One of the projects for my sabbatical is to learn Python. Luckily its easier than I had thought it would be, at least so far. I have started making some jupyter notebooks with useful geodynamics-related calculations, especially related to subduction. For example, the sinking velocity for a Stokes ellipsoid (rather than a sphere), corner flow and plate bending forces. I am posting these jupyter notebooks on my web-page so others can download them and use them in their research or teaching. For me, I’ve found that the notebooks are a great way combine my thinking, derivation of equations, the actual calculation and figures.

# Biology meets Subduction

Subduction is not just about mountain building, volcanoes and driving the plate tectonics systems, its also about biology. Check out this video following an expedition of young geo-biologist, geo-chemist, and geologists exploring how and where biology thrives in the Costa Rica Subduction Zone.

# Research Presentation at Universität Münster, Geophysik

Dr. Billen will be giving a research presentation, “Spontaneous Arc Rifting” on Monday, November 13th at 4 pm in the Geophysics Department at the University of Muenster. The talk will present background on how rifting of arcs evolves to form back arc spreading centers, previous models for how this occurs, numerical models of subduction with a new mode of arc rifting and the implications for thermal structure and melting during rifting, and changes in plate motions. This talk is based on a paper that is in press at Geophysical Research Letters.

# Subduction Modeling Videos

I’ve added a new page to the website making videos of many of our published subduction models available for use in teaching or research talks. Check it out!

# Presentations at GSA 2017

Strangely, I have never been to GSA before, but this year I am making up for this and presenting 3 talks and 1 poster at GSA.

Talks:

A SYNTHESIS OF RECENT RESULTS FROM GEODYNAMIC MODELS OF SUBDUCTION INITIATION AND TERMINATION

THE EFFECT OF SPREADING RIDGES AND BUOYANT CRUST ON THE DYNAMICS OF SUBDUCTION

Poster

EVOLUTION OF SLAB AND WEDGE THERMAL STRUCTURE IN TIME-DEPENDENT DYNAMIC MODELS OF SUBDUCTION

# New Mode of Arc/Forearc Rifting

Numerical models of subduction show that spontaneous rifting of the arc or forearc may occur due to an in situ instability in the mantle wedge corner. This new mode of arc/forearc rifting is explained in a journal article by Dr. Billen, that is now in press at *Geophysical Research Letters.*

# Sabbatical in Munich 2017-2018

I am on sabbatical at Ludwig Maximiliian University in Munich, Germany for the 2017-2018 academic year. I’m being hosted by Prof. Heiner Igel, head of the seismology group.

# Humbolt Fellowship

Prof. Billen has been awarded the Wilhelm Bessell Research Fellowship from the Humboldt Foundation in Germany.