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About Us

We investigate deformation of the Earth's crust due to earthquakes and volcanoes.

Measuring deformation that occurs between earthquakes constrains how much elastic strain accumulates in the crust and helps constrain future earthquake hazard.   Similarly, accumulation of magma in crustal reservoirs causes the earth's surface to swell, critical information for forecasting eruptions.  In both volcanic and tectonic environments we combine measurements with physics-based models of the relevant processes to better understand these systems.


We are investigating the physics of injection-induced seismicity including full poroelastic coupling of stress and pore pressure, and time-dependent earthquake nucleation.

We are working to unify physical-chemical models of erupting volcanoes with resulting deformation, that can be measured with GPS, InSAR, tiltmeters and other instruments.

GPS time series in northeast Japan exhibit nonlinear trends from 1996 to 2011 before the Mw 9.0, 2011 Tohoku-oki earthquake.

One of the most exciting discoveries in recent decades has been the recognition that many subduction zones undergo transient slip events at depths below the locked mega-thrust zone.

GPS position measurements are widely used for studying various geophysical phenomena  including plate movement, strain accumulation, volcanic deformation, post-glacial rebound, subsidence,  and sea-level change.  Understanding the accuracy of GPS data is therefore paramount.  Traditional methods

Recent Publications

Heimisson, E., & Segall, P. (2019, June 3). Fully consistent modeling of dike induced deformation and seismicity: Application to the 2014 Bárðarbunga dike, Iceland.

Paul Segall, Magma chambers: what we can, and cannot, learn from volcano geodesy, 377, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences,

Maurer, J., Johnson, K., & Segall, P. (2018). Bounding the moment deficit rate on crustal faults using geodetic data: Application to Southern California. Journal of Geophysical Research: Solid Earth, 123, 11,048–11,061.

Cattania, C., & Segall, P. (2018). Crack models of repeating earthquakes predict observed moment‐recurrence scaling. Journal of Geophysical Research: Solid Earth, 123.

Heimisson, E. R., & Segall, P. (2018). Constitutive law for earthquake production based on rate‐and‐state friction: Dieterich 1994 revisited. Journal of Geophysical Research: Solid Earth, 123.