Special Guest Seminar - spring-2024

May 14, 2024
2 p.m. - 3 p.m.
3814 Geology

Presented By:

• Eiichiro Kokubo - NAOJ

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In the standard formation models of terrestrial planets in the solar system and close-in super-Earths recently discovered by exoplanet observations, planets are formed by giant impacts of protoplanets or planetary embryos after the dispersal of protoplanetary disk gas in the final stage. This study aims to theoretically clarify a fundamental scaling law for the orbital architecture of planetary systems formed by giant impacts. In the giant impact stage, protoplanets gravitationally scatter and collide with each other to form planets. We investigate the orbital architecture of planetary systems formed from protoplanet systems by giant impacts using N-body simulations. As the orbital architecture parameters we focus on the mean orbital separation between two adjacent planets and the mean orbital eccentricity of planets in a planetary system. We find that the orbital architecture is scaled by the epicycle amplitude for the eccentricity given by the ratio of the two-body surface escape velocity of planets to the Kepler velocity. With this scaling the orbital architecture parameters are independent of the total mass and semimajor axis of planetary systems.

May 23, 2024
2 p.m. - 3 p.m.
3853 Slichter Hall

Presented By:

• Aaron Velasco - University of Texas

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This talk explores the use of collective impact, a model for community engagement, to advance science and to make science responsive to community needs, especially communities that have traditionally been underserved. The status of geosciences in terms of diversity will be presented, highlighting where progress has been made, and the current climate for minority geoscientists. I will introduce collective impact as a means of advancing science, and creating a culture of inclusion that, we hope, will transcends deficiencies in the culture of modern science. The collective impact approach develops a network of community members, organizations, and institutions through the framework of a common agenda, centralized support, continuous communication, mutually reinforcing activities, and shared measurement. I will introduce the Center for Collective Impact in Earthquake Science (C-CIES), a National Science Foundation funded Centers of Innovation and Community Engagement planning grant, which has the vision to become a leading-edge earthquake research center dedicated to improving resiliency from seismic hazards in an equitable, accessible, and sustainable manner. The mission will be to advance earthquake science with the aim of meeting the natural hazard mitigation needs of all communities in regions high consequence, low frequency of incidence (Hi-C-LoFi) earthquake risk. I will explore a specific project in El Paso, TX on the East Franklin Mountains fault, which has a potential for a M6.5-7.0 earthquake, and the science and community input that drives the project.

July 3, 2024
11 a.m. - noon
3814 Geology

Presented By:

• Dr. Shivangi Sharan - Imperial College London

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The JUpiter ICy moons Explorer (JUICE) mission was launched on April 14th 2023 and will arrive in the orbit of Jupiter in July 2031. The aim of the mission is to understand the interior of three Jovian moons- Ganymede, Callisto and Europa. The interest in these moons is due to the possibility of a subsurface ocean that has the potential for habitability. The spacecraft will perform several flybys of the different moons after which it will move into an orbit around Ganymede, making it the first spacecraft to orbit two bodies. JUICE has 10 instruments that will measure different parameters. I will talk about the magnetometer (JMAG) onboard that measures the magnetic field and how it will be used to understand the interior of the moons, more specifically, Ganymede.

Sept. 27, 2024
11:30 a.m. - 1 p.m.
3853 Slichter Hall

Presented By:

• Dr. Tushar Mittal - Pennsylvania State University

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Abstract: Several critical technologies associated with the Energy Transition and climate change mitigation, such as Geologic and Marine Carbon sequestration, Hydrogen generation, critical mineral discovery, and geothermal, rely on an accurate understanding of geological and geochemical processes. For instance, multiple subsurface technologies require effective permeability control through subsurface fracture networks to optimize fluid-rock interaction across a diverse set of temperature, stress, and material conditions. However, to rapidly scale these technologies to the required commercial scales, we need a good predictive, real-world applicable model for optimization and feasibility analysis. This model, in turn, requires addressing the challenges posed by the spatial heterogeneity in natural geologic systems. In this talk, I will introduce two case studies to illustrate this concept and approaches my group is developing for these problems : (a) Rheology/Constitutive model for fractured rocks across the brittle-ductile transition (Geothermal), (b) Basalt mineralization - scaling from lab scale measurements of reaction rate data to field-scale lava flows (Carbon Capture & Storage, relevant for hydrogen generation also). In addition to theory development, we need low-cost measurements of geophysical and geochemical properties that can be used to validate the models and/or provide near real-time control system feedback. Due to the natural heterogeneity, the traditional approach of making a few very precise and expensive measurements isn't sufficient. Following the case studies described above, I will describe a new data fusion approach we are developing that combines fast & cheap methods (e.g., hyperspectral imaging; seismo-acoustic data) with various measurement methods (handheld XRF, LIBS, LA-ICP-MS) that are sequentially restricted to smaller sample sets. Overall, my work highlights the need to incorporate real geologic heterogeneity when considering various new technologies, as well as the opportunity to leverage the expertise in Earth Science for these systems built upon decades-centuries of observations. Bio: Assistant Professor in the Geoscience Department at Penn State. Ph.D., UC Berkeley in Spring 2020; Crosby Postdoc Fellow at MIT from 2020-2022. Research Focus: (A) Volcano Science (Modeling magmatic processes and Submarine volcanism), (B) Planetary geophysics (Planet formation and geodynamics, Planetary science), and (C) Volcano/tectonic-climate interactions (Understanding the impact of solid Earth process on the ocean-atmosphere system across a range of timescales - months to Myr), (D) Geofluids & Geomechanics (Understanding rock rheology and fluid-rock reactions on a micro-scale and developing thermodynamically consistent upscaled models; using seismic information in the lab & field to investigate processes in real-time for detailed process understanding), (E) Earth science knowledge for various applications related to energy transition - geothermal energy (especially enhanced geothermal systems at high temperatures), critical mineral discovery (Li, REE, Copper), geologic carbon sequestration (enhanced rock weathering, basalt carbon sequestration), and hydrogen production (reactive transport). Development of new geophysical and geochemical characterization methods (and associated data processing tools) - e.g., hyperspectral imaging, acoustics, and LIDAR that can be applied at scale, both in terms of the number of samples as well as the spatial coverage, cost-effectively and rapidly in field settings. Please sign up using the link below to meet with the speaker. Link: https://docs.google.com/spreadsheets/d/1rq_VqrLvy2HIFjmq0sRJ1ukfyY3xml0x4DPbOGvhqWk/edit?usp=sharing