The dynamics of glaciers and ice sheets influence rates of sea-level rise, freshwater supplies, and landscape evolution. Decades of research has highlighted key processes and connections between terrestrial ice, the climate, and the solid earth, but limited observations have allowed fundamental questions in glaciers dynamics to remain open. In this talk, we will explore some related questions: What is the viscosity of glacier ice and how does it depend on stress? Why does ice fracture? Building on these fundamental questions, we will highlight new efforts to support polar science and accelerate improvements in our ability to observe and model ice sheets. 

In this talk I am going to explore the interplay between tectonic and surface processes in shaping Cordilleran-type orogenic systems, having the Central Andes as the main study case. The Escoipe Canyon in NW Argentina cross cuts the fold-and-thrust belt of the Eastern Cordillera, which makes the transition from the Puna Plateau to the modern foreland region. A new dataset of multiple low-temperature thermochronometers records the history of orogenic building from rifting to foreland basin, and ultimately the thrust belt forming the present-day orographic barrier of the Central Andes. The apatite (U-Th)/He data, however, dates the last 10 myr of history after the main episode of shortening, and shows a westward trend of younger cooling ages, opposite to the regional cooling trend in the thrust belt. I will explore a hypothesis regarding climate and surface processes controlling rock exhumation in the canyon, and the impacts on orogenic evolution. Additionally to this data-driven study case, I will show some effects of orography in Cordilleran-type systems in the lithospheric scale using geodynamic models, and demonstrate that surface processes might affect strain distribution and lithospheric removal processes.

Climate change is stressing the American West’s century-old system of water storage and conveyance, through longer and more intense droughts and periods of exceptional rainfall and flooding. Nowhere are these challenges more acute than in California’s Central Valley, which produces 25% of the USA’s agricultural output on climatologically marginal farmland. Intense management of mountain discharge into the Central Valley, along with oversubscribed rights to surface water, have resulted in unchecked exploitation of the Valley’s groundwater resources and impeded initiatives to use occasional surface water surpluses for aquifer recharge.

New regulation has sparked interest in better information on groundwater availability. Here at Scripps, our lab uses remotely sensed observations of Earth’s gravity and surface motion to infer the dynamics of the hydrological system that feeds the Central Valley aquifer. These techniques track the evolution of mountain water storage at various timescales, and they reveal how this stored water enters and flows through the Central Valley aquifer. Effective management of groundwater resources in the Central Valley will require adoption of data-informed policies, and our hope is that our insights into Central Valley hydrology will prove useful to this end.

50+ years after the Apollo missions, NASA will be sending astronauts back to the Moon. This time, the astronauts will land near the South Pole of the Moon. The Lunar Environment Monitoring Station (LEMS-A3) is one of the selected Artemis III Deployed Instruments. LEMS-A3 is built to operate independently of the Artemis III crew spacecraft, survive the lunar night and operate for at least two years. The LEMS-A3 payload is a set of astronaut-deployed seismometers, SeisLEMS, consisting of a broadband (BB) and short period (SP) instrument built by the University of Arizona and Silicon Audio Inc. Artemis astronauts will deploy and position LEMS-A3, and bury the BB and SP instruments into an astronaut dug-trench and borehole, respectively.
The BB and SP will continuously record ground motions at 100 samples per second (sps) and relay 15 sps data back to Earth once a month. The LEMS team will use the ground motions to detect and locate lunar seismic events including impact-driven, shallow, and deep moonquakes and iteratively backfill the events with 100 sps data. The proposed Artemis III landing sites all enable seismic surveys of the southern pole and farside of the Moon; geographic regions that have previously be unexplored with seismometers. Through seismic data interpretation we aim to catalog seismicity of the Moon, investigate the crustal and mantle structure of the south pole, determine the structure of the deep interior, and ascertain seismic hazards.
Although LEMS-A3 is designed as a stand-alone seismic station, it is possible that it may operate at the same time as other seismometers, e.g. the Farside Seismic Suite (FSS) and other future lunar missions equipped with seismometers. If FSS and LEMS-A3 are operational at the same time, more science may be accomplished through collaboration of the science teams and shared datasets.

The modern world teems with complex life—the animals, plants, fungi, seaweeds, and a dazzling array of single-celled organisms known as the protists. All of these are part of the eukaryotic clade, descended from a common ancestor that lived more than 1 billion years ago. In this talk, I will provide an overview of early eukaryote evolution and the environmental context in which they evolved.  I will present new research that sheds light on the habitats in which eukaryotes lived and how they might have survived the extreme “snowball Earth” glaciations that entombed the planet in ice 720–635 million years ago (Ma). Finally, I will highlight the outstanding questions that remain, including what drove their rise to dominance during the late Neoproterozoic Era (~600 Ma).

Statically stable density stratification is ubiquitous in geophysical flows. It tends to suppress vertical motions, leading to thin, sheared layers and highly anisotropic structures. This talk discusses recent progress in understanding stratified turbulence, including mixing efficiency and the role of intermittent events, and highlights open questions relevant to oceans and atmospheres.

Juno and Cassini have revealed that Jupiter and Saturn likely contain broad regions where heavy elements are mixed gradually, rather than being sharply separated. A major open question is how these composition gradients can survive for billions of years, even though the planets’ interiors are vigorously convecting.

In this talk, I’ll present numerical simulations that explore how convection mixes compositional gradients in a simplified model of a planet’s interior. I’ll show that rotation can play an important role in shaping the flow and can strongly influence how efficiently composition is mixed. Also, I will show that under certain conditions, the combined effects of temperature and composition cause the fluid to organize itself into stacked convective layers, remarkably similar to the layers that form in a latte. I’ll conclude by discussing the challenges for our understanding of convective mixing and what this means for giant planet interiors.

Planets exhibit extraordinary diversity in physical properties and orbital architectures, spanning more than four orders of magnitude in mass, separation, and age. Interpreting this landscape is challenging as observational biases and orbital migration obscure the pathways of planet formation and evolution across both space and time. While the full picture remains incomplete, a story is emerging for gas giants from radial velocity surveys probing planetary systems from the inside out and high-contrast imaging from the outside in. These complementary approaches are converging at intermediate scales, enabling a more continuous view of giant planet populations. I will present results from recent ground- and space-based efforts to constrain how giant planets assemble and evolve, focusing on accretion disks, population demographics, orbital eccentricities, and stellar spin–orbit misalignments. Together, these are informing the processes of gas accretion, angular momentum exchange, and dynamical evolution that shape planetary systems. I will also highlight how upcoming astrometric discoveries from Gaia—which is expected to reveal thousands of giant planets at intermediate separations later this year—will help bridge the gap between inner and outer planet populations and clarify how giant planets form and interact over time.

In its travel through the Milky Way, the Sun traverses a variety of Galactic
environments, including dense interstellar clouds. Astronomical effects on
Earth’s past climate have been limited to 10,000-year scales variations in
Earth’s orbital parameters while our recent studies suggest that
longer-term climate shifts that occur every few million year may be linked
to compression of the heliosphere (the “cocoon” formed by the solar wind)
when the Sun crosses dense clouds as it travels through the Milky Way.
During such periods Earth was exposed to increased radiation and large
amounts of hydrogen, potentially altering its climate. These events are
consistent with independent 60Fe records indicating nearby astrophysical
encounters at ~2–3 and ~6–7 million years ago (Ma), as well as 10Be
anomalies near ~10 Ma that may reflect prolonged exposure to enhanced
radiation during a cold cloud crossing.  A convergence of recent advances
across astronomy, space physics, and paleoclimate creates an unprecedented
opportunity to rigorously test this hypothesis. We now have high-precision
astrometry from the Gaia mission that allows one to reconstruct the Sun’s
trajectory through the Galaxy and to identify, with remarkable accuracy,
the interstellar structures it has encountered over the past ~10 Ma. Major
theoretical and modeling advances now enable quantitative predictions of
how the heliosphere evolved during these encounters. In this talk I will
discuss our recent work that show that during such periods, Earth was
exposed to increased radiation and large amounts of hydrogen. I will
discuss our preliminary results that show that the increase in hydrogen
augmented mesospheric water vapor, leading to increased formation of both
polar mesospheric clouds and polar stratospheric clouds. The amount of
radiation that Earth experiences from such events depends on the duration
of the crossing and the amount of compression of the heliosphere, with
implications for Earth’s climate. I will discuss our results as well that
indicate that high temporal 10Be signal in ocean records and ice cores can
distinguish between alternative scenarios such as supernova explosions and
cold cloud crossings.

The 2028 Summer Olympics will be held in Los Angeles from July 14–30, making Los Angeles only the third city(after London and Paris)to host the Summer Games three times. Los Angeles is an attractive Olympic venue not only because of its mild climate and global tourist appeal, but also because of its remarkable physical setting: a major coastal metropolis situated adjacent to actively deforming mountain ranges rising to elevations above 10,000 feet. This unique geological context provides an exceptional opportunity to connect a globally watched sporting event with public understanding of how Earth systems operate.
The geology of the Los Angeles region is far more dynamic and diverse than that of other Summer Olympic host cities. The convergence of intense public interest in the Olympics with an unusually compelling natural setting creates a rare opportunity for large-scale informal STEM education focused on Earth science and natural history. Leveraging this moment could engage audiences ranging from K–12 students to lifelong learners, both locally and worldwide. We refer to this proposed effort as the LA2028 GeOlympics.

This initiative aims to capitalize on global attention surrounding the 2028 Games by providing accessible, place-based explanations of the geological history of the Los Angeles region, particularly around Olympic venues, and by illustrating how tectonics, climate, and surface processes have shaped this iconic landscape. Achieving this goal will require coordinated collaboration among the region’s extensive educational and cultural infrastructure, including 14 college and university geology departments, 19 community colleges, approximately 2,000 K–12 schools, 136 museums, hundreds of environmental organizations, and a broad range of media outlets. This presentation outlines the vision for LA2028 GeOlympics, discusses organizational and funding needs, and explores pathways for collaboration with the LA28 Organizing Committee to transform the Olympics into a powerful platform for Earth science education.