<![CDATA[EAS Seminar Series - Dr. Rachel Abercrombie]]>36678 Small earthquakes contain a wealth of information about active structures, and the state of stress in the earth, not least because they are so numerous. The stress release (or stress drop) during an earthquake provides fundamental information about the energy budget, and the slip and area of rupture, which are needed to investigate earthquake triggering and rupture dynamics. Stress drop is also an important element of seismic hazard forecasting since high stress drop earthquakes radiate more high frequency energy, resulting in stronger ground shaking. However, in practice stress drop has proved notoriously hard to measure reliably. Estimates by different researchers, using different methods or datasets, have yielded highly inconsistent values. This wide scatter masks physical trends (such as depth, mechanism, regional variation, or dependence on fault heterogeneity) that may identify the factors governing earthquake rupture.
I will discuss recent work by myself and others focused on improving stress drop estimates, and investigating the uncertainties resulting from modelling assumptions and the ambiguity of separating source and path effects in recorded seismograms. A consistent observation is that there is more small-scale spatial variability and complexity within one individual sequence, than there is between earthquakes in different tectonic settings.
*Refreshments: 10:30 AM - 11:00 AM (Atrium)
]]> tbuchanan9117732317512026-03-11 12:22:3117761841292026-04-14 16:28:4900eventSmall earthquakes contain a wealth of information about active structures, and the state of stress in the earth, not least because they are so numerous. The stress release (or stress drop) during an earthquake provides fundamental information about the energy budget, and the slip and area of rupture, which are needed to investigate earthquake triggering and rupture dynamics. Stress drop is also an important element of seismic hazard forecasting since high stress drop earthquakes radiate more high frequency energy, resulting in stronger ground shaking. However, in practice stress drop has proved notoriously hard to measure reliably. Estimates by different researchers, using different methods or datasets, have yielded highly inconsistent values. This wide scatter masks physical trends (such as depth, mechanism, regional variation, or dependence on fault heterogeneity) that may identify the factors governing earthquake rupture.
I will discuss recent work by myself and others focused on improving stress drop estimates, and investigating the uncertainties resulting from modelling assumptions and the ambiguity of separating source and path effects in recorded seismograms. A consistent observation is that there is more small-scale spatial variability and complexity within one individual sequence, than there is between earthquakes in different tectonic settings.
*Refreshments: 10:30 AM - 11:00 AM (Atrium)
]]>2026-04-23T11:00:00-04:002026-04-23T12:00:00-04:002026-04-23T12:00:00-04:002026-04-23 15:00:002026-04-23 16:00:002026-04-23 16:00:002026-04-23T11:00:00-04:002026-04-23T12:00:00-04:00America/New_YorkAmerica/New_Yorkdatetime2026-04-23 11:00:002026-04-23 12:00:00America/New_YorkAmerica/New_Yorkdatetime<![CDATA[]]>679944679944image<![CDATA[Ambercombie Headshot]]>image/jpeg17761819132026-04-14 15:51:5317761819132026-04-14 15:51:53<![CDATA[]]><![CDATA[EAS 2026 Clough Seminar by Climate Scientist and Author Kate Marvel, Ph.D.]]>36678 How can we best talk to one another about global warming? Climate scientist Kate Marvel, Ph.D. studies the physics of the planet using computational models. But climate change isn't just happening on a computer – it's happening here, in the real world, to us. And even a scientist like Marvel can't help but have feelings about that. Join her as she explores climate science and solutions through the lens of different emotions, from wonder, to anger and fear, and finally to hope. And hear her discuss how we don't need to choose between the hard facts that help us understand climate change and the feelings that help us communicate about it. By embracing both, we gain a fuller picture of what we stand to lose – and all there might be to hope for on a rapidly warming planet.
Book giveaway and refreshments from 6:00–6:25 PM for the first 100 students: Dr. Kate Marvel’s Human Nature: Nine Ways to Feel About Our Changing Planet.
*Refreshments: 7:30-8:30 PM (East Arch Courtyard)
]]> tbuchanan9117701349682026-02-03 16:09:2817760985462026-04-13 16:42:2600eventHow can we best talk to one another about global warming? Climate scientist Kate Marvel, Ph.D. studies the physics of the planet using computational models. But climate change isn't just happening on a computer – it's happening here, in the real world, to us. And even a scientist like Marvel can't help but have feelings about that. Join her as she explores climate science and solutions through the lens of different emotions, from wonder, to anger and fear, and finally to hope. And hear her discuss how we don't need to choose between the hard facts that help us understand climate change and the feelings that help us communicate about it. By embracing both, we gain a fuller picture of what we stand to lose – and all there might be to hope for on a rapidly warming planet.
Book giveaway and refreshments from 6:00–6:25 PM for the first 100 students: Dr. Kate Marvel’s Human Nature: Nine Ways to Feel About Our Changing Planet.
*Refreshments: 7:30-8:30 PM (East Arch Courtyard)
]]>2026-04-29T18:00:00-04:002026-04-29T20:30:00-04:002026-04-29T20:30:00-04:002026-04-29 22:00:002026-04-30 00:30:002026-04-30 00:30:002026-04-29T18:00:00-04:002026-04-29T20:30:00-04:00America/New_YorkAmerica/New_Yorkdatetime2026-04-29 06:00:002026-04-29 08:30:00America/New_YorkAmerica/New_Yorkdatetime<![CDATA[]]>679176679175679176image<![CDATA[Marvel's Headshot]]>image/jpeg17701379682026-02-03 16:59:2817701379682026-02-03 16:59:28679175image<![CDATA[Human Nature: Nine Ways to Feel About Our Changing Planet]]>image/jpeg17701378552026-02-03 16:57:3517701378552026-02-03 16:57:35<![CDATA[Profile - Kate Marvel, Ph.D.]]><![CDATA[Human Nature: Nine Ways to Feel About Our Changing Planet]]><![CDATA[EAS Planetary & Astrobiology Seminar - Dr. Dinah Davison]]>36678 The evolution of cellular differentiation has occurred repeatedly across the tree of life, giving rise to diversity of complex life we see today. We examine whether this repeated transition may have been facilitated by plastic responses to the environment that were later stabilized by developmental-genetic changes. We use the volvocine green algae as a model system as this clade contains undifferentiated multicellular species, species with environmentally induced somatic differentiation, species with undifferentiated cells and developmentally regulated somatic cells, and species with germ-soma division of labor. We examine a multicellular volvocine algae species, Eudorina, which has been historically characterized as undifferentiated but can develop a small proportion of plastic somatic cells following exposure to cold shock. We exposed Eudorina cultures to repeated cold shock and characterized the differentiation status of our lines more than 30 generations after the cessation of the cold treatment. Somatic differentiation evolved rapidly, with most lines showing changes in the regulation of somatic cell development and several lines evolving obligate somatic cells. The increase in the proportion of colonies that were differentiated was correlated with an increase in the number of somatic cells per differentiated colony. The repeated evolution of differentiation was shaped by the selection imposed by cold shock, as differentiated colonies were more likely to survive cold shock. Moreover, genome sequencing revealed that the regulation of multiple genes associated with the response to cold stress were altered and the cold stress pathway was likely decoupled from environmental triggers. Taken together, our results demonstrate that selection can rapidly drive the repeated transition to differentiated multicellularity via the modification of plastic responses to the environment.
*Refreshments: 10:30 AM - 11:00 AM (ES&T L1175)
]]> tbuchanan9117760825132026-04-13 12:15:1317760827532026-04-13 12:19:1300eventThe evolution of cellular differentiation has occurred repeatedly across the tree of life, giving rise to diversity of complex life we see today. We examine whether this repeated transition may have been facilitated by plastic responses to the environment that were later stabilized by developmental-genetic changes. We use the volvocine green algae as a model system as this clade contains undifferentiated multicellular species, species with environmentally induced somatic differentiation, species with undifferentiated cells and developmentally regulated somatic cells, and species with germ-soma division of labor. We examine a multicellular volvocine algae species, Eudorina, which has been historically characterized as undifferentiated but can develop a small proportion of plastic somatic cells following exposure to cold shock. We exposed Eudorina cultures to repeated cold shock and characterized the differentiation status of our lines more than 30 generations after the cessation of the cold treatment. Somatic differentiation evolved rapidly, with most lines showing changes in the regulation of somatic cell development and several lines evolving obligate somatic cells. The increase in the proportion of colonies that were differentiated was correlated with an increase in the number of somatic cells per differentiated colony. The repeated evolution of differentiation was shaped by the selection imposed by cold shock, as differentiated colonies were more likely to survive cold shock. Moreover, genome sequencing revealed that the regulation of multiple genes associated with the response to cold stress were altered and the cold stress pathway was likely decoupled from environmental triggers. Taken together, our results demonstrate that selection can rapidly drive the repeated transition to differentiated multicellularity via the modification of plastic responses to the environment.
*Refreshments: 10:30 AM - 11:00 AM (ES&T L1175)
]]>2026-04-17T11:00:00-04:002026-04-17T12:00:00-04:002026-04-17T12:00:00-04:002026-04-17 15:00:002026-04-17 16:00:002026-04-17 16:00:002026-04-17T11:00:00-04:002026-04-17T12:00:00-04:00America/New_YorkAmerica/New_Yorkdatetime2026-04-17 11:00:002026-04-17 12:00:00America/New_YorkAmerica/New_Yorkdatetime<![CDATA[]]>679919679919image<![CDATA[Davison Headshot]]>image/jpeg17760826442026-04-13 12:17:2417760826442026-04-13 12:17:24<![CDATA[EAS Seminar Series - Dr. Arial Shogren]]>36678 Rivers tell stories: of where water has been, where it is going, and how it might impact downstream ecosystems. Streams and rivers move more than water and dissolved material — they also carry a complex blend of fine particles, including seston and sediment. I am fundamentally intrigued by these stories, and my group worksto interpret the “language” of flowing waters as told by the biogeochemical signals they carry. My research group leverages fundamental tools from stream ecology, biogeochemistry, and watershed science tounderstand how rivers move and modify materials during their downstream journey. Using theseunique and complimentary perspectives, we measure water-mediated biogeochemical transportand transformations across variable temporal and spatial scales. With this talk, I will outline my group’scontributions and progress on three primary research themes: (1) the transport and transformation of particulate material in streams, (2) the effects of dynamic hydrologic expansion and contraction on watershed biogeochemical fluxes, and (3) the impact of concurrent stressors on ecosystem structure and function.
*Refreshments: 10:30 AM - 11:00 AM (Atrium)
]]> tbuchanan9117730705612026-03-09 15:36:0117730713622026-03-09 15:49:2200eventRivers tell stories: of where water has been, where it is going, and how it might impact downstream ecosystems. Streams and rivers move more than water and dissolved material — they also carry a complex blend of fine particles, including seston and sediment. I am fundamentally intrigued by these stories, and my group worksto interpret the “language” of flowing waters as told by the biogeochemical signals they carry. My research group leverages fundamental tools from stream ecology, biogeochemistry, and watershed science tounderstand how rivers move and modify materials during their downstream journey. Using theseunique and complimentary perspectives, we measure water-mediated biogeochemical transportand transformations across variable temporal and spatial scales. With this talk, I will outline my group’scontributions and progress on three primary research themes: (1) the transport and transformation of particulate material in streams, (2) the effects of dynamic hydrologic expansion and contraction on watershed biogeochemical fluxes, and (3) the impact of concurrent stressors on ecosystem structure and function.