Research & Methods

Using Zoned Minerals to Determine Timescales of Eruption Initiation

Understanding the storage conditions and processes that occur within the magma reservoirs beneath volcanoes prior to their eruption is crucial to our ability to monitor such systems and develop effective hazard mitigation plans. My research exploits the magmatic histories recorded in erupted zoned minerals (akin to the rings in a tree) by use of in-situ geochemistry and diffusion chronometry to unravel the life stories and eruption triggers of individual magma bodies prior to their eruption.

Case study: Lava Creek Tuff Supereruption, Yellowstone Caldera

Yellowstone is a well-known volcano due to its catastrophic history and present-day hydrothermal and seismic activity. Our research suggests eruption initiation by magmatic recharge can occur on the scale of a human life (years to decades at most) in the case of the Lava Creek Tuff Supereruption (Shamloo and Till 2019). This work received press coverage in the New York Times and is featured in National Geographic.

USGS.gov

Using Experimental Petrology to Simulate Magmatic Processes

Conducting high-temperature and pressure experiments allows to simulate the conditions and processes that occur in a magma chamber. Experimental petrology is used in my research to recreate small crystallizing magma chambers as well as examine how specific atoms behave at magmatic conditions.

Example: Developing a New Geospeedometer

Diffusion chronometry (also known as geospeedometry) has become a popular tool for determining the tempo of magmatic processes. It is especially important to use multiple chronometers in a single phase for differentiating magmatic processes from one another (e.g., Shamloo and Till 2019). Current research uses a 1-atm vertical furnace to determine how and how fast magnesium diffuses in alkali-feldspar, a ubiquitous phase in silicic volcanic rocks. Results suggest Mg diffuses simultaneously by both a fast- and slow-mode, suggesting diffusion in feldspar is more complex than previously understood (Shamloo et al. in review).

Simple schematic of the experimental design for diffusion experiments (Shamloo et al., in review).

Computational Modeling

Example: Controls on Volcanic Repose Time

Repose time (the timing between successive eruptions at a given volcano) is an important factor when assigning a volcano a specific threat level which informs scientists and the public of its potential hazard (Ewert et al. 2018). However, little work has focused on longer-term patterns of repose time for a volcano as a whole, as well as the underlying geologic mechanisms controlling these patterns. My work examines these controls through statistical modeling of geochronological datasets for a given volcano. (Shamloo et al. in prep; Shamloo et al., AGU Abstracts, 2019)

Learn More About My Research

Peer-Reviewed Publications

H. Shamloo on Google Scholar

Shamloo, H., Till C. B., Hervig, R. L., (accepted upon pending revisions) Magnesium Diffusion in Sanidine: Applications for Geospeedometry in Magmatic Systems. Geochimica et Cosmochimica Acta

Till C.B., Vazquez J.A., Stelten M., Shamloo H. I., Shaffer J., (2019) Co-existing Discrete Bodies of Rhyolite and Punctuated Volcanism Characterize Yellowstone’s Post-Lava Creek Tuff Caldera Evolution. Geochemistry, Geophysics, Geosystems. https://doi.org/10.1029/2019GC008321

Shamloo, H. and Till C.B., (2019) Decadal transition from quiescence to supereruption: Petrologic investigation of the Lava Creek Tuff, Yellowstone Caldera, WY. Contributions to Mineralogy and Petrology, 174(4), 32.

Presentations

Shamloo, H., Till, C.B., (2020) Super-sized and Speedy: The Timing and Initiation of the Lava Creek Tuff Supereruption, Yellowstone Caldera. AGU Fall Meeting Abstract 672837, San Francisco, CA. *Invited Talk

Shamloo, H., Till, C.B., Kent, J. R., Cooper, K. (2019) Constraining first-order controls on volcanic repose time by examining cumulative distribution functions. AGU Fall Meeting Abstract V034, San Francisco, CA.

Till C. B., Vazquez J. A., Shamloo H. I., Stelten M. E., (2019) Records of Magma Evolution & Eruption during Yellowstone's Last Caldera Cycle from Geospeedometry and Zircon Petrochronology. AGU Fall Meeting Abstract V24B-04, San Francisco, CA.

Muller, J.K., Kemmerlin M.S., Gonzalez Santana, J.M., Shamloo, H. I., Tan Y.J., Zhan, Y., Smith, C.A., Myers, M., Gregg, P.A., Abers, G.A., Plank, T.A., Wallace, P.J., Andrews, B.J., Roman, D.C., Bergantz, G., and Cooper, K.M., (2019) Tectonic and compositional controls on magma storage depths globally: Results from CIDER (2019) AGU Fall Meeting Abstract V23D-0256, San Francisco, CA.

Shamloo, H., and C.B. Till, (2019) Mg Diffusion in Alkali Feldspar; Applications for Diffusion Chronometry in Magmatic Systems. Geological Society of America Abstract T35-338595, Phoenix, AZ.

Shamloo, H. and C.B. Till, (2018) Mg Diffusion in Alkali Feldspar; Applications for Diffusion Chronometry in Magmatic Systems. Goldschmidt Abstract 2306, Boston, MA.

Shamloo, H. and C.B. Till, (2017) Petrologic Insights into the Timing and Triggering Mechanism for the Lava Creek Tuff Super-eruption, Yellowstone Caldera, WY. IAVCEI 2017 Scientific Assembly Abstract PE43B-097, Portland, OR.

Shamloo H. and C.B. Till, (2016) Petrologic Insights into the Triggering Mechanism for the Lava Creek Tuff Super-eruption, Yellowstone Caldera, WY. AGU Fall Meeting Abstract V23B-2979, San Francisco, CA.

Shamloo H., Schwartz J.J., Klepeis K., Stowell H.H., Sadorski, J.F., Coble, M.A., (2014) Timescales of Intra-arc Contraction and Extensional Collapse in the Lower and Middle Crust of Cretaceous Convergent-margin Magmatic Arc, Central Fiordland, New Zealand. GSA Annual Conference Abstract 58-3, Vancouver, B.C.

Arvin L., Novoa K., Shamloo H., Philo D., Yuan J., Jordan T., de Groot R., Rousseau N., Smith D., Milner K., (2013) SCEC Undergraduate Studies in Earthquake Information Technology Program: Implementing GIS, UCERF3, and OpenSHA data in SCEC-VDO. SCEC Annual Meeting Abstract, Palm Springs, CA.