I work with VDAP's foreign partners to better understand the eruption histories and hazards of their dangerous volcanoes. My work focusses on volcanic stratigraphy with an emphasis on field-based projects. I also develop regional and local tephrostratigraphies using ash layers in cores and am developing new applications for long-lived plant species to provide insight into past volcanic activity.
Education and Certifications
Ph.D. from Oregon State University
M.Sc. from New Mexico Institute of Mining and Technology
B.Sc. from Western Washington University
Science and Products
Radiocarbon ages, whole-rock geochemical data, and pumice density measurements for the Sacarosa tephra-fall deposit, Misti volcano, southern Peru
The late Pleistocene Sacarosa tephra-fall deposit, Misti Volcano, Arequipa, Peru: Its magma, eruption, and implications for past and future activity
Azorella compacta's long-term growth rate, longevity, and potential for dating geomorphological and archaeological features in the arid southern Peruvian Andes
The Orange Tuff: A Late Pleistocene tephra-fall deposit emplaced by a VEI 5 silicic Plinian eruption in West Java, Indonesia
Geologic field-trip guide of volcaniclastic sediments from snow- and ice-capped volcanoes—Mount St. Helens, Washington, and Mount Hood, Oregon
Bibliography of literature pertaining to Long Valley Caldera and associated volcanic fields
Bibliography of literature pertaining to Long Valley Caldera and associated volcanic fields
Bibliography of literature from 1990-1997 pertaining to Holocene and fumarolic Pleistocene volcanoes of Alaska, Canada, and the conterminous United States
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
- Data
Radiocarbon ages, whole-rock geochemical data, and pumice density measurements for the Sacarosa tephra-fall deposit, Misti volcano, southern Peru
These data are derived from the Pleistocene Sacarosa tephra-fall deposit (TFD) which erupted from Misti volcano, Arequipa, southern Peru. The deposit represents a major eruption of Misti and these data are used to characterize the deposit. The radiocarbon ages are from units bracketing the Sacarosa TFD and constrain its eruption age. Whole-rock major and trace element concentrations for Sacarosa p - Publications
The late Pleistocene Sacarosa tephra-fall deposit, Misti Volcano, Arequipa, Peru: Its magma, eruption, and implications for past and future activity
Between 38.5 ka cal BP and 32.4 ka cal BP, a dacitic Volcanic Explosivity Index 5 eruption at Misti volcano emplaced the Sacarosa tephra-fall deposit. Its biotite phenocrysts, fine grain size, scarce lithics, and abundant loose crystals characterize the deposit at locations sampled. The eruption’s ~ 800 °C magma rose rapidly from ~ 10 km depth, culminating in a Plinian eruption which reached a masAuthorsChristopher Harpel, JJ Cuno, Marie K. Takach, M. Rivera, Rigoberto Aguilar, Frank III Tepley, F. Garcia-ArenalAzorella compacta's long-term growth rate, longevity, and potential for dating geomorphological and archaeological features in the arid southern Peruvian Andes
We determine the long-term growth rate and longevity of an Azorella compacta growing on Misti volcano, near Arequipa, Peru to investigate the species' capacity as a geochronological resource. Using 14C dating on stem pieces sequestered within the plant's cushion, which grows larger through time, we obtain ages of 15 ± 15 14C yrs BP and 165 ± 15 14C yrs BP at depths of 15 cm and 29 cm below the cusAuthorsChristopher Harpel, Catherine Kleier, Rigoberto AguilarThe Orange Tuff: A Late Pleistocene tephra-fall deposit emplaced by a VEI 5 silicic Plinian eruption in West Java, Indonesia
A VEI 5 dacite eruption emplaced the Orange Tuff about between 34.3 cal kBP and 17.2 cal kBP. Gunung Salak is the unit’s source and the Orange Tuff represents the most recent such eruption from any of the volcanoes southwest of Bogor, Indonesia. The Orange Tuff is the region’s first such documented tephra-fall deposit whose characteristics and phenocryst geochemistry make it readily identifiable oAuthorsChristopher Harpel, Kushendratno, James Stimac, Cecilia F. Avendaño Rodriguez de Harpel, Sofyan PrimulyanaGeologic field-trip guide of volcaniclastic sediments from snow- and ice-capped volcanoes—Mount St. Helens, Washington, and Mount Hood, Oregon
This field guide for the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly 2017 focuses on volcaniclastic sediments from Mount St. Helens in Washington and Mount Hood in Oregon. The trip spends four days in the field and includes nine stops at each volcano. For completeness, this guidebook also includes sixteen optional stops in the Mount SAuthorsThomas C. Pierson, Lee Siebert, Christopher J. Harpel, Kevin M. ScottBibliography of literature pertaining to Long Valley Caldera and associated volcanic fields
On May 25-27, 1980, Long Valley caldera was rocked by four M=6 earthquakes that heralded the onset of a wave of seismic activity within the caldera which has continued through the present. Unrest has taken the form of seismic swarms, uplift of the resurgent dome, and areas of vegetation killed by increased CO2 emissions, all interpreted as resulting from magma injection into different levels beneaAuthorsJohn W. Ewert, Christopher J. Harpel, Suzanna K. Brooks, Mae MarcaidaBibliography of literature pertaining to Long Valley Caldera and associated volcanic fields
No abstract available.AuthorsJohn W. Ewert, Christopher J. Harpel, Suzanna K. BrooksBibliography of literature from 1990-1997 pertaining to Holocene and fumarolic Pleistocene volcanoes of Alaska, Canada, and the conterminous United States
The 1980's and 1990's were marked by frequent worldwide destructive volcanic eruptions. Significant loss of life and property during eruptions, and extensive media coverage of volcanic events around the globe have brought volcanic processes and hazards increasingly to the forefront of scientific, governmental, and public attention (e.g., Casadevall, 1994; Pringle, 1994). A result of these circumsAuthorsChristopher J. Harpel, John W. EwertNon-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.