This EAGER project will perform the initial design and development of a new rock deformation apparatus. The purpose of this apparatus is to study microstructural and rheological phenomena at the pressures and temperatures of Earth's lithosphere and upper asthenospheric mantle. As rock deformation apparatus are not readily available on a commercial basis, funding through the EAGER process will support the exploratory stage design of the new apparatus.
The development of a new rock deformation apparatus will benefit the earth sciences community in a number of ways. The apparatus will be optimized for a critical and under-investigated range of deformation conditions, which will open doors for new research into the nature of Earth's upper mantle and the interiors of other terrestrial planets. This project will assist the development of an early-career scientist; support of this kind is essential given the small size of the rock deformation community. Educational opportunities for students and postdoctoral researchers in the PI's lab will be significant, as they will participate in all phases of the design, calibration, and implementation of the new apparatus. This participation will enhance their development as independent scientists, as they learn about some of the underpinnings and assumptions behind their research. The design of the new apparatus will be made publically available, and the details of its construction will be disseminated via the Internet. Access to these designs will benefit early-career scientists and established researchers as they plan their first labs or expand existing labs.
The motion of Earth's plates, broadly described by the theory of plate tectonics, sets the Earth apart from all other planets. The unique habitability of Earth may be due in part to plate tectonics, which cycles water and gasses between the Earth's interior and atmosphere. Similar processes are not observed on other terrestrial planets like Mars or Venus. However the motion of plates brings with it hazards as well. Earthquakes, tsunami, and volcanoes, are all triggered by the relative motion of Earth's tectonic plates. Plate tectonics is a slow process, with average speeds that range from 0.1-10 centimeters per year. Furthermore, many of the important processes that control plate tectonics occur at depths that are inaccessible to human observation. Therefore, the scientific study of plate tectonics requires laboratory experiments that can reproduce the conditions inside the Earth. The equipment to conduct these experiments is not commercially available, and must be designed and built by the scientific community. This grant supported the development of a novel apparatus designed to study how rocks deform along plate boundaries. The apparatus constructed as part of this grant is designed to shear small pieces of rock at high pressure and temperature. The samples deformed by this apparatus are 6 millimeters in diameter, however the results can be used to make predictions about the behavior of rocks over scales of hundreds to thousands of kilometers. The apparatus is designed to generate pressures of up to 6 gigapascals (nearly 60,000 times atmospheric pressure) and temperatures of up to 1300 Celsius. These are the pressures and temperatures found inside the Earth at depths of up to 200 kilometers. Support of this grant has gone to the acquisition of equipment to construct the apparatus. This grant has been instrumental in the development of an early career scientist, who is building a lab to study how rocks deform. This apparatus is entirely unique, and will provide the scientific community with new insight into the processes that control plate tectonics on Earth.
