Dr. Michael H. Ort
Professor
Education
PhD, University of California
Contact
Office: Geology Annex (bldg #13), room 209
Phone: 928-523-9363
E-mail: Michael.Ort@nau.edu
Personal Website
Research interests
My primary research is on volcanoes,
including eruption and emplacement processes, petrology, geochemistry, and the
interactions of humans with volcanoes. My research into eruption and emplacement
processes of pyroclastic flows and surges has focused on large-volume
ignimbrites in Argentina and Italy and on maar volcanoes in Arizona, Alaska,
and Italy.
The driving question is how do these
pyroclastic gravity currents form and move. Because we really only have
deposits to work with, my research designs aim to cut through the
"filter" of the deposition to get at what the current looked and
acted like , at least in the lower part, near the depositional zone. I commonly
use careful field work, petrography (optical and electron), and paleomagnetism
(especially anisotropy of magnetic susceptibility) as tools. My petrologic
interests currently center on the origins of the Hopi Buttes (NE Arizona)
monchiquitic and nephelinitic magmas. I have an isotope clean lab and am a
co-PI on our new multi-collector ICP mass spectrometer, on which we can do much
of the analysis.
I am also currently working on the
interaction between humans and the youngest volcanism in the Southwestern USA,
concentrating on the ~1050 AD Sunset Crater eruption near Flagstaff and the
Little Springs eruption (dated between 1100 and 1200 AD). Both eruptions had
profound effects on the people living there then, so I am working with an
archaeologist and other geologists to understand how the environment changed.
Research
Interests
I am
interested in all things volcanic, from igneous petrology and geochemistry to
pyroclastic processes (from eruption to emplacement) and magma ascent
dynamics. I use whatever instruments or
methods are needed to answer the questions.
These include many different geochemical (e.g. whole rock and mineral
geochemistry, isotopes, melt inclusion volatile content) and paleomagnetic
(e.g. anisotropy of magnetic susceptibility, magnetic remanence) techniques as
well as very detailed stratigraphic work.
In many cases, I can correlate layers with the time of day during an
eruption and then use eruption descriptions to help interpret the depositional
processes. In recent years, my work has
focused on transport and emplacement from large-volume pyroclastic density
currents, explosive water-magma interaction, monogenetic volcanism, and
geoarchaeology, with an emphasis on the hazards implications of these
processes.
Publications
Ort, M.H., Newkirk,
T.N., Vilas, J.F., Vazquez, J.A., submitted, Toward the Definition of AMS
Facies in the Deposits of Pyroclastic Density Currents, Geological Society of
London Special Publication, 32 p text, 3 tables, 12 figures.
Elson, M.D., Ort, M.H., Anderson, K.C.,
submitted, Sunset Crater and Little Springs Volcano eruptions: Hazards
management in the 11th century A.D. prehistoric Southwest;
University of Colorado Press, 45 p text, five figures.
Valentine, G.A., Ort, M.H., Cortés, J.A.,
Hintz, A.R., submitted, Probability of basaltic eruptions in volcanic fields of
the southwestern USA – Initial hazard assessment; Geology, 12 pages, 2 tables,
1 figure, 1 dataset for repository.
Ort, M.H., de Silva, S.L., Jiménez C., N.,
Jicha, B.R., Singer, B.S., in press, Correlation of Ignimbrites Using
Characteristic Remanent Magnetization and Anisotropy of Magnetic
Susceptibility, Central Andes, Bolivia; Geochemistry, Geophysics, Geosystems,
31 p text, 3 tables, 6 figures.
Elson, M.D., Ort, M.H., and Heidke J.M.,
in press, Effects of the ca. A.D.
1100 Sunset Crater eruption on local populations,
northern Arizona. In Proceedings of the 2002 Chacmool Conference, Calgary,
Alberta. University of Calgary, Alberta, Canada, 20 manuscript pages.
Elson, M.D., Ort, M.H., 2012, Fire in the sky: The eruption of
Sunset Crater Volcano, in Downum, C.,
ed., Hisatsinom: Ancient peoples in a land without
water. School for Advanced Research, Santa Fe, p. 26-33.
Elson, M.D., Ort, M,H.,
Anderson, K.C., Heidke, J.M., Sheppard, P.R., and Samples T.L., 2011, In the
Shadow of the Volcano: Prehistoric Settlement in the U.S. 89 Project Area. In M.D. Elson (ed.) Sunset Crater Archaeology: The History of a
Volcanic Landscape. Prehistoric Settlement in the Shadow of the Volcano,
Anthropological Papers No. 37, Center for Desert Archaeology, Tucson, p.
187-211.
Elson, M.D., Ort, M.H.,
Sheppard, P.R., Samples, T.L., Anderson, K.C., May, E.M., and Street, D.J., 2011, Sunset Crater Volcano. In M.D. Elson (ed.) Sunset Crater Archaeology: The History of a
Volcanic Landscape. Prehistoric Settlement in the Shadow of the Volcano,
Anthropological Papers No. 37, Center for Desert Archaeology, Tucson, p.
103-129.
For a complete list of publications and additional information, please download Michael Ort's CV.