Martedì 18 maggio, ore 15: Luca de Siena (nstitute of Geosciences, Johannes Gutenberg University, Mainz, Germany)
Titolo del seminario: “Imaging lithospheric systems”
Martedì 11 maggio, ore 15: Lucia Gualtieri (School of Earth, Energy & Environmental Sciences, Stanford University)
Listening to the environment with seismic waves
The vast majority of the seismic signals we record on Earth are due to the coupling of different Earth’s systems into the solid Earth. Once seen as a nuisance, this novel and unique kind of seismic source provide a new way for monitoring the global environment and exploring the Earth’s interior.
In this talk, I will give an overview of the seismic sources of environmental processes, with an emphasis on the origin of seismic signals associated with ocean storms, landslides, and human infrastructure. I will show how a combination of numerical modeling and seismic observations allows us to complement geological findings, retrieve the time-varying behavior of natural events, and get new insights on the Earth’s structure.
Martedì 4 maggio, ore 15: Gabriele Morra (Department of Physics and School of Geosciences, University of Louisiana at Lafayette)
Martedì 27 aprile, ore 15: Simone Pilia (Department of Earth Sciences, University of Cambridge)
A geophysical extravaganza: probing the lithosphere to solve tectonic puzzles
Geophysics is a powerful tool for studying Earth’s structure, from the very first few meters below our feet, to the inaccessible inner core. When constraining lithospheric structure, geophysical methods can add value to geological interpretations based primarily on surface observations. The focus here is on two case studies in which geophysics, particularly with seismic imaging techniques, played a key role in defining crustal and upper mantle structure.
In the first instance, I will show how a combination of geophysical methods and geological observations were used in tandem to constrain the stratigraphy, velocity structure and crustal thickness beneath the UAE-Oman mountain belt and its bounding sedimentary basins. This new set of results has put tight constraints on the geometry and physical properties of the Semail ophiolite.
The second example will be an overview of the recent results from the nBOSS (northern Borneo Orogeny Seismic Survey) experiment. The fragment of continental lithosphere that is now northern Borneo bears the signature of diachronous opposed subduction systems that ceased only in the Miocene. Intriguingly, there are a number of features that cannot be explained by our current understanding of the subduction cycle. These features include the presence of recent OIB lavas, evidence of sudden subsidence and uplift, peak exhumation rates of more than 7 mm/year from the latest Miocene to the Early Pliocene in Mt. Kinabalu, bringing the mountain to 4095 m height (towering over most peaks in southeast Asia). New seismic images, coupled with geological observations and a new numerical simulation, provide an explanation to the surface evidence of post-subduction tectonics on the continental lithosphere.
Martedì 20 aprile, ore 15: Paolo Stocchi (NIOZ Royal Netherlands Institute for Sea Research)
Martedì 13 aprile, ore 15: Adriano Gualandi (INGV)
Titolo del seminario: “Geodetic imaging of tectonic and hydrological deformation”