Department Seminars will take place in Tate Hall room 105 on Thursdays at 4:00 p.m. Email announcements are sent out the Monday before the seminar. Seminars are open to the public! If you would like to be added to the seminar announcement list, please contact Kaleigh Swift at [email protected].

*denotes seminars that are closed to the public
 

Fall 2026

September 10*

Dr. Justin Revenaugh

Department Head, Earth & Environmental Sciences, University of Minnesota
Welcome to the 2026-2027 School year!

September 17

Dr. Andy Wickert

Associate Professor, Earth & Environmental Sciences, University of Minnesota
Alluvial river dynmaics

September 24

Dr. Reid Cooper

October 1

Dr. Dani Or

Nevada Engineering Distinguished Professor, Civil and Environmental Engineering, University of Nevada Reno and ETH Zurich
On the size distribution of soil bacterial communities and why it matters?

Abstract
Microscale water dynamics within a highly fragmented soil physical environment constrain bacterial dispersion ranges and modulate nutrient diffusion and access to patchy resources. A mechanistic modeling framework that integrates soil hydration status with organic carbon inputs was used to estimate community size distributions and interaction distances of soil bacterial communities. Sizes and spatial patterns of bacterial communities are critical for interpreting soil micro-ecological functioning. The empirical results suggest persistent patterns of soil bacterial cluster sizes that follow an exponentially truncated power law with parameters that vary with mean soil water content and carbon inputs. These community size patterns are analogous to human settlement size distributions, tree sizes and other sessile systems controlled by growth rates that are independent of object size. We hypothesized that soil bacterial community size distribution obeys the so-called Gibrat’s law (originally developed for company size distributions). Our modeling and experimental results persistently yielded log normal distributions of bacterial community sizes lending support to the proposed generalization in soil. Results also suggest that soil bacteria reside in numerous small communities (over 90% of bacterial communities contain less than 100 cells). The log normal parameters vary with biome characteristics (rainfall, carbon inputs that define soil carrying capacity).  Consequences of the resulting cluster size distributions for the onset of anoxic microsites in soil (diffusion limitations in “megacities”), and the potential for using the relations to “unmix” sample scale soil bacterial diversity will be discussed

October 2 (Darcy Lecture - 10am B20)

Dr. Steve Loheide

Professor; Environmental Engineering & Science Associate Chair (CEE), Civil & Environmental Engineering, University of Wisconsin - Madison
Groundwater Recharge Regimes are in Flux

Abstract
Groundwater provides drinking water for people, supports agriculture, and sustains healthy ecosystems, but has been depleted in some regions due to overuse. Groundwater is replenished through the process of groundwater recharge. After precipitation infiltrates into the soil, a portion is returned to the atmosphere through evapotranspiration, but some may percolate downward until it reaches the water table and recharges the aquifer. The process of groundwater recharge varies substantially in space and through time due to soil type, weather conditions, and vegetation. Case studies will be used to illustrate how groundwater recharge regimes are altered by changes in climate and shifts in land use. Groundwater level responses to recharge events were used to quantify groundwater recharge rate differences at locations with different land cover. Numerical modeling was used to diagnose the causes of changing recharge rates and predict the consequences of these changes across a range of environmental settings. A process based understanding of the factors that drive changes in groundwater regimes is critical to sustainable management of groundwater resources under environmental change and avoiding or minimizing unintended consequences of human activities.

October 8

No seminar

October 15

Dr. Allison Tune

hydro-biogeochemist, Cascade Climate
TBD

October 22

Yifan Cheng

Assistant Professor, Department of Earth Sciences, State University of New York at Buffalo
Co-designing Earth System Models with Indigenous Communities: Reflection on Successes and Challenges

October 29

Dr. Kendra Murray

Associate Professor, Department of Geosciences, Idaho State University
TBD

November 5

Dr. Jeffrey Post

Mineralogist and Curator-in-Charge of Gems and Minerals, National Museum of Natural History, Smithsonian
TBD

November 12

Dr. John Spear

Professor, Department of Civil and Environmental Engineering, Colorado School of Mines
Life on the Edge of a Yellowstone Hotspring = Life on Early Earth

November 19

Dr. Alicia Marie Ruteledge

Assistant Professor, Department of Astronomy and Planetary Science, Northern Arizona University
Glacial alteration of Mars analog terrains: Secondary minerals as climate records

November 26

No Seminar - Thanksgiving Break

December 3

Dr. Anne Gothman

Professor of Environmental Studies and Physics, St. Olaf College
TBD

Spring 2027

January 21

January 28

February 4

February 11

February 18

February 25

March 4

March 11

No Seminar - Spring Break

March 18

March 25

April 1

April 8

April 15

April 22

April 29