcanology, geochronology, geochemistry, petrology, paleomagnetism, remote sensing, and other novel methods that help to understand volcanic processes and further understanding of their hazards.
Education and Certifications
2014 - Ph.D., Geology, University of Auckland (New Zealand)
2009 - MSc, Southern Illinois University
2007 - BSc, Southern Illinois University
Science and Products
Overview of the Cenozoic geology of the northern Harrat Rahat volcanic field, Kingdom of Saudi Arabia
The Harrat Rahat volcanic field, located in the west-central part of the Kingdom of Saudi Arabia, is one of the larger Cenozoic harrats among the more than 17 harrats situated upon the Arabia Plate. The map plate contained herein shows, at a scale of 1:100,000, the mapped volcanic geology of northern Harrat Rahat, which consists of the northernmost one-fifth of Harrat Rahat. Northern Harrat Rahat
Chemistry and petrography of early 19th century basaltic andesites and basalts from the Kamakaiʻa Hills in the Southwest Rift Zone of Kīlauea volcano, Hawaiʻi
A multidisciplinary investigation into the eruptive style, processes, and duration of a Cascades back-arc tholeiitic basalt: A case study of the Brushy Butte flow field, northern California, United States
Simultaneous Middle Pleistocene eruption of three widespread tholeiitic basalts in northern California (USA): Insights into crustal magma transport in an actively extending back arc
Geologic map of the Paeroa Fault block and surrounding area, Taupo Volcanic Zone, New Zealand
Eruption age and duration of the ~9 km3 Burney Mountain dacite dome complex, northern California
Reconstructing lava flow emplacement histories with rheological and morphological analyses: the Harrat Rahat volcanic field, Kingdom of Saudi Arabia
Timescales of magmatic differentiation from alkali basalt to trachyte within the Harrat Rahat volcanic field, Kingdom of Saudi Arabia
Volcanic history of the northernmost part of the Harrat Rahat volcanic field, Saudi Arabia
Age of the youngest volcanism at Eagle Lake, northeastern California—40Ar/39Ar and paleomagnetic results
Mihi Breccia: A stack of lacustrine sediments and subaqueous pyroclastic flows within the Taupo Volcanic Zone, New Zealand
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Overview of the Cenozoic geology of the northern Harrat Rahat volcanic field, Kingdom of Saudi Arabia
The Harrat Rahat volcanic field, located in the west-central part of the Kingdom of Saudi Arabia, is one of the larger Cenozoic harrats among the more than 17 harrats situated upon the Arabia Plate. The map plate contained herein shows, at a scale of 1:100,000, the mapped volcanic geology of northern Harrat Rahat, which consists of the northernmost one-fifth of Harrat Rahat. Northern Harrat Rahat
Chemistry and petrography of early 19th century basaltic andesites and basalts from the Kamakaiʻa Hills in the Southwest Rift Zone of Kīlauea volcano, Hawaiʻi
A multidisciplinary investigation into the eruptive style, processes, and duration of a Cascades back-arc tholeiitic basalt: A case study of the Brushy Butte flow field, northern California, United States
Simultaneous Middle Pleistocene eruption of three widespread tholeiitic basalts in northern California (USA): Insights into crustal magma transport in an actively extending back arc
Geologic map of the Paeroa Fault block and surrounding area, Taupo Volcanic Zone, New Zealand
Eruption age and duration of the ~9 km3 Burney Mountain dacite dome complex, northern California
Reconstructing lava flow emplacement histories with rheological and morphological analyses: the Harrat Rahat volcanic field, Kingdom of Saudi Arabia
Timescales of magmatic differentiation from alkali basalt to trachyte within the Harrat Rahat volcanic field, Kingdom of Saudi Arabia
Volcanic history of the northernmost part of the Harrat Rahat volcanic field, Saudi Arabia
Age of the youngest volcanism at Eagle Lake, northeastern California—40Ar/39Ar and paleomagnetic results
Mihi Breccia: A stack of lacustrine sediments and subaqueous pyroclastic flows within the Taupo Volcanic Zone, New Zealand
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.