Introducing Barbara Romanowicz
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1Dear Colleague,
Dear Barbara Romanowicz,
2Earthquakes, tsunamis and volcanic eruptions remind us of the power and speed of terrestrial phenomena, with dramatic consequences for human societies. The difficulty of forecasting illustrates the absolute need for scientific research to gather information about geophysical phenomena, and to anticipate and understand them.
3These earthquakes are the consequence of movements of the rigid and superficial part of the Earth, the crust. Yet while the revolutionary theory of plate tectonics has significantly furthered our knowledge, little is known about convection currents whose role is to facilitate the diffusion of our planet’s internal heat. The Earth’s interior is not accessible for direct observation and requires remote investigation.
4A mathematician by training, you carried out your research in numerous laboratories, at the Smithsonian Institution in Boston, at the Institut de Physique du Globe in Paris (Paris Institute of Global Physics), at MIT, and for twenty years in Berkeley where you were a professor in Geophysics. You have developed new, more efficient methods to analyse the structure of the deep Earth. Under your leadership, these studies have made a leap forward, with the emergence of ever more powerful seismic tomography techniques. This progress is linked to the developments in the field of computer science and to the theory of wave propagation in a three-dimensional Earth, comprised of complex heterogeneous environments.
5You have thus demonstrated the existence of very strong attenuation zones in the intermediary part of the mantle, called transition zone, which you have associated with the hot spots, the sources fuelling very large volcanic regions on the surface of the Earth, such as Hawaii. You have discovered the existence of this type of convection inside the Earth and have started to map it. This is a fundamental step towards understanding our planet’s dynamics, which affords a completely new outlook on its evolution in time.
6Your theoretical contributions – for you are an unparalleled theoretician – have allowed you to go far beyond classical models limited to the travel time of seismic waves. Your scientific curiosity has led you to move out of the Earth’s interior to shed light on the “Earth’s hum”, a beautiful example of terrestrial oscillations involving fluid envelopes like the atmosphere and the ocean.
7You have contributed to the development of the international community’s geophysical tools by creating the first global digital seismometer network on the Earth and in the oceans, as well as a fully-fledged earthquake alert system in Northern California, in collaboration with the US Geological Survey.
8When Adam Dziewonski, one of the most famous seismologists in the world, presented you with the Inge Lehmann Medal of the American Geophysical Union in 2009, he concluded his presentation by saying: “In my opinion, Barbara is the most outstanding woman seismologist after Inge Lehmann”. In 1936 Inge Lehmann had discovered the Earth’s solid inner core. The compliment says a lot about his esteem for you!
9Thanks to your teaching, the Collège de France is ready to embark with you on a new “Journey to the Centre of the Earth”.
Auteur
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