segunda-feira, julho 31, 2006

PhD Carribean plate boundary

Pedem-nos, da GEOPOR, a divulgação da seguinte oferta de emprego:

A PhD position is available at the Tectonophysics group of Utrecht University, the Netherlands, titled: "How plate tearing and slabs drive reorganization of the N Caribbean plate boundary"

For more information, contact Dr. Rob Govers ( or Prof. Rinus Wortel (

Project Summary
New evidence has emerged that the plate boundary between the Caribbean and North America plates is undergoing a major change due to plate breaking in at least one location, near Puerto Rico. Preliminary results show unusually high seismic activity near this tear. How and why plate tearing occurs is not understood. Similar active transitional processes in plate tectonics can only be studied in a few locations around the world. We propose to exploit this opportunity and investigate the current geodynamics of the northern Caribbean region, 1) because the mechanisms involved are only poorly understood, 2) because the potential for earthquakes and tsunamis can only be fully assessed in light of the dramatic consequences of such plate tearing, and 3) because similar transitional aspects of plate tectonics likely played a prominent role in the historical evolution of the geology of the Caribbean and in other regions (e.g., the Mediterranean and Carpathians). Using state-of-the-art quantitative geodynamic models we aim to integrate a wide range of observations (geometric, kinematic, and dynamic) in a physically plausible way. A pivotal role will be played by new results of high-resolution P-travel time tomography that discovered a-seismic slabs in the regional upper mantle, i.e., which were invisible before. We can therefore now start to establish how sinking slabs in the upper mantle drive deformation in the north Caribbean plate boundary zone. Seeking these depth-to-surface relations on time scales of natural hazards to that of many earthquake cycles, we aim to incorporate the growing GPS data set to 1) explain current crustal block motions in the plate boundary zone, 2) find and understand the repetition time scales of plate breaking events, 3) to assess the potential hazard of offshore faults and deeper crustal faults, both of which are not monitored by GPS. Finally, we seek to identify whether on geological time scales the evolution of the north Caribbean plate boundary can be understood as a succession of slab-related events as happen today. The main research instrument is a cutting edge finite element method that solves the coupled 3D momentum and heat equations for elastic, plastic and power-law viscous rheologies. This is a collaborative research project with Uri ten Brink of the USGS and Eric Calais of Purdue University. Work visits to Woods Hole are part of the work plan.

We offer a full-time Ph.D. position for a period of four years, with the intent that it results in a doctorate in Geophysics. Conditions are based on the Collective Employment Agreement of the Dutch Universities. The gross monthly salary starts at EUR 1813 in the first year and increases to EUR 2394 in the fourth year and is supplemented by a holiday allowance of 8% per year. We also offer a pension scheme, a health insurance allowance and flexible employment conditions. The Ph.D. candidate will be based at the Earth Sciences Institute in Utrecht.

For this Ph.D. project we seek an outstanding individual with a recent M.Sc. or equivalent degree, who can demonstrate an excellent background in mathematics and physics, and specifically continuum mechanics. Proficiency in at least one modern computer language is a necessity. Experience with tools for the numerical solution of partial differential equations is appreciated. The successful candidate is able to demonstrate an interest in Earth processes and in geophysical and geological observations. She/he communicates easily in English, both verbally and in writing.

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