Current Research
Global Block Model slip deficit rates. Graham et al. 2018, G-cubed https://doi.org/10.1029/2017GC007391
Global Set of Subduction Zone Earthquake Scenarios and Recurrence Intervals. Graham et al. 2021, G-Cubed https://doi.org/10.1029/2021GC009802
Global Block Modeling
Geodetic observations of motion at the Earth’s surface reveal the complex interplay between long-term tectonic motions and short-term earthquake cycle processes. Observed interseismic deformation can be used to constrain the distribution of elastic strain accumulation, slip partitioning across complex fault patterns, plate rotations, and spatially variable patterns of fault coupling. The global block model was constructed with the goal of unifying global plate motions with fault-based mechanical earthquake cycle models in order to resolve slip deficit rates across the world’s most seismogenic faults.
Construction of a global scaled block model has allowed my collaborators and I to ask and answer such questions as: What is the global moment accumulation rate and how does that compare to earthquake production? How many ‘blocks’ are required to explain GPS velocities to a resolution of 2 mm/yr? What is the frequency distribution of fault slip rates globally? Where on earth do we need more complex models to explain observations? And, how many magnitude > 8.0 earthquakes are possible globally?
All model files and results, as well as source code for the Blocks software are freely available at: https://github.com/brendanjmeade/reference_gbm
Interested in collaborating on Version 2 of the Global block model? Have suggestions for how to improve version 1.0? I would love to hear from you! Please use the contact page and get in touch.
Figure 13(a) from Graham et al. 2014, GJI, https://doi.org/10.1093/gji/ggu167
Mexico Subduction Zone
My research along the Mexico Subduction Zone focuses on crustal deformation during the seismic cycle. I use computer based models to estimate the amount of fault slip before, during, and after earthquakes, as well as interseismic fault coupling. I am interested in the interaction between seismic and aseismic events (e.g. post seismic afterslip and slow slip events), the time-dependent evolution of these processes, and their seismic hazard implications. I currently have NSF funding to research slow slip, interseismic coupling, and a crustal sliver fault along the Mexico subduction zone. To date, this work has involved five undergraduate students at TCNJ.
Upper: Shake results from TCNJ NJAC Championship Field Hockey game vs. Rowan 11/9/19
Lower: BC’s Jon Hilliman runs for 6 yards for a touchdown! Central Michigan vs. Boston College 9/30/17
Athletics and Seismology: Lions and EagleQuakes!
At TCNJ, a portable seismograph was installed at the Field Hockey And Lacrosse Complex to record the crowd response to big plays during big field hockey games. A sudden peak in amplitude followed by sustained cheering can be seen for all three goals and the big save on a penalty stroke.
At Boston College, in collaboration with Alan Kafka in the Department of Earth and Environmental Sciences and Weston Observatory, two portable seismographs (raspberry shakes https://raspberryshake.org/) have been installed in Conte Forum and Alumni Stadium to observe the signals produced by cheering, dancing, or booing(!) fans during athletic contests and school events (e.g. Commencement and a Student-Athlete dance off). Our network has also recorded global earthquakes and large storms. Results have been the source of many fun class discussions, student projects, and ongoing collaborative research.
Updates and recent recordings can be found at: https://twitter.com/Weston_Quakes