Property:CSDMS meeting abstract
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The Orangeburg Scarp along the U.S. east coast is a paleoshoreline that formed during the mid-Pliocene climate optimum (MPCO; 3.3-2.9 Ma), a warm period considered to be an analog for modern climate. At present, the Orangeburg Scarp varies in elevation from ~33 to ~82 m along its ~1000-km length, implying that it has been heterogeneously warped since its formation. Recent studies suggest that some of the variations in the paleoshoreline elevation might be driven by regional sediment loading and unloading. In this study, we use a gravitationally self-consistent sea-level model to quantify the influence of sediment erosion and deposition on sea-level changes since the MPCO along the U.S. east coast. We drive the sea-level model with existing ice models and a new compilation of sediment redistribution, which is inferred from erosion rates in basins draining the Appalachians and deposition rates in the lower portions of these basins and offshore. Preliminary results suggest that sediment redistribution can significantly perturb paleoshoreline elevations along the Orangeburg Scarp, which suggests that accounting for regional erosion and deposition can advance our ability to estimate ice volume during at the MPCO and improve our understanding of the evolution of continental margins. +
The Pacific Northwest is the only region in the conterminous United States with a sizable number of glaciers (328 glaciers totaling ~380 km ). The glaciers of this region have displayed ubiquitous patterns of retreat since the 1980’s mostly in response to warming air temperature. Glacier melt in partially glacierized river basins in the region provides water for downstream anthropogenic systems (e.g., agricultural water supply and hydroelectric power generation) and sensitive ecological systems (e.g., fisheries, upland riparian habitat). While changes in glacier area have been observed and characterized across the region over an extended period of time, the hydrologic consequences of these changes are not fully understood. We applied a state of the art high resolution glacio-hydrological simulation model along with regional gridded historical and projected future meteorological data, distributed observations of glacier mass and area, and observations of river discharge to predict evolving glacio-hydrological processes for the period 1960-2100. We applied this approach to six river basins across the region to characterize the regional response. Using these results, we generalized past and future glacier change across the entire PNW US using a k-means cluster analysis. Our analysis shows that while the rate of glacier recession across the region will increase, the amount of glacier melt and its relative contribution to streamflow displays both positive and negative trends. Among the characteristics that control the direction and magnitude of future trends, elevation dominates and climatic factors play a secondary role. In high elevation river basins enhanced glacier melt will buffer strong declines in seasonal snowmelt contribution to late summer streamflow for some time, before eventually declining. Conversely, in lower elevation basins, reductions in glacier melt will exacerbate negative trends in summer runoff in the near term. +
The Peace-Athabasca Delta (PAD) in Alberta, Canada, is one of the largest inland deltas in the world. The hundreds of shallow lakes and distributary channel networks contribute to the incredible biodiversity in this region and also form the primary transportation routes for summer boat travel and ice roads in winter. Over the last few decades, however, there has been rising concern over declining lake levels. While the complex and changing hydrology is the focus of many studies, little is known about how changing geomorphology will impact lake water storage.
In this work, I will focus on one shallow PAD lake, Mamawi Lake, which is located near the center of the PAD and forms a key hydrologic connection. A subdelta has been forming in Mamawi Lake since 1982 and, as it continues to grow, may compromise hydrologic connectivity and navigability. To investigate past and future subdelta progradation, I will use Delft3D-FLOW as well as field measurements and satellite remote sensing. To develop a model that acceptably mimics subdelta growth, I will compare observed progradation rates and delta form, as determined from the optical satellite record, with predicted delta growth and planform from Delft3D simulations. By iteratively comparing observed and predicted subdelta characteristics, I can optimize model inputs to create a model that best resembles the historical growth of the Mamawi Lake subdelta. Then, with this optimized model, I will run longer simulations (on the order of 100 years) to estimate potential timelines of lake infilling and loss of navigability. +
The San Gorgonio Pass (SGP) within the southern San Andreas Fault zone is a structurally complex region that plays a crucial role in controlling earthquake rupture propagation, making it a key area for seismic hazard assessment. However, significant knowledge gaps persist regarding fault activity over the past 1–100 ka, particularly along the Mill Creek Fault segment in the San Bernardino Mountains. Traditional methods for estimating slip rates are hindered by the scarcity of datable materials and the challenging terrain of the SGP, necessitating innovative approaches to quantify uplift rates along overlooked fault segments. In this study, we employ thermoluminescence (TL) thermochronology to assess differential uplift by quantifying bedrock erosion rates. While Apatite (U-Th)/He (AHe) dating provides insights into long-term exhumation histories over millions of years and cosmogenic ¹⁰Be dating captures surface erosion rates on millennial timescales, neither fully resolves Quaternary uplift patterns essential for understanding active fault dynamics. TL thermochronology, sensitive to exhumation over 10–100 ka, bridges this crucial temporal gap, offering a novel means to decipher recent fault activity. By comparing erosion rates across multiple faults in the SGP, our results confirm that the Mill Creek Fault remains active and, importantly, reveal the geomorphic response to tectonic forcing within the San Bernardino catchment. We detect knickpoint migration, a hallmark of fluvial adjustment to uplift, and leverage TL thermochronology to estimate its lateral migration velocity. This study serves as a proof of concept, demonstrating TL thermochronology’s unique ability to not only quantify differential uplift but also track the interplay between tectonic uplift and fluvial incision. Our findings highlight the immense potential of this method for investigating active tectonics in other similarly complex fault systems worldwide. +
The South Fork Eel River (SFER) in the northern California Coast Ranges exhibits characteristics indicative of transient landscape adjustment: stream terraces, knickpoints, and more slowly eroding headwater terrain. A tectonically-induced uplift wave is commonly invoked as the driver of transience in this region. The wave is attributed to the northward migration of the Mendocino Triple Junction (MTJ) where the San Andreas fault, Cascadia subduction zone, and Mendocino fracture zone meet. Nested basin-mean erosion rates calculated from 10Be detrital quartz sand increase downstream along the SFER that roughly coincides with the direction of MTJ migration. This erosion trend is attributed to the proportion of adjusted and unadjusted landscape portions upstream of the locations where the nested 10BE samples were collected. Yet to be determined are the conditions that led to transient erosion. Adjusted and unadjusted landscape portions are separated by a broad knickzone that contains 28% of topographic relief along the mainstem. Knickzone propagation and considerable stream incision is suggested by projection of the upper SFER above the knickzone through the highest flight of strath terraces. These terraces are approximately 80 m above the modern valley floor near the outlet of the SFER. Here we evaluate the pattern of transient landscape characteristics predicted by multiple uplift scenarios using the Landlab modeling framework and constraints provided by previous work in this region. Notably, model outcome when uplift is simulated as a wave is incompatible with the tectonic history of the region and field observations, and the gradient of uplift along modeled streams has an important control on knickpoint generation. +
The Sundarbans National Forest (SNF) is a critical cultural, ecologic, and economic resource to the country of Bangladesh. Despite widespread land use changes in the surrounding region, sedimentation within the SNF has managed to keep pace with local rates of sea level rise (e.g., Rogers et al., 2013). This study explores some of the controls on sedimentation, with the goal of investigating their vulnerability to future change. Specifically, we examine the depth and frequency of platform inundation, suspended sediment concentration (SSC), sediment grain size, and the volume of water exchanged, and how these factors vary across time scales ranging from spring-neap tidal cycles through monsoon-dry season cycles. We observe pronounced seasonality, with the monsoon season experiencing the most frequent platform inundation, highest SSC, and greatest volume of water exchanged. Sediment grain size appears to vary spatially rather than seasonally, with a gradual decrease in grain size away from the primary tidal channel: the nominal sediment source. Of particular interest is how the seasonality of SSC varies between primary tidal channels like the Shibsa River, and the smaller tidal channels delivering sediment to the platform. On the Shibsa, spring tide SSC maxima during the monsoon and dry season are similar (~1.3 g/l), while neap tide SSC maxima are <0.5 g/l in either season. In channels within the SNF, monsoon spring tides exhibit peak SSC >1 g/l, while dry season SSC is always <0.5 g/l. Understanding why the source of local sediment (i.e., the primary tidal channel) behaves differently from the channels delivery that sediment to the platform presents an important knowledge gap that future research will examine in detail. +
The U.S. Geological Survey (USGS) is one of the largest providers of U.S. hydrologic data, which are used in informing policy, managing water resources, and countless scientific studies. Modern science is increasingly conducted by performing analysis on data that are first loaded from an online database into a local computational environment. To facilitate open and reproducible hydrologic science, the USGS has developed dataRetrieval (R), dataretrieval (Python), and DataRetrieval.jl (Julia): three packages providing multi-language access to hydrologic data from the U.S. Geological Survey, as well as the multi-agency Water Quality Portal. The Julia, Python, and R programming languages are open source, high-level (easy to program), have large communities of scientific users and developers. Notably, these three languages are the core languages supported by Project Jupyter, and run in the Jupyter Notebook, a popular web-based interactive computing platform.
These packages, collectively the “data retrievals,” allow scientists to programmatically access USGS hydrologic data in Julia, Python, and R. The “data retrievals” enable more than simply the retrieval of environmental data, they also provide tooling for data discovery, enabling users to find monitoring sites and identify what types of data are available at which locations. These functions represent foundational building blocks allowing for the creation of fully reproducible hydrologic workflows from data acquisition to output plots, tables, and reports. +
The U.S. Geological Survey is tasked with developing sustainable integrated hydrologic models that are interoperable with models from partner agencies and academia.
As a steppingstone towards integrating hydrologic models in a compiled code framework, we have developed a Python package for hydrologic process development and prototyping. This code base, named “pywatershed”, can seamlessly interact with our compiled code framework (MODFLOW 6) via its BMI interface. One can obtain numerically identical results from a model enhancement prototyped in Python or implemented in compiled code.
The advantages of code prototyped in Python are lower cost (person*hours) and greater approachability (less specialized programming knowledge required). The drawback of prototype code is that it may be slower to run for certain applications. A prototyping approach supports proof-of-concept development and model hypothesis testing, particularly for domain experts who may be more comfortable in Python and who bring new approaches or novel data to integrated model applications. The prototyping approach supports a cost-benefit analysis for making decisions to implement certain hydrologic process representations within the compiled code base.
The current state of this evolving Python package will be described, including: 1) the modular, self-describing design based on control volumes and conservation of mass and energy, 2) numerical performance based on the numpy Python package, the numba Python package (just in time compiling), and compiled Fortran modules called from python, 3) goals and challenges of developing flexibility in the space and time representation of hydrologic processes and the management of fluxes and states between process representations, and 4) the current and upcoming set of hydrologic process representations.
Example notebooks will demonstrate many features of pywatershed. Planned developments will be described and community participation is welcomed.
The US east coast is heavily developed, necessitating adaptive approaches to mitigate property and infrastructure risk from storm events and shoreline changes. One soft-structural approach, beach nourishment, comprises artificial shoreline progradation for property protection. Construction of groins, a hard-structural approach, traps alongshore transported sediments, leading to updrift shoreline growth. Groins create a depositional sediment shadow in their lee, shrinking downdrift shorelines, thereby forcing communities to decide whether to protect properties or to retreat. Our research focuses on how these alternative adaptations may affect coastal risk. We present two field scenarios: West Hampton Dunes, NY, which decided to protect downdrift property through beach nourishment, and Oakwood Beach, NY, which decided to accept buyout offers from federal disaster relief funds. We build a coupled geo-economic model to explore management drivers and controls on coastal morphology and real estate and to analyze the emergent indicators within a two-community system. We quantify benefits as a function of beach width, number of housing rows, and federal property buyouts; costs are a function of groin construction, groin maintenance, and beach nourishment. We compare the net benefits of downdrift nourishment, retreat, and groin removal for different groin lengths, background erosion rates, baseline property values, and discount rates. Results elucidate which approach is most beneficial for coastal adaptation, providing a simple framework to compare future strategies for West Hampton Dunes. This geo-economic tool may prove useful as lawmakers continue to scrutinize fiscal implications of alternative adaptations to coastal risks. +
The USGS Model Catalog compiles and connects data, software, and publications about scientific models developed by the U.S. Geological Survey (USGS) or developed by external organizations and used in USGS investigations. The primary audience for the USGS Model Catalog is researchers who want to learn more about USGS modeling, such as researchers who want to explore existing models and documentation on a specific topic; early career researchers who want to see what models exist in their discipline; or members of large, integrative projects who want to discover opportunities for linking different process models. The catalog is composed of modular features that we hope other projects can build upon. The data model and repository component are published at https://doi.org/10.5066/P9WU0F71 and https://doi.org/10.5066/P9IVG9VZ.
The catalog is never complete! Come take a look at what's there now, learn what we're planning, and give input about what content and features would help you and your communities. Visit the catalog at https://data.usgs.gov/modelcatalog. +
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The Underworld code was designed for solving (very) long timescale geological deformations accurately, tracking deformation and evolving interfaces to very high strains. It uses a particle-in-cell based finite element method to track the material history accurately and highly-tuned multigrid solvers for fast implicit solution of the equations of motion. The implementation has been fully parallel since the inception of the project, and a plugin/component architecture ensures that extensions can be built without significant exposure to the underlying technicalities of the parallel implementation. We also paid considerable attention to model reproducibility and archiving — each run defines its entire input state and the repository state automatically.
A typical geological problems for which the code was designed is the deformation of the crust and lithospheric mantle by regional plate motions — these result in the formation of localised structures (e.g. faults), basins, folds and in the generation of surface topography. The role of surface processes — redistributing surface loads and changing boundary conditions, is known to be significant in modifying the response of the lithosphere to the plate-derived forces. The coupling of surface process codes to Underworld is feasible, but raises some interesting challenges (and opportunities !) such as the need to track horizontal deformations and match changes to the topography at different resolutions in each model. We will share some of our insights into this problem. +
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The WBMsed model offers a unique framework for studying river flux dynamics, ranging from basin to global scales. When it was first published in 2013, WBMsed included a spatially and temporally explicit suspended sediment flux module, developed within the WBMplus (FrAMES) hydrological framework. Since then the model has been used for a range of studies and been extended to include a bedload, water density, and particulete nutrients modules. The model's hydrological and geomorphic processes were improved to better represent riverine and landscape dynamics. These include the introduction of a flooding mechanism, spatially-explicit river slope, and land use inputs. Here we will outline these model development and its use for river and coastal studies. +
The Weather Research and Forecasting Model Hydrological modeling system (WRF-Hydro) is an open-source community model and has been used for a range of projects, including flash flood prediction, regional hydroclimate impacts assessment, seasonal forecasting of water resources, and land-atmosphere coupling studies. We modified the CASCade 2 Dimensional SEDiment (CASC2D-SED) model and adapted it to the WRF-Hydro platform. The model mainly contains two components: (1) sediment erosion and transport from overland to channel, and (2) sediment transport through the channel to the watershed outlet. Based on USLE formula, sediment is eroded by overland flow with consideration of soil type, vegetation type as well as bed slope. Following through the direction of steepest slope, the eroded sediment is transported grid by grid all the way to the channel, meanwhile deposition process is parameterized by sediment’s settling velocity, time step and water depth. Once sediment gets into channel, it will be carried by the stream flow to the watershed outlet. To test its robustness, we adapted WRF-Hydro sediment model to the watershed of Goodwin Creek, Mississippi, USA. A preliminary model-data comparison indicates our model is capable of reproduce water and sediment discharge during a storm event. +
The Whitewater River in southeastern Minnesota is one of numerous tributaries of the upper Mississippi River. However, unlike many of the tributaries to the Mississippi north of the Whitewater River, which received glacially derived sediment and water directly from the Laurentide Ice Sheet margin, the Whitewater watershed remained ice free. Instead, glacial–interglacial cycling predominately shaped the watershed via changes in base-level and sediment inputs on the mainstem Mississippi. Thus, the aggradation and incision of the mainstem upper Mississippi acted as the primary source of glacial signal in the watershed. In this study, we seek to understand how the complex glacial history of the upper Mississippi River impacted the long-profile evolution of the Whitewater River. To do this, we combine one-meter LiDAR topography with the topographic analysis package, LSDTopoTools to study the modern channel network and adjacent terraces. By extracting modern and historic river terraces, we are able to reconstruct channel long-profile changes over time. We pair this study with bedrock geology composition and depth to bedrock for the watershed to understand transitions within the watershed from transport to detachment limited and linkages between bedrock type and channel morphology. This work allows us to better constrain how glacial–interglacial signals propagate through fluvial systems via tributaries. This information can better inform our understanding of how tributaries respond to mainstem changes and how these changes propagate over time. +
The accumulated history of crater production and destruction is recorded in crater size-frequency distributions (CSFDs), which can be leveraged to understand the evolution of planetary surfaces and atmospheres. For example, researchers used the size-frequency distribution of craters interbedded with fluvial deposits to provide an upper-bound of ~1.9 bar on paleo-atmospheric pressure at the time of river activity on Mars. Interpretations of paleo-atmospheric pressure are most sensitive to preservation and mapping of smaller craters (<50 m), which may be influenced by fluvial reworking. We simulated river-delta development with coeval crater production; river-delta simulation is completed with pyDeltaRCM and craters 10 to 300 m are generated according to an imposed crater production function and placed randomly and with a parameterized geometry. We quantified preservation of craters in the stratigraphy after 1, 10, or 100 Ma of coupled landscape evolution. Our results indicate that crater preservation is highly variable (ranging fully eroded to fully preserved), but preserved fraction generally increases with crater diameter. Despite rivers removing a substantial portion of smaller craters (>40% of craters <50 m are at least partially eroded); exponential increase in crater counts with decreasing size overwhelms any meaningful fluvial preservation bias. Our findings bolster previous studies that assert fluvial reworking is a secondary controls to atmospheric ablation on CSFDs, indicating that paleo-atmospheric pressure upper-bounds may be translated into estimates (with uncertainty). +
The accuracy of sediment transport models depends heavily on the selection of an appropriate sediment settling velocity. Determining this value for mud suspensions can be difficult because the cohesive particles within the mud can aggregate to form flocs whose sizes are a function of hydrodynamic and physiochemical conditions of the suspension. Here we present a new model for predicting floc size in a dynamic way as a function of the hydrodynamic conditions and inherited floc sizes. The new model is a simple modification to the existing Winterwerp (1998) floc size model. The modification is significant in that it yields predictions that are more inline with observations and theory regarding the upper limit on ultimate floc size. The modification we propose is to make the ratio of the applied stress on a floc over the strength of the floc a function of the floc size relative to the Kolmogorov microscale. The outcome of this modification is that flocs are not allowed to surpass the Kolmogorov microscale in size and that calibrated aggregation and breakup coefficients obtained at one suspended sediment concentration can be used to predict floc size under other concentration values without recalibration of the coefficients. In this paper, we present the motivation for the modification, the functionality of the modification, and a comparison of the updated model with laboratory and field data. Overall the model shows promise as a tool that could be incorporated into larger hydrodynamic and sediment transport models for improved prediction of cohesive mud transport. +
The active volcano Ol Doinyo Lengai is located in the magma-rich southern Eastern Branch of the East African Rift and erupts unique low-temperature carbonatites. Between 2007 and 2010, the volcano had several explosions and erupted with ash falls, and lava flows (VEI 3) that caused damage to the nearby communities. Although this volcano has been studied for decades, its plumbing system is still poorly understood, in part, because of the lack of precise observations of surface deformation during periods of quiet and unrest. This study investigates the volcanic plumbing system of Ol Doinyo Lengai and surroundings using data from the permanent Global Navigation Satellite System (GNSS) network monitoring the volcano called TZVOLCANO and Interferometric Synthetic Aperture Radar (InSAR) observations. We calculate velocities for 6 continuously operating GNSS sites distributed around Ol Doinyo Lengai for a timespan between 2016 and 2021 and also process InSAR data for nearly the same time-period to constrain surface motions. We then use the GNSS deformation signals and InSAR observations to solve for magma sources embedded in a homogeneous and elastic half space using the USGS inversion code dMODELS. Both GNSS and InSAR inversion results quantify a deflating spherical geometry source at a depth of ~1.3 km with a volume change ∆V of -0.05 ± 0.01x106m3 located east of Ol Doinyo Lengai and southwest of the dormant volcano Gelai. InSAR inversions alone also suggest a closing dike model at a depth of ~9 km similar to the location resolved for the 2007 Ol Doinyo Lengai dike. This work suggests a shallow magma reservoir exists east of Ol Doinyo Lengai and that the 2007 dike is actively contracting. This magma source influences the onset, size, duration and hazard of eruptions of the volcano, and plays a significant role in triggering slip on border faults during early phases of continental rifting through stress transfer. +
The characteristics of soils control the influence of how land use and land cover (LULC) change the global water, energy, and biogeochemical cycles. Plant health, and the exchange of energy, water and biogeochemical components at the surface interface is partly controlled by soil properties. Different soil types modify vegetation responses to existing climate forcings, and each soil type also responds differently to the same land-use practice. Currently, Earth System Models often use single soil columns with averaged properties and the same properties stay constant over time regardless of LULC changes. This leads to uncertainties in assessing LULC impacts. To improve the estimates of land surface change in Earth System Models, we build a soil degradation model to compute annual soil properties from 850 to 2015.
The model includes three parts: first, to quantify human LULC impacts, we collected 1099 observations from 174 published literature of human impacts of agriculture, pasture, grazing, and vegetation harvest on soil organic carbon (SOC), texture, and bulk density. Under each LULC unit, we defined the combined impact of LULC, management, climate (represented by NPP or moisture index), and soil texture on each soil property based on observations and regression models. In the second part, we link an existing LULC dataset to four hydrologic soil groups from 850 to 2015, based on demonstrated soil preferences for eight LULCs under current conditions. We conclude that humans prefer hydrologic soil groups (HSGs) in order from B, D, C, to A (generally from high to low silt content). This ranking was applied to construct the history of LULC on each soil type at the half-degree grid resolution. Results primarily distribute croplands to HSG B in 850, while HSG A has the most undisturbed area. Over time, preferred soils (HSGs B and D) experience increased use for cropland areas, while poor soils (HSGs C and A) are occupied predominantly by increasing areas in grazing land and secondary non-forests. Finally, based on the established LULC and soil relations from 850 to 2015, we altered soil properties in each soil group according to global variations of environmental factors to model human-induced soil degradation. Vertical and temporal variations are applied based on observations. Results demonstrate how soil degradation occurs under historical LULCs and provide better land surface characteristics to improve Earth systems modeling.
The coastline of SE Alaska was submerged by post-Pleistocene sea level rise from at least 16,000 cal yrs BP until it stabilized about 10,600 cal yrs BP. The submerged continental shelf was modeled using bathymetry and other data to identify areas exhibiting high potential for the occurrence of archaeological sites. Two seasons of underwater archaeological survey have been conducted at this location (NSF OPP -#0703980 and 1108367), using multibeam sonar, side-scan sonar, sub-bottom profiler, real-time video from remotely operated vehicle (ROV), and sea floor sampling using a van veen grab sampler and sediment screening. This data has produced a detailed overview of Shakan Bay, located on the northwest corner of Prince of Wales Island. +
The controls exerted on stream channel form by rock properties contribute to landscape morphology. Here we focus on understanding the effects of bedrock properties on surface processes and landscape evolution in the Guadalupe Mountains of South Eastern New Mexico. We surveyed bedrock reaches in three different watersheds, taking rock samples, Schmidt hammer measurements, and videos of reaches. We used structure for motion to generate orthomosaics of surveyed reaches from the video. We then traced fractures and determined fracture intensity, average length of fractures per square meter, for each reach. XRD data taken from samples collected in the field, along with carbonate dissolution techniques, demonstrates the minerology of reaches. In relatively small watersheds there is little climate variation which is demonstrated using PRISM climate data. Lithologic variance and channel steepness are the main control on differences in rock properties within stream channels. Steeper channels cut across more bedding planes than shallow reaches, influencing both fracture intensity and Schmidt hammer values. At the landscape scale rock strength is reflective of differential weathering due to differences in climate for similar rock types. Results from this study will help to reconcile our understanding of the effect of climate and lithology on surface processes at different scales. It will also create a widely applicable methodology for measuring, interpreting, and comparing various metrics of rock properties. +
